US20230226175A1 - Modified exotoxin a proteins - Google Patents

Modified exotoxin a proteins Download PDF

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US20230226175A1
US20230226175A1 US18/001,498 US202118001498A US2023226175A1 US 20230226175 A1 US20230226175 A1 US 20230226175A1 US 202118001498 A US202118001498 A US 202118001498A US 2023226175 A1 US2023226175 A1 US 2023226175A1
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amino acid
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amino acids
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Stefan Jochen KEMMLER
Christian Lizak
Gerald Johann POSCH
Julien Laurent QUEBATTE
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GlaxoSmithKline Biologicals SA
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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
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    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K39/385—Haptens or antigens, bound to carriers
    • A—HUMAN NECESSITIES
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    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K39/02—Bacterial antigens
    • A61K39/025—Enterobacteriales, e.g. Enterobacter
    • A61K39/0266—Klebsiella
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
    • A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
    • A61K47/51—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent
    • A61K47/62—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being a protein, peptide or polyamino acid
    • A61K47/64—Drug-peptide, drug-protein or drug-polyamino acid conjugates, i.e. the modifying agent being a peptide, protein or polyamino acid which is covalently bonded or complexed to a therapeutically active agent
    • A61K47/6415—Toxins or lectins, e.g. clostridial toxins or Pseudomonas exotoxins
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
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    • A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
    • A61K47/51—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent
    • A61K47/62—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being a protein, peptide or polyamino acid
    • A61K47/64—Drug-peptide, drug-protein or drug-polyamino acid conjugates, i.e. the modifying agent being a peptide, protein or polyamino acid which is covalently bonded or complexed to a therapeutically active agent
    • A61K47/646—Drug-peptide, drug-protein or drug-polyamino acid conjugates, i.e. the modifying agent being a peptide, protein or polyamino acid which is covalently bonded or complexed to a therapeutically active agent the entire peptide or protein drug conjugate elicits an immune response, e.g. conjugate vaccines
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
    • A61P31/04—Antibacterial agents
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • C07K14/195—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from bacteria
    • C07K14/21—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from bacteria from Pseudomonadaceae (F)
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • C07K14/195—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from bacteria
    • C07K14/24—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from bacteria from Enterobacteriaceae (F), e.g. Citrobacter, Serratia, Proteus, Providencia, Morganella, Yersinia
    • C07K14/26—Klebsiella (G)
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    • C12N9/00—Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
    • C12N9/10—Transferases (2.)
    • C12N9/1048—Glycosyltransferases (2.4)
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    • C12N9/00—Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
    • C12N9/10—Transferases (2.)
    • C12N9/1048—Glycosyltransferases (2.4)
    • C12N9/1077—Pentosyltransferases (2.4.2)
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    • C12N9/00—Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
    • C12N9/10—Transferases (2.)
    • C12N9/1048—Glycosyltransferases (2.4)
    • C12N9/1081—Glycosyltransferases (2.4) transferring other glycosyl groups (2.4.99)
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    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12Y—ENZYMES
    • C12Y204/00—Glycosyltransferases (2.4)
    • C12Y204/02—Pentosyltransferases (2.4.2)
    • C12Y204/02036—NAD(+)--diphthamide ADP-ribosyltransferase (2.4.2.36)
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12Y—ENZYMES
    • C12Y204/00—Glycosyltransferases (2.4)
    • C12Y204/99—Glycosyltransferases (2.4) transferring other glycosyl groups (2.4.99)
    • C12Y204/99019—Undecaprenyl-diphosphooligosaccharide—protein glycotransferase (2.4.99.19)
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K2039/60—Medicinal preparations containing antigens or antibodies characteristics by the carrier linked to the antigen
    • A61K2039/6031—Proteins
    • A61K2039/6037—Bacterial toxins, e.g. diphteria toxoid [DT], tetanus toxoid [TT]
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K2039/60—Medicinal preparations containing antigens or antibodies characteristics by the carrier linked to the antigen
    • A61K2039/6031—Proteins
    • A61K2039/6068—Other bacterial proteins, e.g. OMP
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K38/00—Medicinal preparations containing peptides
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2319/00—Fusion polypeptide
    • C07K2319/01—Fusion polypeptide containing a localisation/targetting motif
    • C07K2319/02—Fusion polypeptide containing a localisation/targetting motif containing a signal sequence
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/30—Against vector-borne diseases, e.g. mosquito-borne, fly-borne, tick-borne or waterborne diseases whose impact is exacerbated by climate change

Definitions

  • the present invention relates to the field of modified proteins, immunogenic compositions and vaccines comprising the modified proteins, their manufacture and the use of such compositions in medicine. More particularly, it relates to a modified EPA (Exotoxin A of Pseudomonas aeruginosa ) protein.
  • the modified EPA can be used as a carrier protein for other antigens, particularly saccharide antigens or other antigens lacking T cell epitopes.
  • Protein glycosylation is a common posttranslational modification in bacteria by which glycans are covalently attached to surface proteins, flagella, or pili, for example. Glycoproteins play roles in adhesion, stabilization of proteins against proteolysis, and evasion of the host immune response. Two protein glycosylation mechanisms are distinguished by the mode in which the glycans are transferred to proteins: one mechanism involves the transfer of carbohydrates directly from nucleotide-activated sugars to acceptor proteins (used in e.g. protein O-glycosylation in the Golgi apparatus of eukaryotic cells and flagellin O-glycosylation in some bacteria).
  • a second mechanism involves the preassembly of a polysaccharide onto a lipid-carrier (by glycosyltransferases) which is then transferred to a protein acceptor by an oligosaccharyltransferase (OTase) (Faridmoayer et al., J. Bacteriology, pp. 8088-8098, 2007).
  • This second mechanism is used in, e.g.
  • N-glycosylation in the endoplasmic reticulum of eukaryotic cells the well-characterized N-linked glycosylation system of Campylobacter jejuni, and the more recently characterized O-linked glycosylation systems of Neisseria meningitidis, Neisseria gonococcus, and Pseudomonas aeruginosa.
  • O-linked glycosylation O-glycosylation
  • glycans are generally attached to a serine or threonine residue on the protein acceptor.
  • N-linked glycosylation N-linked glycosylation
  • glycans are generally attached to an asparagine residue on the protein acceptor.
  • WO2006/119987 (Aebi et al.) describes proteins, as well as means and methods for producing proteins, with efficiency for N-glycosylation in prokaryotic organisms in vivo. It further describes the introduction of N-glycans into recombinant proteins for modifying immunogenicity, stability, biological, prophylactic and/or therapeutic activity of said proteins, and the provision of a host cell that displays recombinant N-glycosylated proteins of the present invention on its surface. In addition, it describes a recombinant N-glycosylated protein comprising one or more of the following optimized amino acid sequence(s): D/E-X-N-Z-S/T, wherein X and Z may be any natural amino acid except Pro. The introduction of such optimized amino acid sequence(s) into proteins leads to proteins that are N-glycosylated by an oligosaccharyl transferase in these introduced positions.
  • Conjugate vaccines have been a successful approach for vaccination against a variety of bacterial infections.
  • Conjugation of T-independent antigens, for example saccharides, to carrier proteins has long been established as a way of enabling T-cell help to become part of the immune response for a normally T-independent antigen. In this way, an immune response can be enhanced by allowing the development of immune memory and boostability of the response.
  • in vivo methods to produce a “bioconjugate vaccine” have been in development. These in vivo methods leverage the N-glycosylation and O-glycosylation systems discussed above.
  • WO2009/104074 describes a Shigella bioconjugate vaccine comprising a protein carrier comprising exotoxin of Pseudomonas aeruginosa (EPA) that has been modified to contain at least one consensus sequence D/E-X-N-Z-S/T and WO2017/035181 describes E. coli O-antigens covalently bound to a detoxified exotoxin A of P. aeruginosa (EPA) carrier protein.
  • EPA Pseudomonas aeruginosa
  • Exotoxin A of Pseudomonas aeruginosa is a secreted bacterial toxin, a member of the ADP-ribosyltransferasetoxin family.
  • the native protein is a single polypeptide chain of 613 amino acids (67kDa).
  • the protein consists of three main domains, domain Ia and b (receptor-binding domain), domain II (transmembrane domain) and domain III (catalytic NAD-ribosyltransferasedomain) (Allured et al., Proc. Natl. Acad. Sci. USA Vol. 83, pp. 1320-1324, March 1986).
  • the present invention provides modified EPA proteins comprising at least one consensus sequence for glycosylation (e.g. D/E-X-N-Z-S/T) for use in conjugation to an antigen (e.g. bacterial polysaccharide).
  • the glycosylation consensus sequences are introduced into specific regions of the EPA carrier protein.
  • the present inventors have found that the position of the consensus sequence in the EPA amino acid sequence can increase glycosylation efficiency and/or optimize the operation of the N-glycosylation site.
  • Modified EPA proteins of the invention show higher site occupancy, higher sugar:protein ratio and/or higher yield. Differences in protein glycosylation may also influence the biological activity, antigenicity, stability and/or half-life of the protein.
  • the modified EPA proteins described herein are modified such that the number of glycosylation sites in the carrier proteins is optimized. This may allow for lower concentrations of the EPA protein to be administered in its conjugate form, e.g. in an immunogenic composition or vaccine.
  • the present invention also provides further EPA carrier proteins so that there is a choice of EPA carrier proteins with different numbers of consensus sequence sites for different saccharide antigens.
  • the number of glycosites may be selected to optimise the sugar:protein ratio. For example, for shorter saccharide antigens (glycans) a higher number of glycosites (using the modified EPA carrier proteins of the invention as described herein) may be used to increase the sugar:protein ratio.
  • a modified EPA (Exotoxin A of Pseudomonas aeruginosa ) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises one (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the one (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g.
  • a modified EPA (Exotoxin A of Pseudomonas aeruginosa ) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises one (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the one (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g.
  • a conjugate comprising a modified EPA protein of the invention linked to an antigen (e.g. a saccharide antigen, optionally a bacterial polysaccharide antigen).
  • an antigen e.g. a saccharide antigen, optionally a bacterial polysaccharide antigen.
  • a polynucleotide encoding a modified EPA protein of the invention.
  • a vector comprising a polynucleotide encoding a modified EPA protein of the invention.
  • a host cell comprising:
  • nucleotide sequences comprising polysaccharide synthesis genes, optionally for producing a bacterial polysaccharide antigen (e.g. an O-antigen from a Gram negative bacterium optionally from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, or a capsular polysaccharide from a Gram positive bacterium optionally from Streptococcus pneumoniae or Staphylococcus aureus ) or a yeast polysaccharide antigen or a mammalian polysaccharide antigen, optionally integrated into the host cell genome;
  • a bacterial polysaccharide antigen e.g. an O-antigen from a Gram negative bacterium optionally from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsi
  • a nucleotide sequence that encodes a modified EPA protein of the invention optionally within a plasmid.
  • a process for producing a bioconjugate that comprises (or consists of) a modified EPA protein linked to a polysaccharide, said process comprising: (i) culturing the host cell of the invention under conditions suitable for the production of glycoproteins and (ii) isolating the bioconjugate produced by said host cell, optionally isolating the bioconjugate from a periplasmic extract from the host cell.
  • an immunogenic composition comprising a conjugate (e.g. bioconjugate) of the invention and optionally a pharmaceutically acceptable excipient and/or carrier.
  • a vaccine comprising an immunogenic composition of the invention and optionally an adjuvant.
  • a method of inducing an immune response in a subject comprising administering a therapeutically or prophylactically effective amount of a conjugate (e.g. bioconjugate) of the invention, an immunogenic composition of the invention or a vaccine of the invention to a subject (e.g. human) in need thereof.
  • a conjugate e.g. bioconjugate
  • conjugate e.g. bioconjugate
  • an immunogenic composition of the invention e.g. an immunogenic composition of the invention
  • a vaccine of the invention for use in inducing an immune response in a subject (e.g. human).
  • a conjugate e.g. bioconjugate
  • an immunogenic composition of the invention or a vaccine of the invention, for use in the manufacture of a medicament inducing an immune response in a subject (e.g. human).
  • a subject e.g. human
  • FIG. 1 shows 3D structure of EPA presented as cartoon and positions Y208, R274, S318 and A519 selected for insertion of glycosites presented as spheres.
  • FIG. 2 shows sequence alignment of EPA variants containing single glycosite at positions Y208, R274, S318 and A519 compared to EPA without any glycosite.
  • EPA_detox SEQ ID NO: 1
  • EPA_mut_Y208 SEQ ID NO: 34
  • EPA_mutR274 SEQ ID NO: 35
  • EPA_mut_5318 SEQ ID NO: 36
  • EPA_mut_A519 SEQ ID NO: 37
  • FIG. 3 shows SDS-PAGE analysis of IMAC (Immobilized metal affinity chromatography) enriched periplasmic extract of E. coli strains producing KpO-antigen ( Klebsiella pneumoniae O-antigen) polysaccharide and expressing PglB and EPA variants with a glycosite KDQNATK (SEQ ID NO: 4) introduced at the following positions: Y208 (lane 1), K240 (lane 2), R274 (lane 3), S318 (lane 4), A376 (lane 5), A519 (lane 6), and K240 and A376 (lane 7).
  • the bands corresponding to the unglycosylated EPA carrier, and to KpO-antigen-EPA bioconjugates with one and two occupied glycosites are labelled.
  • FIG. 4 shows SDS-PAGE analysis of IMAC enriched periplasmic extract of E. coli strains producing KpO-antigen polysaccharide and expressing PglB and EPA variants with a glycosite KDQNATK (SEQ ID NO: 4) introduced at the following positions: K240 and A376 (lane 1), Y208 and R274 (lane 2), Y208 and S318 (lane 3), Y208 and A519 (lane 4), R274 and S318 (lane 5), R274 and A519 (lane 6), S318 and A519 (lane 7), and Y208 and R274 and A519 (lane 8).
  • the bands corresponding to the unglycosylated EPA carrier, and to KpO-antigen-EPA bioconjugates with one, two and three occupied glycosites are labelled.
  • FIG. 5 shows immunoblot analyses of periplasmic extract of E. coli strains producing KpO-antigen polysaccharide and expressing PglB and EPA variants with 1 to 7 glycosites introduced at the following positions: Y208 (lane 1), K240 (lane 2), R274 (lane 3), S318 (lane 4), A376 (lane 5), A519 (lane 6), and K240 and A376 (lane 7), Y208 and R274 (lane 8), Y208 and S318 (lane 9), Y208 and A519 (lane 10), R274 and S318 (lane 11), R274 and A519 (lane 12), S318 and A519 (lane 13), Y208 and R274 and A519 (lane 14), N-terminal glycotag and K240 and A376 and C-terminal glycotag (lane 15), N-terminal glycotag and Y208 and R274 and A519 (lane 16), N-terminal glycotag and Y208 and R274 and A5
  • the upper panel represents the immunoblot probed with anti-KpO-antigen anti-serum, while the bottom panel represents the immunoblot probed with anti-EPA antibody.
  • the bands corresponding to the unglycosylated EPA carrier, and to KpO-antigen-EPA bioconjugates with one to seven occupied glycosites are labelled.
  • FIG. 6 shows SDS-PAGE analysis of periplasmic extract of E. coli strains producing KpO-antigen polysaccharide and expressing PglB and EPA variants with a glycosite KDQNATK (SEQ ID NO: 4) introduced at the following positions: N-terminal glycotag and Y208 and R274 and A519 and C-terminal glycotag (lane 1), N-terminal glycotag and Y208 and S318 and A519 and C-terminal glycotag (lane 2), N-terminal glycotag and R274 and S318 and A519 and C-terminal glycotag (lane 3), N-terminal glycotag and Y208 and R274 and S318 and A519 and C-terminal glycotag (lane 4), N-terminal glycotag and Y208 and K240 and R274 and S318 and A519 (lane 5), N-terminal glycotag and Y208 and K240 and R274 and S318 and A519 and C-terminal glycotag (lane
  • FIG. 7 shows SDS-PAGE analysis of IMAC enriched periplasmic extracts of E. coli strain producing Sf2a Shigella flexneri 2a (left) or Sp11A Streptococcus pneumoniae 11A (right) polysaccharide and expressing PglB and EPA variants with a glycosite introduced at K240 and a second glycosite at A376 (lane 1) or three glycosites at positions Y208, R274, and A519 (lane 2).
  • FIG. 8 shows SDS-PAGE analysis of IMAC enriched periplasmic extracts of E. coli strain producing two different Klebsiella pneumoniae O-antigen polysaccharides (left and right) and expressing PglB and EPA variants with glycosites at positions Y208 and R274 and A519 (lane 1), or with N-terminal glycotag and glycosites at positions Y208 and R274 and A519 (lane 2).
  • FIG. 9 shows immunoblot analyses of periplasmic extract of E. coli strains producing Sf2a, Sp33F, PaO6 and PaO11 antigen polysaccharide (bottom panel) and expressing PglB and EPA variants with 1 glycosite KDQNATK (SEQ ID NO: 4) introduced at the following positions: Y208 (lane 1), D218 (lane 2), R274 (lane 3), R279 (lane 4), S318 (lane 5), G323 (lane 6), A376 (lane 7), A519 (lane 8), and G525 (lane 9).
  • the bands corresponding to EPA bioconjugates and unglycosylated EPA carrier protein are labelled with arrows.
  • Carrier protein a protein which may be covalently attached to an antigen (e.g. saccharide antigen, such as a bacterial polysaccharide antigen) to create a conjugate (e.g. bioconjugate).
  • an antigen e.g. saccharide antigen, such as a bacterial polysaccharide antigen
  • a carrier protein activates T-cell mediated immunity in relation to the antigen to which it is conjugated.
  • Exotoxin A of Pseudomonas aeruginosa also known as “Exotoxin of P. aeruginosa ”, “EPA”, or “ETA”
  • proline refers to an amino acid selected from the group consisting of alanine (ala, A), arginine (arg, R), asparagine (asn, N) , aspartic acid (asp,D), cysteine (cys, C), glutamine (gln, Q), glutamic acid (glu, E), glycine (gly, G), histidine (his, H), isoleucine (ile, I), leucine (leu, L), lysine (lys, K), methionine (met, M), phenylalanine (phe, F), serine (ser, S), threonine (thr, T), tryptophan (trp, W), tyrosine (tyr, Y), and valine (val, V).
  • alanine ala, A
  • arginine arg, R
  • asparagine asparagine
  • aspartic acid aspartic acid
  • cysteine cysteine
  • Naturally occurring amino acid residues amino acids that are naturally incorporated into polypeptides.
  • the 20 amino acids encoded by the universal genetic code alanine (ala, A), arginine (arg, R), asparagine (asn, N) , aspartic acid (asp,D), cysteine (cys, C) ,glutamine (gln, Q), glutamic acid (glu, E), glycine (gly, G), histidine (his, H), isoleucine (ile,I), leucine (leu, L), lysine (lys, K), methionine (met, M), phenylalanine (phe, F), proline (pro, P), serine (ser, S), threonine (thr, T), tryptophan (trp, W), tyrosine (tyr, Y), and valine (val, V).
  • Glycosyltransferases enzymes that establish glycosidic linkages.
  • Glycosyltransferases are enzymes that catalyze the formation of the glycosidic linkage to form a glycoside. For example, they catalyze the transfer of saccharide moieties from an activated nucleotide sugar (also known as the “glycosyl donor”) to a nucleophilic glycosyl acceptor molecule, the nucleophile of which can be oxygen-carbon-, nitrogen-, or sulfur-based.
  • O-Antigens also known as O-specific polysaccharides or O-side chains
  • LPS surface lipopolysaccharide
  • examples include O-antigens from Pseudomonas aeruginosa and Klebsiella pneumoniae.
  • LPS Lipopolysaccharide
  • Capsular polysaccharide polysaccharide found on the bacterial cell wall. Examples include capsular polysaccharide from Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis and Staphylococcus aureus.
  • wzy a polysaccharide polymerase gene encoding an enzyme which catalyzes polysaccharide polymerization.
  • the encoded enzyme transfers oligosaccharide units to the non-reducing end forming a glycosidic bond.
  • waaL a O antigen ligase gene encoding a membrane bound enzyme.
  • the encoded enzyme transfers undecaprenyl-diphosphate (UPP)-bound O antigen to the lipid A core oligosaccharide, forming lipopolysaccharide.
  • UFP undecaprenyl-diphosphate
  • conjugate refers to carrier protein covalently linked to an antigen.
  • bioconjugate refers to conjugate between a protein (e.g. a carrier protein) and an antigen (e.g. a saccharide antigen, such as a bacterial polysaccharide antigen) prepared in a host cell background, wherein host cell machinery links the antigen to the protein (e.g. N-linked glycosylation).
  • a protein e.g. a carrier protein
  • an antigen e.g. a saccharide antigen, such as a bacterial polysaccharide antigen
  • modified protein means a protein that is altered (in one or more way) as compared to wild type (e.g. a “modified EPA protein” excludes a wild type EPA protein).
  • immunogenic fragment means a portion of an antigen smaller than the whole, that is capable of eliciting a humoral and/or cellular immune response in a host animal, e.g. human, specific for that fragment.
  • Fragments of a protein can be produced using techniques known in the art, e.g. recombinantly, by proteolytic digestion, or by chemical synthesis.
  • Internal or terminal fragments of a polypeptide can be generated by removing one or more nucleotides from one end (for a terminal fragment) or both ends (for an internal fragment) of a nucleic acid which encodes the polypeptide.
  • fragments comprise at least 10, 20, 30, 40 or 50 contiguous amino acids of the full length sequence.
  • Fragments may be readily modified by adding or removing 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40 or 50 amino acids from either or both of the N and C termini.
  • a fragment of a modified EPA protein still comprises the recited modifications that are made to the EPA protein.
  • the term “conservative amino acid substitution” involves substitution of a native amino acid residue with a non-native residue such that there is little or no effect on the size, polarity, charge, hydrophobicity, or hydrophilicity of the amino acid residue at that position, and without resulting in decreased immunogenicity.
  • these may be substitutions within the following groups: valine, glycine; glycine, alanine; valine, isoleucine, leucine; aspartic acid, glutamic acid; asparagine, glutamine; serine, threonine; lysine, arginine; and phenylalanine, tyrosine.
  • Conservative amino acid modifications to the sequence of a polypeptide (and the corresponding modifications to the encoding nucleotides) may produce polypeptides having functional and chemical characteristics similar to those of a parental polypeptide.
  • deletion is the removal of one or more amino acid residues from the protein sequence. Typically, no more than about from 1 to 6 residues (e.g. 1 to 4 residues) are deleted at any one site within the protein molecule.
  • insertion or “addition” (including other tenses thereof such as “inserted”) means the addition of one or more non-native amino acid residues in the protein sequence or, as the context requires, addition of one or more non-native nucleotides in the polynucleotide sequence. Typically, no more than about from 1 to 10 residues, (e.g. 1 to 7 residues, 1 to 6 residues, or 1 to 4 residues) are inserted at any one site within the protein molecule.
  • the term “added next to” is the addition of one or more non-native amino acid residues in the protein sequence at a position adjacent to the referenced amino acid or amino acid region.
  • “added next to one or more amino acids between amino acid residues 198-218” means the addition at a position adjacent to any one of amino acid residues 198-218 (including adjacent to amino acid residues 198 or 218).
  • glycosite refers to an amino acid sequence recognized by a bacterial oligosaccharyltransferase, e.g. PglB of C. jejuni.
  • a “consensus sequence” is a sequence have a specific structure and/or function. As used herein, the term “consensus sequence” is a sequence comprising a glycosite.
  • a consensus sequence may be selected from: a five amino acid consensus sequence D/E-X-N-Z-S/T (SEQ ID NO: 2), a seven amino acid consensus sequence K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)).
  • the term “introduced at” is used herein to reference the location and manner of inserting a consensus sequence into an amino acid sequence.
  • a glycosite which is introduced at an N-terminal or C-terminal position of a protein may be added next to the amino acid sequence at the N-terminus or C-terminus, whereas a consensus sequence (or glycosite) which is introduced at a specific amino acid residue within the protein, e.g. Y208, may be substituted for that amino acid.
  • numeric range e.g. “25-30” is inclusive of endpoints (i.e. includes the values 25 and 30).
  • endpoints i.e. includes the values 25 and 30.
  • “between amino acids 198 to 218 . . . of SEQ ID NO: 1” refers to position in the amino acid sequence between amino acid 198 and amino acid 218 of SEQ ID NO: 1 including both amino acids 198 and 218.
  • nucleotide sequences or amino acid sequences that are the same or have a specified percentage of nucleotide residues or amino acid residues that are the same (e.g. 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identity over a specified region), when compared and aligned for maximum correspondence using, for example, sequence comparison algorithms or by manual alignment and visual inspection.
  • Identity between polypeptides may be calculated by various algorithms. In general, when calculating percentage identity the two sequences to be compared are aligned to give a maximum correlation between the sequences. This may include inserting “gaps” in either one or both sequences, to enhance the degree of alignment.
  • Needleman Wunsch algorithm (Needleman and Wunsch 1970, J. Mol. Biol. 48: 443-453) for global alignment, or the Smith Waterman algorithm (Smith and Waterman 1981, J. Mol. Biol. 147: 195-197) for local alignment may be used, e.g. using the default parameters (Smith Waterman uses BLOSUM 62 scoring matrix with a Gap opening penalty of 10 and a Gap extension penalty of 1).
  • a preferred algorithm is described by Dufresne et al. in Nature Biotechnology in 2002 (vol. 20, pp. 1269-71) and is used in the software GenePAST (Genome Quest Life Sciences, Inc. Boston, Mass.).
  • the GenePAST “percent identity” algorithm finds the best fit between the query sequence and the subject sequence, and expresses the alignment as an exact percentage. GenePAST makes no alignment scoring adjustments based on considerations of biological relevance between query and subject sequences. Identity between two sequences is calculated across the entire length of both sequences and is expressed as a percentage of the reference sequence (e.g. SEQ ID NO: 1 of the present invention).
  • recombinant means artificial or synthetic.
  • a “recombinant protein” refers to a protein that has been made using recombinant nucleotide sequences (nucleotide sequences introduced into a host cell).
  • the nucleotide sequence that encodes a “recombinant protein” is heterologous to the host cell.
  • an isolated or purified protein mean a protein, conjugate (e.g. bioconjugate), polynucleotide, or vector in a form not found in nature. This includes, for example, a a protein, conjugate (e.g. bioconjugate), polynucleotide, or vector having been separated from host cell or organism (including crude extracts) or otherwise removed from its natural environment.
  • an isolated or purified protein is a protein essentially free from all other polypeptides with which the protein is innately associated (or innately in contact with).
  • the term “subject” refers to an animal, in particular a mammal such as a primate (e.g. human).
  • an “effective amount” in the context of administering a therapy (e.g. an immunogenic composition or vaccine of the invention) to a subject refers to the amount of a therapy which has a prophylactic and/or therapeutic effect(s).
  • an “effective amount” refers to the amount of a therapy which is sufficient to achieve one, two, three, four, or more of the following effects: (i) reduce or ameliorate the severity of a bacterial infection or symptom associated therewith; (ii) reduce the duration of a bacterial infection or symptom associated therewith; (iii) prevent the progression of a bacterial infection or symptom associated therewith; (iv) cause regression of a bacterial infection or symptom associated therewith; (v) prevent the development or onset of a bacterial infection, or symptom associated therewith; (vi) prevent the recurrence of a bacterial infection or symptom associated therewith; (vii) reduce organ failure associated with a bacterial infection; (viii) reduce hospitalization of a subject
  • the word “is” may be used as a substitute for “consists of” or “consisting of”.
  • the abbreviation, “e.g.” is derived from the Latin exempli gratia, and is used herein to indicate a non-limiting example. Thus, the abbreviation “e.g.” is synonymous with the term “for example”.
  • Exotoxin A of Pseudomonas aeruginosa is a secreted bacterial toxin, a member of the ADP-ribosyltransferasetoxin family.
  • An EPA protein useful in the invention can be produced by methods known in the art in view of the present disclosure, see for example Ihssen etas. (2010) Microbial Cell Factories 9:61, WO 2006/119987, WO 2009/104074 and WO2015124769A1.
  • Exotoxin A from Pseudomonas aeruginosa strain PA103 was cloned and sequenced by Gray etas. (1984) Proc. Nati. Acad. Sci.
  • a modified EPA protein of the invention may be genetically detoxified (i.e. by mutation).
  • the genetically detoxified sequences may remove undesirable activities such as ADP-ribosyltransferase activity, in order to reduce the toxicity, whilst retaining the ability to induce anti-EPA protective and/or neutralizing antibodies following administration to a human.
  • the genetically detoxified sequences may maintain their immunogenic epitopes.
  • a modified EPA protein may be genetically detoxified by one or more point mutations.
  • detoxification can be achieved by mutating and deleting catalytically essential residues, such as substitution of leucine 552 to valine (L552V) and by deletion of glutamic acid-553 ( ⁇ E553), according to Lukac et al. (1988), Infect Immun, 56: 3095-3098, and Ho et al. (2006), Hum Vaccin, 2:89-98.
  • Detoxification can be achieved by mutating/deleting the catalytically essential residues L552V ⁇ E553 using quick change mutagenesis (Stratagene) and phosphorylated oligonucleotides 5′-GAAGGCGGGCGCGTGACCATTCTCGGC (SEQ. ID NO.
  • Detoxification can be measured by determining the inhibition of ADP-ribosyltransferase and cytotoxic activity according to the methodology described in Lukac et al. (1988), Infect Immun, 56: 3095-3098, and references cited therein, namely Douglas et al (1987) J. Bacteriol 169: 4962-4966 and Douglas et al (1987).
  • a detoxified EPA has ADP-ribosyltransferase and cytotoxic activites lower than wild-type EPA, suitably the same as or less than that of the modified EPA described in Lukac et al (1988) i.e. ⁇ E553 EPA (EPA having deletion of glutamic acid-533).
  • the modified EPA protein of the invention may be the amino acid sequence of SEQ ID NO: 1 (or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1).
  • the modified EPA protein may comprise substitution of leucine 552 to valine (L552V) and deletion of glutamine 553 ( ⁇ E553) with reference to the amino acid sequence of SEQ ID NO: 1 (or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1).
  • the modified EPA protein of the invention may be the amino acid sequence of SEQ ID NO: 1 (or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1) comprising substitution of leucine 552 to valine (L552V).
  • the modified EPA protein of the invention may be the amino acid sequence of SEQ ID NO: 1 (or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1) comprising deletion of glutamine 553 ( ⁇ E553).
  • the modified EPA protein of the invention is modified by substitution of leucine 552 to valine (L552V) and deletion of glutamine 553 ( ⁇ E553).
  • the modified EPA protein of the invention is the amino acid sequence of SEQ ID NO: 1 (or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1) comprising substitution of leucine 552 to valine (L552V) and deletion of glutamine 553 ( ⁇ E553).
  • EPA protein has the amino acid sequence of SEQ ID NO: 1:
  • modified EPA protein refers to a EPA amino acid sequence (for example, having a amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1), which EPA amino acid sequence has been modified by the addition, substitution or deletion of one or more amino acids (for example, by addition of a consensus sequence(s) selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) and/or an extended consensus sequence (e.g.
  • J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)).; and/or by substitution of one or more amino acids by a consensus sequence(s) selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3)).
  • a modified EPA protein may be an EPA amino acid sequence of SEQ ID NO: 1 which has been modified in that the amino acid sequence comprises one (or more) consensus sequence(s) selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) and/or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)).
  • SEQ ID NO: 2 D/E-X-N-Z-S/T
  • K-D/E-X-N-Z-S/T-K SEQ ID NO: 3
  • an extended consensus sequence e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)
  • X and Z are independently any amino acid except proline; preferably, X is Q (glutamine) and Z is A (alanine).
  • the modified EPA protein may also comprise further modifications (additions, substitutions, deletions).
  • the modified EPA protein of the invention comprises substitution of leucine 552 to valine (L552V) and deletion of glutamine 553 ( ⁇ E553) with reference to the amino acid sequence of SEQ ID NO: 1 (or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1).
  • the modified EPA protein of the invention is a non-naturally occurring EPA protein (i.e. not native).
  • a modified EPA protein of the invention may have an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a modified EPA protein of the invention may have an amino acid sequence at least 80% identical to SEQ ID NO: 1.
  • a modified EPA protein of the invention may have an amino acid sequence at least 85% identical to SEQ ID NO: 1.
  • a modified EPA protein of the invention may have an amino acid sequence at least 90% identical to SEQ ID NO: 1.
  • a modified EPA protein of the invention may have an amino acid sequence at least 91% identical to SEQ ID NO: 1.
  • a modified EPA protein of the invention may have an amino acid sequence at least 92% identical to SEQ ID NO: 1.
  • a modified EPA protein of the invention may have an amino acid sequence at least 93% identical to SEQ ID NO: 1.
  • a modified EPA protein of the invention may have an amino acid sequence at least 94% identical to SEQ ID NO: 1.
  • a modified EPA protein of the invention may have an amino acid sequence at least 95% identical to SEQ ID NO: 1.
  • a modified EPA protein of the invention may have an amino acid sequence at least 96% identical to SEQ ID NO: 1.
  • a modified EPA protein of the invention may have an amino acid sequence at least 97% identical to SEQ ID NO: 1.
  • a modified EPA protein of the invention may have an amino acid sequence at least 98% identical to SEQ ID NO: 1.
  • a modified EPA protein of the invention may have an amino acid sequence at least 99% identical to SEQ ID NO: 1.
  • the present invention provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa ) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises one (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein the one (or more) consensus sequences have each been added next to or substituted for one or more amino acids, selected from specific amino acid residues within the EPA protein (consensus sequence sites).
  • consensus sequence sites are independently selected from (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), and (iv) one or more amino acids between amino acid residues 509-529 (e.g.
  • amino acids between amino acid residues 514-524 e.g. amino acid residue A519) of SEQ ID NO: 1 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the present invention provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa ) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises one (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the one (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g.
  • amino acids between amino acid residues 203-213, e.g. amino acid residue Y208 one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208
  • amino acid residues 264-284 one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274
  • amino acid residues 308-328 one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318)
  • amino acids between amino acid residues 509-529 e.g. one or more amino acids between amino acid residues 514-524; e.g.
  • the present invention also provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa ) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises one (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the one (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g.
  • the present invention also provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa ) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises two (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein the two (or more) consensus sequences have each been added next to or substituted for one or more amino acids, selected from specific amino acid residues within the EPA protein (consensus sequence sites).
  • EPA Exotoxin A of Pseudomonas aeruginosa
  • consensus sequence sites are independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), (iv) one or more amino acids between amino acid residues 509-529 (e.g.
  • the present invention provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa ) having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises two (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the two (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g.
  • amino acid residue A519) amino acid residue A517
  • amino acid residues 230-250 one or more amino acids between amino acid residues 235-245; e.g. amino acid residue K240
  • amino acid residue K240 amino acid residue K240
  • the present invention also provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa ) having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises two (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein the two (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g.
  • the two (or more) consensus sequences may also be independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213; or one or more amino acids between 205-211; e.g. amino acid residue D218; e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279; or one or more amino acids between amino acid residues 271-277, e.g. amino acid residue R279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g.
  • the present invention also provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa ) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises three (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein the three (or more) consensus sequences have each been added next to or substituted for one or more amino acids, selected from specific amino acid residues within the EPA protein (consensus sequence sites).
  • EPA Exotoxin A of Pseudomonas aeruginosa
  • consensus sequence sites are independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), (iv) one or more amino acids between amino acid residues 509-529 (e.g.
  • the present invention provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa ) having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises three (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the three (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g.
  • amino acid residue A519) of SEQ ID NO: 1 (v) one or more amino acids between amino acid residues 230-250 (e.g. one or more amino acids between amino acid residues 235-245; e.g. amino acid residue K240) or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the three (or more) consensus sequences may also be independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213; or one or more amino acids between 205-211; e.g. amino acid residue D218; e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279; or one or more amino acids between amino acid residues 271-277, e.g. amino acid residue R279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g.
  • the present invention also provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa ) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises four (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein the four (or more) consensus sequences have each been added next to or substituted for one or more amino acids, selected from specific amino acid residues within the EPA protein (consensus sequence sites).
  • SEQ ID NO: 2 D/E-X-N-Z-S/T
  • SEQ ID NO: 3 K-D/E-X-N-Z-S/T-K
  • consensus sequence sites are independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), (iv) one or more amino acids between amino acid residues 509-529 (e.g.
  • the present invention provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa ) having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises four (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the four (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g.
  • amino acid residue A519) of SEQ ID NO: 1 (v) one or more amino acids between amino acid residues 230-250 (e.g. one or more amino acids between amino acid residues 235-245; e.g. amino acid residue K240) or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the four (or more) consensus sequences may also be independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213; or one or more amino acids between 205-211; e.g. amino acid residue D218; e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279; or one or more amino acids between amino acid residues 271-277, e.g. amino acid residue R279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g.
  • the modified EPA protein of the invention may be derived from an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 which is an immunogenic fragment and/or a variant of SEQ ID NO: 1.
  • the modified EPA protein of the invention may be derived from an immunogenic fragment of SEQ ID NO: 1 comprising at least about 15, at least about 20, at least about 40, or at least about 60 contiguous amino acid residues of SEQ ID NO: 1, wherein said polypeptide is capable of eliciting an antibodies which bind to SEQ ID NO: 1.
  • the immunogenic fragment of SEQ ID NO: 1 comprises the eight cysteines of SEQ ID NO: 1: Cys-11, Cys-15, Cys-197, Cys-214, Cys-265, Cys-287, Cys-372 and Cys-379 (i.e. these residues are not modified).
  • the modified EPA protein of the invention comprises the eight cysteines of SEQ ID NO: 1: Cys-11, Cys-15, Cys-197, Cys-214, Cys-265, Cys -287, Cys-372 and Cys-379 or equivalent cysteines within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may be derived from an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 which is a variant of SEQ ID NO: 1 and differs from SEQ ID NO: 1 by the deletion and/or addition and/or substitution of one or more amino acids (e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 amino acids). Amino acid substitution may be conservative or non-conservative. In one aspect, amino acid substitution is conservative. Substitutions, deletions, additions or any combination thereof may be combined in a single variant so long as the variant is an immunogenic polypeptide.
  • the modified EPA protein of the present invention may be derived from a variant of SEQ ID NO: 1 in which 1 to 10, 5 to 10, 1 to 5, 1 to 3, 1 to 2 or 1 amino acids of SEQ ID NO: 1 have been substituted or deleted.
  • the immunogenic fragment and/or a variant of SEQ ID NO: 1 comprises a B-cell or T-cell epitope.
  • Such epitopes may be predicted using a combination of 2D-structure prediction, e.g. using the PSIPRED program (from David Jones, Brunel Bioinformatics Group, Dept. Biological Sciences, Brunel University, Uxbridge UB8 3PH, UK) and antigenic index calculated on the basis of the method described by Jameson and Wolf (CABIOS 4:181-186 [1988]).
  • one or more consensus sequences have each been added next to, or substituted for one or more amino acids of SEQ ID NO: 1 or a EPA amino acid sequence at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • one or more amino acids e.g. 1-7 amino acids, e.g.
  • one amino acid) of the EPA amino acid sequence (for example, having an amino acid sequence of SEQ ID NO: 1 or a EPA amino acid sequence at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1) is/are substituted by a five amino acid D/E-X-N-Z-S/T (SEQ ID NO: 2) or by a seven amino acid K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4) also referred to as “KDQNATK”) consensus sequence.
  • a single amino acid in the EPA amino acid sequence may be substituted (i.e. replaced) with a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence.
  • SEQ ID NO: 1 a single amino acid in the EPA amino acid sequence
  • SEQ ID NO: 3 e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4) consensus sequence.
  • 2, 3, 4, 5, 6 or 7 amino acids in the EPA amino acid sequence e.g.
  • SEQ ID NO: 1 or a EPA amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1) may be substituted (i.e. replaced) with a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence.
  • SEQ ID NO: 2 e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4) consensus sequence.
  • an internal consensus sequence site i.e.
  • a consensus sequence site that is within the EPA amino acid sequence rather than added next to the N-terminal or C-terminal amino acid
  • a single amino acid in the EPA amino acid sequence e.g. SEQ ID NO: 1
  • a K-D-Q-N-A-T-K SEQ ID NO: 4
  • the classical 5 amino acid glycosylation consensus sequence D/E-X-N-Z-S/T (SEQ ID NO: 2)
  • SEQ ID NO: 2 may also be extended by 1-5 other amino acid residues either side of the consensus sequence for more efficient glycosylation.
  • an extended consensus sequence may be J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5).
  • J and U are independently 1 to 5 naturally occurring amino acid residues, preferably J and U are independently 1 to 5 amino acid residues independently selected from glycine and/or serine, e.g. B may be G-S-G-G-G and U may be G-S-G-G.
  • an extended consensus sequence may be G-S-G-G-G-D/E-X-N-Z-S/T-G-S-G-G (SEQ ID NO: 25).
  • an extended consensus sequence such as J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) or G-S-G-G-G-D/E-X-N-Z-S/T-G-S-G-G (SEQ ID NO: 25) is used where the consensus sequence is added next to the N-terminal or C-terminal amino acid of the EPA protein.
  • a combination of consensus sequences selected from: a five amino acid consensus sequence D/E-X-N-Z-S/T (SEQ ID NO: 1), a seven amino acid consensus sequence K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) and an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)) may be used.
  • a five amino acid consensus sequence D/E-X-N-Z-S/T (SEQ ID NO: 1)
  • a seven amino acid consensus sequence K-D/E-X-N-Z-S/T-K SEQ ID NO: 3
  • an extended consensus sequence e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)
  • amino acids within the carrier protein amino acid sequence may each independently be substituted (i.e.
  • X and Z are independently any amino acid except proline (preferably wherein X is Q (glutamine), Z is A (alanine)) (e.g.
  • K-D-Q-N-A-T-K (SEQ ID NO: 4), and 1 or 2 consensus sequences J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) wherein J and U are independently 1 to 5 naturally occurring amino acid residues (preferably J and U are independently 1 to 5 amino acid residues independently selected from glycine and/or serine, e.g. G-S-G-G-G-D/E-X-N-Z-S/T-G-S-G-G (SEQ ID NO: 25)) may be added next to the N-terminal or C-terminal amino acids of the carrier protein.
  • a carrier protein may comprise 1, 2, 3, 4 or 5 consensus sequences selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline (preferably wherein X is Q (glutamine), Z is A (alanine)), and the carrier protein may further comprise 1 or 2 extended consensus sequences J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) wherein J and U are independently 1 to 5 naturally occurring amino acid residues (preferably J and U are independently 1 to 5 amino acid residues independently selected from glycine and/or serine, e.g.
  • G-S-G-G-G-D/E-X-N-Z-S/T-G-S-G-G (SEQ ID NO: 25).
  • Introduction of one or more consensus sequence(s) selected from: a five amino acid consensus sequence D/E-X-N-Z-S/T (SEQ ID NO: 2), a seven amino acid consensus sequence K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) and/or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)) enables the modified EPA protein to be glycosylated.
  • the present invention also provides a modified EPA protein of the invention wherein the modified EPA protein is glycosylated.
  • the present inventors have found that the position of the consensus sequence at specific regions/amino acids in the EPA amino acid sequence can increase glycosylation efficiency and/or optimize the operation of the N-glycosylation site.
  • a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) between amino acids 198-218 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue Y208 or D218 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be added next to or substituted for one or more amino acids residues between amino acids 205-211 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue Y208 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) between amino acids 264-284 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue R274 or R279 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be added next to or substituted for one or more amino acids residues between amino acids 271-277 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue R274 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) between amino acids 308-328 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue S318 or G323 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be added next to or substituted for one or more amino acids residues between amino acids 313-323 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue S318 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) between amino acids 509-529 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue A519 or G525 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be added next to or substituted for one or more amino acids residues between amino acids 516-522 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue A519 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) between amino acids 230-250 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be added next to or substituted for one or more amino acids residues between amino acids 237-243 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue K240 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence (e.g.
  • J-D/E-X-N-Z-S/T-U may be added next to or substituted for one or more amino acids residue(s) within the N-terminal 10 amino acids of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. More particularly, a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g.
  • K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)) may be added next to or substituted for one or more amino acids residue(s) within the N-terminal 5 amino acids of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5))
  • SEQ ID NO: 5 e.g. J-D/E-X-N-Z-S/T-U
  • a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence (e.g.
  • J-D/E-X-N-Z-S/T-U may be added next to or substituted for one or more amino acids residue(s) within the C-terminal 10 amino acids of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. More particularly, a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g.
  • K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)) may be added next to or substituted for one or more amino acids residue(s) within the C-terminal 5 amino acids of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5))
  • SEQ ID NO: 5 e.g. J-D/E-X-N-Z-S/T-U
  • the consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), may each be independently substituted for one or more amino acids (e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, D218, R274, R279, S318,
  • each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318 and A519) of the amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • two or more consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) may each be independently substituted for one or more amino acids (e.g.
  • each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, D218, R274, R279, S318, G323, A519, G525 and K240; e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318, A519 and K240) of the amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • three or more consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) may each be independently substituted for one or more amino acids (e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, D218, R274, R279, S318, G323, A519, G525 and K240; e.g.
  • each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318, A519 and K240) of the amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • four or more consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) may each be independently substituted for one or more amino acids (e.g.
  • five or more consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) may each be independently substituted for one or more amino acids (e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, D218, R274, R279, S318, G323, A519, G525 and K240; e.g.
  • each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318, A519 and K240) of the amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) (e.g.
  • G-S-G-G-G-D/E-X-N-Z-S/T-G-S-G-G (SEQ ID NO: 25)) may be added next to or substituted for one or more amino acids residue(s) at the N-terminus of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may comprise a further consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5), wherein X and Z are independently any amino acid except proline and J and U are independently 1 to 5 naturally occurring amino acid residues, added next to, or substituted for, one or more amino acids, at the N-terminus of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may comprise a further consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5), wherein X and Z are independently any amino acid except proline and J and U are independently 1 to 5 naturally occurring amino acid residues, added next to the N-terminal amino acid of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) (e.g.
  • G-S-G-G-G-D/E-X-N-Z-S/T-G-S-G-G (SEQ ID NO: 25)) may be added next to or substituted for one or more amino acids residue(s) at the C-terminus of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may comprise a further consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5), wherein X and Z are independently any amino acid except proline and J and U are independently 1 to 5 naturally occurring amino acid residues, added next to, or substituted for, one or more amino acids, at the C-terminus of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may comprise a further consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5), wherein X and Z are independently any amino acid except proline and J and U are independently 1 to 5 naturally occurring amino acid residues, added next to the C-terminal amino acid of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • three or more consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) may each be independently substituted for one or more amino acids (e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318, A519 and K240) and a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g.
  • K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) at the N-terminus (e.g. added next to the N-terminal amino acid) and a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) C-terminus (e.g. added next to the C-terminal amino acid) of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318, A519 and K240
  • a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) e.g.
  • K-D-Q-N-A-T-K (SEQ ID NO: 4) may be added next to or substituted for one or more amino acids residue(s) at the N-terminus (e.g. added next to the N-terminal amino acid) and/or a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) C-terminus (e.g. added next to the C-terminal amino acid) of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • five or more consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) may be substituted for one or more amino acids (e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318, A519 and K240) and a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g.
  • K-D-Q-N-A-T-K (SEQ ID NO: 4) may be added next to or substituted for one or more amino acids residue(s) at the N-terminus (e.g. added next to the N-terminal amino acid) and/or a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) C-terminus (e.g. added next to the C-terminal amino acid) of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may comprise at least one consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, has been added next to, or substituted for: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g.
  • amino acid residue S318) amino acid residue S318), or (iii) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519) of SEQ ID NO: 1 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may contain a consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), which has been added next to, or substituted for one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208) of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may contain a consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), which has been added next to, or substituted for one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318) of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • SEQ ID NO: 2 D/E-X-N-Z-S/T
  • SEQ ID NO: 3 K-D/E-X-N-Z-S/T-K
  • the modified EPA protein of the invention may contain a consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), which has been added next to, or substituted for one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519) of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • SEQ ID NO: 2 D/E-X-N-Z-S/T
  • SEQ ID NO: 3 K-D/E-X-N-Z-S/T-K
  • the modified EPA protein of the invention may contain two consensus sequences.
  • the modified EPA protein may have an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 modified in that the amino acid sequence comprises two consensus sequences, e.g. wherein two consensus sequences are added next to or substituted for two amino acid residues of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • modified EPA protein of the invention may contain two consensus sequences, optionally substituted for amino acid residues selected from: (i) Y208 and R274, (ii) Y208 and S318, (iii) Y208 and A519, (iv) R274 and S318, (v) R274 and A519, or (vi) S318 and A519 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may contain two consensus sequences substituted for amino acid residues Y208 and R274 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 6.
  • the modified EPA protein of the invention may contain two consensus sequences substituted for amino acid residues Y208 and S318 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 28.
  • the modified EPA protein of the invention may contain two consensus sequences substituted for amino acid residues Y208 and A519 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 29.
  • the modified EPA protein of the invention may contain two consensus sequences substituted for amino acid residues R274 and S318 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 30.
  • the modified EPA protein of the invention may contain two consensus sequences substituted for amino acid residues R274 and A519 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 31.
  • the modified EPA protein of the invention may contain two consensus sequences substituted for amino acid residues S318 and A519 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 7.
  • the modified EPA protein of the invention may contain three consensus sequences.
  • the modified EPA protein may have an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 modified in that the amino acid sequence comprises three consensus sequences, e.g. wherein three consensus sequences are added next to or substituted for three independently selected amino acid residues of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may contain three consensus sequences, optionally substituted for amino acid residues Y208, R274 and A519 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 7.
  • the modified EPA protein of the invention may contain four consensus sequences.
  • the modified EPA protein may have an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 modified in that the amino acid sequence comprises four consensus sequences, e.g. wherein four consensus sequences are added next to or substituted for four independently selected amino acid residues of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may contain four consensus sequences, optionally substituted for amino acid residues Y208, R274, A519 and added next to the N-terminal amino acid of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 8.
  • the modified EPA protein of the invention may contain five consensus sequences.
  • the modified EPA protein may have an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 modified in that the amino acid sequence comprises five consensus sequences, e.g. wherein five consensus sequences are added next to or substituted for five independently selected amino acid residues of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • modified EPA protein of the invention may contain five consensus sequences, optionally selected from: substitution of amino acid residue Y208, substitution of amino acid residue R274, substitution of amino acid residue S318, substitution of amino acid residue A519, addition at the N-terminus (i.e. added at the N-terminus) and addition at the C-terminus (i.e. added at the C-terminus) of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a modified EPA protein may comprise (or consist of) (i) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 9, (ii) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 10, or (iii) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 11.
  • the modified EPA protein of the invention may contain six consensus sequences.
  • the modified EPA protein may have an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 modified in that the amino acid sequence comprises six consensus sequences, e.g. wherein six consensus sequences are added next to or substituted for six independently selected amino acid residues of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • modified EPA protein of the invention may contain six consensus sequences, optionally selected from: substitution of amino acid residue Y208, substitution of amino acid residue K240, substitution of amino acid residue R274, substitution of amino acid residue S318, substitution of amino acid residue A519, addition at the N-terminus (i.e. added at the N-terminus) and addition at the C-terminus (i.e. added at the C-terminus) of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a modified EPA protein of the invention may comprise (or consist of) (i) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 12, or (ii) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 13.
  • the modified EPA protein of the invention may contain seven consensus sequences.
  • the modified EPA protein may have an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 modified in that the amino acid sequence comprises seven consensus sequences, e.g. wherein seven consensus sequences are added next to or substituted for seven independently selected amino acid residues of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may contain seven consensus sequences, optionally substitution of amino acid residues Y208, K240, R274, S318, A519, addition at the N-terminus (i.e. added at the N-terminus) and addition at the C-terminus (i.e. added at the C-terminus) of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 14.
  • K-D-Q-N-A-T-K (SEQ ID NO: 4)) has been added next to or substituted for one or more amino acids between amino acid residues 198-218”, the consensus sequence may have been added next to or substituted for any one (or more) of amino acid numbers 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218 in SEQ ID NO: 1.
  • the EPA amino acid sequence is a variant and/or fragment of an amino acid sequence of SEQ ID NO: 1, such as an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, the reference to “between amino acids . . .
  • sequence alignment tools are not limited to Clustal Omega (www(.)ebi(.)ac(.)ac(.)uk) MUSCLE (www(.)ebi(.)ac(.)uk), or T-coffee (www(.)tcoffee(.)org).
  • the sequence alignment tool used is Clustal Omega (www(.)ebi(.)ac(.)ac(.)uk).
  • amino acid numbers referred to herein correspond to the amino acids in SEQ ID NO: 1 and as described above, a person skilled in the art can determine equivalent amino acid positions in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 by alignment.
  • the addition or deletion of amino acids from the variant and/or fragment of SEQ ID NO:1 could lead to a difference in the actual amino acid position of the consensus sequence in the mutated sequence, however, by lining the mutated sequence up with the reference sequence, the amino acid in in an equivalent position to the corresponding amino acid in the reference sequence can be identified and hence the appropriate position for addition or substitution of the consensus sequence can be established.
  • the modified EPA protein of the invention may be an isolated modified EPA protein.
  • the modified EPA protein of the invention may be a recombinant modified EPA protein.
  • the modified EPA protein of the invention may be an isolated recombinant modified EPA protein.
  • the modified EPA protein of the invention comprises a D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) or J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) consensus sequence, wherein X and Z are independently any amino acid except proline and J and U are independently 1 to 5 naturally occurring amino acid residues.
  • the classical 5 amino acid glycosylation consensus sequence (D/E-X-N-Z-S/T (SEQ ID NO: 2)) may be extended by 1-5 other amino acid residues either side of the consensus sequence for more efficient glycosylation J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) (e.g. G-S-G-G-G-D/E-X-N-Z-S/T-G-S-G-G (SEQ ID NO: 25)).
  • the classical 5 amino acid glycosylation consensus sequence (D/E-X-N-Z-S/T (SEQ ID NO: 2)) may be extended by lysine residues for more efficient glycosylation (e.g.
  • consensus sequences in the modified EPA protein of the invention may comprises (or consist) of a D/E-X-N-Z-S/T (SEQ ID NO: 2) consensus sequence.
  • the consensus sequence(s) may be selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) or J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) wherein X is Q (glutamine) and Z is A (alanine).
  • the consensus sequence(s) may be selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X is Q (glutamine) and Z is A (alanine).
  • the consensus sequence is D/E-X-N-Z-S/T (SEQ ID NO: 2), wherein X is Q (glutamine) and Z is A (alanine), e.g. D-Q-N-A-T (SEQ ID NO: 25) also referred to as “DQNAT”.
  • the consensus sequence is K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X is Q (glutamine) and Z is A (alanine), e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4) also referred to as “KDQNATK”.
  • the consensus sequence(s) may be selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) or J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) wherein X is Q (glutamine), Z is A (alanine), J and U are independently 1 to 5 amino acid residues independently selected from glycine and/or serine.
  • the modified EPA protein of the invention comprises at least two D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences. In an embodiment, the modified EPA protein of the invention comprises at least three D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences.
  • the modified EPA protein of the invention comprises at least four D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences. In an embodiment, the modified EPA protein of the invention comprises at least five D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences.
  • the modified EPA protein of the invention comprises at least six D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences. In an embodiment, the modified EPA protein of the invention comprises at least seven D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences.
  • the modified EPA protein of the invention contains three to seven D/E-X-N-X-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences. In an embodiment, the modified EPA protein of the invention contains four to seven D/E-X-N-X-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences.
  • the modified EPA protein of the invention contains five to seven D/E-X-N-X-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences.
  • glycosylation sites can be accomplished by, e.g. adding new amino acids to the primary structure of the protein (i.e. the glycosylation sites are added, in full or in part), or by mutating existing amino acids in the protein in order to generate the glycosylation sites (i.e. amino acids are not added to the protein, but selected amino acids of the protein are mutated so as to form glycosylation sites).
  • the consensus sequence(s) are recombinantly introduced into the EPA amino acid sequence of SEQ ID NO: 1 or a EPA amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • the modified EPA protein of the invention may further comprise a “peptide tag” or “tag”, i.e. a sequence of amino acids that allows for the isolation and/or identification of the modified EPA protein.
  • a tag i.e. a sequence of amino acids that allows for the isolation and/or identification of the modified EPA protein.
  • adding a tag to a modified EPA protein of the invention can be useful in the purification of that protein and, hence, the purification of conjugate (e.g. bioconjugate) vaccines comprising the tagged modified EPA protein.
  • Exemplary tags that can be used herein include, without limitation, histidine (HIS) tags (e.g. hexa histidine-tag, or 6XHis-Tag), FLAG-TAG, and HA tags.
  • the tag is a hexa-histidine tag.
  • the modified EPA protein of the invention may further comprise a peptide tag.
  • the peptide tag is located at the C-terminus of the amino acid sequence.
  • the peptide tag comprises six histidine residues at the C-terminus of the amino acid sequence.
  • the modified EPA protein of the invention comprises (or consists of) an amino acid sequence which is at least 80%, 85%, 90%, 92%, 95%, 97%, 98%, 99% or 100% identical to any one of the sequences of SEQ ID NOs: 6 to 14 and a peptide tag (e.g. six histidine residues at the C-terminus of the amino acid sequence).
  • a peptide tag e.g. six histidine residues at the C-terminus of the amino acid sequence.
  • the modified EPA protein of the invention comprises a signal sequence which is capable of directing the EPA protein to the periplasm of a host cell (e.g. bacterium).
  • Signal sequences including periplasmic signal sequences, are usually removed during translocation of the protein into, for example, the periplasm by signal peptidases (i.e. a mature protein is a protein from which at least the signal sequence has been removed).
  • the signal sequence may be from E. coli flagellin (FlgI) [MIKFLSALILLLVTTAAQA (SEQ ID NO: 15)], E. coli outer membrane porin A (OmpA) [MKKTAIAIAVALAGFATVAQA (SEQ ID NO: 16)], E.
  • E. coli maltose binding protein [MKIKTGARILALSALTTMMFSASALA (SEQ ID NO: 17)], Erwin carotovorans pectate lyase (PelB) [MKYLLPTAAAGLLLLAAQPAMA (SEQ ID NO: 18)], heat labile E. coli enterotoxin LTIIb [MSFKKIIKAFVIMAALVSVQAHA (SEQ ID NO: 19)], Bacillus subtilis endoxylanase XynA [MFKFKKKFLVGLTAAFMSISMFSATASA (SEQ ID NO: 20)], E.
  • the signal sequence is from E. coli DsbA [MKKIWLALAGLVLAFSASA (SEQ ID NO: 21)].
  • the present invention provides a modified EPA protein, wherein the amino acid sequence further comprises a signal sequence which is capable of directing the EPA protein to the periplasm of a host cell (e.g. bacterium), optionally said signal sequence being DsbA (SEQ ID NO: 21).
  • a signal sequence of the protein DsbA from E. coli can be genetically fused to the N-terminus of the mature EPA sequence.
  • a plasmid derived from pEC415 [Schulz, H., Hennecke, H., and Thony-Meyer, L., Science, 281, 1197-1200, 1998] containing the DsbA signal peptide code followed by a RNase sequence can be digested (NdeI to EcoRI) to keep the DsbA signal and remove the RNase insert.
  • EPA is then amplified using PCR (forward oligo 5′-AAGCTAGCGCCGCCGAGGAAGCCTTCGACC (SEQ. ID NO. 32) and reverse oligo 5′-AAGAA TTCTCAGTGGTGGTGGTGGTGGTGCTTCAGGTCCTCGCGCGGCGG (SEQ. ID NO.
  • pGVXN69 encodes a protein product with an DsbA signal peptide, the mature EPA sequence and a hexa-histag.
  • a further aspect of the invention is a polynucleotide encoding a modified EPA protein of the invention.
  • a polynucleotide encoding a modified EPA protein having a nucleotide sequence that encodes a polypeptide with an amino acid sequence that is at least 97%, 98%, 99% or 100% identical to any one of SEQ ID NOs: 6 to 14.
  • nucleotide sequence for example, a nucleotide sequence according to SEQ ID NO: 43 or a nucleotide sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 43.
  • the nucleotide sequence comprises nucleotides encoding for amino acids corresponding to one (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3).
  • a modified EPA protein having a consensus sequence substituted at one or more of positions Y208, R274, S318 and/or A519 in an amino acid sequence of SEQ ID NO: 1 or at an equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • a vector comprising such a polynucleotide is a further aspect of the invention.
  • the present invention also provides a conjugate (e.g. bioconjugate) comprising (or consisting of) a modified EPA protein of the invention linked to an antigen (e.g. a saccharide antigen, optionally a bacterial polysaccharide antigen).
  • an antigen e.g. a saccharide antigen, optionally a bacterial polysaccharide antigen.
  • the antigen may be a bacterial polysaccharide antigen, or a yeast polysaccharide antigen, or a mammalian polysaccharide antigen.
  • the conjugate comprises a conjugate (e.g. bioconjugate) comprising (or consisting of) a modified EPA protein of the invention covalently linked to an antigen (e.g. a saccharide antigen, optionally a bacterial polysaccharide antigen), wherein the antigen is linked (either directly or through a linker).
  • an antigen e.g. a saccharide antigen, optionally a bacterial polysaccharide antigen
  • the antigen is directly linked to the modified EPA protein of the invention.
  • the antigen is directly linked to an amino acid residue of the modified EPA protein.
  • the modified EPA protein is covalently linked to the antigen through a chemical linkage obtainable using a chemical conjugation method (i.e. the conjugate is produced by chemical conjugation).
  • the chemical conjugation method may be selected from the group consisting of carbodiimide chemistry, reductive animation, cyanylation chemistry (for example CDAP chemistry), maleimide chemistry, hydrazide chemistry, ester chemistry, and N-hydroysuccinimide chemistry.
  • Conjugates can be prepared by direct reductive amination methods as described in, US200710184072 (Hausdorff) U.S. Pat. No. 4,365,170 (Jennings) and U.S. Pat. No. 4,673,574 (Anderson).
  • conjugation method may alternatively rely on activation of the saccharide with 1-cyano-4-dimethylamino pyridinium tetrafluoroborate (CDAP) to form a cyanate ester.
  • CDAP 1-cyano-4-dimethylamino pyridinium tetrafluoroborate
  • Such conjugates are described in PCT published application WO 93/15760 Uniformed Services University and WO 95/08348 and WO 96/29094. See also Chu C. et al. Infect. Immunity, 1983 245 256.
  • Carboxyl for instance via aspartic acid or glutamic acid.
  • this group is linked to amino groups on saccharides directly or to an amino group on a linker with carbodiimide chemistry e.g. with EDAC.
  • Amino group (for instance via lysine).
  • this group is linked to carboxyl groups on saccharides directly or to a carboxyl group on a linker with carbodiimide chemistry e.g. with EDAC.
  • this group is linked to hydroxyl groups activated with CDAP or CNBr on saccharides directly or to such groups on a linker; to saccharides or linkers having an aldehyde group; to saccharides or linkers having a succinimide ester group.
  • Sulphydryl for instance via cysteine.
  • this group is linked to a bromo or chloro acetylated saccharide or linker with maleimide chemistry.
  • this group is activated/modified with bis diazobenzidine.
  • Imidazolyl group (for instance via histidine). In one embodiment this group is activated/modified with bis diazobenzidine.
  • Aldehyde groups can be generated after different treatments such as: periodate, acid hydrolysis, hydrogen peroxide, etc.
  • Conjugates can be purified by any method known in the art for purification of a protein, for example, by chromatography (e.g. ion exchange, anionic exchange, affinity, and sizing column chromatography), centrifugation, differential solubility, or by any other standard technique for the purification of proteins. See, e.g., Saraswat et al. , 2013, Biomed. Res. Int. ID0312709 (p. 1-18); see also the methods described in WO 2009/104074.
  • the actual conditions used to purify a particular conjugate will depend, in past, on the synthesis strategy (e.g., synthetic production vs. recombinant production) and on factors such as net charge, hydrophobicity, and/or hydrophilicity of the bioconjugate.
  • the amino acid residue on the modified EPA protein to which the antigen is linked is selected from the group consisting of: Ala, Arg, Asp, Cys, Gly, Glu, Gln, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr, and Val.
  • the amino acid is: an amino acid containing a terminal amine group, a lysine, an arginine, a glutaminic acid, an aspartic acid, a cysteine, a tyrosine, a histidine or a tryptophan.
  • the amino acid residue on the modified EPA protein to which the antigen is linked is not an asparagine residue and in this case, the conjugate is typically produced by chemical conjugation.
  • the antigen is linked to an amino acid on the modified EPA protein selected from asparagine, aspartic acid, glutamic acid, lysine, cysteine, tyrosine, histidine, arginine or tryptophan (e.g. asparagine) and in the case of asparagine, the conjugate may be a bioconjugate (for example an enzymatic conjugation using a oligosaccharyltransferase such as PglB).
  • the amino acid residue on the modified EPA protein to which the antigen is linked is an asparagine residue.
  • the amino acid residue on the modified EPA protein to which the antigen is linked is part of the consensus sequence, e.g. the asparagine in D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) or J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) consensus sequence.
  • the conjugate of the invention may be a conjugate of a recombinant modified EPA protein (e.g. chemical conjugate or bioconjugate).
  • the conjugate of the invention may be a conjugate of an isolated recombinant modified EPA protein and a recombinant antigen, e.g. recombinant saccharide (i.e. bioconjugate).
  • the antigen may be a saccharide antigen, e.g. a bacterial polysaccharide, for example an O-antigen or a capsular polysaccharide, a yeast polysaccharide or a mammalian polysaccharide.
  • Polysaccharides comprise 2 or more monosaccharides, typically greater than 10 monosaccharides.
  • the antigen in a conjugate (e.g. bioconjugate) of the invention is a bacterial polysaccharide selected from a Shigella species, Pseudomonas species, Klebsiella species, Streptococcus species, or Staphylococcus species (e.g.
  • the antigen is a bacterial polysaccharide antigen (e.g.
  • an O-antigen from a Gram negative bacterium optionally from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, or a capsular polysaccharide from a Gram positive bacterium, optionally Streptococcus pneumoniae or Staphylococcus aureus ).
  • the antigen is an O-antigen from a Gram negative bacterium.
  • the antigen in a conjugate (e.g. bioconjugate) of the invention is a bacterial polysaccharide selected from from a Shigella species, Klebsiella species, or Streptococcus species (e.g.
  • the antigen in a conjugate (e.g. bioconjugate) of the invention is a bacterial polysaccharide selected from Shigella flexneri, Klebsiella pneumoniae and Streptococcus pneumoniae ).
  • the antigen is a bacterial polysaccharide from Klebsiella pneumoniae.
  • the present invention provides a conjugate (e.g.
  • bioconjugate comprising a modified EPA protein of the invention linked to an antigen wherein the antigen is a saccharide, optionally a bacterial polysaccharide (e.g. from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae or Staphylococcus aureus ).
  • the antigen is an O-antigen.
  • the antigen is a capsular polysaccharide.
  • the antigen is an O-antigen e.g. from a Gram-negative bacterium. In certain embodiments, the antigen is an O-antigen from Salmonella species, Shigella species, Pseudomonas species or Klebsiella species. In certain embodiments, the antigen is an O-antigen from Shigella species, Pseudomonas species or Klebsiella species (e.g. Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, or Klebsiella pneumoniae ).
  • Shigella dysenteriae Shigella flexneri
  • Shigella sonnei Shigella sonnei
  • Pseudomonas aeruginosa or Klebsiella pneumoniae
  • the antigen is an O-antigen from Shigella dysenteriae, Shigella flexneri or Shigella sonnei.
  • the antigen may be an O-antigen from S. dysenteriae type 1, S. sonnei, and S. flexneri type 6, and S. flexneri 2a and 3a 0 (Dmitriev, B.A., et al. Somatic Antigens of Shigella Eur J. Biochem, 1979. 98: p. 8; Liu et al Structure and genetics of Shigella O antigens FEMS Microbiology Review, 2008. 32: p. 27).
  • the antigen is an O-antigen from Pseudomonas aeruginosa.
  • the antigen may be an O-antigen from Pseudomonas aeruginosa serotypes 1-20 (Raymond et al., J Bacteriol. 2002 184(13):3614-22).
  • the antigen is an O-antigen from Klebsiella pneumoniae.
  • the antigen is a capsular polysaccharide from Neisseria meningitidis serogroup A (MenA), N. meningitidis serogroup C (MenC), N. meningitidis serogroup Y (MenY), N. meningitidis serogroup W (MenW), H. influenzae type b (Hib), Group B Streptococcus (GBS), Streptococcus pneumoniae, or Staphylococcus aureus.
  • the antigen is a capsular polysaccharide from Streptococcus species or Staphylococcus species. (e.g.
  • the antigen is a capsular polysaccharide from Staphylococcus aureus.
  • the antigen may be a capsular polysaccharide from Staphylococcus aureus type 5 and 8.
  • the antigen is a capsular polysaccharide from Streptococcus pneumoniae.
  • the present invention also provides a host cell comprising:
  • nucleotide sequences comprising polysaccharide synthesis genes, optionally for producing a bacterial polysaccharide antigen (e.g. an O-antigen from a Gram negative bacterium optionally from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, or a capsular polysaccharide from a Gram positive bacterium optionally from Streptococcus pneumoniae or Staphylococcus aureus ) or a yeast polysaccharide antigen or a mammalian polysaccharide antigen, optionally integrated into the host cell genome;
  • a bacterial polysaccharide antigen e.g. an O-antigen from a Gram negative bacterium optionally from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsi
  • a nucleotide sequence that encodes a modified EPA protein of the invention optionally within a plasmid.
  • Host cells that can be used to produce the bioconjugates of the invention include archea, prokaryotic host cells, and eukaryotic host cells.
  • the host cell is a non-human host cell.
  • Exemplary prokaryotic host cells for use in production of the bioconjugates of the invention include Escherichia species, Shigella species, Klebsiella species, Xhantomonas species, Salmonella species, Yersinia species, Lactococcus species, Lactobacillus species, Pseudomonas species, Corynebacterium species, Streptomyces species, Streptococcus species, Staphylococcus species, Bacillus species, and Clostridium species.
  • the host cell is E. coli (e.g. E. coli K12 W3110).
  • Host cells may be modified to delete or modify genes in the host cell genetic background (genome) that compete or interfere with the synthesis of the polysaccharide of interest (e.g. compete or interfere with one or more heterologous polysaccharide synthesis genes that are recombinantly introduced into the host cell).
  • These genes can be deleted or modified in the host cell background (genome) in a manner that makes them inactive/dysfunctional (i.e. the host cell nucleotide sequences that are deleted/modified do not encode a functional protein or do not encode a protein whatsoever).
  • nucleotide sequences are deleted from the genome of the host cells of the invention, they are replaced by a desirable sequence, e.g.
  • genes that can be deleted in host cells include genes of host cells involved in glycolipid biosynthesis, such as waaL (see, e.g. Feldman et al. 2005, PNAS USA 102:3016-3021), the O antigen cluster (rfb or wb), enterobacterial common antigen cluster (wec), the lipid A core biosynthesis cluster (waa), galactose cluster (gal), arabinose cluster (ara), colonic acid cluster (wc), capsular polysaccharide cluster, undecaprenol-pyrophosphate biosynthesis genes (e.g.
  • uppS Undecaprenyl pyrophosphate synthase
  • uppP Undecaprenyl diphosphatase
  • Und-P recycling genes metabolic enzymes involved in nucleotide activated sugar biosynthesis, enterobacterial common antigen cluster, and prophage O antigen modification clusters like the gtrABS cluster.
  • one or more of the waaL gene, gtrA gene, gtrBgene, gtrSgene, or a gene or genes from the wec cluster or a gene, or a gene or genes from the colonic acid cluster (wc), or a gene or genes from the rfb gene cluster are deleted or functionally inactivated from the genome of a prokaryotic host cell of the invention.
  • one or more of the waaL gene, gtrA gene, gtrB gene, gtrS gene, or a gene or genes from the wec cluster or a gene or genes from the rfb gene cluster are deleted or functionally inactivated from the genome of a prokaryotic host cell of the invention.
  • the host cell of the invention is E. coli, wherein the native enterobacterial common antigen cluster (ECA, wec) with the exception of wecA, the colanic acid cluster (wca), and the 016-antigen cluster have been deleted.
  • ECA enterobacterial common antigen cluster
  • wca colanic acid cluster
  • 016-antigen cluster the native lipopolysaccharide O-antigen ligase waaL may be deleted from the host cell of the invention.
  • the native gtrA gene, gtrB gene and gtrS gene may be deleted from the host cell of the invention.
  • the host cells of the present invention are engineered to comprise heterologous nucleotide sequences.
  • the host cells of the present invention are engineered to comprise a nucleotide sequence that encodes a modified EPA protein of the invention, optionally within a plasmid.
  • the host cells of the invention also comprise one or more nucleotide sequences comprising polysaccharide synthesis genes.
  • host cells of the invention can produce a bioconjugate comprising an antigen, for example a saccharide antigen (e.g. a bacterial, yeast or mammalian polysaccharide antigen) which is attached to a modified EPA protein of the invention.
  • a saccharide antigen e.g. a bacterial, yeast or mammalian polysaccharide antigen
  • One or more heterologous nucleotide sequences may encode for the polysaccharide synthesis proteins to produce the bacterial polysaccharide antigen, yeast polysaccharide antigen or mammalian polysaccharide antigen.
  • a host cell comprising:
  • one or more heterologous nucleotide sequences comprising polysaccharide synthesis genes for producing a bacterial polysaccharide antigen (e.g. an O-antigen from a Gram negative bacterium optionally from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, or a capsular polysaccharide from a Gram positive bacterium optionally from Streptococcus pneumoniae or Staphylococcus aureus ) or a yeast polysaccharide antigen or a mammalian polysaccharide antigen, optionally integrated into the host cell genome;
  • a bacterial polysaccharide antigen e.g. an O-antigen from a Gram negative bacterium optionally from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Kle
  • a nucleotide sequence that encodes a modified EPA protein of the invention optionally within a plasmid.
  • the host cells of the invention may comprise one or more nucleotide sequences sufficient for producing a saccharide antigen (e.g. a bacterial polysaccharide antigen), in particular for producing a saccharide antigen (e.g. a bacterial polysaccharide antigen) that is heterologous to the host cell.
  • a saccharide antigen e.g. a bacterial polysaccharide antigen
  • the host cell may comprise one more nucleotide sequences comprising polysaccharide synthesis genes sufficient for producing a bacterial polysaccharide antigen of a bacteria which is not an E. coli polysaccharide antigen.
  • the bacterial polysaccharide antigen may be an O-antigen or a capsular polysaccharide antigen.
  • the present invention also provides a host cell comprising:
  • nucleotide sequences comprising polysaccharide synthesis genes, for producing a bacterial polysaccharide antigen (e.g. an O-antigen from a Gram negative bacterium, optionally from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, or a capsular polysaccharide from a Gram positive bacterium optionally from Streptococcus pneumoniae or Staphylococcus aureus ), optionally integrated into the host cell genome;
  • a bacterial polysaccharide antigen e.g. an O-antigen from a Gram negative bacterium, optionally from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, or a capsular polysaccharide from a Gram positive bacterium optionally from Str
  • a nucleotide sequence that encodes a modified EPA protein of the invention optionally within a plasmid.
  • Polysaccharide synthesis genes encode proteins involved in synthesis of a polysaccharide (polysaccharide synthesis proteins).
  • the host cells may comprise one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from a Gram negative bacterium selected from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa and Klebsiella pneumoniae, or a capsular polysaccharide from a Gram positive bacterium selected from Streptococcus pneumoniae and Staphylococcus aureus.
  • the host cells may comprise one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from a Gram negative bacterium selected from Shigella flexneri and Klebsiella pneumoniae, or a capsular polysaccharide from a Gram positive bacterium selected from Streptococcus pneumoniae and Staphylococcus aureus.
  • the host cells of the invention may comprise one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen.
  • the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from Salmonella species, Shigella species, Pseudomonas species or Klebsiella species.
  • the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from Shigella species, Pseudomonas species or Klebsiella species. (e.g.
  • the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from Shigella species or Klebsiella species. (e.g. Shigella dysenteriae, Shigella flexneri, Shigella sonnei or Klebsiella pneumoniae ).
  • the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from Shigella dysenteriae, Shigella flexneri or Shigella sonnei.
  • the host cell may comprise one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from S. dysenteriae type 1, S. sonnei, and S. flexneri type 6, and S. flexneri 2a and 3a 0 (Dmitriev, B. A., et al Somatic Antigens of Shigella Eur J. Biochem, 1979. 98: p.
  • the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from Pseudomonas aeruginosa e.g. Pseudomonas aeruginosa serotypes 1-20.
  • the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from Klebsiella pneumoniae.
  • the host cells of the invention may comprise one or more nucleotide sequences comprising polysaccharide synthesis genes for producing a capsular polysaccharide.
  • the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing a capsular polysaccharide from N. meningitidis serogroup A (MenA), N. meningitidis serogroup C (MenC), N. meningitidis serogroup Y (MenY), N. meningitidis serogroup W (MenW), H.
  • the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing a capsular polysaccharide from Streptococcus species, or Staphylococcus species. (e.g. Streptococcus pneumoniae or Staphylococcus aureus ).
  • the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing a capsular polysaccharide from Staphylococcus aureus, e.g. from Staphylococcus aureus type 5 and 8.
  • the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing a capsular polysaccharide from Streptococcus pneumoniae.
  • Host Cells Comprising Heterologous Nucleotide Sequences for Producing a Bacterial Polysaccharide Antigen
  • the host cells of the present invention may naturally express one or more nucleotide sequences comprising polysaccharide synthesis genes for production of a saccharide antigen (e.g. a bacterial polysaccharide antigen), or the host cells may be engineered to express one or more such nucleotide sequences.
  • host cells of the present invention may utilize endogenous or heterologous glycosyltransferases for sequential assembly of oligosaccharides in the cytosol (cytosolic glycosyltransferases).
  • Heterologous nucleotide sequences e.g. nucleotide sequences that encode carrier proteins and/or nucleotide sequences that encode other proteins, e.g.
  • heterologous nucleotide sequences are introduced into the host cells of the invention using a plasmid, e.g. the heterologous nucleotide sequences are expressed in the host cells by a plasmid (e.g. an expression vector).
  • heterologous nucleotide sequences are introduced into the host cells of the invention using the method of insertion described in WO14/037585.
  • the host cell of the present invention comprises one or more nucleotide sequences comprising polysaccharide synthesis genes which are heterologous to the host cell.
  • one or more of said nucleotide sequences comprising polysaccharide synthesis genes which are heterologous to the host cell are integrated into the genome of the host cell.
  • the heterologous nucleotide sequences may encode, without limitation, glycosyltransferases, oligosaccharyl transferases, epimerases, flippases, and/or polymerases.
  • the host cells of the invention comprise one or more heterologous nucleotide sequences encoding glycosyltransferase(s).
  • Said glycosyltransferase(s) can be derived from, e.g. Escherichia species, Shigella species, Klebsiella species, Salmonella species, Pseudomonas species, Streptococcus species, or Staphylococcus species.
  • the host cells of the invention may comprise one or more heterologous nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen.
  • the host cell comprises one or more nucleotide sequences from Salmonella species, Shigella species, Pseudomonas species or Klebsiella species that encode polysaccharide synthesis proteins for producing an O-antigen.
  • the host cell comprises one or more nucleotide sequences from Shigella species, Pseudomonas species or Klebsiella species. (e.g.
  • the host cell comprises one or more nucleotide sequences from Shigella species or Klebsiella species. (e.g. Shigella dysenteriae, Shigella flexneri, Shigella sonnei, or Klebsiella pneumoniae ) that encode polysaccharide synthesis proteins for producing an O-antigen.
  • the host cell comprises one or more nucleotide sequences from Shigella dysenteriae, Shigella flexneri or Shigella sonnei. that encode polysaccharide synthesis proteins for producing an O-antigen.
  • the host cell may comprise one or more nucleotide sequences from S. dysenteriae type 1, S. sonnei, and S. flexneri type 6, and S. flexneri 2a and 3a that encode polysaccharide synthesis proteins for producing an O-antigen.
  • the host cell comprises one or more nucleotide sequences from Pseudomonas aeruginosa, e.g.
  • the host cell comprises one or more nucleotide sequences from Klebsiella pneumoniae that encode polysaccharide synthesis proteins for producing an O-antigen.
  • the nucleotide sequences that encode an O-antigen may be an rfb cluster.
  • rfb cluster refer to a gene cluster that encodes enzymatic machinery capable of synthesis of an O antigen.
  • the host cells may comprise an rfb gene cluster from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae.
  • the host cells of the invention may comprise one or more heterologous nucleotide sequences comprising polysaccharide synthesis genes for producing a capsular saccharide.
  • the host cell comprises one or more nucleotide sequences from N. meningitidis serogroup A (MenA), N. meningitidis serogroup C (MenC), N. meningitidis serogroup Y (MenY), N. meningitidis serogroup W (MenW), H. influenzae type b (Hib), Group B Streptococcus (GBS), Streptococcus pneumoniae, or Staphylococcus aureus that encode polysaccharide synthesis proteins for producing a capsular saccharide.
  • MenA N. meningitidis serogroup A
  • MenC N. meningitidis serogroup C
  • MenY N. meningitidis serogroup Y
  • MenW N. meningitidis
  • the host cell comprises one or more nucleotide sequences from Streptococcus species, or Staphylococcus species. (e.g. Streptococcus pneumoniae or Staphylococcus aureus ) that encode polysaccharide synthesis proteins for producing a capsular polysaccharide.
  • the host cell comprises one or more nucleotide sequences from Staphylococcus aureus, e.g. from Staphylococcus aureus type 5 and 8, that encode polysaccharide synthesis proteins for producing a capsular polysaccharide.
  • the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing a capsular polysaccharide from Streptococcus pneumoniae.
  • the nucleotide sequences may be a capsular polysaccharide gene cluster.
  • the host cells may comprise a capsular polysaccharide gene cluster from a Streptococcus strain (e.g. S. pneumoniae, S. pyrogens, S. agalacticae ), a Staphylococcus strain (e.g. S. aureus ).
  • the capsular polysaccharide gene cluster for Streptococcus pneumoniae maps between dexB and aliA in the pneumococcal chromosome (Llull et al., 1999, J. Exp. Med. 190, 241-251). There are typically four relatively conserved genes: (wzg), (wzh), (wza), (wze) at the 5′ end of the capsular polysaccharide gene cluster (Jiang et al., 2001, Infect. Immun. 69, 1244-1255). Also included in the capsular polysaccharide gene cluster of S. pneumoniae are wzx (polysaccharide flippase gene) and wzy (polysaccharide polymerase gene).
  • the host cells of the invention may further comprise a nucleotide sequence encoding a polymerase (e.g. wzy), a flippase (e.g. wzx) and optionally a nucleotide sequence encoding and/or a chain length regulator (e.g. wzz).
  • a polymerase e.g. wzy
  • the host cells may also comprise heterologous nucleotide sequences that are located outside of an rfb cluster or a capsular polysaccharide cluster.
  • heterologous nucleotide sequences that are located outside of an rfb cluster or a capsular polysaccharide cluster.
  • nucleotide sequences encoding glycosyltransferases and acetyltransferases that are found outside of rfb clusters or capsular polysaccharide clusters and that modify recombinant polysaccharides can be introduced into the host cells.
  • N-linked protein glycosylation (the addition of carbohydrate molecules to an asparagine residue in the polypeptide chain of the target protein) is the most common type of post-translational modification occurring in the endoplasmic reticulum of eukaryotic organisms.
  • the process is accomplished by the enzymatic oligosaccharyltransferase complex (OST) responsible for the transfer of a preassembled oligosaccharide from a lipid carrier (dolichol phosphate) to an asparagine residue of a nascent protein within the conserved sequence Asn-X-Ser/Thr (where X is any amino acid except proline) in the Endoplasmic reticulum.
  • OST enzymatic oligosaccharyltransferase complex
  • the host cells of the present invention comprise a nucleotide sequence encoding a heterologous oligosaccharyl transferase, optionally within a plasmid.
  • the oligosaccharyl transferase is an oligosaccharyl transferase from Campylobacter.
  • the oligosaccharyl transferase is a pglB, optionally from Campylobacter jejuni (i.e. pglB; see, e.g. Wacker et al. 2002, Science 298:1790-1793; see also, e.g. NCBI Gene ID: 3231775, UniProt Accession No. 086154) SEQ ID NO: 24:
  • host cells of the present invention may comprise a nucleotide sequence encoding pglB, optionally pglB from Campylobacter jejuni, optionally a nucleotide sequence encoding pglB from Campylobacter jejuni having a sequence at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 24, optionally within a plasmid.
  • Host cells of the present invention may also comprise a nucleotide sequence that encodes a polymerase (e.g. wzy).
  • the polymerase e.g. wzy
  • the polymerase is introduced into a host cell of the invention (i.e. the polymerase is heterologous to the host cell).
  • the polymerase is a bacterial polymerase.
  • the polymerase is a capsular polysaccharide polymerase (e.g. wzy) or an O antigen polymerase (e.g. wzy).
  • the polymerase is an O-antigen polysaccharide polymerase (e.g. wzy), e.g.
  • the polymerase is a capsular polysaccharide polymerase (e.g. wzy), e.g. from N. meningitidis serogroup A (MenA), N. meningitidis serogroup C (MenC), N. meningitidis serogroup Y (MenY), N. meningitidis serogroup W (MenW), H.
  • MenA meningitidis serogroup A
  • MenC N. meningitidis serogroup C
  • MenY N. meningitidis serogroup W
  • H H.
  • the polymerase is a capsular polysaccharide polymerase (e.g. wzy) of Streptococcus pneumoniae.
  • Said wzy polymerase may be incorporated (e.g. inserted into the genome or expressed by a plasmid) in said host cell as part of a rfb cluster or capsular polysaccharide cluster.
  • a host cell of the invention may further comprise a nucleotide sequence encoding a heterologous wzy polymerase.
  • a host cell of the invention may also comprise a nucleotide sequence encoding a flippase (e.g. wzx), e.g. a heterologous flippase.
  • Flippases translocate wild type repeating units and/or their corresponding engineered (hybrid) repeat units from the cytoplasm into the periplam of host cells (e.g. E. coli ).
  • the flippase is a bacterial flippase, e.g. a flippase of the polysaccharide biosynthetic pathway of interest.
  • the host cell of the invention comprises a nucleotide sequence encoding a flippase (e.g.
  • the flippase is a capsular polysaccharide flippase (e.g. wzx) of Streptococcus pneumoniae.
  • Other flippases that can be introduced into the host cells of the invention are for example from Campylobacter jejuni (e.g. pglK).
  • nucleotide sequences encoding one or more accessory enzymes are introduced into the host cells of the invention.
  • a host cell of the invention may further comprise one or more of these accessory enzymes.
  • Such nucleotide sequences encoding one or more accessory enzymes can be either plasmid-borne or integrated into the genome of the host cells of the invention.
  • Exemplary accessory enzymes include, without limitation, epimerases (see e.g. WO2011/062615), branching, modifying (e.g. to add cholins, glycerolphosphates, pyruvates), amidating, chain length regulating, acetylating, formylating, polymerizing enzymes.
  • a host cell of the invention may also comprise a nucleotide sequence encoding a chain length regulator (e.g. wzz), e.g. a heterologous chain length regulator.
  • a chain length regulator e.g. wzz
  • the chain length regulator is a capsular polysaccharide chain length regulator (e.g. wzz) of Streptococcus pneumoniae.
  • the present invention provides a bioconjugate comprising a modified EPA protein of the invention linked to an antigen (e.g. a bacterial polysaccharide antigen or a yeast polysaccharide antigen or a mammalian polysaccharide antigen).
  • an antigen e.g. a bacterial polysaccharide antigen or a yeast polysaccharide antigen or a mammalian polysaccharide antigen.
  • said antigen is an O-antigen or a capsular polysaccharide.
  • the antigen is an O-antigen from a Gram negative bacterium.
  • the present invention provides a bioconjugate comprising a modified EPA protein of the invention linked to an antigen wherein the antigen is a saccharide, optionally a bacterial polysaccharide (e.g.
  • the present invention provides a bioconjugate comprising a modified EPA protein of the invention linked to an antigen wherein the antigen is a bacterial polysaccharide (e.g. from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Klebsiella pneumoniae, or Streptococcus pneumoniae ).
  • a bioconjugate comprising a modified EPA protein of the invention linked to an antigen wherein the antigen is a bacterial polysaccharide (e.g. from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Klebsiella pneumoniae, or Streptococcus pneumoniae ).
  • the present invention provides a bioconjugate comprising a modified EPA protein of the invention linked to an antigen wherein the antigen is a bacterial polysaccharide from Shigella flexneri, Klebsiella pneumoniae or Streptococcus pneumoniae.
  • the antigen is linked to an amino acid on the modified EPA protein selected from asparagine, aspartic acid, glutamic acid, lysine, cysteine, tyrosine, histidine, arginine or tryptophan (e.g. asparagine).
  • Bioconjugates, as described herein have advantageous properties over chemical conjugates of antigen-carrier protein, in that they require less chemicals in manufacture and are more consistent in terms of the final product generated.
  • a further aspect of the invention is a process for producing a bioconjugate that comprises (or consists of) a modified EPA protein linked to a saccharide, said process comprising (i) culturing the host cell of the invention under conditions suitable for the production of glycoproteins and (ii) isolating the bioconjugate produced by said host cell, optionally isolating the bioconjugate from a periplasmic extract from the host cell.
  • bioconjugates can be made using the shakeflask process, e.g. in a LB shake flask.
  • a fed-batch process for the production of recombinant glycosylated proteins in bacteria can be used to produce bioconjugates of the invention.
  • Bioconjugates of the present invention can be manufactured on a commercial scale by developing an optimized manufacturing method using typical E. coli production processes.
  • feed strategies such as batch, chemostat and fed-batch can be used.
  • the bioconjugates of the invention can be purified for example, by chromatography (e.g. ion exchange, anionic exchange, affinity, and sizing column chromatography), centrifugation, differential solubility, or by any other standard technique for the purification of proteins. See, e.g. Saraswat et al. 2013, Biomed. Res. Int. ID #312709 (p. 1-18); see also the methods described in WO 2009/104074. Further, the bioconjugates may be fused to heterologous polypeptide sequences described herein or otherwise known in the art to facilitate purification.
  • Hydrazinolysis can be used to analyze glycans.
  • polysaccharides are released from their protein carriers by incubation with hydrazine according to the manufacturer's instructions (Ludger Liberate Hydrazinolysis Glycan Release Kit, Oxfordshire, UK).
  • the nucleophile hydrazine attacks the glycosidic bond between the polysaccharide and the carrier protein and allows release of the attached glycans.
  • N-acetyl groups are lost during this treatment and have to be reconstituted by re-N-acetylation.
  • the free glycans are purified on carbon columns and subsequently labeled at the reducing end with the fluorophor 2-amino benzamide.
  • the resulting fluorescence chromatogram indicates the polysaccharide length and number of repeating units. Structural information can be gathered by collecting individual peaks and subsequently performing MS/MS analysis. Thereby the monosaccharide composition and sequence of the repeating unit can be confirmed and additionally in homogeneity of the polysaccharide composition can be identified. Alternatively, high mass MS and size exclusion HPLC can be applied to measure the size of the complete bioconjugates.
  • Yield may be measured as carbohydrate amount derived from a liter of bacterial production culture grown in a bioreactor under controlled and optimized conditions. After purification of bioconjugate, the carbohydrate yields can be directly measured by either the anthrone assay or ELISA using carbohydrate specific antisera. Indirect measurements are possible by using the protein amount (measured by BCA, Lowry, or bardford assays) and the glycan length and structure to calculate a theoretical carbohydrate amount per gram of protein. In addition, yield can also be measured by drying the glycoprotein preparation from a volatile buffer and using a balance to measure the weight.
  • PAGE (or other techniques that separate by size) differ by only a single repeat unit. These discrete differences are exploited when analyzing glycoproteins for glycan size: the unglycosylated carrier protein and the bioconjugate with different polymer chain lengths separate according to their electrophoretic mobilities.
  • the first detectable repeat unit number (n 1 ) and the average repeat unit number (n average ) present on a bioconjugate are measured. These parameters can be used to demonstrate batch to batch consistency or polysaccharide stability, for example.
  • Glycosylation site usage may be quantified by, for example, glycopeptide LC-MS/MS: conjugates are digested with protease(s), and the peptides are separated by a suitable chromatographic method (C18, Hydrophilic interaction HPLC HILIC, GlycoSepN columns, SE HPLC, AE HPLC), and the different peptides are identified using MS/MS. This method can be used with or without previous sugar chain shortening by chemical (smith degradation) or enzymatic methods. Quantification of glycopeptide peaks using UV detection at 215 to 280 nm allows relative determination of glycosylation site usage.
  • site usage may be quantified by size exclusion HPLC: Higher glycosylation site usage is reflected by an earlier elution time from a SE HPLC column.
  • site usage may be quantified by quantitative densitometry of purified bioconjugates stained with Coomassie Briliant Blue following sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).
  • conjugates e.g. bioconjugate
  • the conjugates are particularly suited for inclusion in immunogenic compositions and vaccines.
  • the present invention provides an immunogenic composition
  • a conjugate e.g. bioconjugate
  • a pharmaceutically acceptable excipient and/or carrier optionally a pharmaceutically acceptable excipient and/or carrier.
  • Immunogenic compositions comprise an immunologically effective amount of the modified EPA protein or conjugate (e.g. bioconjugate) of the invention, as well as any other components.
  • immunologically effective amount it is meant that the administration of that amount to an individual, either as a single dose or as part of a series is effective for treatment or prevention. This amount varies depending on the health and physical condition of the individual to be treated, age, the degree of protection desired, the formulation of the vaccine and other relevant factors.
  • Pharmaceutically acceptable excipients and carriers are described, for example, in Remington's Pharmaceutical Sciences, by E. W. Martin, Mack Publishing Co. Easton, Pa., 5th Edition (1975).
  • Pharmaceutically acceptable excipients can include a buffer, such as a phosphate buffer (e.g. sodium phosphate).
  • Pharmaceutically acceptable excipients can include a salt, for example sodium chloride.
  • Pharmaceutically acceptable excipients can include a solubilizing/stabilizing agent, for example, polysorbate (e.g. TWEEN 80).
  • Pharmaceutically acceptable excipients can include a preservative, for example 2-phenoxyethanol or thiomersal.
  • Pharmaceutically acceptable excipients can include a carrier such as water or saline.
  • Also provided is a method of making the immunogenic composition of the invention comprising the step of mixing the modified EPA protein or the conjugate (e.g. bioconjugate) of the invention with a pharmaceutically acceptable excipient and/or carrier.
  • the present invention also provides an immunogenic composition (e.g., a vaccine composition) optionally comprising an adjuvant.
  • an immunogenic composition e.g., a vaccine composition
  • an adjuvant e.g., an adjuvant
  • adjuvant refers to a compound that when administered in conjunction with or as part of an immunogenic composition of vaccine of the invention augments, enhances and/or boosts the immune response to modified EPA protein conjugate/bioconjugate, but when the compound is administered alone does not generate an immune response to the modified EPA protein conjugate/bioconjugate.
  • adjuvants can enhance an immune response by several mechanisms including, e.g. lymphocyte recruitment, stimulation of B and/or T cells, and stimulation of macrophages.
  • adjuvants include, but are not limited to, aluminum salts (alum) (such as aluminum hydroxide, aluminum phosphate, and aluminum sulfate), 3 De-O-acylated monophosphoryl lipid A (MPL) (see United Kingdom Patent GB2220211), MF59 (Novartis), AS01 (GlaxoSmithKline), and saponins, such as QS21 (see Kensil et al. in Vaccine Design: The Subunit and Adjuvant Approach (eds. Powell & Newman, Plenum Press, NY, 1995); U.S. Pat. No. 5,057,540).
  • the adjuvant is Freund's adjuvant (complete or incomplete).
  • adjuvants are oil in water emulsions (such as squalene or peanut oil), optionally in combination with immune stimulants, such as monophosphoryl lipid A (see Stoute et al. N. Engl. J. Med. 336, 86-91 (1997)).
  • Vaccine preparation is generally described in Vaccine Design (“The subunit and adjuvant approach” (eds Powell M. F. & Newman M. J.) (1995) Plenum Press New York).
  • the immunogenic compositions of the invention can be included in a container, pack, or dispenser together with instructions for administration.
  • the immunogenic compositions or vaccines of the invention can be stored before use, e.g.
  • compositions can be stored frozen (e.g. at about ⁇ 20° C. or at about ⁇ 70° C.); stored in refrigerated conditions (e.g. at about 4° C.); or stored at room temperature.
  • the immunogenic compositions or vaccines of the invention may be stored in solution or lyophilized.
  • the solution is lyophilized in the presence of a sugar such as sucrose, trehalose or lactose.
  • the vaccines of the invention are lyophilized and extemporaneously reconstituted prior to use.
  • Immunogenic compositions or vaccines of the invention may be used to protect or treat a subject (e.g. mammal), by means of administering said immunogenic composition or vaccine via systemic or mucosal route.
  • administrations may include injection via the intramuscular (IM), intraperitoneal, intradermal (ID) or subcutaneous (SC) routes; or via mucosal administration to the oral/alimentary, respiratory, genitourinary tracts.
  • the immunogenic composition or vaccine of the invention is administered by the intramuscular delivery route.
  • Intramuscular administration may be to the thigh or the upper arm. Injection is typically via a needle (e.g. a hypodermic needle), but needle-free injection may alternatively be used.
  • a typical intramuscular dose is 0.5 ml.
  • the immunogenic composition or vaccine of the invention is administered by the intradermal administration.
  • Human skin comprises an outer “horny” cuticle, called the stratum corneum, which overlays the epidermis. Underneath this epidermis is a layer called the dermis, which in turn overlays the subcutaneous tissue.
  • the conventional technique of intradermal injection, the “mantoux procedure”, comprises steps of cleaning the skin, and then stretching with one hand, and with the bevel of a narrow gauge needle (26 to 31 gauge) facing upwards the needle is inserted at an angle of between 10 to 15° . Once the bevel of the needle is inserted, the barrel of the needle is lowered and further advanced whilst providing a slight pressure to elevate it under the skin. The liquid is then injected very slowly thereby forming a bleb or bump on the skin surface, followed by slow withdrawal of the needle.
  • the immunogenic composition or vaccine of the invention is administered by the intranasal administration.
  • the immunogenic composition or vaccine is administered locally to the nasopharyngeal area, e.g. without being inhaled into the lungs.
  • an intranasal delivery device which delivers the immunogenic composition or vaccine formulation to the nasopharyngeal area, without or substantially without it entering the lungs.
  • Suitable devices for intranasal administration of the vaccines according to the invention are spray devices. Suitable commercially available nasal spray devices include ACCUSPRAYTM (Becton Dickinson).
  • the amount of conjugate (e.g. bioconjugate) in each immunogenic composition or vaccine dose is selected as an amount which induces an immunoprotective response without significant, adverse side effects in typical vaccines. Such amount will vary depending upon which specific immunogen is employed and how it is presented.
  • the content of conjugate (e.g. bioconjugate) will typically be in the range 1-100 ⁇ g, suitably 5-50 ⁇ g.
  • the present invention also provides an immunogenic composition of the invention, or the vaccine of the invention, for use in medicine.
  • the present invention provides a method of inducing an immune response in a subject (e.g. human), the method comprising administering a therapeutically or prophylactically effective amount of a conjugate (e.g. bioconjugate) of the invention, an immunogenic composition of the invention or a vaccine of the invention, to a subject (e.g. human) in need thereof.
  • a conjugate e.g. bioconjugate
  • an immunogenic composition of the invention or a vaccine of the invention for use in inducing an immune response in a subject (e.g. human).
  • the present invention also provides a conjugate (e.g. bioconjugate) of the invention, the immunogenic composition of the invention or the vaccine of the invention for use in the manufacture of a medicament for inducing an immune response in a subject (e.g. human).
  • a conjugate e.g. bioconjugate
  • the conjugate (e.g. bioconjugate) of the invention an immunogenic composition of the invention or a vaccine of the invention can be used to induce an immune response against a bacterium, e.g. Shigella species, Pseudomonas aeruginosa, Klebsiella pneumoniae, N. meningitidis, H.
  • the conjugate (e.g. bioconjugate) of the invention an immunogenic composition of the invention or a vaccine of the invention can be used to induce an immune response against a bacterium, e.g. Streptococcus species, Shigella species, Pseudomonas species, Klebsiella species, or Staphylococcus species.
  • a bacterium e.g. Streptococcus species, Shigella species, Pseudomonas species, Klebsiella species, or Staphylococcus species.
  • said subject has bacterial infection at the time of administration. In another embodiment, said subject does not have a bacterial infection at the time of administration.
  • Also provided herein are methods of inducing the production of opsonophagocytic antibodies in a subject against a bacterium comprising administering to the subject a conjugate (e.g. bioconjugate) of the invention an immunogenic composition of the invention or a vaccine of the invention.
  • the conjugate (e.g. bioconjugate) of the invention an immunogenic composition of the invention or a vaccine of the invention can be used to induce the production of opsonophagocytic antibodies in a subject against a bacterium, e.g. Shigella species, Pseudomonas aeruginosa, Klebsiella pneumoniae, N. meningitidis, H.
  • the conjugate (e.g. bioconjugate) of the invention an immunogenic composition of the invention or a vaccine of the invention can be used to induce the production of opsonophagocytic antibodies in a subject against a bacterium, e.g. Streptococcus species, Shigella species, Pseudomonas species, Klebsiella species, or Staphylococcus species.
  • a bacterium e.g. Streptococcus species, Shigella species, Pseudomonas species, Klebsiella species, or Staphylococcus species.
  • Shigella dysenteriae Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae or Staphylococcus aureus ).
  • the present invention also provides methods of treating and/or preventing a yeast or bacterial infection in a subject comprising administering to the subject a conjugate (e.g. bioconjugate) of the invention.
  • the conjugate e.g. bioconjugate
  • the conjugate may be in the form of an immunogenic composition or vaccine.
  • the present invention provides a method of treating and/or preventing a yeast or bacterial infection in a subject (e.g. human), the method comprising administering a therapeutically or prophylactically effective amount of a conjugate (e.g. bioconjugate) of the invention, an immunogenic composition of the invention or a vaccine of the invention, to a subject (e.g. human) in need thereof.
  • the present invention also provides a conjugate (e.g.
  • bioconjugate of the invention, an immunogenic composition of the invention or a vaccine of the invention, for use in treating and/or preventing a yeast or bacterial infection in a subject (e.g. human).
  • the present invention also provides a conjugate (e.g. bioconjugate) of the invention, the immunogenic composition of the invention or the vaccine of the invention for use in the manufacture of a medicament for treating and/or preventing a yeast or bacterial infections in a subject (e.g. human).
  • the immunogenic composition or vaccine of the invention is used in the prevention of infection of a subject by a bacterium.
  • Bacteria infections that can be treated and/or prevented using the conjugate (e.g. bioconjugate) of the invention include those caused by N.
  • H. influenzae type b Hib
  • Streptococcus species Shigella species, Pseudomonas species, Klebsiella species, or Staphylococcus species.
  • Shigella dysenteriae Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae or Staphylococcus aureus ).
  • SEQ NO: 9 GSGGG DQNAT GSGGGAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAI ADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIRLEGGVEPNK PVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPI YTIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQP RREKRWSEWASGKVLCLLDPLDGVYN KDQNATK LAQQRCNLDDTWEGKI YRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFT KDQNATK HRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQVIRNAL ASPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGNDEAGAASA DVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSF
  • SEQ ID NO: 12 GSGGG DQNAT GSGGGAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAI ADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIRLEGGVEPNK PVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPI YTIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQP RREKRWSEWASGKVLCLLDPLDGVYN KDQNATK LAQQRCNLDDTWEGKI YRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFT KDQNATK HRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQVIRNAL A KDQNATK SPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGND EAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPT
  • SEQ ID NO: 14 GSGGG DQNAT GSGGGAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAI ADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIRLEGGVEPNK PVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPI YTIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQP RREKRWSEWASGKVLCLLDPLDGVYN KDQNATK LAQQRCNLDDTWEGKI YRVLAGNPAKHDLDIK DNNNST PTVISHRLHFPEGGSLAALTAHQACHL PLEAFT KDQNATK HRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQ VIRNALA KDQNATK SPGSGGDLGEAIREQPEQARLALTLAAAESERFVR QGTGNDEAGAASADVVSLTCPVAAGECAGPADSGDALLERN
  • This gene was cloned with the DsbA signal sequence at the N-terminus and a His 6 tag at C-terminus into a plasmid derived from pEC415 (Schulz, H., Hennecke, H., Thony-Meyer, L., Prototype of a heme chaperone essential for cytochrome c maturation. In Science 281, 1197-1200, 1998).
  • Each selected amino acid residue was substituted with the glycosylation sequon KDQNATK (SEQ ID NO: 4) leading to 67 EPA variants in total, each containing a single glycosylation site (glycosite).
  • E. coli strain W3110 ⁇ waaL was transformed with three plasmids: a pEC415 plasmid carrying an EPA variant, a plasmid expressing PglB and with a plasmid expressing enzyme for the biosynthesis of the polysaccharide of interest (as described below).
  • the non-pathogenic E. coli K12 strain W3110 was obtained from the Coli Genetic Stock Center (Yale University, New Haven (Conn.), USA, product number CGSC #4474). In some cases, glycosylation test were performed with an E.
  • the selection criteria for EPA variants with single glycosite included the total expression level and the level of produced glycoconjugate, the later indicating suitability of glycosite position for modification by PglB.
  • the used E. coli strains are derivatives of strain W3110, which include a deletion in the lipopolysaccharide O-antigen ligase gene waaL, the deletion or replacement of the O16 O-antigen cluster rfband the replacement of a genomic cluster with the cluster responsible for the biosynthesis of the wanted recombinant glycan of Klebsiella pneumoniae O-antigen (KpO-antigen) Shigella flexneri 2a (Sf2a) or Streptococcus pneumoniae 11A (Sp11A) and 33F (Sp33F) capsular polysaccharides and Pseudomonas aeruginosa O-antigens (PaO6 and PaO11).
  • KpO-antigen Shigella flexneri 2a
  • Sp11A Streptococcus pneumoniae 11A
  • Sp33F capsular polysaccharides and Pseudomonas aeruginosa O-antigens
  • the E. coli strain used for the recombinant production of the K. pneumoniae O-antigen in FIG. 6 and FIG. 8 contains in addition genomic deletions of potentially interfering elements: genes wzzE-wecG from the enterobacterial common antigen (ECA) wec cluster, the colanic acid wca cluster, gtrABSand wzzBgenes involved in the O16 biosynthesis.
  • ECA enterobacterial common antigen
  • the E. coli strain producing KpO-antigen for FIG. 1 - 5 or KpO-antigen for FIG. 8 (P018_0167) glycan was transformed with a pEC415 plasmid carrying an EPA variant and a plasmid expressing PglB.
  • 5 ml TB (Terrific Broth) medium containing 10 mM MgCl 2 and appropriate antibiotics was inoculated with a streak of colonies from the transformation plate and grown at 37° C. o/n (overnight).
  • the E. coli strain producing KpO-antigen for FIG. 6 and FIG. 8 (P018-0183) was transformed with a plasmid expressing both EPA variant and PglB. These cultures were induced only by addition of 0.1 mM Isopropyl ⁇ -D-1-thiogalactopyranoside (IPTG) and expression and glycosylation of EPA variants was continued at 37° C. o/n.
  • IPTG Isopropyl ⁇ -D-1-thiogalactopyranoside
  • the amount of cells from o/n cultures corresponding to OD 600 60 (measured using a spectrophotometer) was harvested by centrifugation.
  • the cell pellets were resuspended in 1.5 ml of lysis buffer (30 mM Tris-HCl pH 8.5, 1 mM EDTA (Ethylenediaminetetraacetic acid), 20% sucrose) and lysozyme was added to a final concentration of 1 mg/ml.
  • the suspensions were incubated with slight shaking for 25 minutes at 4° C. and then centrifuged at 16,000 rcf for 10 min. After centrifugation, the supernatant corresponding to periplasmic extract (PPE) was transferred to a fresh tube.
  • PPE periplasmic extract
  • the His-tagged EPA variants were purified using one-step purification on Ni-NTA (Nickel Nitrilo-triacetic Acid) agarose.
  • 1 ml of PPE was mixed with 250 ⁇ l of 5 ⁇ binding buffer (150 mM Tris-HCl pH 8.0, 50 mM imidazole, 2.5 M NaCl, 20 mM MgCl 2 ) followed by addition of 200 ⁇ l of pre-equilibrated Ni-NTA slurry and incubated with slight shaking for 30 min.
  • the IMAC enriched PPE was analysed by SDS-PAGE (Laemmli, U. K. (1970). “Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4”. Nature. 227 (5259): 680-685. Bibcode:1970Natur.227.680L. doi:10.1038/227680a0. ISSN 0028-0836.
  • Periplasmic extracts were also analysed by immunoblots against EPA (Sigma-Aldrich, Cat. number P2318) and against polysaccharide attached to EPA.
  • EPA Sigma-Aldrich, Cat. number P2318
  • polysaccharide attached to EPA For detection of KpO-antigen, anti-serum against a K-capsular mutant of Klebsiella pneumoniae was used.
  • SDS-PAGE analysis was carried out on IMAC enriched periplasmic extract of E. coli strains producing KpO-antigen polysaccharide and expressing PglB and EPA variants with a glycosite KDQNATK (SEQ ID NO: 4) introduced at the following positions into SEQ ID NO: 1: Y208 (lane 1), K240 (lane 2), R274 (lane 3), S318 (lane 4), A376 (lane 5), A519 (lane 6), and K240 and A376 (lane 7).
  • the bands shown in FIG. 3 correspond to the unglycosylated EPA carrier, and to KpO-antigen-EPA bioconjugates with one and two occupied glycosites.
  • Glycosylation of EPA with KpO-antigen at each of the new positions was confirmed to be equally good or superior compared to positions K240 and A376.
  • Y208, S318 and A519 look superior compared to positions K240 and A376.
  • Y208 has higher total expression and all 3 have higher amount of conjugates than positions K240 and A376.
  • the upper panel represents the immunoblot probed with anti-KpO-antigen anti-serum
  • the bottom panel represents the immunoblot probed with anti-EPA antibody.
  • the bands correspond to the unglycosylated EPA carrier, and to KpO-antigen-EPA bioconjugates with one to seven occupied glycosites.
  • glycosylation at up to 7 glycosites is possible by combining the glycosite positions when using a variant of EPA which includes the combination of seven consensus sequences.
  • Klebsiella pneumoniae serotype O-antigen can be used to show glycosylation efficiency of EPA having more than 3 glycosites.
  • Immunoblot analysis was carried out on periplasmic extract of E. coli strains producing Sf2a-, Sp33F, PaO6 or PaO11 antigen polysaccharide and expressing PglB and EPA variants with 1 glycosite introduced at the following positions: Y208 (lane 1), D218 (lane 2), R274 (lane 3), R279 (lane 4), S318 (lane 5), G323 (lane 6), A376 (lane 7), A519 (lane 8), and G525 (lane 9).
  • the panel with Sf2a represents the immunoblot probed with anti-EPA antibody, while the other three panels represent the immunoblot probed with anti-His antibody.
  • the bands correspond to the unglycosylated EPA carrier, and to O-antigen-EPA bioconjugates with one occupied glycosite.
  • SEQUENCE LISTINGS SEQ ID NO: 1 EPA sequence from Pseudomonas aeruginosa AEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIR LEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIYTIEMGDELLAKLARDA TFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVYNYLAQQRCNLDDTWE GKIYRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTRHRQPRGWEQLEQCGYPVQRLV ALYLAARLSWNQVDQVIRNALASPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGNDEAGAASADWS LTCPVAAGECAGPADSGDALLERNYPTGAEF
  • coli flagellin FLSALILLLVTTAAQA SEQ ID NO: 16
  • E. coli outer membrane porin A OmpA
  • MKKTAIAIAVALAGFATVAQA SEQ ID NO: 17
  • E. coli maltose binding protein MKIKTGARILALSALTTMMFSASALA
  • Edwinia carotovorans pectate lyase PelB
  • MKYLLPTAAAGLLLLAAQPAMA SEQ ID NO: 19 heat labile E .

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Abstract

The present invention relates to the field of modified proteins, immunogenic compositions and vaccines comprising the modified proteins, their manufacture and the use of such compositions in medicine. More particularly, it relates to a modified EPA (Exotoxin A of Pseudomonas aeruginosa) protein. The modified EPA can be used as a carrier protein for other antigens, particularly saccharide antigens or other antigens lacking T cell epitopes.

Description

    FIELD OF THE INVENTION
  • The present invention relates to the field of modified proteins, immunogenic compositions and vaccines comprising the modified proteins, their manufacture and the use of such compositions in medicine. More particularly, it relates to a modified EPA (Exotoxin A of Pseudomonas aeruginosa) protein. The modified EPA can be used as a carrier protein for other antigens, particularly saccharide antigens or other antigens lacking T cell epitopes.
    • BACKGROUND TO THE INVENTION
  • Protein glycosylation is a common posttranslational modification in bacteria by which glycans are covalently attached to surface proteins, flagella, or pili, for example. Glycoproteins play roles in adhesion, stabilization of proteins against proteolysis, and evasion of the host immune response. Two protein glycosylation mechanisms are distinguished by the mode in which the glycans are transferred to proteins: one mechanism involves the transfer of carbohydrates directly from nucleotide-activated sugars to acceptor proteins (used in e.g. protein O-glycosylation in the Golgi apparatus of eukaryotic cells and flagellin O-glycosylation in some bacteria). A second mechanism involves the preassembly of a polysaccharide onto a lipid-carrier (by glycosyltransferases) which is then transferred to a protein acceptor by an oligosaccharyltransferase (OTase) (Faridmoayer et al., J. Bacteriology, pp. 8088-8098, 2007). This second mechanism is used in, e.g. N-glycosylation in the endoplasmic reticulum of eukaryotic cells, the well-characterized N-linked glycosylation system of Campylobacter jejuni, and the more recently characterized O-linked glycosylation systems of Neisseria meningitidis, Neisseria gonococcus, and Pseudomonas aeruginosa. For O-linked glycosylation (O-glycosylation), glycans are generally attached to a serine or threonine residue on the protein acceptor. For N-linked glycosylation (N-glycosylation), glycans are generally attached to an asparagine residue on the protein acceptor. It is possible to reconstitute the N-glycosylation of C. jejuni proteins by recombinantly expressing the pgl locus and acceptor glycoprotein in E. coli at the same time (Wacker et al. (2002) Science 298, 1790-1793).
  • WO2006/119987 (Aebi et al.) describes proteins, as well as means and methods for producing proteins, with efficiency for N-glycosylation in prokaryotic organisms in vivo. It further describes the introduction of N-glycans into recombinant proteins for modifying immunogenicity, stability, biological, prophylactic and/or therapeutic activity of said proteins, and the provision of a host cell that displays recombinant N-glycosylated proteins of the present invention on its surface. In addition, it describes a recombinant N-glycosylated protein comprising one or more of the following optimized amino acid sequence(s): D/E-X-N-Z-S/T, wherein X and Z may be any natural amino acid except Pro. The introduction of such optimized amino acid sequence(s) into proteins leads to proteins that are N-glycosylated by an oligosaccharyl transferase in these introduced positions.
  • Conjugate vaccines (vaccines comprising a carrier protein covalently linked to an immunogenic antigen) have been a successful approach for vaccination against a variety of bacterial infections. Conjugation of T-independent antigens, for example saccharides, to carrier proteins has long been established as a way of enabling T-cell help to become part of the immune response for a normally T-independent antigen. In this way, an immune response can be enhanced by allowing the development of immune memory and boostability of the response. To increase conjugate vaccine production efficiency, in vivo methods (to produce a “bioconjugate vaccine”) have been in development. These in vivo methods leverage the N-glycosylation and O-glycosylation systems discussed above. For example, WO2009/104074 describes a Shigella bioconjugate vaccine comprising a protein carrier comprising exotoxin of Pseudomonas aeruginosa (EPA) that has been modified to contain at least one consensus sequence D/E-X-N-Z-S/T and WO2017/035181 describes E. coli O-antigens covalently bound to a detoxified exotoxin A of P. aeruginosa (EPA) carrier protein. However, it has been found that certain antigens, are less immunogenic than other antigens when conjugated to EPA carrier protein.
  • Exotoxin A of Pseudomonas aeruginosa (also known as “EPA”, or “ETA”), is a secreted bacterial toxin, a member of the ADP-ribosyltransferasetoxin family. The native protein is a single polypeptide chain of 613 amino acids (67kDa). The protein consists of three main domains, domain Ia and b (receptor-binding domain), domain II (transmembrane domain) and domain III (catalytic NAD-ribosyltransferasedomain) (Allured et al., Proc. Natl. Acad. Sci. USA Vol. 83, pp. 1320-1324, March 1986). The last four residues (400-404) of Domain II together with Domain III (405-613) form the catalytic subunit of the toxin with ADP-ribosyltransferaseactivity (Siegal et al., 1989 J. Biol.Chem. 264, 14256-14261). A mutant form of Pseudomonas aeruginosa exotoxin A (ETA) carrying a deletion of glutamic acid-553, an important active-site residue, was expressed in an ETA-negative strain of P. aeruginosa and shown to be exported from the cells as efficiently as wild-type ETA. The mutant protein, purified from the culture medium, was devoid of ADP-ribosyltransferase activity (Kileen et al. Biochimica et Biophysica Acta, 1138 (1992) 162-166).
  • There exists a need for further EPA carrier proteins suitable for use in conjugation in vivo. There exists a need for further EPA carrier proteins so that there is a choice of EPA carrier proteins for different saccharide antigens. There also exists a need for further EPA carrier proteins which comprise at least one consensus sequence D/E-X-N-Z-S/T and display favourable or improved properties, e.g. increased glycosylation efficiency.
    • SUMMARY OF THE INVENTION
  • The present invention provides modified EPA proteins comprising at least one consensus sequence for glycosylation (e.g. D/E-X-N-Z-S/T) for use in conjugation to an antigen (e.g. bacterial polysaccharide). In the modified EPA proteins of the invention, the glycosylation consensus sequences are introduced into specific regions of the EPA carrier protein. The present inventors have found that the position of the consensus sequence in the EPA amino acid sequence can increase glycosylation efficiency and/or optimize the operation of the N-glycosylation site. Modified EPA proteins of the invention show higher site occupancy, higher sugar:protein ratio and/or higher yield. Differences in protein glycosylation may also influence the biological activity, antigenicity, stability and/or half-life of the protein. In addition, increased glycosylation can assist the purification of proteins by chromatography. In a specific embodiment, the modified EPA proteins described herein are modified such that the number of glycosylation sites in the carrier proteins is optimized. This may allow for lower concentrations of the EPA protein to be administered in its conjugate form, e.g. in an immunogenic composition or vaccine. The present invention also provides further EPA carrier proteins so that there is a choice of EPA carrier proteins with different numbers of consensus sequence sites for different saccharide antigens. The number of glycosites may be selected to optimise the sugar:protein ratio. For example, for shorter saccharide antigens (glycans) a higher number of glycosites (using the modified EPA carrier proteins of the invention as described herein) may be used to increase the sugar:protein ratio.
  • Accordingly, there is provided in one aspect of the present invention, a modified EPA (Exotoxin A of Pseudomonas aeruginosa) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises one (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the one (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), and (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519) of SEQ ID NO: 1 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • There is also provided, a modified EPA (Exotoxin A of Pseudomonas aeruginosa) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises one (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the one (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213; or one or more amino acids between 205-211; e.g. amino acid residue D218; e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279; or one or more amino acids between amino acid residues 271-277, e.g. amino acid residue R279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323; or one or more amino acids between amino acid residues 315-321, e.g. amino acid residue G323, e.g. amino acid residue S318), and (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; or one or more amino acids between amino acid residues 516-522; e.g. amino acid residue G525, e.g. amino acid residue A519) of SEQ ID NO: 1 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • According to a further aspect of the invention, there is provided a conjugate (e.g. bioconjugate) comprising a modified EPA protein of the invention linked to an antigen (e.g. a saccharide antigen, optionally a bacterial polysaccharide antigen).
  • According to a further aspect of the invention, there is provided a polynucleotide encoding a modified EPA protein of the invention.
  • According to a further aspect of the invention, there is provided a vector comprising a polynucleotide encoding a modified EPA protein of the invention.
  • According to a further aspect of the invention, there is provided a host cell comprising:
  • i) one or more nucleotide sequences comprising polysaccharide synthesis genes, optionally for producing a bacterial polysaccharide antigen (e.g. an O-antigen from a Gram negative bacterium optionally from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, or a capsular polysaccharide from a Gram positive bacterium optionally from Streptococcus pneumoniae or Staphylococcus aureus) or a yeast polysaccharide antigen or a mammalian polysaccharide antigen, optionally integrated into the host cell genome;
  • ii) a nucleotide sequence encoding a heterologous oligosaccharyl transferase, optionally within a plasmid;
  • iii) a nucleotide sequence that encodes a modified EPA protein of the invention, optionally within a plasmid.
  • According to a further aspect of the invention, there is provided a process for producing a bioconjugate that comprises (or consists of) a modified EPA protein linked to a polysaccharide, said process comprising: (i) culturing the host cell of the invention under conditions suitable for the production of glycoproteins and (ii) isolating the bioconjugate produced by said host cell, optionally isolating the bioconjugate from a periplasmic extract from the host cell.
  • According to a further aspect of the invention, there is provided an immunogenic composition comprising a conjugate (e.g. bioconjugate) of the invention and optionally a pharmaceutically acceptable excipient and/or carrier.
  • According to a further aspect of the invention, there is provided a vaccine comprising an immunogenic composition of the invention and optionally an adjuvant.
  • According to a further aspect of the invention, there is provided a method of inducing an immune response in a subject (e.g. human), the method comprising administering a therapeutically or prophylactically effective amount of a conjugate (e.g. bioconjugate) of the invention, an immunogenic composition of the invention or a vaccine of the invention to a subject (e.g. human) in need thereof.
  • According to a further aspect of the invention, there is provided a conjugate (e.g. bioconjugate) of the invention, an immunogenic composition of the invention, or a vaccine of the invention, for use in inducing an immune response in a subject (e.g. human).
  • According to a further aspect of the invention, there is provided a conjugate (e.g. bioconjugate) of the invention, an immunogenic composition of the invention, or a vaccine of the invention, for use in the manufacture of a medicament inducing an immune response in a subject (e.g. human).
    • DESCRIPTION OF DRAWINGS/FIGURES
  • FIG. 1 shows 3D structure of EPA presented as cartoon and positions Y208, R274, S318 and A519 selected for insertion of glycosites presented as spheres.
  • FIG. 2 shows sequence alignment of EPA variants containing single glycosite at positions Y208, R274, S318 and A519 compared to EPA without any glycosite. EPA_detox (SEQ ID NO: 1), EPA_mut_Y208 (SEQ ID NO: 34), EPA_mutR274 (SEQ ID NO: 35), EPA_mut_5318 (SEQ ID NO: 36), and EPA_mut_A519 (SEQ ID NO: 37).
  • FIG. 3 shows SDS-PAGE analysis of IMAC (Immobilized metal affinity chromatography) enriched periplasmic extract of E. coli strains producing KpO-antigen (Klebsiella pneumoniae O-antigen) polysaccharide and expressing PglB and EPA variants with a glycosite KDQNATK (SEQ ID NO: 4) introduced at the following positions: Y208 (lane 1), K240 (lane 2), R274 (lane 3), S318 (lane 4), A376 (lane 5), A519 (lane 6), and K240 and A376 (lane 7). The bands corresponding to the unglycosylated EPA carrier, and to KpO-antigen-EPA bioconjugates with one and two occupied glycosites are labelled.
  • FIG. 4 shows SDS-PAGE analysis of IMAC enriched periplasmic extract of E. coli strains producing KpO-antigen polysaccharide and expressing PglB and EPA variants with a glycosite KDQNATK (SEQ ID NO: 4) introduced at the following positions: K240 and A376 (lane 1), Y208 and R274 (lane 2), Y208 and S318 (lane 3), Y208 and A519 (lane 4), R274 and S318 (lane 5), R274 and A519 (lane 6), S318 and A519 (lane 7), and Y208 and R274 and A519 (lane 8). The bands corresponding to the unglycosylated EPA carrier, and to KpO-antigen-EPA bioconjugates with one, two and three occupied glycosites are labelled.
  • FIG. 5 shows immunoblot analyses of periplasmic extract of E. coli strains producing KpO-antigen polysaccharide and expressing PglB and EPA variants with 1 to 7 glycosites introduced at the following positions: Y208 (lane 1), K240 (lane 2), R274 (lane 3), S318 (lane 4), A376 (lane 5), A519 (lane 6), and K240 and A376 (lane 7), Y208 and R274 (lane 8), Y208 and S318 (lane 9), Y208 and A519 (lane 10), R274 and S318 (lane 11), R274 and A519 (lane 12), S318 and A519 (lane 13), Y208 and R274 and A519 (lane 14), N-terminal glycotag and K240 and A376 and C-terminal glycotag (lane 15), N-terminal glycotag and Y208 and R274 and A519 (lane 16), N-terminal glycotag and Y208 and R274 and A519 and C-terminal glycotag (lane 17), N-terminal glycotag and Y208 and S318 and A519 and C-terminal glycotag (lane 18), N-terminal glycotag and R274 and S318 and A519 and C-terminal glycotag (lane 19), N-terminal glycotag and Y208 and R274 and S318 and A519 and C-terminal glycotag (lane 20), N-terminal glycotag and Y208 and K240 and R274 and S318 and A519 (lane 21), and N-terminal glycotag and Y208 and K240 and R274 and S318 and A519 and C-terminal glycotag (lane 22). The upper panel represents the immunoblot probed with anti-KpO-antigen anti-serum, while the bottom panel represents the immunoblot probed with anti-EPA antibody. The bands corresponding to the unglycosylated EPA carrier, and to KpO-antigen-EPA bioconjugates with one to seven occupied glycosites are labelled.
  • FIG. 6 shows SDS-PAGE analysis of periplasmic extract of E. coli strains producing KpO-antigen polysaccharide and expressing PglB and EPA variants with a glycosite KDQNATK (SEQ ID NO: 4) introduced at the following positions: N-terminal glycotag and Y208 and R274 and A519 and C-terminal glycotag (lane 1), N-terminal glycotag and Y208 and S318 and A519 and C-terminal glycotag (lane 2), N-terminal glycotag and R274 and S318 and A519 and C-terminal glycotag (lane 3), N-terminal glycotag and Y208 and R274 and S318 and A519 and C-terminal glycotag (lane 4), N-terminal glycotag and Y208 and K240 and R274 and S318 and A519 (lane 5), N-terminal glycotag and Y208 and K240 and R274 and S318 and A519 and C-terminal glycotag (lane 6), and N-terminal glycotag and Y208 and R274 and A519 (lane 7). The bands corresponding to KpO-antigen-EPA bioconjugates are labelled with arrows. The first row of the table indicates the number of glycosites.
  • FIG. 7 shows SDS-PAGE analysis of IMAC enriched periplasmic extracts of E. coli strain producing Sf2a Shigella flexneri 2a (left) or Sp11A Streptococcus pneumoniae 11A (right) polysaccharide and expressing PglB and EPA variants with a glycosite introduced at K240 and a second glycosite at A376 (lane 1) or three glycosites at positions Y208, R274, and A519 (lane 2).
  • FIG. 8 shows SDS-PAGE analysis of IMAC enriched periplasmic extracts of E. coli strain producing two different Klebsiella pneumoniae O-antigen polysaccharides (left and right) and expressing PglB and EPA variants with glycosites at positions Y208 and R274 and A519 (lane 1), or with N-terminal glycotag and glycosites at positions Y208 and R274 and A519 (lane 2).
  • FIG. 9 shows immunoblot analyses of periplasmic extract of E. coli strains producing Sf2a, Sp33F, PaO6 and PaO11 antigen polysaccharide (bottom panel) and expressing PglB and EPA variants with 1 glycosite KDQNATK (SEQ ID NO: 4) introduced at the following positions: Y208 (lane 1), D218 (lane 2), R274 (lane 3), R279 (lane 4), S318 (lane 5), G323 (lane 6), A376 (lane 7), A519 (lane 8), and G525 (lane 9). The bands corresponding to EPA bioconjugates and unglycosylated EPA carrier protein are labelled with arrows.
    • DETAILED DESCRIPTION OF THE INVENTION Definitions
  • Carrier protein: a protein which may be covalently attached to an antigen (e.g. saccharide antigen, such as a bacterial polysaccharide antigen) to create a conjugate (e.g. bioconjugate). A carrier protein activates T-cell mediated immunity in relation to the antigen to which it is conjugated.
  • EPA: Exotoxin A of Pseudomonas aeruginosa (also known as “Exotoxin of P. aeruginosa”, “EPA”, or “ETA”)
  • Any amino acid except proline (pro, P): refers to an amino acid selected from the group consisting of alanine (ala, A), arginine (arg, R), asparagine (asn, N) , aspartic acid (asp,D), cysteine (cys, C), glutamine (gln, Q), glutamic acid (glu, E), glycine (gly, G), histidine (his, H), isoleucine (ile, I), leucine (leu, L), lysine (lys, K), methionine (met, M), phenylalanine (phe, F), serine (ser, S), threonine (thr, T), tryptophan (trp, W), tyrosine (tyr, Y), and valine (val, V).
  • Naturally occurring amino acid residues: amino acids that are naturally incorporated into polypeptides. In particular, the 20 amino acids encoded by the universal genetic code: alanine (ala, A), arginine (arg, R), asparagine (asn, N) , aspartic acid (asp,D), cysteine (cys, C) ,glutamine (gln, Q), glutamic acid (glu, E), glycine (gly, G), histidine (his, H), isoleucine (ile,I), leucine (leu, L), lysine (lys, K), methionine (met, M), phenylalanine (phe, F), proline (pro, P), serine (ser, S), threonine (thr, T), tryptophan (trp, W), tyrosine (tyr, Y), and valine (val, V).
  • Glycosyltransferases (GTFs, Gtfs): enzymes that establish glycosidic linkages. Glycosyltransferases are enzymes that catalyze the formation of the glycosidic linkage to form a glycoside. For example, they catalyze the transfer of saccharide moieties from an activated nucleotide sugar (also known as the “glycosyl donor”) to a nucleophilic glycosyl acceptor molecule, the nucleophile of which can be oxygen-carbon-, nitrogen-, or sulfur-based.
  • O-Antigens (also known as O-specific polysaccharides or O-side chains): a component of the surface lipopolysaccharide (LPS) of Gram-negative bacteria. Examples include O-antigens from Pseudomonas aeruginosa and Klebsiella pneumoniae.
  • Lipopolysaccharide (LPS): large molecules consisting of a lipid and a polysaccharide composed joined by a covalent bond.
  • Capsular polysaccharide (CP): polysaccharide found on the bacterial cell wall. Examples include capsular polysaccharide from Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis and Staphylococcus aureus.
  • wzy: a polysaccharide polymerase gene encoding an enzyme which catalyzes polysaccharide polymerization. The encoded enzyme transfers oligosaccharide units to the non-reducing end forming a glycosidic bond.
  • waaL: a O antigen ligase gene encoding a membrane bound enzyme. The encoded enzyme transfers undecaprenyl-diphosphate (UPP)-bound O antigen to the lipid A core oligosaccharide, forming lipopolysaccharide.
  • As used herein, the term “conjugate” refers to carrier protein covalently linked to an antigen.
  • As used herein, the term “bioconjugate” refers to conjugate between a protein (e.g. a carrier protein) and an antigen (e.g. a saccharide antigen, such as a bacterial polysaccharide antigen) prepared in a host cell background, wherein host cell machinery links the antigen to the protein (e.g. N-linked glycosylation).
  • As used herein, the term “modified protein” means a protein that is altered (in one or more way) as compared to wild type (e.g. a “modified EPA protein” excludes a wild type EPA protein).
  • As used herein, the term “immunogenic fragment” means a portion of an antigen smaller than the whole, that is capable of eliciting a humoral and/or cellular immune response in a host animal, e.g. human, specific for that fragment. Fragments of a protein can be produced using techniques known in the art, e.g. recombinantly, by proteolytic digestion, or by chemical synthesis. Internal or terminal fragments of a polypeptide can be generated by removing one or more nucleotides from one end (for a terminal fragment) or both ends (for an internal fragment) of a nucleic acid which encodes the polypeptide. Typically, fragments comprise at least 10, 20, 30, 40 or 50 contiguous amino acids of the full length sequence. Fragments may be readily modified by adding or removing 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40 or 50 amino acids from either or both of the N and C termini. A fragment of a modified EPA protein still comprises the recited modifications that are made to the EPA protein.
  • As used herein, the term “conservative amino acid substitution” involves substitution of a native amino acid residue with a non-native residue such that there is little or no effect on the size, polarity, charge, hydrophobicity, or hydrophilicity of the amino acid residue at that position, and without resulting in decreased immunogenicity. For example, these may be substitutions within the following groups: valine, glycine; glycine, alanine; valine, isoleucine, leucine; aspartic acid, glutamic acid; asparagine, glutamine; serine, threonine; lysine, arginine; and phenylalanine, tyrosine. Conservative amino acid modifications to the sequence of a polypeptide (and the corresponding modifications to the encoding nucleotides) may produce polypeptides having functional and chemical characteristics similar to those of a parental polypeptide.
  • As used herein, the term “deletion” is the removal of one or more amino acid residues from the protein sequence. Typically, no more than about from 1 to 6 residues (e.g. 1 to 4 residues) are deleted at any one site within the protein molecule.
  • As used herein, the terms “insertion” or “addition” (including other tenses thereof such as “inserted”) means the addition of one or more non-native amino acid residues in the protein sequence or, as the context requires, addition of one or more non-native nucleotides in the polynucleotide sequence. Typically, no more than about from 1 to 10 residues, (e.g. 1 to 7 residues, 1 to 6 residues, or 1 to 4 residues) are inserted at any one site within the protein molecule.
  • As used herein, the term “added next to” is the addition of one or more non-native amino acid residues in the protein sequence at a position adjacent to the referenced amino acid or amino acid region. For example, “added next to one or more amino acids between amino acid residues 198-218” means the addition at a position adjacent to any one of amino acid residues 198-218 (including adjacent to amino acid residues 198 or 218).
  • As used herein, the term “glycosite” refers to an amino acid sequence recognized by a bacterial oligosaccharyltransferase, e.g. PglB of C. jejuni.
  • A “consensus sequence” is a sequence have a specific structure and/or function. As used herein, the term “consensus sequence” is a sequence comprising a glycosite. A consensus sequence may be selected from: a five amino acid consensus sequence D/E-X-N-Z-S/T (SEQ ID NO: 2), a seven amino acid consensus sequence K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)).
  • As used herein, the term “introduced at” is used herein to reference the location and manner of inserting a consensus sequence into an amino acid sequence. A glycosite which is introduced at an N-terminal or C-terminal position of a protein may be added next to the amino acid sequence at the N-terminus or C-terminus, whereas a consensus sequence (or glycosite) which is introduced at a specific amino acid residue within the protein, e.g. Y208, may be substituted for that amino acid.
  • Unless specifically stated otherwise, providing a numeric range (e.g. “25-30”) is inclusive of endpoints (i.e. includes the values 25 and 30). For example, “between amino acids 198 to 218 . . . of SEQ ID NO: 1” refers to position in the amino acid sequence between amino acid 198 and amino acid 218 of SEQ ID NO: 1 including both amino acids 198 and 218.
  • The terms “identical” or percent “identity” refer to nucleotide sequences or amino acid sequences that are the same or have a specified percentage of nucleotide residues or amino acid residues that are the same (e.g. 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identity over a specified region), when compared and aligned for maximum correspondence using, for example, sequence comparison algorithms or by manual alignment and visual inspection. Identity between polypeptides may be calculated by various algorithms. In general, when calculating percentage identity the two sequences to be compared are aligned to give a maximum correlation between the sequences. This may include inserting “gaps” in either one or both sequences, to enhance the degree of alignment. For example the Needleman Wunsch algorithm (Needleman and Wunsch 1970, J. Mol. Biol. 48: 443-453) for global alignment, or the Smith Waterman algorithm (Smith and Waterman 1981, J. Mol. Biol. 147: 195-197) for local alignment may be used, e.g. using the default parameters (Smith Waterman uses BLOSUM 62 scoring matrix with a Gap opening penalty of 10 and a Gap extension penalty of 1). A preferred algorithm is described by Dufresne et al. in Nature Biotechnology in 2002 (vol. 20, pp. 1269-71) and is used in the software GenePAST (Genome Quest Life Sciences, Inc. Boston, Mass.). The GenePAST “percent identity” algorithm finds the best fit between the query sequence and the subject sequence, and expresses the alignment as an exact percentage. GenePAST makes no alignment scoring adjustments based on considerations of biological relevance between query and subject sequences. Identity between two sequences is calculated across the entire length of both sequences and is expressed as a percentage of the reference sequence (e.g. SEQ ID NO: 1 of the present invention).
  • As used herein the term “recombinant” means artificial or synthetic. In certain embodiments, a “recombinant protein” refers to a protein that has been made using recombinant nucleotide sequences (nucleotide sequences introduced into a host cell). In certain embodiments, the nucleotide sequence that encodes a “recombinant protein” is heterologous to the host cell.
  • As used herein the terms “isolated” or “purified” mean a protein, conjugate (e.g. bioconjugate), polynucleotide, or vector in a form not found in nature. This includes, for example, a a protein, conjugate (e.g. bioconjugate), polynucleotide, or vector having been separated from host cell or organism (including crude extracts) or otherwise removed from its natural environment. In certain embodiments, an isolated or purified protein is a protein essentially free from all other polypeptides with which the protein is innately associated (or innately in contact with).
  • As used herein, the term “subject” refers to an animal, in particular a mammal such as a primate (e.g. human).
  • As used herein, the term “effective amount,” in the context of administering a therapy (e.g. an immunogenic composition or vaccine of the invention) to a subject refers to the amount of a therapy which has a prophylactic and/or therapeutic effect(s). In certain embodiments, an “effective amount” refers to the amount of a therapy which is sufficient to achieve one, two, three, four, or more of the following effects: (i) reduce or ameliorate the severity of a bacterial infection or symptom associated therewith; (ii) reduce the duration of a bacterial infection or symptom associated therewith; (iii) prevent the progression of a bacterial infection or symptom associated therewith; (iv) cause regression of a bacterial infection or symptom associated therewith; (v) prevent the development or onset of a bacterial infection, or symptom associated therewith; (vi) prevent the recurrence of a bacterial infection or symptom associated therewith; (vii) reduce organ failure associated with a bacterial infection; (viii) reduce hospitalization of a subject having a bacterial infection; (ix) reduce hospitalization length of a subject having a bacterial infection; (x) increase the survival of a subject with a bacterial infection; (xi) eliminate a bacterial infection in a subject; (xii) inhibit or reduce a bacterial replication in a subject; and/or (xiii) enhance or improve the prophylactic or therapeutic effect(s) of another therapy.
  • The term “comprises” is open-ended and means “includes.” Thus, unless the context requires otherwise, the word “comprises” or “has”, and variations thereof (including “comprise” and “comprising” or “have” and “having”, respectively), will be understood to imply the inclusion of a stated compound(s), molecule(s), composition(s), or steps, but not to the exclusion of any other compound(s), molecule(s), composition(s), or steps. The terms “comprising” and “having” when used as a transition phrase herein are open-ended whereas the term “consisting of” when used as a transition phrase herein is closed (i.e., limited to that which is listed and nothing more). In certain embodiments and for readability, the word “is” may be used as a substitute for “consists of” or “consisting of”. The abbreviation, “e.g.” is derived from the Latin exempli gratia, and is used herein to indicate a non-limiting example. Thus, the abbreviation “e.g.” is synonymous with the term “for example”.
    • EPA Protein
  • Exotoxin A of Pseudomonas aeruginosa (also known as “EPA”, or “ETA”), is a secreted bacterial toxin, a member of the ADP-ribosyltransferasetoxin family. An EPA protein useful in the invention can be produced by methods known in the art in view of the present disclosure, see for example Ihssen etas. (2010) Microbial Cell Factories 9:61, WO 2006/119987, WO 2009/104074 and WO2015124769A1. Exotoxin A from Pseudomonas aeruginosa strain PA103 was cloned and sequenced by Gray etas. (1984) Proc. Nati. Acad. Sci. USA Vol. 81, pp. 2645-2649. Comparison of the deduced NH2-terminal amino acid sequence with that determined by sequence analysis of the secreted protein indicated that EPA was made as a 638 amino acid precursor from which a highly hydrophobic leader peptide of 25 amino acids is removed during the secretion process (see FIG. 1 of Gray et al. (1984)). Sequences within the EPA structural gene structural gene appear to be well-conserved from strain to strain (Vasil etas. (1986) Infection and Immunity, May 1986 pages 538 to 548).
  • Because EPA is a toxin, it needs to be detoxified (i.e. rendered non-toxic to a mammal, e.g. human, when provided at a dosage suitable for protection) before it can be administered in vivo. A modified EPA protein of the invention may be genetically detoxified (i.e. by mutation). The genetically detoxified sequences may remove undesirable activities such as ADP-ribosyltransferase activity, in order to reduce the toxicity, whilst retaining the ability to induce anti-EPA protective and/or neutralizing antibodies following administration to a human. The genetically detoxified sequences may maintain their immunogenic epitopes. A modified EPA protein may be genetically detoxified by one or more point mutations. For example, detoxification can be achieved by mutating and deleting catalytically essential residues, such as substitution of leucine 552 to valine (L552V) and by deletion of glutamic acid-553 (ΔE553), according to Lukac et al. (1988), Infect Immun, 56: 3095-3098, and Ho et al. (2006), Hum Vaccin, 2:89-98. Detoxification can be achieved by mutating/deleting the catalytically essential residues L552V ΔE553 using quick change mutagenesis (Stratagene) and phosphorylated oligonucleotides 5′-GAAGGCGGGCGCGTGACCATTCTCGGC (SEQ. ID NO. 38) and 5′-GCCGAGAATGGTCACGCGCCCGCCTTC (SEQ. ID NO. 39) resulting in construct pGVXN70. Detoxification can be measured by determining the inhibition of ADP-ribosyltransferase and cytotoxic activity according to the methodology described in Lukac et al. (1988), Infect Immun, 56: 3095-3098, and references cited therein, namely Douglas et al (1987) J. Bacteriol 169: 4962-4966 and Douglas et al (1987). A detoxified EPA has ADP-ribosyltransferase and cytotoxic activites lower than wild-type EPA, suitably the same as or less than that of the modified EPA described in Lukac et al (1988) i.e. ΔE553 EPA (EPA having deletion of glutamic acid-533). Accordingly, the modified EPA protein of the invention may be the amino acid sequence of SEQ ID NO: 1 (or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1). The modified EPA protein may comprise substitution of leucine 552 to valine (L552V) and deletion of glutamine 553 (ΔE553) with reference to the amino acid sequence of SEQ ID NO: 1 (or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1). The modified EPA protein of the invention may be the amino acid sequence of SEQ ID NO: 1 (or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1) comprising substitution of leucine 552 to valine (L552V). The modified EPA protein of the invention, may be the amino acid sequence of SEQ ID NO: 1 (or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1) comprising deletion of glutamine 553 (ΔE553). Preferably, the modified EPA protein of the invention, is modified by substitution of leucine 552 to valine (L552V) and deletion of glutamine 553 (ΔE553). Preferably, the modified EPA protein of the invention, is the amino acid sequence of SEQ ID NO: 1 (or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1) comprising substitution of leucine 552 to valine (L552V) and deletion of glutamine 553 (ΔE553). 1.
  • In one aspect of the invention, EPA protein has the amino acid sequence of SEQ ID NO: 1:
  • EPA sequence
    SEQ ID NO: 1
    AEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIR
    LEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIYTIEMGDELLAKLARDA
    TFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVYNYLAQQRCNLDDTWE
    GKIYRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTRHRQPRGWEQLEQCGYPVQRLV
    ALYLAARLSWNQVDQVIRNALASPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGNDEAGAASADWS
    LTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRGTQNWTVERLLQAHRQLEERGYVFVGYHGT
    FLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVPRWSLPGFYRTGL
    TLAAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILGWPLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQAI
    SALPDYASQPGKPPREDLK
    EPA sequence (amino acids 1 to 612 with numbering)
    SEQ ID NO: 1
            10         20         30         40         50         60
    AEEAFDLWNE CAKACVLDLK DGVRSSRMSV DPAIADTNGQ GVLHYSMVLE GGNDALKLAI
            70         80         90        100        110        120
    DNALSITSDG LTIRLEGGVE PNKPVRYSYT RQARGSWSLN WLVPIGHEKP SNIKVFIHEL
           130        140        150        160        170        180
    NAGNQLSHMS PIYTIEMGDE LLAKLARDAT FFVRAHESNE MQPTLAISHA GVSVVMAQAQ
           190        200        210        220        230        240
    PRREKRWSEW ASGKVLCLLD PLDGVYNYLA QQRCNLDDTW EGKIYRVLAG NPAKHDLDIK
           250        260        270        280        290        300
    PTVISHRLHF PEGGSLAALT AHQACHLPLE AFTRHRQPRG WEQLEQCGYP VQRLVALYLA
           310        320        330        340        350        360
    ARLSWNQVDQ VIRNALASPG SGGDLGEAIR EQPEQARLAL TLAAAESERF VRQGTGNDEA
           370        380        390        400        410        420
    GAASADVVSL TCPVAAGECA GPADSGDALL ERNYPTGAEF LGDGGDVSFS TRGTQNWTVE
           430        440        450        460        470        480
    RLLQAHRQLE ERGYVFVGYH GTFLEAAQSI VFGGVRARSQ DLDAIWRGFY IAGDPALAYG
           490        500        510        520        530        540
    YAQDQEPDAR GRIRNGALLR VYVPRWSLPG FYRTGLTLAA PEAAGEVERL IGHPLPLRLD
           550        560        570        580        590        600
    AITGPEEEGG RVTILGWPLA ERTVVIPSAI PTDPRNVGGD LDPSSIPDKE QAISALPDYA
           610
    SQPGKPPRED LK
  • The term “modified EPA protein” refers to a EPA amino acid sequence (for example, having a amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1), which EPA amino acid sequence has been modified by the addition, substitution or deletion of one or more amino acids (for example, by addition of a consensus sequence(s) selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) and/or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)).; and/or by substitution of one or more amino acids by a consensus sequence(s) selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3)). For example, a modified EPA protein may be an EPA amino acid sequence of SEQ ID NO: 1 which has been modified in that the amino acid sequence comprises one (or more) consensus sequence(s) selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) and/or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)). As used herein, in consensus sequences of the present invention X and Z are independently any amino acid except proline; preferably, X is Q (glutamine) and Z is A (alanine). The modified EPA protein may also comprise further modifications (additions, substitutions, deletions). Preferably, the modified EPA protein of the invention comprises substitution of leucine 552 to valine (L552V) and deletion of glutamine 553 (ΔE553) with reference to the amino acid sequence of SEQ ID NO: 1 (or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1). In an embodiment, the modified EPA protein of the invention is a non-naturally occurring EPA protein (i.e. not native). A modified EPA protein of the invention may have an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. A modified EPA protein of the invention may have an amino acid sequence at least 80% identical to SEQ ID NO: 1. A modified EPA protein of the invention may have an amino acid sequence at least 85% identical to SEQ ID NO: 1. A modified EPA protein of the invention may have an amino acid sequence at least 90% identical to SEQ ID NO: 1. A modified EPA protein of the invention may have an amino acid sequence at least 91% identical to SEQ ID NO: 1. A modified EPA protein of the invention may have an amino acid sequence at least 92% identical to SEQ ID NO: 1. A modified EPA protein of the invention may have an amino acid sequence at least 93% identical to SEQ ID NO: 1. A modified EPA protein of the invention may have an amino acid sequence at least 94% identical to SEQ ID NO: 1. A modified EPA protein of the invention may have an amino acid sequence at least 95% identical to SEQ ID NO: 1. A modified EPA protein of the invention may have an amino acid sequence at least 96% identical to SEQ ID NO: 1. A modified EPA protein of the invention may have an amino acid sequence at least 97% identical to SEQ ID NO: 1. A modified EPA protein of the invention may have an amino acid sequence at least 98% identical to SEQ ID NO: 1. A modified EPA protein of the invention may have an amino acid sequence at least 99% identical to SEQ ID NO: 1.
  • The present invention provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises one (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein the one (or more) consensus sequences have each been added next to or substituted for one or more amino acids, selected from specific amino acid residues within the EPA protein (consensus sequence sites). These consensus sequence sites are independently selected from (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), and (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519) of SEQ ID NO: 1 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Thus, the present invention provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises one (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the one (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), and (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519) of SEQ ID NO: 1 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. The numbering of the amino acid residues as specified herein, for example in (i) to (iv) above, refers to the amino acid position in SEQ ID NO: 1 (or where an amino acid sequence is at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 to an equivalent position to that of SEQ ID NO: 1 if this sequence was lined up with an amino acid sequence of SEQ ID NO: 1 in order to maximise the sequence identity between the two sequences).
  • The present invention also provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises one (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the one (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213; or one or more amino acids between 205-211; e.g. amino acid residue D218; e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279; or one or more amino acids between amino acid residues 271-277, e.g. amino acid residue R279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323; or one or more amino acids between amino acid residues 315-321, e.g. amino acid residue G323, e.g. amino acid residue S318), and (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; or one or more amino acids between amino acid residues 516-522; e.g. amino acid residue G525, e.g. amino acid residue A519) of SEQ ID NO: 1 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. The numbering of the amino acid residues as specified herein, for example in (i) to (iv) above, refers to the amino acid position in SEQ ID NO: 1 (or where an amino acid sequence is at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 to an equivalent position to that of SEQ ID NO: 1 if this sequence was lined up with an amino acid sequence of SEQ ID NO: 1 in order to maximise the sequence identity between the two sequences).
  • The present invention also provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises two (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein the two (or more) consensus sequences have each been added next to or substituted for one or more amino acids, selected from specific amino acid residues within the EPA protein (consensus sequence sites). These consensus sequence sites are independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519) of SEQ ID NO: 1, and (v) one or more amino acids between amino acid residues 230-250 (e.g. one or more amino acids between amino acid residues 235-245; e.g. amino acid residue K240) or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Thus, the present invention provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa) having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises two (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the two (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519), and (v) one or more amino acids between amino acid residues 230-250 (e.g. one or more amino acids between amino acid residues 235-245; e.g. amino acid residue K240), of SEQ ID NO: 1 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. The present invention also provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa) having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises two (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein the two (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), and (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519), of SEQ ID NO: 1 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • The two (or more) consensus sequences may also be independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213; or one or more amino acids between 205-211; e.g. amino acid residue D218; e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279; or one or more amino acids between amino acid residues 271-277, e.g. amino acid residue R279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323; or one or more amino acids between amino acid residues 315-321, e.g. amino acid residue G323, e.g. amino acid residue S318), and (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; or one or more amino acids between amino acid residues 516-522; e.g. amino acid residue G525, e.g. amino acid residue A519), and (v) one or more amino acids between amino acid residues 230-250 (e.g. one or more amino acids between amino acid residues 235-245; e.g. amino acid residue K240) or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • The present invention also provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises three (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein the three (or more) consensus sequences have each been added next to or substituted for one or more amino acids, selected from specific amino acid residues within the EPA protein (consensus sequence sites). These consensus sequence sites are independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519) of SEQ ID NO: 1, and (v) one or more amino acids between amino acid residues 230-250 (e.g. one or more amino acids between amino acid residues 235-245; e.g. amino acid residue K240) or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Thus, the present invention provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa) having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises three (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the three (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519) of SEQ ID NO: 1, and (v) one or more amino acids between amino acid residues 230-250 (e.g. one or more amino acids between amino acid residues 235-245; e.g. amino acid residue K240) or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • The three (or more) consensus sequences may also be independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213; or one or more amino acids between 205-211; e.g. amino acid residue D218; e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279; or one or more amino acids between amino acid residues 271-277, e.g. amino acid residue R279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323; or one or more amino acids between amino acid residues 315-321, e.g. amino acid residue G323, e.g. amino acid residue S318), and (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; or one or more amino acids between amino acid residues 516-522; e.g. amino acid residue G525, e.g. amino acid residue A519), and (v) one or more amino acids between amino acid residues 230-250 (e.g. one or more amino acids between amino acid residues 235-245; e.g. amino acid residue K240) or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • The present invention also provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises four (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein the four (or more) consensus sequences have each been added next to or substituted for one or more amino acids, selected from specific amino acid residues within the EPA protein (consensus sequence sites). These consensus sequence sites are independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519) of SEQ ID NO: 1, and (v) one or more amino acids between amino acid residues 230-250 (e.g. one or more amino acids between amino acid residues 235-245; e.g. amino acid residue K240) or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Thus, the present invention provides a modified EPA (Exotoxin A of Pseudomonas aeruginosa) having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises four (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the four (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519) of SEQ ID NO: 1, and (v) one or more amino acids between amino acid residues 230-250 (e.g. one or more amino acids between amino acid residues 235-245; e.g. amino acid residue K240) or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • The four (or more) consensus sequences may also be independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213; or one or more amino acids between 205-211; e.g. amino acid residue D218; e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279; or one or more amino acids between amino acid residues 271-277, e.g. amino acid residue R279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323; or one or more amino acids between amino acid residues 315-321, e.g. amino acid residue G323, e.g. amino acid residue S318), and (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; or one or more amino acids between amino acid residues 516-522; e.g. amino acid residue G525, e.g. amino acid residue A519), and (v) one or more amino acids between amino acid residues 230-250 (e.g. one or more amino acids between amino acid residues 235-245; e.g. amino acid residue K240) or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • EPA sequence (with numbering) with amino acids Y208, K240, R274, S318,
    and A519 underlined
    SEQ ID NO: 1
            10         20         30         40         50         60
    AEEAFDLWNE CAKACVLDLK DGVRSSRMSV DPAIADTNGQ GVLHYSMVLE GGNDALKLAI
            70         80         90        100        110        120
    DNALSITSDG LTIRLEGGVE PNKPVRYSYT RQARGSWSLN WLVPIGHEKP SNIKVFIHEL
           130        140        150        160        170        180
    NAGNQLSHMS PIYTIEMGDE LLAKLARDAT FFVRAHESNE MQPTLAISHA GVSVVMAQAQ
           190        200        210        220        230        240
    PRREKRWSEW ASGKVLCLLD PLDGVYNYLA QQRCNLDDTW EGKIYRVLAG NPAKHDLDIK
           250        260        270        280        290        300
    PTVISHRLHF PEGGSLAALT AHQACHLPLE AFTRHRQPRG WEQLEQCGYP VQRLVALYLA
           310        320        330        340        350        360
    ARLSWNQVDQ VIRNALASPG SGGDLGEAIR EQPEQARLAL TLAAAESERF VRQGTGNDEA
           370        380        390        400        410        420
    GAASADVVSL TCPVAAGECA GPADSGDALL ERNYPTGAEF LGDGGDVSFS TRGTQNWTVE
           430        440        450        460        470        480
    RLLQAHRQLE ERGYVFVGYH GTFLEAAQSI VFGGVRARSQ DLDAIWRGFY IAGDPALAYG
           490        500        510        520        530        540
    YAQDQEPDAR GRIRNGALLR VYVPRWSLPG FYRTGLTLAA PEAAGEVERL IGHPLPLRLD
           550        560        570        580        590        600
    AITGPEEEGG RVTILGWPLA ERTVVIPSAI PTDPRNVGGD LDPSSIPDKE QAISALPDYA
           610
    SQPGKPPRED LK
  • In an embodiment, the modified EPA protein of the invention may be derived from an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 which is an immunogenic fragment and/or a variant of SEQ ID NO: 1.
  • In an embodiment, the modified EPA protein of the invention may be derived from an immunogenic fragment of SEQ ID NO: 1 comprising at least about 15, at least about 20, at least about 40, or at least about 60 contiguous amino acid residues of SEQ ID NO: 1, wherein said polypeptide is capable of eliciting an antibodies which bind to SEQ ID NO: 1.
  • Native EPA is known to consist of three distinct structural domains (Allured et al., Proc. Natl. Acad. Sci. USA Vol. 83, pp. 1320-1324, March 1986):
      • Domain I, is an antiparallel β-structure. It includes residues 1-252 and residues 365-404. It has 17 β-strands. The first 13 strands form the structural core of an elongated β-barrel. Following strand 13 of domain I, the peptide chain traverses one face of the barrel, leading into the second domain.
      • Domain II (residues 253-364) is composed of six consecutive a-helices with one disulfide linking helix A and helix B. Helices B and E are approximately 30 Å in length; helices C and D are approximately 15 Å long.
        • Domain III is comprised of the carboxyl-terminal third of the molecule, residues 405-613. The most notable structural feature of domain III is its extended cleft. The domain has a less regular secondary structure than domains I and II.
          An immunogenic fragment of EPA protein of the invention may be generated by removing and/or modifying one or more of these domains. In an embodiment, the immunogenic fragment of SEQ ID NO: 1 may comprise the amino acid residues of Domain I (residues 1-252 and residues 365-404) of SEQ ID NO: 1. In another embodiment, the immunogenic fragment of SEQ ID NO: 1 may comprise the amino acid residues of Domain II (residues 253-364) of SEQ ID NO: 1. In another embodiment, the immunogenic fragment of SEQ ID NO: 1 may comprise at least the amino acid residues of Domain III (residues 405-612) of SEQ ID NO: 1. In another embodiment, the immunogenic fragment of SEQ ID NO: 1 may comprise the amino acid residues of Domain I (residues 1-252 and residues 365-404) of SEQ ID NO: 1 and Domain II (residues 253-364) of SEQ ID NO: 1. In another embodiment, the immunogenic fragment of SEQ ID NO: 1 may comprise at least the amino acid residues of Domain II (residues 253-364) of SEQ ID NO: 1 and Domain III (residues 405-612) of SEQ ID NO: 1.
  • In EPA there are eight cysteines form forming disulfides in sequential order: Cys-11 forms a disulfide with Cys-15, Cys-197 forms a disulfide with Cys-214, Cys-265 forms a disulfide with Cys-287, and Cys-372 forms a disulfide with Cys-379. Suitably, the immunogenic fragment of SEQ ID NO: 1 comprises the eight cysteines of SEQ ID NO: 1: Cys-11, Cys-15, Cys-197, Cys-214, Cys-265, Cys-287, Cys-372 and Cys-379 (i.e. these residues are not modified). Thus, suitably the modified EPA protein of the invention comprises the eight cysteines of SEQ ID NO: 1: Cys-11, Cys-15, Cys-197, Cys-214, Cys-265, Cys -287, Cys-372 and Cys-379 or equivalent cysteines within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • In an embodiment, the modified EPA protein of the invention may be derived from an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 which is a variant of SEQ ID NO: 1 and differs from SEQ ID NO: 1 by the deletion and/or addition and/or substitution of one or more amino acids (e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 amino acids). Amino acid substitution may be conservative or non-conservative. In one aspect, amino acid substitution is conservative. Substitutions, deletions, additions or any combination thereof may be combined in a single variant so long as the variant is an immunogenic polypeptide. In an embodiment, the modified EPA protein of the present invention may be derived from a variant of SEQ ID NO: 1 in which 1 to 10, 5 to 10, 1 to 5, 1 to 3, 1 to 2 or 1 amino acids of SEQ ID NO: 1 have been substituted or deleted.
  • Suitably the immunogenic fragment and/or a variant of SEQ ID NO: 1 comprises a B-cell or T-cell epitope. Such epitopes may be predicted using a combination of 2D-structure prediction, e.g. using the PSIPRED program (from David Jones, Brunel Bioinformatics Group, Dept. Biological Sciences, Brunel University, Uxbridge UB8 3PH, UK) and antigenic index calculated on the basis of the method described by Jameson and Wolf (CABIOS 4:181-186 [1988]).
  • In modified EPA proteins of the invention one or more consensus sequences have each been added next to, or substituted for one or more amino acids of SEQ ID NO: 1 or a EPA amino acid sequence at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. In an embodiment of the invention, one or more amino acids (e.g. 1-7 amino acids, e.g. one amino acid) of the EPA amino acid sequence (for example, having an amino acid sequence of SEQ ID NO: 1 or a EPA amino acid sequence at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1) is/are substituted by a five amino acid D/E-X-N-Z-S/T (SEQ ID NO: 2) or by a seven amino acid K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4) also referred to as “KDQNATK”) consensus sequence. For example, a single amino acid in the EPA amino acid sequence (e.g. SEQ ID NO: 1) may be substituted (i.e. replaced) with a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence. Alternatively, 2, 3, 4, 5, 6 or 7 amino acids in the EPA amino acid sequence (e.g. SEQ ID NO: 1 or a EPA amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1) may be substituted (i.e. replaced) with a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence. Preferably, at an internal consensus sequence site (i.e. a consensus sequence site that is within the EPA amino acid sequence rather than added next to the N-terminal or C-terminal amino acid), a single amino acid in the EPA amino acid sequence (e.g. SEQ ID NO: 1) is substituted (i.e. replaced) with a K-D-Q-N-A-T-K (SEQ ID NO: 4) consensus sequence. The classical 5 amino acid glycosylation consensus sequence (D/E-X-N-Z-S/T (SEQ ID NO: 2)) may also be extended by 1-5 other amino acid residues either side of the consensus sequence for more efficient glycosylation. For example, an extended consensus sequence may be J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5). As used herein, J and U are independently 1 to 5 naturally occurring amino acid residues, preferably J and U are independently 1 to 5 amino acid residues independently selected from glycine and/or serine, e.g. B may be G-S-G-G-G and U may be G-S-G-G. For example, an extended consensus sequence may be G-S-G-G-G-D/E-X-N-Z-S/T-G-S-G-G (SEQ ID NO: 25). Preferably, an extended consensus sequence, such as J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) or G-S-G-G-G-D/E-X-N-Z-S/T-G-S-G-G (SEQ ID NO: 25) is used where the consensus sequence is added next to the N-terminal or C-terminal amino acid of the EPA protein.
  • A combination of consensus sequences selected from: a five amino acid consensus sequence D/E-X-N-Z-S/T (SEQ ID NO: 1), a seven amino acid consensus sequence K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) and an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)) may be used. For example, 1, 2, 3, 4 or 5, amino acids within the carrier protein amino acid sequence may each independently be substituted (i.e. replaced) with a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequence, wherein X and Z are independently any amino acid except proline (preferably wherein X is Q (glutamine), Z is A (alanine)) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4), and 1 or 2 consensus sequences J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) wherein J and U are independently 1 to 5 naturally occurring amino acid residues (preferably J and U are independently 1 to 5 amino acid residues independently selected from glycine and/or serine, e.g. G-S-G-G-G-D/E-X-N-Z-S/T-G-S-G-G (SEQ ID NO: 25)) may be added next to the N-terminal or C-terminal amino acids of the carrier protein. Thus, a carrier protein may comprise 1, 2, 3, 4 or 5 consensus sequences selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline (preferably wherein X is Q (glutamine), Z is A (alanine)), and the carrier protein may further comprise 1 or 2 extended consensus sequences J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) wherein J and U are independently 1 to 5 naturally occurring amino acid residues (preferably J and U are independently 1 to 5 amino acid residues independently selected from glycine and/or serine, e.g. G-S-G-G-G-D/E-X-N-Z-S/T-G-S-G-G (SEQ ID NO: 25). Introduction of one or more consensus sequence(s) selected from: a five amino acid consensus sequence D/E-X-N-Z-S/T (SEQ ID NO: 2), a seven amino acid consensus sequence K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) and/or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)) according to the present invention enables the modified EPA protein to be glycosylated. Thus, the present invention also provides a modified EPA protein of the invention wherein the modified EPA protein is glycosylated.
    • Position of the Consensus Sequence(s)
  • As described above, the present inventors have found that the position of the consensus sequence at specific regions/amino acids in the EPA amino acid sequence can increase glycosylation efficiency and/or optimize the operation of the N-glycosylation site.
  • In modified EPA proteins of the invention, a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) between amino acids 198-218 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. More particularly, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be added next to or substituted for one or more amino acids residues between amino acids 203-213 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue Y208 or D218 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Even more particularly, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be added next to or substituted for one or more amino acids residues between amino acids 205-211 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Preferably, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue Y208 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • In modified EPA proteins of the invention, a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) between amino acids 264-284 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. More particularly, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be added next to or substituted for one or more amino acids residues between amino acids 269-279 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue R274 or R279 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Even more particularly, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be added next to or substituted for one or more amino acids residues between amino acids 271-277 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Preferably, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue R274 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • In modified EPA proteins of the invention, a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) between amino acids 308-328 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. More particularly, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be added next to or substituted for one or more amino acids residues between amino acids 313-323 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue S318 or G323 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Even more particularly, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be added next to or substituted for one or more amino acids residues between amino acids 313-323 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Preferably, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue S318 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • In modified EPA proteins of the invention, a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) between amino acids 509-529 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. More particularly, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be added next to or substituted for one or more amino acids residues between amino acids 514-524 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue A519 or G525 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Even more particularly, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be added next to or substituted for one or more amino acids residues between amino acids 516-522 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Preferably, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue A519 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • In modified EPA proteins of the invention, a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) between amino acids 230-250 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. More particularly, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be added next to or substituted for one or more amino acids residues between amino acids 235-245 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Even more particularly, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be added next to or substituted for one or more amino acids residues between amino acids 237-243 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Preferably, a D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) consensus sequence may be substituted for amino acid residue K240 of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • In modified EPA proteins of the invention, a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)) may be added next to or substituted for one or more amino acids residue(s) within the N-terminal 10 amino acids of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. More particularly, a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)) may be added next to or substituted for one or more amino acids residue(s) within the N-terminal 5 amino acids of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Preferably, a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)) may be added next to the N-terminal amino acid of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • In modified EPA proteins of the invention, a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)) may be added next to or substituted for one or more amino acids residue(s) within the C-terminal 10 amino acids of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. More particularly, a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)) may be added next to or substituted for one or more amino acids residue(s) within the C-terminal 5 amino acids of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Preferably, a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence (e.g. J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5)) may be added next to the C-terminal amino acid of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • In the modified EPA protein of the invention, the consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), may each be independently substituted for one or more amino acids (e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, D218, R274, R279, S318,
  • G323, A519 and G525; e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318 and A519) of the amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. In the modified EPA protein of the invention, two or more consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) may each be independently substituted for one or more amino acids (e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, D218, R274, R279, S318, G323, A519, G525 and K240; e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318, A519 and K240) of the amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. In the modified EPA protein of the invention, three or more consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) may each be independently substituted for one or more amino acids (e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, D218, R274, R279, S318, G323, A519, G525 and K240; e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318, A519 and K240) of the amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. In the modified EPA protein of the invention, four or more consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) may each be independently substituted for one or more amino acids (e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, D218, R274, R279, S318, G323, A519, G525 and K240; e.g. each consensus sequence may be substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318, A519 and K240) of the amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. In the modified EPA protein of the invention, five or more consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) may each be independently substituted for one or more amino acids (e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, D218, R274, R279, S318, G323, A519, G525 and K240; e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318, A519 and K240) of the amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • In modified EPA proteins of the invention, a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) (e.g. G-S-G-G-G-D/E-X-N-Z-S/T-G-S-G-G (SEQ ID NO: 25)) may be added next to or substituted for one or more amino acids residue(s) at the N-terminus of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Thus, the modified EPA protein of the invention may comprise a further consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5), wherein X and Z are independently any amino acid except proline and J and U are independently 1 to 5 naturally occurring amino acid residues, added next to, or substituted for, one or more amino acids, at the N-terminus of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, the modified EPA protein of the invention may comprise a further consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5), wherein X and Z are independently any amino acid except proline and J and U are independently 1 to 5 naturally occurring amino acid residues, added next to the N-terminal amino acid of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • In modified EPA proteins of the invention, a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) or an extended consensus sequence J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) (e.g. G-S-G-G-G-D/E-X-N-Z-S/T-G-S-G-G (SEQ ID NO: 25)) may be added next to or substituted for one or more amino acids residue(s) at the C-terminus of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Thus, the modified EPA protein of the invention may comprise a further consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5), wherein X and Z are independently any amino acid except proline and J and U are independently 1 to 5 naturally occurring amino acid residues, added next to, or substituted for, one or more amino acids, at the C-terminus of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, the modified EPA protein of the invention may comprise a further consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5), wherein X and Z are independently any amino acid except proline and J and U are independently 1 to 5 naturally occurring amino acid residues, added next to the C-terminal amino acid of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • In the modified EPA protein of the invention, three or more consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) may each be independently substituted for one or more amino acids (e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318, A519 and K240) and a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) at the N-terminus (e.g. added next to the N-terminal amino acid) and a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) C-terminus (e.g. added next to the C-terminal amino acid) of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • In the modified EPA protein of the invention, four or more consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) may each be independently substituted for one or more amino acids (e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318, A519 and K240) and a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) at the N-terminus (e.g. added next to the N-terminal amino acid) and/or a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) C-terminus (e.g. added next to the C-terminal amino acid) of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • In the modified EPA protein of the invention, five or more consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) may be substituted for one or more amino acids (e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318, A519 and K240) and a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) at the N-terminus (e.g. added next to the N-terminal amino acid) and/or a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) may be added next to or substituted for one or more amino acids residue(s) C-terminus (e.g. added next to the C-terminal amino acid) of SEQ ID NO: 1 or an equivalent position in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • The modified EPA protein of the invention may comprise at least one consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, has been added next to, or substituted for: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), or (iii) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519) of SEQ ID NO: 1 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, the modified EPA protein of the invention may contain a consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), which has been added next to, or substituted for one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208) of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, the modified EPA protein of the invention may contain a consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), which has been added next to, or substituted for one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318) of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, the modified EPA protein of the invention may contain a consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), which has been added next to, or substituted for one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519) of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • The modified EPA protein of the invention may contain two consensus sequences. The modified EPA protein may have an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 modified in that the amino acid sequence comprises two consensus sequences, e.g. wherein two consensus sequences are added next to or substituted for two amino acid residues of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Thus the modified EPA protein of the invention may contain two consensus sequences, optionally substituted for amino acid residues selected from: (i) Y208 and R274, (ii) Y208 and S318, (iii) Y208 and A519, (iv) R274 and S318, (v) R274 and A519, or (vi) S318 and A519 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. The modified EPA protein of the invention may contain two consensus sequences substituted for amino acid residues Y208 and R274 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 6. The modified EPA protein of the invention may contain two consensus sequences substituted for amino acid residues Y208 and S318 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 28. The modified EPA protein of the invention may contain two consensus sequences substituted for amino acid residues Y208 and A519 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 29. The modified EPA protein of the invention may contain two consensus sequences substituted for amino acid residues R274 and S318 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 30. The modified EPA protein of the invention may contain two consensus sequences substituted for amino acid residues R274 and A519 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 31. The modified EPA protein of the invention may contain two consensus sequences substituted for amino acid residues S318 and A519 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 7.
  • The modified EPA protein of the invention may contain three consensus sequences. The modified EPA protein may have an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 modified in that the amino acid sequence comprises three consensus sequences, e.g. wherein three consensus sequences are added next to or substituted for three independently selected amino acid residues of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Thus the modified EPA protein of the invention may contain three consensus sequences, optionally substituted for amino acid residues Y208, R274 and A519 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 7.
  • The modified EPA protein of the invention may contain four consensus sequences. The modified EPA protein may have an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 modified in that the amino acid sequence comprises four consensus sequences, e.g. wherein four consensus sequences are added next to or substituted for four independently selected amino acid residues of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Thus the modified EPA protein of the invention may contain four consensus sequences, optionally substituted for amino acid residues Y208, R274, A519 and added next to the N-terminal amino acid of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, the modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 8.
  • The modified EPA protein of the invention may contain five consensus sequences. The modified EPA protein may have an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 modified in that the amino acid sequence comprises five consensus sequences, e.g. wherein five consensus sequences are added next to or substituted for five independently selected amino acid residues of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Thus the modified EPA protein of the invention may contain five consensus sequences, optionally selected from: substitution of amino acid residue Y208, substitution of amino acid residue R274, substitution of amino acid residue S318, substitution of amino acid residue A519, addition at the N-terminus (i.e. added at the N-terminus) and addition at the C-terminus (i.e. added at the C-terminus) of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, a modified EPA protein may comprise (or consist of) (i) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 9, (ii) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 10, or (iii) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 11.
  • The modified EPA protein of the invention may contain six consensus sequences. The modified EPA protein may have an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 modified in that the amino acid sequence comprises six consensus sequences, e.g. wherein six consensus sequences are added next to or substituted for six independently selected amino acid residues of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Thus the modified EPA protein of the invention may contain six consensus sequences, optionally selected from: substitution of amino acid residue Y208, substitution of amino acid residue K240, substitution of amino acid residue R274, substitution of amino acid residue S318, substitution of amino acid residue A519, addition at the N-terminus (i.e. added at the N-terminus) and addition at the C-terminus (i.e. added at the C-terminus) of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, a modified EPA protein of the invention may comprise (or consist of) (i) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 12, or (ii) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 13.
  • The modified EPA protein of the invention may contain seven consensus sequences. The modified EPA protein may have an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 modified in that the amino acid sequence comprises seven consensus sequences, e.g. wherein seven consensus sequences are added next to or substituted for seven independently selected amino acid residues of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. Thus the modified EPA protein of the invention may contain seven consensus sequences, optionally substitution of amino acid residues Y208, K240, R274, S318, A519, addition at the N-terminus (i.e. added at the N-terminus) and addition at the C-terminus (i.e. added at the C-terminus) of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1. For example, a modified EPA protein of the invention may comprise (or consist of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 14.
  • It will be understood by a person skilled in the art, that reference to “between amino acids . . . ” (for example “between amino acids 198-218”) is referring to the amino acid number counting consecutively from the N-terminus of the amino acid sequence, for example “between amino acids 198 to 218 . . . of SEQ ID NO: 1” refers to position in the amino acid sequence between amino acid 198 and amino acid 218 of SEQ ID NO: 1 including both amino acids 198 and 218. Thus, in an embodiment where “a consensus sequence selected from D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) (e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4)) has been added next to or substituted for one or more amino acids between amino acid residues 198-218”, the consensus sequence may have been added next to or substituted for any one (or more) of amino acid numbers 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218 in SEQ ID NO: 1. A person skilled in the art will understand that when the EPA amino acid sequence is a variant and/or fragment of an amino acid sequence of SEQ ID NO: 1, such as an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, the reference to “between amino acids . . . ” refers to a the position that would be equivalent to the defined position, if this sequence was lined up with an amino acid sequence of SEQ ID NO: 1 in order to maximise the sequence identity between the two sequences (Sequence alignment tools are not limited to Clustal Omega (www(.)ebi(.)ac(.)ac(.)uk) MUSCLE (www(.)ebi(.)ac(.)uk), or T-coffee (www(.)tcoffee(.)org). In one aspect, the sequence alignment tool used is Clustal Omega (www(.)ebi(.)ac(.)ac(.)uk).
  • The amino acid numbers referred to herein correspond to the amino acids in SEQ ID NO: 1 and as described above, a person skilled in the art can determine equivalent amino acid positions in an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1 by alignment. The addition or deletion of amino acids from the variant and/or fragment of SEQ ID NO:1 could lead to a difference in the actual amino acid position of the consensus sequence in the mutated sequence, however, by lining the mutated sequence up with the reference sequence, the amino acid in in an equivalent position to the corresponding amino acid in the reference sequence can be identified and hence the appropriate position for addition or substitution of the consensus sequence can be established.
  • The modified EPA protein of the invention may be an isolated modified EPA protein. The modified EPA protein of the invention may be a recombinant modified EPA protein. The modified EPA protein of the invention may be an isolated recombinant modified EPA protein.
    • Consensus Sequence
  • The modified EPA protein of the invention comprises a D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) or J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) consensus sequence, wherein X and Z are independently any amino acid except proline and J and U are independently 1 to 5 naturally occurring amino acid residues. The classical 5 amino acid glycosylation consensus sequence (D/E-X-N-Z-S/T (SEQ ID NO: 2)) may be extended by 1-5 other amino acid residues either side of the consensus sequence for more efficient glycosylation J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) (e.g. G-S-G-G-G-D/E-X-N-Z-S/T-G-S-G-G (SEQ ID NO: 25)). The classical 5 amino acid glycosylation consensus sequence (D/E-X-N-Z-S/T (SEQ ID NO: 2)) may be extended by lysine residues for more efficient glycosylation (e.g. K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3)). Thus consensus sequences in the modified EPA protein of the invention may comprises (or consist) of a D/E-X-N-Z-S/T (SEQ ID NO: 2) consensus sequence.
  • In the modified EPA protein of the invention, the consensus sequence(s) may be selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) or J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) wherein X is Q (glutamine) and Z is A (alanine). In the modified EPA protein of the invention, the consensus sequence(s) may be selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X is Q (glutamine) and Z is A (alanine). In an embodiment, the consensus sequence is D/E-X-N-Z-S/T (SEQ ID NO: 2), wherein X is Q (glutamine) and Z is A (alanine), e.g. D-Q-N-A-T (SEQ ID NO: 25) also referred to as “DQNAT”. In an embodiment, the consensus sequence is K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X is Q (glutamine) and Z is A (alanine), e.g. K-D-Q-N-A-T-K (SEQ ID NO: 4) also referred to as “KDQNATK”. In the modified EPA protein of the invention, the consensus sequence(s) may be selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) or J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) wherein X is Q (glutamine), Z is A (alanine), J and U are independently 1 to 5 amino acid residues independently selected from glycine and/or serine.
  • In an embodiment, the modified EPA protein of the invention comprises at least two D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences. In an embodiment, the modified EPA protein of the invention comprises at least three D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences. In an embodiment, the modified EPA protein of the invention comprises at least four D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences. In an embodiment, the modified EPA protein of the invention comprises at least five D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences. In an embodiment, the modified EPA protein of the invention comprises at least six D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences. In an embodiment, the modified EPA protein of the invention comprises at least seven D/E-X-N-Z-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences. In an embodiment, the modified EPA protein of the invention contains three to seven D/E-X-N-X-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences. In an embodiment, the modified EPA protein of the invention contains four to seven D/E-X-N-X-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences. In an embodiment, the modified EPA protein of the invention contains five to seven D/E-X-N-X-S/T (SEQ ID NO: 2) or K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) consensus sequences.
  • Introduction of such glycosylation sites can be accomplished by, e.g. adding new amino acids to the primary structure of the protein (i.e. the glycosylation sites are added, in full or in part), or by mutating existing amino acids in the protein in order to generate the glycosylation sites (i.e. amino acids are not added to the protein, but selected amino acids of the protein are mutated so as to form glycosylation sites). In an embodiment, the consensus sequence(s) are recombinantly introduced into the EPA amino acid sequence of SEQ ID NO: 1 or a EPA amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • The modified EPA protein of the invention may further comprise a “peptide tag” or “tag”, i.e. a sequence of amino acids that allows for the isolation and/or identification of the modified EPA protein. For example, adding a tag to a modified EPA protein of the invention can be useful in the purification of that protein and, hence, the purification of conjugate (e.g. bioconjugate) vaccines comprising the tagged modified EPA protein. Exemplary tags that can be used herein include, without limitation, histidine (HIS) tags (e.g. hexa histidine-tag, or 6XHis-Tag), FLAG-TAG, and HA tags. In one embodiment, the tag is a hexa-histidine tag. The tags used herein are removable, e.g. removal by chemical agents or by enzymatic means, once they are no longer needed, e.g. after the protein has been purified. Thus, the modified EPA protein of the invention may further comprise a peptide tag. Optionally the peptide tag is located at the C-terminus of the amino acid sequence. Optionally the peptide tag comprises six histidine residues at the C-terminus of the amino acid sequence. In one aspect, the modified EPA protein of the invention comprises (or consists of) an amino acid sequence which is at least 80%, 85%, 90%, 92%, 95%, 97%, 98%, 99% or 100% identical to any one of the sequences of SEQ ID NOs: 6 to 14 and a peptide tag (e.g. six histidine residues at the C-terminus of the amino acid sequence).
  • In an embodiment, the modified EPA protein of the invention comprises a signal sequence which is capable of directing the EPA protein to the periplasm of a host cell (e.g. bacterium). Signal sequences, including periplasmic signal sequences, are usually removed during translocation of the protein into, for example, the periplasm by signal peptidases (i.e. a mature protein is a protein from which at least the signal sequence has been removed). The signal sequence may be from E. coli flagellin (FlgI) [MIKFLSALILLLVTTAAQA (SEQ ID NO: 15)], E. coli outer membrane porin A (OmpA) [MKKTAIAIAVALAGFATVAQA (SEQ ID NO: 16)], E. coli maltose binding protein (MalE) [MKIKTGARILALSALTTMMFSASALA (SEQ ID NO: 17)], Erwin carotovorans pectate lyase (PelB) [MKYLLPTAAAGLLLLAAQPAMA (SEQ ID NO: 18)], heat labile E. coli enterotoxin LTIIb [MSFKKIIKAFVIMAALVSVQAHA (SEQ ID NO: 19)], Bacillus subtilis endoxylanase XynA [MFKFKKKFLVGLTAAFMSISMFSATASA (SEQ ID NO: 20)], E. coli DsbA [MKKIWLALAGLVLAFSASA (SEQ ID NO: 21)], TolB [MKQALRVAFGFLILWASVLHA (SEQ ID NO: 22)] or SipA [MKMNKKVLLTSTMAASLLSVASVQAS (SEQ ID NO: 23)]. In a specific embodiment, the signal sequence is from E. coli DsbA [MKKIWLALAGLVLAFSASA (SEQ ID NO: 21)].
  • Thus, the present invention provides a modified EPA protein, wherein the amino acid sequence further comprises a signal sequence which is capable of directing the EPA protein to the periplasm of a host cell (e.g. bacterium), optionally said signal sequence being DsbA (SEQ ID NO: 21). A signal peptide of the protein DsbA from E. coli can be genetically fused to the N-terminus of the mature EPA sequence. For example, a plasmid derived from pEC415 [Schulz, H., Hennecke, H., and Thony-Meyer, L., Science, 281, 1197-1200, 1998] containing the DsbA signal peptide code followed by a RNase sequence can be digested (NdeI to EcoRI) to keep the DsbA signal and remove the RNase insert. EPA is then amplified using PCR (forward oligo 5′-AAGCTAGCGCCGCCGAGGAAGCCTTCGACC (SEQ. ID NO. 32) and reverse oligo 5′-AAGAA TTCTCAGTGGTGGTGGTGGTGGTGCTTCAGGTCCTCGCGCGGCGG (SEQ. ID NO. 33)) and digested Nhel/EcoRI and ligated to replace the RNase sequence removed previously. The resulting construct (pGVXN69) encodes a protein product with an DsbA signal peptide, the mature EPA sequence and a hexa-histag.
  • A further aspect of the invention is a polynucleotide encoding a modified EPA protein of the invention. For example, a polynucleotide encoding a modified EPA protein, having a nucleotide sequence that encodes a polypeptide with an amino acid sequence that is at least 97%, 98%, 99% or 100% identical to any one of SEQ ID NOs: 6 to 14. For example, a nucleotide sequence according to SEQ ID NO: 40 or a nucleotide sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 40. For example, a nucleotide sequence according to SEQ ID NO: 41 or a nucleotide sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 41. For example, a nucleotide sequence according to SEQ ID NO: 42 or a nucleotide sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 42.
  • For example, a nucleotide sequence according to SEQ ID NO: 43 or a nucleotide sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 43. The nucleotide sequence comprises nucleotides encoding for amino acids corresponding to one (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3). For example, encoding for a modified EPA protein having a consensus sequence substituted at one or more of positions Y208, R274, S318 and/or A519 in an amino acid sequence of SEQ ID NO: 1 or at an equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
  • A vector comprising such a polynucleotide is a further aspect of the invention.
    • Conjugates
  • The present invention also provides a conjugate (e.g. bioconjugate) comprising (or consisting of) a modified EPA protein of the invention linked to an antigen (e.g. a saccharide antigen, optionally a bacterial polysaccharide antigen). The antigen may be a bacterial polysaccharide antigen, or a yeast polysaccharide antigen, or a mammalian polysaccharide antigen.
  • In an embodiment, the conjugate comprises a conjugate (e.g. bioconjugate) comprising (or consisting of) a modified EPA protein of the invention covalently linked to an antigen (e.g. a saccharide antigen, optionally a bacterial polysaccharide antigen), wherein the antigen is linked (either directly or through a linker). In an embodiment, the antigen is directly linked to the modified EPA protein of the invention. In an embodiment, the antigen is directly linked to an amino acid residue of the modified EPA protein.
  • In an embodiment, the modified EPA protein is covalently linked to the antigen through a chemical linkage obtainable using a chemical conjugation method (i.e. the conjugate is produced by chemical conjugation). The chemical conjugation method may be selected from the group consisting of carbodiimide chemistry, reductive animation, cyanylation chemistry (for example CDAP chemistry), maleimide chemistry, hydrazide chemistry, ester chemistry, and N-hydroysuccinimide chemistry. Conjugates can be prepared by direct reductive amination methods as described in, US200710184072 (Hausdorff) U.S. Pat. No. 4,365,170 (Jennings) and U.S. Pat. No. 4,673,574 (Anderson). Other methods are described in EP-0-161-188, EP-208375 and EP-0-477508. The conjugation method may alternatively rely on activation of the saccharide with 1-cyano-4-dimethylamino pyridinium tetrafluoroborate (CDAP) to form a cyanate ester. Such conjugates are described in PCT published application WO 93/15760 Uniformed Services University and WO 95/08348 and WO 96/29094. See also Chu C. et al. Infect. Immunity, 1983 245 256.
  • In general the following types of chemical groups on a modified EPA protein can be used for coupling/conjugation:
  • A) Carboxyl (for instance via aspartic acid or glutamic acid). In one embodiment this group is linked to amino groups on saccharides directly or to an amino group on a linker with carbodiimide chemistry e.g. with EDAC.
  • B) Amino group (for instance via lysine). In one embodiment this group is linked to carboxyl groups on saccharides directly or to a carboxyl group on a linker with carbodiimide chemistry e.g. with EDAC. In another embodiment this group is linked to hydroxyl groups activated with CDAP or CNBr on saccharides directly or to such groups on a linker; to saccharides or linkers having an aldehyde group; to saccharides or linkers having a succinimide ester group.
  • C) Sulphydryl (for instance via cysteine). In one embodiment this group is linked to a bromo or chloro acetylated saccharide or linker with maleimide chemistry. In one embodiment this group is activated/modified with bis diazobenzidine.
  • D) Hydroxyl group (for instance via tyrosine). In one embodiment this group is activated/modified with bis diazobenzidine.
  • E) Imidazolyl group (for instance via histidine). In one embodiment this group is activated/modified with bis diazobenzidine.
  • F) Guanidyl group (for instance via arginine).
  • G) Indolyl group (for instance via tryptophan).
  • On a saccharide, in general the following groups can be used for a coupling: OH, COOH or NH2. Aldehyde groups can be generated after different treatments such as: periodate, acid hydrolysis, hydrogen peroxide, etc.
  • Conjugates can be purified by any method known in the art for purification of a protein, for example, by chromatography (e.g. ion exchange, anionic exchange, affinity, and sizing column chromatography), centrifugation, differential solubility, or by any other standard technique for the purification of proteins. See, e.g., Saraswat et al. , 2013, Biomed. Res. Int. ID0312709 (p. 1-18); see also the methods described in WO 2009/104074. The actual conditions used to purify a particular conjugate will depend, in past, on the synthesis strategy (e.g., synthetic production vs. recombinant production) and on factors such as net charge, hydrophobicity, and/or hydrophilicity of the bioconjugate.
  • In an embodiment, the amino acid residue on the modified EPA protein to which the antigen is linked is selected from the group consisting of: Ala, Arg, Asp, Cys, Gly, Glu, Gln, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr, and Val. Optionally, the amino acid is: an amino acid containing a terminal amine group, a lysine, an arginine, a glutaminic acid, an aspartic acid, a cysteine, a tyrosine, a histidine or a tryptophan. In an embodiment, the amino acid residue on the modified EPA protein to which the antigen is linked is not an asparagine residue and in this case, the conjugate is typically produced by chemical conjugation. Alternatively, the antigen is linked to an amino acid on the modified EPA protein selected from asparagine, aspartic acid, glutamic acid, lysine, cysteine, tyrosine, histidine, arginine or tryptophan (e.g. asparagine) and in the case of asparagine, the conjugate may be a bioconjugate (for example an enzymatic conjugation using a oligosaccharyltransferase such as PglB). In an embodiment, the amino acid residue on the modified EPA protein to which the antigen is linked is an asparagine residue. Preferably, the amino acid residue on the modified EPA protein to which the antigen is linked is part of the consensus sequence, e.g. the asparagine in D/E-X-N-Z-S/T (SEQ ID NO: 2), K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) or J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5) consensus sequence.
  • The conjugate of the invention may be a conjugate of a recombinant modified EPA protein (e.g. chemical conjugate or bioconjugate). The conjugate of the invention may be a conjugate of an isolated recombinant modified EPA protein and a recombinant antigen, e.g. recombinant saccharide (i.e. bioconjugate).
    • Antigens
  • The antigen may be a saccharide antigen, e.g. a bacterial polysaccharide, for example an O-antigen or a capsular polysaccharide, a yeast polysaccharide or a mammalian polysaccharide. Polysaccharides comprise 2 or more monosaccharides, typically greater than 10 monosaccharides. In an embodiment, the antigen in a conjugate (e.g. bioconjugate) of the invention is a bacterial polysaccharide selected from a Shigella species, Pseudomonas species, Klebsiella species, Streptococcus species, or Staphylococcus species (e.g. Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae, or Staphylococcus aureus). In an embodiment, the antigen is a bacterial polysaccharide antigen (e.g. an O-antigen from a Gram negative bacterium, optionally from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, or a capsular polysaccharide from a Gram positive bacterium, optionally Streptococcus pneumoniae or Staphylococcus aureus). In an embodiment, the antigen is an O-antigen from a Gram negative bacterium. In an embodiment, the antigen in a conjugate (e.g. bioconjugate) of the invention is a bacterial polysaccharide selected from from a Shigella species, Klebsiella species, or Streptococcus species (e.g. Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Klebsiella pneumoniae or Streptococcus pneumoniae). In an embodiment, the antigen in a conjugate (e.g. bioconjugate) of the invention is a bacterial polysaccharide selected from Shigella flexneri, Klebsiella pneumoniae and Streptococcus pneumoniae). In an embodiment, the antigen is a bacterial polysaccharide from Klebsiella pneumoniae. Thus, the present invention provides a conjugate (e.g. bioconjugate) comprising a modified EPA protein of the invention linked to an antigen wherein the antigen is a saccharide, optionally a bacterial polysaccharide (e.g. from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae or Staphylococcus aureus). In an embodiment, the antigen is an O-antigen. In another embodiment, the antigen is a capsular polysaccharide.
  • In certain embodiments, the antigen is an O-antigen e.g. from a Gram-negative bacterium. In certain embodiments, the antigen is an O-antigen from Salmonella species, Shigella species, Pseudomonas species or Klebsiella species. In certain embodiments, the antigen is an O-antigen from Shigella species, Pseudomonas species or Klebsiella species (e.g. Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, or Klebsiella pneumoniae). In an embodiment, the antigen is an O-antigen from Shigella dysenteriae, Shigella flexneri or Shigella sonnei. For example, the antigen may be an O-antigen from S. dysenteriae type 1, S. sonnei, and S. flexneri type 6, and S. flexneri 2a and 3a 0 (Dmitriev, B.A., et al. Somatic Antigens of Shigella Eur J. Biochem, 1979. 98: p. 8; Liu et al Structure and genetics of Shigella O antigens FEMS Microbiology Review, 2008. 32: p. 27).
  • In an embodiment, the antigen is an O-antigen from Pseudomonas aeruginosa. For example, the antigen may be an O-antigen from Pseudomonas aeruginosa serotypes 1-20 (Raymond et al., J Bacteriol. 2002 184(13):3614-22). In an embodiment, the antigen is an O-antigen from Klebsiella pneumoniae.
  • In certain embodiments, the antigen is a capsular polysaccharide from Neisseria meningitidis serogroup A (MenA), N. meningitidis serogroup C (MenC), N. meningitidis serogroup Y (MenY), N. meningitidis serogroup W (MenW), H. influenzae type b (Hib), Group B Streptococcus (GBS), Streptococcus pneumoniae, or Staphylococcus aureus. In certain embodiments, the antigen is a capsular polysaccharide from Streptococcus species or Staphylococcus species. (e.g. Streptococcus pneumoniae or Staphylococcus aureus). In an embodiment, the antigen is a capsular polysaccharide from Staphylococcus aureus. For example, the antigen may be a capsular polysaccharide from Staphylococcus aureus type 5 and 8. In an embodiment, the antigen is a capsular polysaccharide from Streptococcus pneumoniae.
  • Host cell
  • The present invention also provides a host cell comprising:
  • i) one or more nucleotide sequences comprising polysaccharide synthesis genes, optionally for producing a bacterial polysaccharide antigen (e.g. an O-antigen from a Gram negative bacterium optionally from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, or a capsular polysaccharide from a Gram positive bacterium optionally from Streptococcus pneumoniae or Staphylococcus aureus) or a yeast polysaccharide antigen or a mammalian polysaccharide antigen, optionally integrated into the host cell genome;
  • ii) a nucleotide sequence encoding a heterologous oligosaccharyl transferase, optionally within a plasmid;
  • iii) a nucleotide sequence that encodes a modified EPA protein of the invention, optionally within a plasmid.
  • Disclosures of methods for making such host cells which are capable of producing bioconjugates are found in WO 06/119987, WO 09/104074, WO 11/62615, WO 11/138361, WO 14/57109, WO14/72405 and WO16/20499.
  • Host cells that can be used to produce the bioconjugates of the invention, include archea, prokaryotic host cells, and eukaryotic host cells. In certain embodiments, the host cell is a non-human host cell. Exemplary prokaryotic host cells for use in production of the bioconjugates of the invention include Escherichia species, Shigella species, Klebsiella species, Xhantomonas species, Salmonella species, Yersinia species, Lactococcus species, Lactobacillus species, Pseudomonas species, Corynebacterium species, Streptomyces species, Streptococcus species, Staphylococcus species, Bacillus species, and Clostridium species. Preferably, the host cell is E. coli (e.g. E. coli K12 W3110).
  • Host cells may be modified to delete or modify genes in the host cell genetic background (genome) that compete or interfere with the synthesis of the polysaccharide of interest (e.g. compete or interfere with one or more heterologous polysaccharide synthesis genes that are recombinantly introduced into the host cell). These genes can be deleted or modified in the host cell background (genome) in a manner that makes them inactive/dysfunctional (i.e. the host cell nucleotide sequences that are deleted/modified do not encode a functional protein or do not encode a protein whatsoever). In an embodiment, when nucleotide sequences are deleted from the genome of the host cells of the invention, they are replaced by a desirable sequence, e.g. a sequence that is useful for glycoprotein production. Exemplary genes that can be deleted in host cells (and, in some cases, replaced with other desired nucleotide sequences) include genes of host cells involved in glycolipid biosynthesis, such as waaL (see, e.g. Feldman et al. 2005, PNAS USA 102:3016-3021), the O antigen cluster (rfb or wb), enterobacterial common antigen cluster (wec), the lipid A core biosynthesis cluster (waa), galactose cluster (gal), arabinose cluster (ara), colonic acid cluster (wc), capsular polysaccharide cluster, undecaprenol-pyrophosphate biosynthesis genes (e.g. uppS (Undecaprenyl pyrophosphate synthase), uppP(Undecaprenyl diphosphatase)), Und-P recycling genes, metabolic enzymes involved in nucleotide activated sugar biosynthesis, enterobacterial common antigen cluster, and prophage O antigen modification clusters like the gtrABS cluster. In an embodiment, one or more of the waaL gene, gtrA gene, gtrBgene, gtrSgene, or a gene or genes from the wec cluster or a gene, or a gene or genes from the colonic acid cluster (wc), or a gene or genes from the rfb gene cluster are deleted or functionally inactivated from the genome of a prokaryotic host cell of the invention. In another embodiment, one or more of the waaL gene, gtrA gene, gtrB gene, gtrS gene, or a gene or genes from the wec cluster or a gene or genes from the rfb gene cluster are deleted or functionally inactivated from the genome of a prokaryotic host cell of the invention. In a specific embodiment the host cell of the invention is E. coli, wherein the native enterobacterial common antigen cluster (ECA, wec) with the exception of wecA, the colanic acid cluster (wca), and the 016-antigen cluster have been deleted. In addition, the native lipopolysaccharide O-antigen ligase waaL may be deleted from the host cell of the invention. In addition, the native gtrA gene, gtrB gene and gtrS gene, may be deleted from the host cell of the invention.
  • The host cells of the present invention are engineered to comprise heterologous nucleotide sequences. The host cells of the present invention are engineered to comprise a nucleotide sequence that encodes a modified EPA protein of the invention, optionally within a plasmid. The host cells of the invention also comprise one or more nucleotide sequences comprising polysaccharide synthesis genes. Thus, host cells of the invention can produce a bioconjugate comprising an antigen, for example a saccharide antigen (e.g. a bacterial, yeast or mammalian polysaccharide antigen) which is attached to a modified EPA protein of the invention. One or more heterologous nucleotide sequences may encode for the polysaccharide synthesis proteins to produce the bacterial polysaccharide antigen, yeast polysaccharide antigen or mammalian polysaccharide antigen. Thus the present invention also provides a host cell comprising:
  • i) one or more heterologous nucleotide sequences comprising polysaccharide synthesis genes for producing a bacterial polysaccharide antigen (e.g. an O-antigen from a Gram negative bacterium optionally from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, or a capsular polysaccharide from a Gram positive bacterium optionally from Streptococcus pneumoniae or Staphylococcus aureus) or a yeast polysaccharide antigen or a mammalian polysaccharide antigen, optionally integrated into the host cell genome;
  • ii) a nucleotide sequence encoding a heterologous oligosaccharyl transferase, optionally within a plasmid;
  • iii) a nucleotide sequence that encodes a modified EPA protein of the invention, optionally within a plasmid.
  • The host cells of the invention may comprise one or more nucleotide sequences sufficient for producing a saccharide antigen (e.g. a bacterial polysaccharide antigen), in particular for producing a saccharide antigen (e.g. a bacterial polysaccharide antigen) that is heterologous to the host cell. For example, where the host cell is E. coli the host cell may comprise one more nucleotide sequences comprising polysaccharide synthesis genes sufficient for producing a bacterial polysaccharide antigen of a bacteria which is not an E. coli polysaccharide antigen. The bacterial polysaccharide antigen may be an O-antigen or a capsular polysaccharide antigen. Thus the present invention also provides a host cell comprising:
  • i) one or more nucleotide sequences comprising polysaccharide synthesis genes, for producing a bacterial polysaccharide antigen (e.g. an O-antigen from a Gram negative bacterium, optionally from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, or a capsular polysaccharide from a Gram positive bacterium optionally from Streptococcus pneumoniae or Staphylococcus aureus), optionally integrated into the host cell genome;
  • ii) a nucleotide sequence encoding a heterologous oligosaccharyl transferase, optionally within a plasmid;
  • iii) a nucleotide sequence that encodes a modified EPA protein of the invention, optionally within a plasmid.
  • Polysaccharide synthesis genes encode proteins involved in synthesis of a polysaccharide (polysaccharide synthesis proteins). In an embodiment, the host cells may comprise one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from a Gram negative bacterium selected from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa and Klebsiella pneumoniae, or a capsular polysaccharide from a Gram positive bacterium selected from Streptococcus pneumoniae and Staphylococcus aureus. In another embodiment, the host cells may comprise one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from a Gram negative bacterium selected from Shigella flexneri and Klebsiella pneumoniae, or a capsular polysaccharide from a Gram positive bacterium selected from Streptococcus pneumoniae and Staphylococcus aureus.
    • Host Cells for Production of a Bacterial Polysaccharide Antigen
  • The host cells of the invention may comprise one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen. In certain embodiments, the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from Salmonella species, Shigella species, Pseudomonas species or Klebsiella species. In certain embodiments, the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from Shigella species, Pseudomonas species or Klebsiella species. (e.g. Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, or Klebsiella pneumoniae). In certain embodiments, the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from Shigella species or Klebsiella species. (e.g. Shigella dysenteriae, Shigella flexneri, Shigella sonnei or Klebsiella pneumoniae). In an embodiment, the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from Shigella dysenteriae, Shigella flexneri or Shigella sonnei. For example, the host cell may comprise one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from S. dysenteriae type 1, S. sonnei, and S. flexneri type 6, and S. flexneri 2a and 3a 0 (Dmitriev, B. A., et al Somatic Antigens of Shigella Eur J. Biochem, 1979. 98: p. 8; Liu et al Structure and genetics of Shigella O antigens FEMS Microbiology Review, 2008. 32: p. 27). In an embodiment, the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from Pseudomonas aeruginosa e.g. Pseudomonas aeruginosa serotypes 1-20. In an embodiment, the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen from Klebsiella pneumoniae.
  • The host cells of the invention may comprise one or more nucleotide sequences comprising polysaccharide synthesis genes for producing a capsular polysaccharide. In certain embodiments, the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing a capsular polysaccharide from N. meningitidis serogroup A (MenA), N. meningitidis serogroup C (MenC), N. meningitidis serogroup Y (MenY), N. meningitidis serogroup W (MenW), H. influenzae type b (Hib), Group B Streptococcus (GBS), Streptococcus pneumoniae, or Staphylococcus aureus. In certain embodiments, the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing a capsular polysaccharide from Streptococcus species, or Staphylococcus species. (e.g. Streptococcus pneumoniae or Staphylococcus aureus). In an embodiment, the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing a capsular polysaccharide from Staphylococcus aureus, e.g. from Staphylococcus aureus type 5 and 8. In an embodiment, the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing a capsular polysaccharide from Streptococcus pneumoniae.
    • Host Cells Comprising Heterologous Nucleotide Sequences for Producing a Bacterial Polysaccharide Antigen
  • The host cells of the present invention may naturally express one or more nucleotide sequences comprising polysaccharide synthesis genes for production of a saccharide antigen (e.g. a bacterial polysaccharide antigen), or the host cells may be engineered to express one or more such nucleotide sequences. For example, host cells of the present invention may utilize endogenous or heterologous glycosyltransferases for sequential assembly of oligosaccharides in the cytosol (cytosolic glycosyltransferases). Heterologous nucleotide sequences (e.g. nucleotide sequences that encode carrier proteins and/or nucleotide sequences that encode other proteins, e.g. proteins involved in glycosylation) can be introduced into the host cells of the invention using methods such as electroporation, chemical transformation by heat shock, natural transformation, phage transduction, and conjugation. In specific embodiments, heterologous nucleotide sequences are introduced into the host cells of the invention using a plasmid, e.g. the heterologous nucleotide sequences are expressed in the host cells by a plasmid (e.g. an expression vector). In another specific embodiment, heterologous nucleotide sequences are introduced into the host cells of the invention using the method of insertion described in WO14/037585. In certain embodiments, the host cell of the present invention comprises one or more nucleotide sequences comprising polysaccharide synthesis genes which are heterologous to the host cell. In certain embodiments, one or more of said nucleotide sequences comprising polysaccharide synthesis genes which are heterologous to the host cell are integrated into the genome of the host cell. The heterologous nucleotide sequences may encode, without limitation, glycosyltransferases, oligosaccharyl transferases, epimerases, flippases, and/or polymerases. In certain embodiments, the host cells of the invention comprise one or more heterologous nucleotide sequences encoding glycosyltransferase(s). Said glycosyltransferase(s) can be derived from, e.g. Escherichia species, Shigella species, Klebsiella species, Salmonella species, Pseudomonas species, Streptococcus species, or Staphylococcus species.
  • The host cells of the invention may comprise one or more heterologous nucleotide sequences comprising polysaccharide synthesis genes for producing an O-antigen. In certain embodiments, the host cell comprises one or more nucleotide sequences from Salmonella species, Shigella species, Pseudomonas species or Klebsiella species that encode polysaccharide synthesis proteins for producing an O-antigen. In certain embodiments, the host cell comprises one or more nucleotide sequences from Shigella species, Pseudomonas species or Klebsiella species. (e.g. Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, or Klebsiella pneumoniae) that encode polysaccharide synthesis proteins for producing an O-antigen. In certain embodiments, the host cell comprises one or more nucleotide sequences from Shigella species or Klebsiella species. (e.g. Shigella dysenteriae, Shigella flexneri, Shigella sonnei, or Klebsiella pneumoniae) that encode polysaccharide synthesis proteins for producing an O-antigen. In an embodiment, the host cell comprises one or more nucleotide sequences from Shigella dysenteriae, Shigella flexneri or Shigella sonnei. that encode polysaccharide synthesis proteins for producing an O-antigen. For example, the host cell may comprise one or more nucleotide sequences from S. dysenteriae type 1, S. sonnei, and S. flexneri type 6, and S. flexneri 2a and 3a that encode polysaccharide synthesis proteins for producing an O-antigen. In an embodiment, the host cell comprises one or more nucleotide sequences from Pseudomonas aeruginosa, e.g. Pseudomonas aeruginosa serotypes 1-20, that encode polysaccharide synthesis proteins for producing an O-antigen. In an embodiment, the host cell comprises one or more nucleotide sequences from Klebsiella pneumoniae that encode polysaccharide synthesis proteins for producing an O-antigen. The nucleotide sequences that encode an O-antigen may be an rfb cluster. As used herein, rfb cluster refer to a gene cluster that encodes enzymatic machinery capable of synthesis of an O antigen. The host cells may comprise an rfb gene cluster from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae.
  • The host cells of the invention may comprise one or more heterologous nucleotide sequences comprising polysaccharide synthesis genes for producing a capsular saccharide. In certain embodiments, the host cell comprises one or more nucleotide sequences from N. meningitidis serogroup A (MenA), N. meningitidis serogroup C (MenC), N. meningitidis serogroup Y (MenY), N. meningitidis serogroup W (MenW), H. influenzae type b (Hib), Group B Streptococcus (GBS), Streptococcus pneumoniae, or Staphylococcus aureus that encode polysaccharide synthesis proteins for producing a capsular saccharide. In certain embodiments, the host cell comprises one or more nucleotide sequences from Streptococcus species, or Staphylococcus species. (e.g. Streptococcus pneumoniae or Staphylococcus aureus) that encode polysaccharide synthesis proteins for producing a capsular polysaccharide. In an embodiment, the host cell comprises one or more nucleotide sequences from Staphylococcus aureus, e.g. from Staphylococcus aureus type 5 and 8, that encode polysaccharide synthesis proteins for producing a capsular polysaccharide. In an embodiment, the host cell comprises one or more nucleotide sequences comprising polysaccharide synthesis genes for producing a capsular polysaccharide from Streptococcus pneumoniae. The nucleotide sequences may be a capsular polysaccharide gene cluster. The host cells may comprise a capsular polysaccharide gene cluster from a Streptococcus strain (e.g. S. pneumoniae, S. pyrogens, S. agalacticae), a Staphylococcus strain (e.g. S. aureus). The capsular polysaccharide gene cluster for Streptococcus pneumoniae maps between dexB and aliA in the pneumococcal chromosome (Llull et al., 1999, J. Exp. Med. 190, 241-251). There are typically four relatively conserved genes: (wzg), (wzh), (wza), (wze) at the 5′ end of the capsular polysaccharide gene cluster (Jiang et al., 2001, Infect. Immun. 69, 1244-1255). Also included in the capsular polysaccharide gene cluster of S. pneumoniae are wzx (polysaccharide flippase gene) and wzy (polysaccharide polymerase gene). The CP gene clusters of all 90 5. pneumoniae serotypes have been sequenced by Sanger Institute (http://www.sanger.ac.uk/Projects/S_pneumoniae/CPS/), and wzx and wzy of 89 serotypes have been annotated and analyzed (Kong et al., 2005, J. Med. Microbiol. 54, 351-356). The capsular biosynthetic genes of S. pneumoniae are further described in Bentley et al. (PLoS Genet. 2006 March; 2(3): e31 and the sequences are provided in GenBank. Thus, in an embodiment the host cells of the invention may further comprise a nucleotide sequence encoding a polymerase (e.g. wzy), a flippase (e.g. wzx) and optionally a nucleotide sequence encoding and/or a chain length regulator (e.g. wzz).
  • In certain embodiments, the host cells may also comprise heterologous nucleotide sequences that are located outside of an rfb cluster or a capsular polysaccharide cluster. For example, nucleotide sequences encoding glycosyltransferases and acetyltransferases that are found outside of rfb clusters or capsular polysaccharide clusters and that modify recombinant polysaccharides can be introduced into the host cells.
    • Oligosaccharyl Transferase
  • N-linked protein glycosylation (the addition of carbohydrate molecules to an asparagine residue in the polypeptide chain of the target protein) is the most common type of post-translational modification occurring in the endoplasmic reticulum of eukaryotic organisms. The process is accomplished by the enzymatic oligosaccharyltransferase complex (OST) responsible for the transfer of a preassembled oligosaccharide from a lipid carrier (dolichol phosphate) to an asparagine residue of a nascent protein within the conserved sequence Asn-X-Ser/Thr (where X is any amino acid except proline) in the Endoplasmic reticulum.
  • It has been shown that a bacterium, the food-borne pathogen Campylobacter jejuni, can also N-glycosylate its proteins (Wacker et al. Science. 2002; 298(5599):1790-3) due to the fact that it possesses its own glycosylation machinery. The machinery responsible of this reaction is encoded by a cluster called “pgl” (for protein glycosylation). The C. jejuni glycosylation machinery can be transferred to E. coli to allow for the glycosylation of recombinant proteins expressed by the E. coli cells. Previous studies have demonstrated how to generate E. coli strains that can perform N-glycosylation (see, e.g. Wacker et al. Science. 2002; 298 (5599):1790-3; Nita-Lazar etal. Glycobiology. 2005; 15(4):361-7; Feldman et al. Proc Natl Acad Sci U S A. 2005; 102(8):3016-21; Kowarik et al. EMBO J. 2006; 25(9):1957-66; Wacker et al. Proc Natl Acad Sci USA. 2006; 103(18):7088-93; International Patent Application Publication Nos. WO2003/074687, WO2006/119987, WO 2009/104074, and WO/2011/06261, and WO2011/138361).
  • The host cells of the present invention comprise a nucleotide sequence encoding a heterologous oligosaccharyl transferase, optionally within a plasmid. In a specific embodiment, the oligosaccharyl transferase is an oligosaccharyl transferase from Campylobacter. In another specific embodiment, the oligosaccharyl transferase is a pglB, optionally from Campylobacter jejuni (i.e. pglB; see, e.g. Wacker et al. 2002, Science 298:1790-1793; see also, e.g. NCBI Gene ID: 3231775, UniProt Accession No. 086154) SEQ ID NO: 24:
  • MLKKEYLKNPYLVLFAMIILAYVFSVFCRFYWVWWASEFNEYFFNNQLM
    IISNDGYAFAEGARDMIAGFHQPNDLSYYGSSLSALTYWLYKITPFSFE
    SIILYMSTFLSSLVVIPTILLANEYKRPLMGFVAALLASIANSYYNRTM
    SGYYDTDMLVIVLPMFILFFMVRMILKKDFFSLIALPLFIGIYLWWYPS
    SYTLNVALIGLFLIYTLIFHRKEKIFYIAVILSSLTLSNIAWFYQSAII
    VILFALFALEQKRLNFMIIGILGSATLIFLILSGGVDPILYQLKFYIFR
    SDESANLTQGFMYFNVNQTIQEVENVDLSEFMRRISGSEIVFLFSLFGF
    VWLLRKHKSMIMALPILVLGFLALKGGLRFTIYSVPVMALGFGFLLSEF
    KAIMVKKYSQLTSNVCIVFATILTLAPVFIHIYNYKAPTVFSQNEASLL
    NQLKNIANREDYVVTWWDYGYPVRYYSDVKTLVDGGKHLGKDNFFPSFA
    LSKDEQAAANMARLSVEYTEKSFYAPQNDILKTDILQAMMKDYNQSNVD
    LHLASLSKPDFKIDIPKIRDIYLYMPARMSLIFSiVASFSHINLDIGVL
    DKPEIHSIAYPLDVKNGEIYLSNGVVLSDDFRSFKIGDNWVSVNSIVEI
    NSIKQGEYKITPIDDKAQFYIFYLKDSAIPYAQFILMDKTMFNSAYVQM
    FFLGNYDKNLFDLVINSRDAKVFKLKI
  • Thus host cells of the present invention may comprise a nucleotide sequence encoding pglB, optionally pglB from Campylobacter jejuni, optionally a nucleotide sequence encoding pglB from Campylobacter jejuni having a sequence at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 24, optionally within a plasmid.
    • Polymerase
  • Host cells of the present invention may also comprise a nucleotide sequence that encodes a polymerase (e.g. wzy). In an embodiment, the polymerase (e.g. wzy) is introduced into a host cell of the invention (i.e. the polymerase is heterologous to the host cell). In an embodiment, the polymerase is a bacterial polymerase. In an embodiment, the polymerase is a capsular polysaccharide polymerase (e.g. wzy) or an O antigen polymerase (e.g. wzy). In an embodiment, the polymerase is an O-antigen polysaccharide polymerase (e.g. wzy), e.g. from Shigella species, Pseudomonas species or Escherichia species. (e.g. Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, or E. coli). In an embodiment, the polymerase is a capsular polysaccharide polymerase (e.g. wzy), e.g. from N. meningitidis serogroup A (MenA), N. meningitidis serogroup C (MenC), N. meningitidis serogroup Y (MenY), N. meningitidis serogroup W (MenW), H. influenzae type b (Hib), Group B Streptococcus (GBS), Streptococcus pneumoniae, or Staphylococcus aureus. In an embodiment, the polymerase is a capsular polysaccharide polymerase (e.g. wzy) of Streptococcus pneumoniae. Said wzy polymerase may be incorporated (e.g. inserted into the genome or expressed by a plasmid) in said host cell as part of a rfb cluster or capsular polysaccharide cluster. Thus, a host cell of the invention may further comprise a nucleotide sequence encoding a heterologous wzy polymerase.
    • Flippases
  • A host cell of the invention may also comprise a nucleotide sequence encoding a flippase (e.g. wzx), e.g. a heterologous flippase. Flippases translocate wild type repeating units and/or their corresponding engineered (hybrid) repeat units from the cytoplasm into the periplam of host cells (e.g. E. coli). In an embodiment, the flippase is a bacterial flippase, e.g. a flippase of the polysaccharide biosynthetic pathway of interest. In a specific embodiment, the host cell of the invention comprises a nucleotide sequence encoding a flippase (e.g. wzx gene) of a polysaccharide biosynthetic pathway of a Streptococcus species, Shigella species, Escherichia species, Pseudomonas species, or Staphylococcus species. (e.g. Streptococcus pneumoniae, Shigella dysenteriae, Shigella flexneri, Shigella sonnei, E. coli, Pseudomonas aeruginosa, or Staphylococcus aureus. In an embodiment, the flippase is a capsular polysaccharide flippase (e.g. wzx) of Streptococcus pneumoniae. Other flippases that can be introduced into the host cells of the invention are for example from Campylobacter jejuni (e.g. pglK).
    • Accessory Enzymes
  • In an embodiment, nucleotide sequences encoding one or more accessory enzymes are introduced into the host cells of the invention. Thus, a host cell of the invention may further comprise one or more of these accessory enzymes. Such nucleotide sequences encoding one or more accessory enzymes can be either plasmid-borne or integrated into the genome of the host cells of the invention. Exemplary accessory enzymes include, without limitation, epimerases (see e.g. WO2011/062615), branching, modifying (e.g. to add cholins, glycerolphosphates, pyruvates), amidating, chain length regulating, acetylating, formylating, polymerizing enzymes. Thus a host cell of the invention may also comprise a nucleotide sequence encoding a chain length regulator (e.g. wzz), e.g. a heterologous chain length regulator. In an embodiment, the chain length regulator is a capsular polysaccharide chain length regulator (e.g. wzz) of Streptococcus pneumoniae.
    • Bioconjugates
  • The present invention provides a bioconjugate comprising a modified EPA protein of the invention linked to an antigen (e.g. a bacterial polysaccharide antigen or a yeast polysaccharide antigen or a mammalian polysaccharide antigen). In a specific embodiment, said antigen is an O-antigen or a capsular polysaccharide. In an embodiment, the antigen is an O-antigen from a Gram negative bacterium. In an embodiment, the present invention provides a bioconjugate comprising a modified EPA protein of the invention linked to an antigen wherein the antigen is a saccharide, optionally a bacterial polysaccharide (e.g. from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae or Staphylococcus aureus). In an embodiment, the present invention provides a bioconjugate comprising a modified EPA protein of the invention linked to an antigen wherein the antigen is a bacterial polysaccharide (e.g. from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Klebsiella pneumoniae, or Streptococcus pneumoniae). In another embodiment, the present invention provides a bioconjugate comprising a modified EPA protein of the invention linked to an antigen wherein the antigen is a bacterial polysaccharide from Shigella flexneri, Klebsiella pneumoniae or Streptococcus pneumoniae. The antigen is linked to an amino acid on the modified EPA protein selected from asparagine, aspartic acid, glutamic acid, lysine, cysteine, tyrosine, histidine, arginine or tryptophan (e.g. asparagine). Bioconjugates, as described herein, have advantageous properties over chemical conjugates of antigen-carrier protein, in that they require less chemicals in manufacture and are more consistent in terms of the final product generated.
  • A further aspect of the invention is a process for producing a bioconjugate that comprises (or consists of) a modified EPA protein linked to a saccharide, said process comprising (i) culturing the host cell of the invention under conditions suitable for the production of glycoproteins and (ii) isolating the bioconjugate produced by said host cell, optionally isolating the bioconjugate from a periplasmic extract from the host cell. For example, bioconjugates can be made using the shakeflask process, e.g. in a LB shake flask. In aspect of the invention, a fed-batch process for the production of recombinant glycosylated proteins in bacteria can be used to produce bioconjugates of the invention. The aim is to increase glycosylation efficiency and recombinant protein yield per cell and while maintaining simplicity and reproducibility in the process. Bioconjugates of the present invention can be manufactured on a commercial scale by developing an optimized manufacturing method using typical E. coli production processes. Various types of feed strategies, such as batch, chemostat and fed-batch can be used.
  • The bioconjugates of the invention can be purified for example, by chromatography (e.g. ion exchange, anionic exchange, affinity, and sizing column chromatography), centrifugation, differential solubility, or by any other standard technique for the purification of proteins. See, e.g. Saraswat et al. 2013, Biomed. Res. Int. ID #312709 (p. 1-18); see also the methods described in WO 2009/104074. Further, the bioconjugates may be fused to heterologous polypeptide sequences described herein or otherwise known in the art to facilitate purification.
    • Analytical Methods
  • Various methods can be used to analyze the structural compositions and sugar chain lengths of the bioconjugates of the invention and to determine glycosylation site usage.
  • Hydrazinolysis can be used to analyze glycans. First, polysaccharides are released from their protein carriers by incubation with hydrazine according to the manufacturer's instructions (Ludger Liberate Hydrazinolysis Glycan Release Kit, Oxfordshire, UK). The nucleophile hydrazine attacks the glycosidic bond between the polysaccharide and the carrier protein and allows release of the attached glycans. N-acetyl groups are lost during this treatment and have to be reconstituted by re-N-acetylation. The free glycans are purified on carbon columns and subsequently labeled at the reducing end with the fluorophor 2-amino benzamide. See Bigge J C, Patel T P, Bruce J A, Goulding P N, Charles S M, Parekh R B: Nonselective and efficient fluorescent labeling of glycans using 2-amino benzamide and anthranilic acid. Anal Biochem 1995, 230(2):229-238. The labeled polysaccharides are separated on a GlycoSep-N column (GL Sciences) according to the HPLC protocol of Royle et al. See Royle L, Mattu T S, Hart E, Langridge J I, Merry A H, Murphy N, Harvey D J, Dwek R A, Rudd P M: An analytical and structural database provides a strategy for sequencing O-glycans from microgram quantities of glycoproteins. Anal Biochem 2002, 304(1):70-90. The resulting fluorescence chromatogram indicates the polysaccharide length and number of repeating units. Structural information can be gathered by collecting individual peaks and subsequently performing MS/MS analysis. Thereby the monosaccharide composition and sequence of the repeating unit can be confirmed and additionally in homogeneity of the polysaccharide composition can be identified. Alternatively, high mass MS and size exclusion HPLC can be applied to measure the size of the complete bioconjugates.
  • Yield may be measured as carbohydrate amount derived from a liter of bacterial production culture grown in a bioreactor under controlled and optimized conditions. After purification of bioconjugate, the carbohydrate yields can be directly measured by either the anthrone assay or ELISA using carbohydrate specific antisera. Indirect measurements are possible by using the protein amount (measured by BCA, Lowry, or bardford assays) and the glycan length and structure to calculate a theoretical carbohydrate amount per gram of protein. In addition, yield can also be measured by drying the glycoprotein preparation from a volatile buffer and using a balance to measure the weight.
  • Various methods can be used to analyze the conjugates of the invention including, for example, SDS-PAGE or capillary gel electrophoresis. Polymer length is defined by the number of repeat units that are linearly assembled. This means that the typical ladder like pattern is a consequence of different repeat unit numbers that compose the glycan. Thus, two bands next to each other in SDS
  • PAGE (or other techniques that separate by size) differ by only a single repeat unit. These discrete differences are exploited when analyzing glycoproteins for glycan size: the unglycosylated carrier protein and the bioconjugate with different polymer chain lengths separate according to their electrophoretic mobilities. The first detectable repeat unit number (n1) and the average repeat unit number (naverage) present on a bioconjugate are measured. These parameters can be used to demonstrate batch to batch consistency or polysaccharide stability, for example.
  • Glycosylation site usage may be quantified by, for example, glycopeptide LC-MS/MS: conjugates are digested with protease(s), and the peptides are separated by a suitable chromatographic method (C18, Hydrophilic interaction HPLC HILIC, GlycoSepN columns, SE HPLC, AE HPLC), and the different peptides are identified using MS/MS. This method can be used with or without previous sugar chain shortening by chemical (smith degradation) or enzymatic methods. Quantification of glycopeptide peaks using UV detection at 215 to 280 nm allows relative determination of glycosylation site usage. In another embodiment, site usage may be quantified by size exclusion HPLC: Higher glycosylation site usage is reflected by an earlier elution time from a SE HPLC column. In yet another embodiment, site usage may be quantified by quantitative densitometry of purified bioconjugates stained with Coomassie Briliant Blue following sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).
    • Immunogenic Compositions and Vaccines
  • The conjugates (e.g. bioconjugate), of the invention are particularly suited for inclusion in immunogenic compositions and vaccines.
  • The present invention provides an immunogenic composition comprising a conjugate (e.g. bioconjugate) of the invention, and optionally a pharmaceutically acceptable excipient and/or carrier.
  • Immunogenic compositions comprise an immunologically effective amount of the modified EPA protein or conjugate (e.g. bioconjugate) of the invention, as well as any other components. By “immunologicaly effective amount”, it is meant that the administration of that amount to an individual, either as a single dose or as part of a series is effective for treatment or prevention. This amount varies depending on the health and physical condition of the individual to be treated, age, the degree of protection desired, the formulation of the vaccine and other relevant factors.
  • Pharmaceutically acceptable excipients and carriers are described, for example, in Remington's Pharmaceutical Sciences, by E. W. Martin, Mack Publishing Co. Easton, Pa., 5th Edition (1975). Pharmaceutically acceptable excipients can include a buffer, such as a phosphate buffer (e.g. sodium phosphate). Pharmaceutically acceptable excipients can include a salt, for example sodium chloride. Pharmaceutically acceptable excipients can include a solubilizing/stabilizing agent, for example, polysorbate (e.g. TWEEN 80). Pharmaceutically acceptable excipients can include a preservative, for example 2-phenoxyethanol or thiomersal. Pharmaceutically acceptable excipients can include a carrier such as water or saline.
  • Also provided is a method of making the immunogenic composition of the invention comprising the step of mixing the modified EPA protein or the conjugate (e.g. bioconjugate) of the invention with a pharmaceutically acceptable excipient and/or carrier.
  • The present invention also provides an immunogenic composition (e.g., a vaccine composition) optionally comprising an adjuvant.
  • The term “adjuvant” refers to a compound that when administered in conjunction with or as part of an immunogenic composition of vaccine of the invention augments, enhances and/or boosts the immune response to modified EPA protein conjugate/bioconjugate, but when the compound is administered alone does not generate an immune response to the modified EPA protein conjugate/bioconjugate. Adjuvants can enhance an immune response by several mechanisms including, e.g. lymphocyte recruitment, stimulation of B and/or T cells, and stimulation of macrophages. Specific examples of adjuvants include, but are not limited to, aluminum salts (alum) (such as aluminum hydroxide, aluminum phosphate, and aluminum sulfate), 3 De-O-acylated monophosphoryl lipid A (MPL) (see United Kingdom Patent GB2220211), MF59 (Novartis), AS01 (GlaxoSmithKline), and saponins, such as QS21 (see Kensil et al. in Vaccine Design: The Subunit and Adjuvant Approach (eds. Powell & Newman, Plenum Press, NY, 1995); U.S. Pat. No. 5,057,540). In some embodiments, the adjuvant is Freund's adjuvant (complete or incomplete). Other adjuvants are oil in water emulsions (such as squalene or peanut oil), optionally in combination with immune stimulants, such as monophosphoryl lipid A (see Stoute et al. N. Engl. J. Med. 336, 86-91 (1997)).
  • Also provided is a method of making the immunogenic composition of the invention comprising the step of mixing the modified EPA protein or the conjugate (e.g. bioconjugate) of the invention with a pharmaceutically acceptable excipient and/or carrier and an adjuvant. Vaccine preparation is generally described in Vaccine Design (“The subunit and adjuvant approach” (eds Powell M. F. & Newman M. J.) (1995) Plenum Press New York).
  • The immunogenic compositions of the invention can be included in a container, pack, or dispenser together with instructions for administration.
  • The immunogenic compositions or vaccines of the invention can be stored before use, e.g.
  • the compositions can be stored frozen (e.g. at about −20° C. or at about −70° C.); stored in refrigerated conditions (e.g. at about 4° C.); or stored at room temperature. The immunogenic compositions or vaccines of the invention may be stored in solution or lyophilized. In an embodiment, the solution is lyophilized in the presence of a sugar such as sucrose, trehalose or lactose. In another embodiment, the vaccines of the invention are lyophilized and extemporaneously reconstituted prior to use.
    • Administration and Dosage
  • Immunogenic compositions or vaccines of the invention may be used to protect or treat a subject (e.g. mammal), by means of administering said immunogenic composition or vaccine via systemic or mucosal route. These administrations may include injection via the intramuscular (IM), intraperitoneal, intradermal (ID) or subcutaneous (SC) routes; or via mucosal administration to the oral/alimentary, respiratory, genitourinary tracts.
  • In one aspect, the immunogenic composition or vaccine of the invention is administered by the intramuscular delivery route. Intramuscular administration may be to the thigh or the upper arm. Injection is typically via a needle (e.g. a hypodermic needle), but needle-free injection may alternatively be used. A typical intramuscular dose is 0.5 ml.
  • In another aspect, the immunogenic composition or vaccine of the invention is administered by the intradermal administration. Human skin comprises an outer “horny” cuticle, called the stratum corneum, which overlays the epidermis. Underneath this epidermis is a layer called the dermis, which in turn overlays the subcutaneous tissue. The conventional technique of intradermal injection, the “mantoux procedure”, comprises steps of cleaning the skin, and then stretching with one hand, and with the bevel of a narrow gauge needle (26 to 31 gauge) facing upwards the needle is inserted at an angle of between 10 to 15° . Once the bevel of the needle is inserted, the barrel of the needle is lowered and further advanced whilst providing a slight pressure to elevate it under the skin. The liquid is then injected very slowly thereby forming a bleb or bump on the skin surface, followed by slow withdrawal of the needle.
  • In another aspect, the immunogenic composition or vaccine of the invention is administered by the intranasal administration. Typically, the immunogenic composition or vaccine is administered locally to the nasopharyngeal area, e.g. without being inhaled into the lungs. It is desirable to use an intranasal delivery device which delivers the immunogenic composition or vaccine formulation to the nasopharyngeal area, without or substantially without it entering the lungs. Suitable devices for intranasal administration of the vaccines according to the invention are spray devices. Suitable commercially available nasal spray devices include ACCUSPRAY™ (Becton Dickinson).
  • The amount of conjugate (e.g. bioconjugate) in each immunogenic composition or vaccine dose is selected as an amount which induces an immunoprotective response without significant, adverse side effects in typical vaccines. Such amount will vary depending upon which specific immunogen is employed and how it is presented. The content of conjugate (e.g. bioconjugate) will typically be in the range 1-100 μg, suitably 5-50 μg.
    • Prophylactic and Therapeutic Uses
  • The present invention also provides an immunogenic composition of the invention, or the vaccine of the invention, for use in medicine.
  • The present invention provides a method of inducing an immune response in a subject (e.g. human), the method comprising administering a therapeutically or prophylactically effective amount of a conjugate (e.g. bioconjugate) of the invention, an immunogenic composition of the invention or a vaccine of the invention, to a subject (e.g. human) in need thereof. The present invention also provides a conjugate (e.g. bioconjugate) of the invention, an immunogenic composition of the invention or a vaccine of the invention, for use in inducing an immune response in a subject (e.g. human). The present invention also provides a conjugate (e.g. bioconjugate) of the invention, the immunogenic composition of the invention or the vaccine of the invention for use in the manufacture of a medicament for inducing an immune response in a subject (e.g. human).
  • Also provided herein are methods of inducing an immune response in a subject against a bacterium, comprising administering to the subject a conjugate (e.g. bioconjugate) of the invention an immunogenic composition of the invention or a vaccine of the invention. The conjugate (e.g. bioconjugate) of the invention an immunogenic composition of the invention or a vaccine of the invention can be used to induce an immune response against a bacterium, e.g. Shigella species, Pseudomonas aeruginosa, Klebsiella pneumoniae, N. meningitidis, H. influenzae type b (Hib), Group B Streptococcus (GBS), Streptococcus pneumoniae, or Staphylococcus aureus. In an embodiment, the conjugate (e.g. bioconjugate) of the invention an immunogenic composition of the invention or a vaccine of the invention can be used to induce an immune response against a bacterium, e.g. Streptococcus species, Shigella species, Pseudomonas species, Klebsiella species, or Staphylococcus species. (e.g. Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae, or Staphylococcus aureus). In one embodiment, said subject has bacterial infection at the time of administration. In another embodiment, said subject does not have a bacterial infection at the time of administration.
  • Also provided herein are methods of inducing the production of opsonophagocytic antibodies in a subject against a bacterium, comprising administering to the subject a conjugate (e.g. bioconjugate) of the invention an immunogenic composition of the invention or a vaccine of the invention. The conjugate (e.g. bioconjugate) of the invention an immunogenic composition of the invention or a vaccine of the invention can be used to induce the production of opsonophagocytic antibodies in a subject against a bacterium, e.g. Shigella species, Pseudomonas aeruginosa, Klebsiella pneumoniae, N. meningitidis, H. influenzae type b (Hib), Group B Streptococcus (GBS), Streptococcus pneumoniae, or Staphylococcus aureus. In an embodiment, the conjugate (e.g. bioconjugate) of the invention an immunogenic composition of the invention or a vaccine of the invention can be used to induce the production of opsonophagocytic antibodies in a subject against a bacterium, e.g. Streptococcus species, Shigella species, Pseudomonas species, Klebsiella species, or Staphylococcus species. (e.g. Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae or Staphylococcus aureus).
  • The present invention also provides methods of treating and/or preventing a yeast or bacterial infection in a subject comprising administering to the subject a conjugate (e.g. bioconjugate) of the invention. The conjugate (e.g. bioconjugate) may be in the form of an immunogenic composition or vaccine. Thus the present invention provides a method of treating and/or preventing a yeast or bacterial infection in a subject (e.g. human), the method comprising administering a therapeutically or prophylactically effective amount of a conjugate (e.g. bioconjugate) of the invention, an immunogenic composition of the invention or a vaccine of the invention, to a subject (e.g. human) in need thereof. The present invention also provides a conjugate (e.g. bioconjugate) of the invention, an immunogenic composition of the invention or a vaccine of the invention, for use in treating and/or preventing a yeast or bacterial infection in a subject (e.g. human). The present invention also provides a conjugate (e.g. bioconjugate) of the invention, the immunogenic composition of the invention or the vaccine of the invention for use in the manufacture of a medicament for treating and/or preventing a yeast or bacterial infections in a subject (e.g. human). In a specific embodiment, the immunogenic composition or vaccine of the invention is used in the prevention of infection of a subject by a bacterium. Bacteria infections that can be treated and/or prevented using the conjugate (e.g. bioconjugate) of the invention include those caused by N. meningitidis, H. influenzae type b (Hib), Streptococcus species, Shigella species, Pseudomonas species, Klebsiella species, or Staphylococcus species. (e.g. Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae or Staphylococcus aureus).
  • Embodiments of the invention are further described in the subsequent numbered paragraphs:
    • 1. A modified EPA (Exotoxin A of Pseudomonas aeruginosa) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises one (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the one (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213; or one or more amino acids between 205-211; e.g. amino acid residue D218; e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279; or one or more amino acids between amino acid residues 271-277, e.g. amino acid residue R279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323; or one or more amino acids between amino acid residues 315-321, e.g. amino acid residue G323, e.g. amino acid residue S318), and (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; or one or more amino acids between amino acid residues 516-522; e.g. amino acid residue G525, e.g. amino acid residue A519) of SEQ ID NO: 1 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
    • 2. The modified EPA (Exotoxin A of Pseudomonas aeruginosa) of paragraph 1 having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises two (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the two (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519), and (v) one or more amino acids between amino acid residues 230-250 (e.g. one or more amino acids between amino acid residues 235-245; e.g. amino acid residue K240), of SEQ ID NO: 1 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
    • 3. A modified EPA (Exotoxin A of Pseudomonas aeruginosa) protein of paragraph 1 having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises three (or more) consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the three (or more) consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 264-284 (e.g. one or more amino acids between amino acid residues 269-279, e.g. amino acid residue R274), (iii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), (iv) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519) of SEQ ID NO: 1, and (v) one or more amino acids between amino acid residues 230-250 (e.g. one or more amino acids between amino acid residues 235-245; e.g. amino acid residue K240) or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
    • 4. The modified EPA protein of any of paragraphs 1 to 3, wherein the consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), have each been independently substituted for one or more amino acids (e.g. each consensus sequence is substituted for a single amino acid residue, such as a single amino acid residue selected from Y208, R274, S318 and A519) of the amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
    • 5. The modified EPA protein of any of paragraphs 1 to 4, wherein a further consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5), wherein X and Z are independently any amino acid except proline and J and U are independently 1 to 5 naturally occurring amino acid residues, has been added next to, or substituted for, one or more amino acids, at the N-terminus of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
    • 6. The modified EPA protein of any of paragraphs 1 to 5, wherein a further consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5), wherein X and Z are independently any amino acid except proline and J and U are independently 1 to 5 naturally occurring amino acid residues, has been added next to, or substituted for, one or more amino acids, at the C-terminus of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
    • 7. The modified EPA protein of any of paragraphs 1 to 6, wherein at least one consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, has been added next to, or substituted for: (i) one or more amino acids between amino acid residues 198-218 (e.g. one or more amino acids between amino acid residues 203-213, e.g. amino acid residue Y208), (ii) one or more amino acids between amino acid residues 308-328 (e.g. one or more amino acids between amino acid residues 313-323, e.g. amino acid residue S318), or (iii) one or more amino acids between amino acid residues 509-529 (e.g. one or more amino acids between amino acid residues 514-524; e.g. amino acid residue A519) of SEQ ID NO: 1 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
    • 8. The modified EPA protein of any of paragraphs 1 to 7, wherein the modified EPA protein contains two consensus sequences, optionally substituted for amino acid residues selected from: (i) Y208 and R274, (ii) Y208 and S318, (iii) Y208 and A519, (iv) R274 and S318, (v) R274 and A519, or (vi) S318 and A519 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
    • 9. The modified EPA protein of paragraph 8 wherein the modified EPA protein contains two consensus sequences substituted for amino acid residues Y208 and R274 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, optionally comprising (or consisting of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 6:
  • AEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVL
    EGGNDALKLAIDNALSITSDGLTIRLEGGVEPNKPVRYSYTRQARGSWS
    LNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIYTIEMGDELLAKLAR
    DATFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVL
    CLLDPLDGVYNKDQNATKLAQQRCNLDDTWEGKIYRVLAGNPAKHDLDI
    KPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTKDQNATKHRQPRGWE
    QLEQCGYPVQRLVALYLAARLSWNQVDQVIRNALASPGSGGDLGEAIRE
    QPEQARLALTLAAAESERFVRQGTGNDEAGAASADVVSLTCPVAAGECA
    GPADSGDALLERNYPTGAEFLGDGGDVSFSTRGTQNWTVERLLQAHRQL
    EERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALA
    YGYAQDQEPDARGRIRNGALLRVYVPRWSLPGFYRTGLTLAAPEAAGEV
    ERLIGHPLPLRLDAITGPEEEGGRVTILGWPLAERTVVIPSAIPTDPRN
    VGGDLDPSSIPDKEQAISALPDYASQPGKPPREDLK
    • 10. The modified EPA protein of any of paragraphs 1 to 7, wherein the modified EPA protein contains three consensus sequences, optionally substituted for amino acid residues Y208, R274 and A519 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
    • 11. The modified EPA protein of paragraph 10 wherein the modified EPA protein contains three consensus sequences substituted for amino acid residues Y208, R274 and A519 of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, optionally comprising (or consisting of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 7:
  • AEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVL
    EGGNDALKLAIDNALSITSDGLTIRLEGGVEPNKPVRYSYTRQARGSWS
    LNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIYTIEMGDELLAKLAR
    DATFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVL
    CLLDPLDGVYNKDQNATKLAQQRCNLDDTWEGKIYRVLAGNPAKHDLDI
    KPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTKDQNATKHRQPRGWE
    QLEQCGYPVQRLVALYLAARLSWNQVDQVIRNALASPGSGGDLGEAIRE
    QPEQARLALTLAAAESERFVRQGTGNDEAGAASADVVSLTCPVAAGECA
    GPADSGDALLERNYPTGAEFLGDGGDVSFSTRGTQNWTVERLLQAHRQL
    EERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALA
    YGYAQDQEPDARGRIRNGALLRVYVPRWSLPGFYRTGLTLKDQNATKAP
    EAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILGWPLAERTVVIPSAI
    PTDPRNVGGDLDPSSIPDKEQAISALPDYASQPGKPPREDLK
    • 12. The modified EPA protein of any of paragraphs 1 to 7, wherein the modified EPA protein contains four consensus sequences, optionally substituted for amino acid residues Y208, R274, A519 and added next to the N-terminal amino acid of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
    • 13. The modified EPA protein of paragraph 12, wherein the modified EPA protein contains four consensus sequences substituted for amino acid residues Y208, R274, A519 and added next to the N-terminal amino acid of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, optionally comprising (or consisting of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 8:
  • GSGGGDQNATGSGGGKLAEEAFDLWNECAKACVLDLKDGVRSSRMSVDP
    AIADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIRLEGGVEP
    NKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMS
    PIYTIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQA
    QPRREKRWSEWASGKVLCLLDPLDGVYNKDQNATKLAQQRCNLDDTWEG
    KIYRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEA
    FTKDQNATKHRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQVIRN
    ALASPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGNDEAGAA
    SADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTR
    GTQNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVRARSQD
    LDAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVPRWSLPG
    FYRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVT
    ILGWPLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQAISALPDYASQ
    PGKPPREDLK
    • 14. The modified EPA protein of any of paragraphs 1 to 7, wherein the modified EPA protein contains five consensus sequences, optionally selected from: substitution of amino acid residue Y208, substitution of amino acid residue R274, substitution of amino acid residue S318, substitution of amino acid residue A519, addition at the N-terminus and addition at the C-terminus of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
    • 15. The modified EPA protein of paragraph 14, wherein the modified EPA protein contains five consensus sequences selected from: substitution of amino acid residue Y208, substitution of amino acid residue R274, substitution of amino acid residue S318, substitution of amino acid residue A519, addition at the N-terminus and addition at the C-terminus of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, optionally comprising (or consisting of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 9, 10 or 11:
  • SEQ NO: 9:
    GSGGGDQNATGSGGGAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAI
    ADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIRLEGGVEPNK
    PVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPI
    YTIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQP
    RREKRWSEWASGKVLCLLDPLDGVYNKDQNATKLAQQRCNLDDTWEGKI
    YRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFT
    KDQNATKHRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQVIRNAL
    ASPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGNDEAGAASA
    DVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRGT
    QNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLD
    AIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVPRWSLPGFY
    RTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTIL
    GWPLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQAISALPDYASQPG
    KPPREDLGSGGGDQNATGSGG
    SEQ ID NO: 10:
    GSGGGDQNATGSGGGAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAI
    ADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIRLEGGVEPNK
    PVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPI
    YTIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQP
    RREKRWSEWASGKVLCLLDPLDGVYNKDQNATKLAQQRCNLDDTWEGKI
    YRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFT
    RHRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQVIRNALAKDQNA
    TKSPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGNDEAGAAS
    ADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRG
    TQNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVRARSQDL
    DAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVPRWSLPGF
    YRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTI
    LGWPLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQAISALPDYASQP
    GKPPREDLGSGGGDQNATGSGG
    SEQ ID NO: 11:
    GSGGGDQNATGSGGGAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAI
    ADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIRLEGGVEPNK
    PVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPI
    YTIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQP
    RREKRWSEWASGKVLCLLDPLDGVYNYLAQQRCNLDDTWEGKIYRVLAG
    NPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTKDQNAT
    KHRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQVIRNALAKDQNA
    TKSPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGNDEAGAAS
    ADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRG
    TQNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVRARSQDL
    DAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVPRWSLPGF
    YRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTI
    LGWPLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQAISALPDYASQP
    GKPPREDLGSGGGDQNATGSGG
    • 16. The modified EPA protein of any of paragraphs 1 to 7, wherein the modified EPA protein contains six consensus sequences, optionally selected from: substitution of amino acid residue Y208, substitution of amino acid residue K240, substitution of amino acid residue R274, substitution of amino acid residue S318, substitution of amino acid residue A519, addition at the N-terminus and addition at the C-terminus of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
    • 17. The modified EPA protein of paragraph 16, wherein the modified EPA protein contains six consensus sequences selected from: substitution of amino acid residue Y208, substitution of amino acid residue K240, substitution of amino acid residue R274, substitution of amino acid residue S318, substitution of amino acid residue A519, addition at the N-terminus and addition at the C-terminus of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, optionally comprising (or consisting of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO: 12 or 13:
  • SEQ ID NO: 12:
    GSGGGDQNATGSGGGAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAI
    ADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIRLEGGVEPNK
    PVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPI
    YTIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQP
    RREKRWSEWASGKVLCLLDPLDGVYNKDQNATKLAQQRCNLDDTWEGKI
    YRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFT
    KDQNATKHRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQVIRNAL
    AKDQNATKSPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGND
    EAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDV
    SFSTRGTQNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVR
    ARSQDLDAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVPR
    WSLPGFYRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAITGPEEE
    GGRVTILGWPLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQAISALP
    DYASQPGKPPREDLGSGGGDQNATGSGG
    SEQ ID NO: 13
    GSGGGDQNATGSGGGAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAI
    ADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIRLEGGVEPNK
    PVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPI
    YTIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQP
    RREKRWSEWASGKVLCLLDPLDGVYNKDQNATKLAQQRCNLDDTWEGKI
    YRVLAGNPAKHDLDIKDNNNSTPTVISHRLHFPEGGSLAALTAHQACHL
    PLEAFTKDQNATKHRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQ
    VIRNALAKDQNATKSPGSGGDLGEAIREQPEQARLALTLAAAESERFVR
    QGTGNDEAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFL
    GDGGDVSFSTRGTQNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSI
    VFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALL
    RVYVPRWSLPGFYRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAI
    TGPEEEGGRVTILGWPLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQ
    AISALPDYASQPGKPPREDLK
    • 18. The modified EPA protein of any of paragraphs 1 to 7, wherein the modified EPA protein contains seven consensus sequences, optionally substitution of amino acid residues Y208, K240, R274, S318, A519, addition at the N-terminus and addition at the C-terminus of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
    • 19. The modified EPA protein of paragraph 8, wherein the modified EPA protein contains seven consensus sequences, substituted for amino acid residues Y208, K240, R274, S318, A519, addition at the N-terminus and addition at the C-terminus of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, optionally comprising (or consisting of) an amino acid sequence which is at least 95%, 96%, 97%, 98%, 15 99% or 100% identical to SEQ ID NO: 14:
  • SEQ ID NO: 14:
    GSGGGDQNATGSGGGAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAI
    ADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIRLEGGVEPNK
    PVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPI
    YTIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQP
    RREKRWSEWASGKVLCLLDPLDGVYNKDQNATKLAQQRCNLDDTWEGKI
    YRVLAGNPAKHDLDIKDNNNSTPTVISHRLHFPEGGSLAALTAHQACHL
    PLEAFTKDQNATKHRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQ
    VIRNALAKDQNATKSPGSGGDLGEAIREQPEQARLALTLAAAESERFVR
    QGTGNDEAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFL
    GDGGDVSFSTRGTQNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSI
    VFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALL
    RVYVPRWSLPGFYRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAI
    TGPEEEGGRVTILGWPLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQ
    AISALPDYASQPGKPPREDLGSGGGDQNATGSGG
    • 20. The modified EPA protein of any one of paragraphs 1 to 19, wherein X is Q (glutamine) and Z is A (alanine).
    • 21. The modified EPA protein of any of paragraphs 1 to 20, wherein the amino acid sequence comprises substitution of leucine 552 to valine (L552V) (or at a position equivalent to L552 of SEQ ID NO:1) and deletion of glutamine 553 (ΔE553) (or at a position equivalent to E553 of SEQ ID NO:1).
    • 22. The modified EPA protein of any of paragraphs 1 to 21, wherein the amino acid sequence further comprises a peptide tag, optionally said peptide tag comprising six histidine residues and optionally said peptide tag located at the C-terminus of the amino acid sequence.
    • 23. The modified EPA protein of any of paragraphs 1 to 22, wherein the amino acid sequence further comprises a signal sequence which is capable of directing the EPA protein to the periplasm of a host cell (e.g. bacterium), optionally said signal sequence being DsbA (SEQ ID NO: 21).
    • 24. A conjugate (e.g. a bioconjugate) comprising a modified EPA protein of any of paragraphs 1 to 23 linked to an antigen (e.g. a saccharide antigen, optionally a bacterial polysaccharide antigen).
    • 25. The conjugate according to paragraph 24, wherein the modified EPA protein is covalently linked to an antigen through a chemical linkage obtainable using a chemical conjugation method, either directly or via a linker.
    • 26. The conjugate (e.g. bioconjugate) of paragraph 24, wherein the antigen is covalently linked to an amino acid on the modified EPA protein selected from asparagine, aspartic acid, glutamic acid, lysine, cysteine, tyrosine, histidine, arginine or tryptophan (e.g. asparagine).
    • 27. The conjugate (e.g. bioconjugate) of any one of paragraphs 24 to 26, wherein the antigen is a saccharide, optionally a bacterial polysaccharide (e.g. from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae or Staphylococcus aureus), optionally an O-antigen from a Gram negative bacterium.
    • 28. A polynucleotide encoding the modified EPA protein of any of paragraphs 1 to 23.
    • 29. A vector comprising the polynucleotide of paragraph 28.
    • 30. A host cell comprising:
      • i) one or more nucleotide sequences comprising polysaccharide synthesis genes, optionally for producing a bacterial polysaccharide antigen (e.g. an O-antigen from a Gram negative bacterium optionally from Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumoniae or a capsular polysaccharide from a Gram positive bacterium optionally from Streptococcus pneumoniae or Staphylococcus aureus) or a yeast polysaccharide antigen or a mammalian polysaccharide antigen, optionally integrated into the host cell genome;
      • ii) a nucleotide sequence encoding a heterologous oligosaccharyl transferase, optionally within a plasmid;
      • iii) a nucleotide sequence that encodes a modified EPA protein according to any of paragraphs 1 to 23, optionally within a plasmid.
    • 31. A host cell according to paragraph 30 further comprising a nucleotide sequence encoding a polymerase (e.g. wzy), a flippase (e.g. wz4 and optionally a nucleotide sequence encoding and/or a chain length regulator (e.g. wzz).
    • 32. The host cell according to paragraph 30 or paragraph 31 wherein the oligosaccharyl transferase is a Pg/B, optionally derived from Campylobacter jejuni.
    • 33. The host cell according to any of paragraphs 30 to 31, wherein the host cell is E. coli (e.g. E. coli K12 W3110).
    • 34. A process for producing a bioconjugate that comprises a modified EPA protein linked to a polysaccharide, said process comprising (i) culturing the host cell of any one of paragraphs 30 to 33 under conditions suitable for the production of glycoproteins and (ii) isolating the bioconjugate, optionally isolating the bioconjugate from a periplasmic extract from the host cell.
    • 35. An immunogenic composition comprising a conjugate (e.g. bioconjugate) of any of paragraphs 24 to 27, and optionally a pharmaceutically acceptable excipient and/or carrier.
    • 36. A vaccine comprising the immunogenic composition of paragraph 35 and optionally an adjuvant.
    • 37. A method of inducing an immune response in a subject (e.g. human), the method comprising administering a therapeutically or prophylactically effective amount of the conjugate (e.g. bioconjugate) of any of paragraphs 24 to 27, the immunogenic composition of paragraph 35 or the vaccine of paragraph 36, to a subject (e.g. human) in need thereof.
    • 38. The conjugate (e.g. bioconjugate) of any of paragraphs 24 to 27, the immunogenic composition of paragraph 35 or the vaccine of paragraph 36, for use in inducing an immune response in a subject (e.g. human).
    • 39. The conjugate (e.g. bioconjugate) of any of paragraphs 24 to 27, the immunogenic composition of paragraph 35 or the vaccine of paragraph 36, for use in the manufacture of a medicament for inducing an immune response in a subject (e.g. human).
    • 40. A method of treating and/or preventing a yeast or bacterial infection in a subject (e.g. human), the method comprising administering a therapeutically or prophylactically effective amount of the conjugate (e.g. bioconjugate) of any of paragraphs 24 to 27, the immunogenic composition of paragraph 35 or the vaccine of paragraph 36, to a subject (e.g. human) in need thereof.
    • 41. The conjugate (e.g. bioconjugate) of any of paragraphs 24 to 27, the immunogenic composition of paragraph 35 or the vaccine of paragraph 36, for use in treating and/or preventing a yeast or bacterial infection in a subject (e.g. human).
    • 42. The conjugate (e.g. bioconjugate) of any of paragraphs 24 to 27, the immunogenic composition of paragraph 35 or the vaccine of paragraph 36, for use in the manufacture of a medicament for treating and/or preventing a yeast or bacterial infection in a subject (e.g. human).
      In order that this invention may be better understood, the following examples are set forth. These examples are for purposes of illustration only, and are not to be construed as limiting the scope of the invention in any manner.
    EXAMPLES
  • Material and Methods
  • Engineering of EPA for Glycosylation with Antigenic Glycans
  • In order to predict suitable positions for insertion of glycosites, the crystal structure of EPA was analyzed. 67 solvent accessible amino acid residues were selected for site directed mutagenesis. As a template for mutagenesis the genetically detoxified EPA containing mutations L552VΔE553 was used (Lukac et al (1988), Infect Immun, 56: 3095-3098, and Ho et al. (2006), Hum Vaccin, 2:89-98). This gene was cloned with the DsbA signal sequence at the N-terminus and a His6 tag at C-terminus into a plasmid derived from pEC415 (Schulz, H., Hennecke, H., Thony-Meyer, L., Prototype of a heme chaperone essential for cytochrome c maturation. In Science 281, 1197-1200, 1998). Each selected amino acid residue was substituted with the glycosylation sequon KDQNATK (SEQ ID NO: 4) leading to 67 EPA variants in total, each containing a single glycosylation site (glycosite). For generation of EPA variants containing two, three and four glycosites additional rounds of mutagenesis in the available and selected single-site EPA variants was performed. For generation of EPA variants containing more than four glycosites gene synthesis was applied. Out of 67 tested variants, 4 positions were selected for further combinations presented in this work: Y208, R274, S318 and A519. These mutations were found to be advantageous because (i) they did not reduce protein expression level, indicating that the overall protein structure was not influenced i.e. destabilized by insertion of the gylcosite at these positions, and (ii) the selected positions were found to provide efficient glycosylation i.e. high site occupancy. Additional positions in the region close to Y208, R274, S318 and A519 were also investigated for suitability for glycosite insertion (D218, R279, G232 and G525).
  • Glycosylation Tests with Engineered EPA Containing One or More Glycosites
  • The 67 EPA variants containing a single inserted glycosite were tested for in vivo glycosylation efficiency using various antigenic glycans. For such glycosylation tests, E. coli strain W3110 ΔwaaL was transformed with three plasmids: a pEC415 plasmid carrying an EPA variant, a plasmid expressing PglB and with a plasmid expressing enzyme for the biosynthesis of the polysaccharide of interest (as described below). The non-pathogenic E. coli K12 strain W3110 was obtained from the Coli Genetic Stock Center (Yale University, New Haven (Conn.), USA, product number CGSC #4474). In some cases, glycosylation test were performed with an E. coli strain in which the cluster of genes for polysaccharide biosynthesis was integrated into the E. coli genome (see WO2014/057109 and WO2015/052344 for further details relating to integration), which allowed transformation only with two plasmids expressing EPA variant and PglB.
  • The selection criteria for EPA variants with single glycosite included the total expression level and the level of produced glycoconjugate, the later indicating suitability of glycosite position for modification by PglB.
  • For the data set presented in this work, the used E. coli strains are derivatives of strain W3110, which include a deletion in the lipopolysaccharide O-antigen ligase gene waaL, the deletion or replacement of the O16 O-antigen cluster rfband the replacement of a genomic cluster with the cluster responsible for the biosynthesis of the wanted recombinant glycan of Klebsiella pneumoniae O-antigen (KpO-antigen) Shigella flexneri 2a (Sf2a) or Streptococcus pneumoniae 11A (Sp11A) and 33F (Sp33F) capsular polysaccharides and Pseudomonas aeruginosa O-antigens (PaO6 and PaO11). The E. coli strain used for the recombinant production of the K. pneumoniae O-antigen in FIG. 6 and FIG. 8 (P018-0183) glycan contains in addition genomic deletions of potentially interfering elements: genes wzzE-wecG from the enterobacterial common antigen (ECA) wec cluster, the colanic acid wca cluster, gtrABSand wzzBgenes involved in the O16 biosynthesis.
  • The E. coli strain producing KpO-antigen for FIG. 1-5 or KpO-antigen for FIG. 8 (P018_0167) glycan was transformed with a pEC415 plasmid carrying an EPA variant and a plasmid expressing PglB. To prepare a pre-culture, 5 ml TB (Terrific Broth) medium containing 10 mM MgCl2 and appropriate antibiotics was inoculated with a streak of colonies from the transformation plate and grown at 37° C. o/n (overnight). The pre-culture was used to inoculate 50 ml of supplemented TB medium in a shake flask to give a starting OD600=0.1. The cultures were grown at 37° C., with 200 rpm shaking until reaching OD600=0.8-1 and then induced by addition of 0.001% arabinose (EPA) and 0.1 mM IPTG
  • (PglB). The expression and glycosylation of EPA variants was continued at 37° C. o/n.
  • The E. coli strain producing KpO-antigen for FIG. 6 and FIG. 8 (P018-0183) was transformed with a plasmid expressing both EPA variant and PglB. These cultures were induced only by addition of 0.1 mM Isopropyl β-D-1-thiogalactopyranoside (IPTG) and expression and glycosylation of EPA variants was continued at 37° C. o/n.
  • Periplasmic Extract Preparation
  • The amount of cells from o/n cultures corresponding to OD600=60 (measured using a spectrophotometer) was harvested by centrifugation. The cell pellets were resuspended in 1.5 ml of lysis buffer (30 mM Tris-HCl pH 8.5, 1 mM EDTA (Ethylenediaminetetraacetic acid), 20% sucrose) and lysozyme was added to a final concentration of 1 mg/ml. The suspensions were incubated with slight shaking for 25 minutes at 4° C. and then centrifuged at 16,000 rcf for 10 min. After centrifugation, the supernatant corresponding to periplasmic extract (PPE) was transferred to a fresh tube.
  • Enrichment of Periplasmic Extract by Immobilized Metal Affinity Chromatography (IMAC)
  • In order to enrich periplasmic extracts with EPA variants and allow more direct read-out by SDS-PAGE, the His-tagged EPA variants were purified using one-step purification on Ni-NTA (Nickel Nitrilo-triacetic Acid) agarose. 1 ml of PPE was mixed with 250 μl of 5× binding buffer (150 mM Tris-HCl pH 8.0, 50 mM imidazole, 2.5 M NaCl, 20 mM MgCl2) followed by addition of 200 μl of pre-equilibrated Ni-NTA slurry and incubated with slight shaking for 30 min. After that the resin was washed with 1× binding buffer (30 mM Tris pH 8.0, 10 mM imidazole, 500 mM NaCl) and the bound protein eluted with elution buffer (30 mM Tris pH 8.0, 500 mM imidazole, 200 mM NaCl). The IMAC enriched PPE was analysed by SDS-PAGE (Laemmli, U. K. (1970). “Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4”. Nature. 227 (5259): 680-685. Bibcode:1970Natur.227.680L. doi:10.1038/227680a0. ISSN 0028-0836. PMID 5432063). Unglycosylated carrier and EPA glycoconjugates glycosylated at 1 and more positions were detected on the gel by Coomassie staining (Fazekas de St. Groth, S.; Webster, R. G.; Datyner, A. (1963). “Two new staining procedures for quantitative estimation of proteins on electrophoretic strips”. Biochimica et Biophysica Acta. 71: 377-391. doi:10.1016/0006-3002(63)91092-8. PMID 18421828).
  • Western Blot Analysis of Periplasmic Extract
  • Periplasmic extracts were also analysed by immunoblots against EPA (Sigma-Aldrich, Cat. number P2318) and against polysaccharide attached to EPA. For detection of KpO-antigen, anti-serum against a K-capsular mutant of Klebsiella pneumoniae was used.
  • The results of these experiments are shown in FIGS. 3 to 6 and as described in the following Examples.
    • Example 1: (FIG. 3)
  • SDS-PAGE analysis was carried out on IMAC enriched periplasmic extract of E. coli strains producing KpO-antigen polysaccharide and expressing PglB and EPA variants with a glycosite KDQNATK (SEQ ID NO: 4) introduced at the following positions into SEQ ID NO: 1: Y208 (lane 1), K240 (lane 2), R274 (lane 3), S318 (lane 4), A376 (lane 5), A519 (lane 6), and K240 and A376 (lane 7). The bands shown in FIG. 3 correspond to the unglycosylated EPA carrier, and to KpO-antigen-EPA bioconjugates with one and two occupied glycosites.
  • Conclusion:
  • Glycosylation of EPA with KpO-antigen at each of the new positions was confirmed to be equally good or superior compared to positions K240 and A376. In particular, Y208, S318 and A519 look superior compared to positions K240 and A376. Y208 has higher total expression and all 3 have higher amount of conjugates than positions K240 and A376.
    • Example 2: (FIG. 4)
  • SDS-PAGE analysis was carried out on IMAC enriched periplasmic extract of E. coli strains producing KpO-antigen polysaccharide and expressing PglB and EPA variants with a glycosite KDQNATK (SEQ ID NO: 4) introduced at the following positions: K240 and A376 (lane 1, SEQ ID NO: 26), Y208 and R274 (lane 2, SEQ ID NO: 6), Y208 and S318 (lane 3; SEQ ID NO: 28), Y208 and A519 (lane 4; SEQ ID NO: 29), R274 and S318 (lane 5; SEQ ID NO: 30), R274 and A519 (lane 6; SEQ ID NO: 31), S318 and A519 (lane 7, SEQ ID NO: 7), and Y208 and R274 and A519 (lane 8). The bands shown in FIG. 4 correspond to the unglycosylated EPA carrier, and to KpO-antigen-EPA bioconjugates with one, two and three occupied glycosites.
  • Conclusion:
  • Glycosylation of EPA-2S variants (i.e. variants of EPA having 2 glycosylation sites added) containing glycosites at the new positions with KpO-antigen was confirmed to be equally good or superior compared to EPA-2S with glycosites at positions K240 and A376. From the gel shown in FIG. 4 , Y208+A519 and S318+A519 have higher total protein and all 2S combinations have higher ratio of double to single glycosylated EPA. EPA-3S (i.e. variants of EPA having 3 glycosylation sites added) with glycosites at positions Y208, R274 and A519 was also well glycosylated with KpO-antigen.
    • Example 3: (FIG. 5)
  • Immunoblot analysis was carried out on periplasmic extract of E. coli strains producing KpO-antigen polysaccharide and expressing PglB and EPA variants with 1 to 7 glycosites introduced at the following positions: Y208 (lane 1), K240 (lane 2), R274 (lane 3), S318 (lane 4), A376 (lane 5), A519 (lane 6), and K240 and A376 (lane 7), Y208 and R274 (lane 8, SEQ ID NO: 6), Y208 and S318 (lane 9), Y208 and A519 (lane 10), R274 and S318 (lane 11), R274 and A519 (lane 12), S318 and A519 (lane 13), Y208 and R274 and A519 (lane 14, SEQ ID NO:7), N-terminal glycotag and K240 and A376 and C-terminal glycotag (lane 15), N-terminal glycotag and Y208 and R274 and A519 (lane 16, SEQ ID NO: 8), N-terminal glycotag and Y208 and R274 and A519 and C-terminal glycotag (lane 17; SEQ ID NO: 9), N-terminal glycotag and Y208 and S318 and A519 and C-terminal glycotag (lane 18, SEQ ID NO: 10), N-terminal glycotag and R274 and S318 and A519 and C-terminal glycotag (lane 19, SEQ ID NO: 11), N-terminal glycotag and Y208 and R274 and S318 and A519 and C-terminal glycotag (lane 20, SEQ ID NO: 12), N-terminal glycotag and Y208 and K240 and R274 and S318 and A519 (lane 21, SEQ ID NO: 13), and N-terminal glycotag and Y208 and K240 and R274 and S318 and A519 and C-terminal glycotag (lane 22, SEQ ID NO: 14). In FIG. 5 , the upper panel represents the immunoblot probed with anti-KpO-antigen anti-serum, while the bottom panel represents the immunoblot probed with anti-EPA antibody. The bands correspond to the unglycosylated EPA carrier, and to KpO-antigen-EPA bioconjugates with one to seven occupied glycosites.
  • Conclusion:
  • This demonstrated that glycosylation at up to 7 glycosites is possible by combining the glycosite positions when using a variant of EPA which includes the combination of seven consensus sequences.
    • Example 4: (FIG. 6)
  • SDS-PAGE analysis was carried out on periplasmic extract of E. coli strains producing KpO-antigen polysaccharide (of a different serotype to that presented in FIG. 1-5 , Examples 1-3) and expressing PglB and EPA variants with a glycosite KDQNATK (SEQ ID NO: 4) introduced at the following positions: N-terminal glycotag and Y208 and R274 and A519 and C-terminal glycotag (lane 1, SEQ ID NO: 9), N-terminal glycotag and Y208 and S318 and A519 and C-terminal glycotag (lane 2, SEQ ID NO: 10), N-terminal glycotag and R274 and S318 and A519 and C-terminal glycotag (lane 3, SEQ ID NO: 11), N-terminal glycotag and Y208 and R274 and S318 and A519 and C-terminal glycotag (lane 4, SEQ ID NO: 12), N-terminal glycotag and Y208 and K240 and R274 and S318 and A519 (lane 5, SEQ ID NO: 13), N-terminal glycotag and Y208 and K240 and R274 and S318 and A519 and C-terminal glycotag (lane 6, SEQ ID NO:14), and N-terminal glycotag and Y208 and R274 and A519 (lane 7, SEQ ID NO: 8). In FIG. 6 , the bands corresponding to KpO-antigen-EPA bioconjugates are labelled with arrows.
  • Conclusion:
  • Another Klebsiella pneumoniae serotype O-antigen can be used to show glycosylation efficiency of EPA having more than 3 glycosites.
    • Example 5: (FIG. 7)
  • SDS-PAGE analysis was carried out on IMAC enriched periplasmic extracts of E. coli strain producing Sf2a (see FIG. 7 —left) or Sp11A (see FIG. 7 —right) polysaccharide and expressing PglB and EPA variants with a glycosite introduced at K240 and a second glycosite at A376 (lane 1, SEQ ID NO: 26) or three glycosites at positions Y208, R274, and A519 (lane 2, SEQ ID NO: 7).
  • Results:
  • TABLE 1
    Sugar quantificatuon in purified Sf2a-EPA bioconjugates
    Sf2a-EPA2S Sf2a-EPA3S
    Parameter (Y208, R274 and A519) (K240 and A376)
    Yield [mg PS/L FV] 14 90
    Sugar/Protein ratio [%] 22 48
    Site occupancy [%] 93:7:0 0:43:57
    Mono:Di:Tri
  • Conclusion: EPA3S (Y208, R274 and A519) lead to higher site occupancy, higher sugar:protein ratio and higher sugar yield compared to EPA2S (K240 and A376). The data shows an increase in di-glycosylation as well as tri-glycosylation with EPA3S compared to EPA2S.
    • Example 6: (FIG. 8)
  • SDS-PAGE analysis was carried out on IMAC enriched periplasmic extracts of E. coli strain producing two different Klebsiella pneumoniae O-antigen polysaccharides (left and right) and expressing PglB and EPA variants with glycosites at positions Y208 and R274 and A519 (lane 1, SEQ ID NO: 7), or with N-terminal glycotag and glycosites at positions Y208 and R274 and A519 (lane 2, SEQ ID NO: 8).
  • Conclusion: Addition of an N-terminal glycosite to the 3-site EPA (Y208, R274 and A519) increased modal molecular weight of the conjugate, indicating high site occupancy of this additional site.
    • Example 7: (FIG. 9)
  • Immunoblot analysis was carried out on periplasmic extract of E. coli strains producing Sf2a-, Sp33F, PaO6 or PaO11 antigen polysaccharide and expressing PglB and EPA variants with 1 glycosite introduced at the following positions: Y208 (lane 1), D218 (lane 2), R274 (lane 3), R279 (lane 4), S318 (lane 5), G323 (lane 6), A376 (lane 7), A519 (lane 8), and G525 (lane 9). In FIG. 9 , the panel with Sf2a represents the immunoblot probed with anti-EPA antibody, while the other three panels represent the immunoblot probed with anti-His antibody. The bands correspond to the unglycosylated EPA carrier, and to O-antigen-EPA bioconjugates with one occupied glycosite.
  • Conclusion:
  • This comparative data demonstrated that besides successful glycosylation at the positions Y208, R274, S318 and A519, it is possible to introduce glycosites at additional positions within the sequence range 198-218 (example position D218), 264-284 (example position R279), 308-328 (example position G323) and 509-529 (example position G525). Glycosylation at these additional positions is in most of the cases efficient, but not superior than at the primarily chosen position within the specified range. When comparing glycosylation at the positions D218, R279, G323 and G525 with the position A376, it can be concluded that there is dependence on the type of antigen polysachharide. Overall, it seems that the additional positions D218, R279, G323 and G525 are not always superior than A376, but in many cases they show equal glycosylation level. These additional sites for glycosylation offer further possibilities for combination with other glycosylation sites, which can lead to higher total sugar to protein ratio i.e. higher glycan yield and ultimately reduce the amount of bioconjugate that needs to be used for immunizations. Having more positions suitable for glycosylation also increases flexibility in bioconjugate design and allows to select the best combination for each antigen polysaccharide.
  • SEQUENCE LISTINGS
    SEQ ID NO: 1 EPA sequence from Pseudomonas aeruginosa
    AEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIR
    LEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIYTIEMGDELLAKLARDA
    TFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVYNYLAQQRCNLDDTWE
    GKIYRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTRHRQPRGWEQLEQCGYPVQRLV
    ALYLAARLSWNQVDQVIRNALASPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGNDEAGAASADWS
    LTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRGTQNWTVERLLQAHRQLEERGYVFVGYHGT
    FLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVPRWSLPGFYRTGL
    TLAAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILGWPLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQAI
    SALPDYASQPGKPPREDLK
    SEQ ID NO: 2 Consensus sequence (artificial sequence)
    D/E-X-N-Z-S/T
    SEQ ID NO:3 Consensus sequence (artificial sequence)
    K-D/E-X-N-Z-S/T-K
    SEQ ID NO: 4 Consensus sequence (artificial sequence)
    K-D-Q-N-A-T-K
    SEQ ID NO: 5 Consensus sequence (artificial sequence)
    J-D/E-X-N-Z-S/T-U
    SEQ ID NO: 6 Modified EPA sequence with consensus sequences inserted at Y208 + R274
    (artificial sequence)
    AEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIR
    LEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIYTIEMGDELLAKLARDA
    TFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVYNKDQNATKLAQQRCN
    LDDTWEGKIYRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTKDQNATKHRQPRGWEQ
    LEQCGYPVQRLVALYLAARLSWNQVDQVIRNALASPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGN
    DEAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRGTQNWTVERLLQAHRQLE
    ERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVP
    RWSLPGFYRTGLTLAAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILGWPLAERTVVIPSAIPTDPRNVGGD
    LDPSSIPDKEQAISALPDYASQPGKPPREDLK
    SEQ ID NO: 7 Modified EPA sequence with consensus sequences inserted at Y208 + R274 + A519
    (artificial sequence)
    AEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIR
    LEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIYTIEMGDELLAKLARDA
    TFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVYNKDQNATKLAQQRCN
    LDDTWEGKIYRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTKDQNATKHRQPRGWEQ
    LEQCGYPVQRLVALYLAARLSWNQVDQVIRNALASPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGN
    DEAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRGTQNWTVERLLQAHRQLE
    ERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVP
    RWSLPGFYRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILGWPLAERTVVIPSAIPTDP
    RNVGGDLDPSSIPDKEQAISALPDYASQPGKPPREDLK
    SEQ ID NO: 8 Modified EPA sequence with consensus sequences inserted at N-terminal +
    Y208 + R274 + A519 (artificial sequence)
    GSGGGDQNATGSGGGKLAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDA
    LKLAIDNALSITSDGLTIRLEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMS
    PIYTIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDG
    VYNKDQNATKLAQQRCNLDDTWEGKIYRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAF
    TKDQNATKHRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQVIRNALASPGSGGDLGEAIREQPEQARLA
    LTLAAAESERFVRQGTGNDEAGAASADWVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRG
    TQNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQE
    PDARGRIRNGALLRVYVPRWSLPGFYRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILG
    WPLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQAISALPDYASQPGKPPREDLK
    SEQ ID NO: 9 Modified EPA sequence with consensus sequences inserted at N-terminal +
    Y208 + R274 + A519 + C-terminal (artificial sequence)
    GSGGGDQNATGSGGGAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALK
    LAIDNALSITSDGLTIRLEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIY
    TIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVY
    NKDQNATKLAQQRCNLDDTWEGKIYRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTK
    DQNATKHRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQVIRNALASPGSGGDLGEAIREQPEQARLALT
    LAAAESERFVRQGTGNDEAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRGTQ
    NWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQEPD
    ARGRIRNGALLRVYVPRWSLPGFYRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILGW
    PLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQAISALPDYASQPGKPPREDLGSGGGDQNATGSGG
    SEQ ID NO: 10 Modified EPA sequence with consensus sequences inserted at N-terminal +
    Y208 + S318 + A519 + C-terminal (artificial sequence)
    GSGGGDQNATGSGGGAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALK
    LAIDNALSITSDGLTIRLEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIY
    TIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVY
    NKDQNATKLAQQRCNLDDTWEGKIYRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTR
    HRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQVIRNALAKDQNATKSPGSGGDLGEAIREQPEQARLAL
    TLAAAESERFVRQGTGNDEAGAASADWSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRGT
    QNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQEP
    DARGRIRNGALLRVYVPRWSLPGFYRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILG
    WPLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQAISALPDYASQPGKPPREDLGSGGGDQNATGSGG
    SEQ ID NO: 11 Modified EPA sequence with consensus sequences inserted at N-terminal+ 
    R274 + S318 + A519 + C-terminal (artificial sequence)
    GSGGGDQNATGSGGGAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALK
    LAIDNALSITSDGLTIRLEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIY
    TIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVY
    NYLAQQRCNLDDTWEGKIYRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTKDQNATK
    HRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQVIRNALAKDQNATKSPGSGGDLGEAIREQPEQARLAL
    TLAAAESERFVRQGTGNDEAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRGT
    QNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQEP
    DARGRIRNGALLRVYVPRWSLPGFYRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILG
    WPLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQAISALPDYASQPGKPPREDLGSGGGDQNATGSGG
    SEQ ID NO: 12 Modified EPA sequence with consensus sequences inserted at N-terminal +
    Y208 + R274 + S318 + A519 + C-terminal (artificial sequence)
    GSGGGDQNATGSGGGAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALK
    LAIDNALSITSDGLTIRLEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIY
    TIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVY
    NKDQNATKLAQQRCNLDDTWEGKIYRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTK
    DQNATKHRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQVIRNALAKDQNATKSPGSGGDLGEAIREQP
    EQARLALTLAAAESERFVRQGTGNDEAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDV
    SFSTRGTQNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALAYGY
    AQDQEPDARGRIRNGALLRVYVPRWSLPGFYRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAITGPEEEGG
    RVTILGWPLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQAISALPDYASQPGKPPREDLGSGGGDQNATGSGG
    SEQ ID NO: 13 Modified EPA sequence with consensus sequences inserted at N-terminal +
    Y208 + K240 + R274 + S318 + A519 (artificial sequence)
    GSGGGDQNATGSGGGAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALK
    LAIDNALSITSDGLTIRLEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIY
    TIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVY
    NKDQNATKLAQQRCNLDDTWEGKIYRVLAGNPAKHDLDIKDNNNSTPTVISHRLHFPEGGSLAALTAHQACHL
    PLEAFTKDQNATKHRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQVIRNALAKDQNATKSPGSGGDLG
    EAIREQPEQARLALTLAAAESERFVRQGTGNDEAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFL
    GDGGDVSFSTRGTQNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGD
    PALAYGYAQDQEPDARGRIRNGALLRVYVPRWSLPGFYRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAIT
    GPEEEGGRVTILGWPLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQAISALPDYASQPGKPPREDLK
    SEQ ID NO: 14 Modified EPA sequence with consensus sequences inserted at N-terminal +
    Y208 + K240 + R274 + S318 + A519+C-terminal (artificial sequence)
    GSGGGDQNATGSGGGAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALK
    LAIDNALSITSDGLTIRLEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIY
    TIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVY
    NKDQNATKLAQQRCNLDDTWEGKIYRVLAGNPAKHDLDIKDNNNSTPTVISHRLHFPEGGSLAALTAHQACHL
    PLEAFTKDQNATKHRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQVIRNALAKDQNATKSPGSGGDLG
    EAIREQPEQARLALTLAAAESERFVRQGTGNDEAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFL
    GDGGDVSFSTRGTQNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGD
    PALAYGYAQDQEPDARGRIRNGALLRVYVPRWSLPGFYRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAIT
    GPEEEGGRVTILGWPLAERTVVIPSAIPTDPRNVGGDLDPSSIPDKEQAISALPDYASQPGKPPREDLGSGGGDQ
    NATGSGG
    SEQ ID NO: 15 E. coli flagellin (FlgI) signal sequence
    MIKFLSALILLLVTTAAQA
    SEQ ID NO: 16 E. coli outer membrane porin A (OmpA) signal sequence
    MKKTAIAIAVALAGFATVAQA
    SEQ ID NO: 17 E. coli maltose binding protein (MalE) signal sequence
    MKIKTGARILALSALTTMMFSASALA
    SEQ ID NO: 18 Erwinia carotovorans pectate lyase (PelB) signal sequence
    MKYLLPTAAAGLLLLAAQPAMA
    SEQ ID NO: 19 heat labile E. coli enterotoxin LTIIb signal sequence
    MSFKKIIKAFVIMAALVSVQAHA
    SEQ ID NO: 20 Bacillus subtilis endoxylanase XynA signal sequence
    MFKFKKKFLVGLTAAFMSISMFSATASA
    SEQ ID NO: 21 E. coli DsbA signal sequence
    MKKIWLALAGLVLAFSASA
    SEQ ID NO: 22 E.coli TolB signal sequence
    MKQALRVAFGFLILWASVLHA
    SEQ ID NO: 23 Streptococcus agalactiae SipA signal sequence
    MKMNKKVLLTSTMAASLLSVASVQAS
    SEQ ID NO: 24 pglB from Campylobacter jejuni
    MLKKEYLKNPYLVLFAMIILAYVFSVFCRFYWVWWASEFNEYFFNNQLMIISNDGYAFAEGARDMIAGFHQPND
    LSYYGSSLSALTYWLYKITPFSFESIILYMSTFLSSLVVIPTILLANEYKRPLMGFVAALLASIANSYYNRTMSGYYD
    TDMLVIVLPMFILFFMVRMILKKDFFSLIALPLFIGIYLWWYPSSYTLNVALIGLFLIYTLIFHRKEKIFYIAVILSSLT
    LSNIAWFYQSAIIVILFALFALEQKRLNFMIIGILGSATLIFLILSGGVDPILYQLKFYIFRSDESANLTQGFMYFNVN
    QTIQEVENVDLSEFMRRISGSEIVFLFSLFGFVWLLRKHKSMIMALPILVLGFLALKGGLRFTIYSVPVMALGFGFL
    LSEFKAIMVKKYSQLTSNVCIVFATILTLAPVFIHIYNYKAPTVFSQNEASLLNQLKNIANREDYVVTWWDYGYPV
    RYYSDVKTLVDGGKHLGKDNFFPSFALSKDEQAAANMARLSVEYTEKSFYAPQNDILKTDILQAMMKDYNQSNV
    DLFLASLSKPDFKIDTPKTRDIYLYMPARMSLIFSTVASFSFINLDTGVLDKPFTFSTAYPLDVKNGEIYLSNGVVLS
    DDFRSFKIGDNWVSVNSIVEINSIKQGEYKITPIDDKAQFYIFYLKDSAIPYAQFILMDKTMFNSAYVQMFFLGNY
    DKNLFDLVINSRDAKVFKLKI
    SEQ ID NO: 25 Consensus sequence (artificial)
    G-S-G-G-G-D/E-X-N-Z-S/T-G-S-G-G
    SEQ ID NO: 26 Modified EPA sequence with consensus sequences inserted at K240 + A376
    (artificial sequence)
    AEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIR
    LEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIYTIEMGDELLAKLARDA
    TFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVYNYLAQQRCNLDDTWE
    GKIYRVLAGNPAKHDLDIKDNNNSTPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTRHRQPRGWEQLEQCGY
    PVQRLVALYLAARLSWNQVDQVIRNALASPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGNDEAGAA
    SADVVSLTCPVAKDQNRTKGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRGTQNWTVERLLQAHRQLE
    ERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVP
    RWSLPGFYRTGLTLAAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILGWPLAERTVVIPSAIPTDPRNVGGD
    LDPSSIPDKEQAISALPDYASQPGKPPREDLK
    SEQ ID NO: 27 Modified EPA sequence with consensus sequences inserted at N-terminal +
    K240 + A376 + C-terminal (artificial sequence)
    GSGGGDQNATGSGGGKLAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDA
    LKLAIDNALSITSDGLTIRLEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMS
    PIYTIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDG
    VYNYLAQQRCNLDDTWEGKIYRVLAGNPAKHDLDIKDNNNSTPTVISHRLHFPEGGSLAALTAHQACHLPLEAF
    TRHRQPRGWEQLEQCGYPVQRLVALYLAARLSWNQVDQVIRNALASPGSGGDLGEAIREQPEQARLALTLAAA
    ESERFVRQGTGNDEAGAASADVVSLTCPVAKDQNRTKGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTR
    GTQNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQ
    EPDARGRIRNGALLRVYVPRWSLPGFYRTGLTLAAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILGWPLAE
    RTVVIPSAIPTDPRNVGGDLDPSSIPDKEQAISALPDYASQPGKPPREDLKLGSGGGDQNAT
    SEQ ID NO: 28 Modified EPA sequence with consensus sequences inserted at Y208 + S318
    (artificial sequence)
    AEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIR
    LEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIYTIEMGDELLAKLARDA
    TFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVYNKDQNATKLAQQRCN
    LDDTWEGKIYRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTRHRQPRGWEQLEQCGY
    PVQRLVALYLAARLSWNQVDQVIRNALAKDQNATKPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGN
    DEAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRGTQNWTVERLLQAHRQLE
    ERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVP
    RWSLPGFYRTGLTLAAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILGWPLAERTVVIPSAIPTDPRNVGGD
    LDPSSIPDKEQAISALPDYASQPGKPPREDLK
    SEQ ID NO: 29 Modified EPA sequence with consensus sequences inserted at Y208 + A519
    (artificial sequence)
    AEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIR
    LEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIYTIEMGDELLAKLARDA
    TFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVYNKDQNATKLAQQRCN
    LDDTWEGKIYRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTRHRQPRGWEQLEQCGY
    PVQRLVALYLAARLSWNQVDQVIRNALASPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGNDEAGAA
    SADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRGTQNWTVERLLQAHRQLEERGYVF
    VGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVPRWSLPG
    FYRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILGWPLAERTVVIPSAIPTDPRNVGGD
    LDPSSIPDKEQAISALPDYASQPGKPPREDLK
    SEQ ID NO: 30 Modified EPA sequence with consensus sequences inserted at R274 + S318
    (artificial sequence)
    AEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTIR
    LEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIYTIEMGDELLAKLARDA
    TFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVYNYLAQQRCNLDDTWE
    GKIYRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTKDQNATKHRQPRGWEQLEQCGY
    PVQRLVALYLAARLSWNQVDQVIRNALAKDQNATKPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGN
    DEAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRGTQNWTVERLLQAHRQLE
    ERGYVFVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVP
    RWSLPGFYRTGLTLAAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILGWPLAERTVVIPSAIPTDPRNVGGD
    LDPSSIPDKEQAISALPDYASQPGKPPREDLK
    SEQ ID NO: 31 Modified EPA sequence with consensus sequences inserted at R274 + A519
    (artificial sequence)
    AAEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALKLAIDNALSITSDGLTI
    RLEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHELNAGNQLSHMSPIYTIEMGDELLAKLARD
    ATFFVRAHESNEMQPTLAISHAGVSVVMAQAQPRREKRWSEWASGKVLCLLDPLDGVYNYLAQQRCNLDDTW
    EGKIYRVLAGNPAKHDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTKDQNATKHRQPRGWEQLEQCG
    YPVQRLVALYLAARLSWNQVDQVIRNALASPGSGGDLGEAIREQPEQARLALTLAAAESERFVRQGTGNDEAGA
    ASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLGDGGDVSFSTRGTQNWTVERLLQAHRQLEERGYV
    FVGYHGTFLEAAQSIVFGGVRARSQDLDAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVPRWSLP
    GFYRTGLTLKDQNATKAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILGWPLAERTVVIPSAIPTDPRNVGG
    DLDPSSIPDKEQAISALPDYASQPGKPPREDLK
    SEQ ID NO: 32 Forward primer (artificial sequence)
    AAGCTAGCGCCGCCGAGGAAGCCTTCGACC
    SEQ ID NO: 33 Reverse primer (artificial sequence)
    AAGAATTCTCAGTGGTGGTGGTGGTGGTGCTTCAGGTCCTCGCGCGGCGG
    SEQ ID NO: 34 EPA_mut_Y208
    AEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALKLAI
    DNALSITSDGLTIRLEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHEL
    NAGNQLSHMSPIYTIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQ
    PRREKRWSEWASGKVLCLLDPLDGVYNKDQNATKLAQQRCNLDDTWEGKIYRVLAGNPAK
    HDLDIKPTVISHRLHHPEGGSLAALTAHQACHLPLETFTRHRQPRGWEQLEQCG
    YPVQRLVALYLAARLSWNQVDQVIRNALASPGSGGDLGEAIREQPEQARLALTL
    AAAESERFVRQGTGNDEAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLG
    DGGDVSFSTRGTQNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVRARSQDL
    DAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVPRPSLPGFYRTGLTLA
    APEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILGWPLAERTVVIPSAIPTDPRN
    VGGDLDPSSIPDKEQAISALPDYASQPGKPPREDLK
    SEQ ID NO: 36 EPA_mut_S318
    AEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALKLAI
    DNALSITSDGLTIRLEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHEL
    NAGNQLSHMSPIYTIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQ
    PRREKRWSEWASGKVLCLLDPLDGVYNYLAQQRCNLDDTWEGKIYRVLAGNPAK
    HDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTRHRQPRGWEQLEQCG
    YPVQRLVALYLAARLSWNQVDQVIRNALAKDQNATKPGSGGDLGEAIREQPEQARLALTL
    AAAESERFVRQGTGNDEAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLG
    DGGDVSFSTRGTQNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVRARSQDL
    DAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVPRWSLPGFYRTGLTLA
    APEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILGWPLAERTVVIPSAIPTDPRN
    VGGDLDPSSIPDKEQAISALPDYASQPGKPPREDLK
    SEQ ID NO: 37 EPA_mut_A519
    AEEAFDLWNECAKACVLDLKDGVRSSRMSVDPAIADTNGQGVLHYSMVLEGGNDALKLAI
    DNALSITSDGLTIRLEGGVEPNKPVRYSYTRQARGSWSLNWLVPIGHEKPSNIKVFIHEL
    NAGNQLSHMSPIYTIEMGDELLAKLARDATFFVRAHESNEMQPTLAISHAGVSVVMAQAQ
    PRREKRWSEWASGKVLCLLDPLDGVYNYLAQQRCNLDDTWEGKIYRVLAGNPAK
    HDLDIKPTVISHRLHFPEGGSLAALTAHQACHLPLEAFTRHRQPRGWEQLEQCG
    YPVQRLVALYLAARLSWNQVDQVIRNALASPGSGGDLGEAIREQPEQARLALTL
    AAAESERFVRQGTGNDEAGAASADVVSLTCPVAAGECAGPADSGDALLERNYPTGAEFLG
    DGGDVSFSTRGTQNWTVERLLQAHRQLEERGYVFVGYHGTFLEAAQSIVFGGVRARSQDL
    DAIWRGFYIAGDPALAYGYAQDQEPDARGRIRNGALLRVYVPRWSLPGFYRTGLTLKDQN
    ATKAPEAAGEVERLIGHPLPLRLDAITGPEEEGGRVTILGWPLAERTVVIPSAIPTDPRN
    VGGDLDPSSIPDKEQAISALPDYASQPGKPPREDLK
    SEQ ID NO: 38 Primer
    GAAGGCGGGCGCGTGACCATTCTCGGC
    SEQ ID NO: 39 Primer
    GCCGAGAATGGTCACGCGCCCGCCTTC
    SEQ ID NO: 40 Nucleotide sequence EPA with mutation Y208 > KDQNATK
    ATGAAAAAGATTTGGCTGGCGCTGGCTGGTTTAGTTTTAGCGTTTAGCGCTAGCGCCGCCGAGGAAGCCTTC
    GACCTCTGGAACGAATGCGCCAAGGCCTGCGTGCTCGACCTCAAGGACGGCGTGCGTTCCAGCCGCATGAG
    CGTCGACCCGGCCATCGCCGACACCAACGGCCAGGGCGTGCTGCACTACTCCATGGTCCTGGAGGGCGGCA
    ACGACGCGCTCAAGCTGGCCATCGACAACGCCCTCAGCATCACCAGCGACGGCCTGACCATCCGCCTCGAAG
    GTGGCGTCGAGCCGAACAAGCCGGTGCGCTACAGCTACACGCGCCAGGCGCGCGGCAGTTGGTCGCTGAAC
    TGGCTGGTGCCGATCGGCCACGAGAAGCCTTCGAACATCAAGGTGTTCATCCACGAACTGAACGCCGGTAAC
    CAGCTCAGCCACATGTCGCCGATCTACACCATCGAGATGGGCGACGAGTTGCTGGCGAAGCTGGCGCGCGA
    TGCCACCTTCTTCGTCAGGGCGCACGAGAGCAACGAGATGCAGCCGACGCTCGCCATCAGCCATGCCGGGGT
    CAGCGTGGTCATGGCCCAGGCCCAGCCGCGCCGGGAAAAGCGCTGGAGCGAATGGGCCAGCGGCAAGGTGT
    TGTGCCTGCTCGACCCGCTGGACGGGGTCTACAACAAAGATCAGAACGCGACCAAACTCGCCCAGCAGCGCT
    GCAACCTCGACGATACCTGGGAAGGCAAGATCTACCGGGTGCTCGCCGGCAACCCGGCGAAGCATGACCTG
    GACATCAAGCCCACGGTCATCAGTCATCGCCTGCATTTCCCCGAGGGCGGCAGCCTGGCCGCGCTGACCGCG
    CACCAGGCCTGCCACCTGCCGCTGGAGACCTTCACCCGTCATCGCCAGCCGCGCGGCTGGGAACAACTGGAG
    CAGTGCGGCTATCCGGTGCAGCGGCTGGTCGCCCTCTACCTGGCGGCGCGGCTGTCGTGGAACCAGGTCGA
    CCAGGTGATCCGCAACGCCCTGGCCAGCCCCGGCAGCGGCGGCGACCTGGGCGAAGCGATCCGCGAGCAGC
    CGGAGCAGGCCCGTCTGGCCCTGACCCTGGCCGCCGCCGAGAGCGAGCGCTTCGTCCGGCAGGGCACCGGC
    AACGACGAGGCCGGCGCGGCCAGCGCCGACGTGGTGAGCCTGACCTGCCCGGTCGCCGCCGGTGAATGCGC
    GGGCCCGGCGGACAGCGGCGACGCCCTGCTGGAGCGCAACTATCCCACTGGCGCGGAGTTCCTCGGCGACG
    GCGGCGACGTCAGCTTCAGCACCCGCGGCACGCAGAACTGGACGGTGGAGCGGCTGCTCCAGGCGCACCGC
    CAACTGGAGGAGCGCGGCTATGTGTTCGTCGGCTACCACGGCACCTTCCTCGAAGCGGCGCAAAGCATCGTC
    TTCGGCGGGGTGCGCGCGCGCAGCCAGGACCTCGACGCGATCTGGCGCGGTTTCTATATCGCCGGCGATCC
    GGCGCTGGCCTACGGCTACGCCCAGGACCAGGAACCCGACGCGCGCGGCCGGATCCGCAACGGTGCCCTGC
    TGCGGGTCTATGTGCCGCGCCCGAGTCTGCCGGGCTTCTACCGCACCGGCCTGACCCTGGCCGCGCCGGAG
    GCGGCGGGCGAGGTCGAACGGCTGATCGGCCATCCGCTGCCGCTGCGCCTGGACGCCATCACCGGCCCCGA
    GGAGGAAGGCGGGCGCGTGACCATTCTCGGCTGGCCGCTGGCCGAGCGCACCGTGGTGATTCCCTCGGCGA
    TCCCCACCGACCCGCGCAACGTCGGCGGCGACCTCGACCCGTCCAGCATCCCCGACAAGGAACAGGCGATCA
    GCGCCCTGCCGGACTACGCCAGCCAGCCCGGCAAACCGCCGCGCGAGGACTTGAAGCACCACCACCACCACC
    ACTGA
    SEQ ID NO: 41 Nucleotide sequence EPA with mutation R274 > KDQNATK
    ATGAAAAAGATTTGGCTGGCGCTGGCTGGTTTAGTTTTAGCGTTTAGCGCTAGCGCCGCCGAGGAAGCCTTC
    GACCTCTGGAACGAATGCGCCAAGGCCTGCGTGCTCGACCTCAAGGACGGCGTGCGTTCCAGCCGCATGAG
    CGTCGACCCGGCCATCGCCGACACCAACGGCCAGGGCGTGCTGCACTACTCCATGGTCCTGGAGGGCGGCA
    ACGACGCGCTCAAGCTGGCCATCGACAACGCCCTCAGCATCACCAGCGACGGCCTGACCATCCGCCTCGAAG
    GCGGCGTCGAGCCGAACAAGCCGGTGCGCTACAGCTACACGCGCCAGGCGCGCGGCAGTTGGTCGCTGAAC
    TGGCTGGTACCGATCGGCCACGAGAAGCCCTCGAACATCAAGGTGTTCATCCACGAACTGAACGCCGGTAAC
    CAGCTCAGCCACATGTCGCCGATCTACACCATCGAGATGGGCGACGAGTTGCTGGCGAAGCTGGCGCGCGA
    TGCCACCTTCTTCGTCAGGGCGCACGAGAGCAACGAGATGCAGCCGACGCTCGCCATCAGCCATGCCGGGGT
    CAGCGTGGTCATGGCTCAGGCCCAGCCGCGCCGGGAAAAGCGCTGGAGCGAATGGGCCAGCGGCAAGGTGT
    TGTGCCTGCTCGACCCGCTGGACGGGGTCTACAACTACCTCGCCCAGCAGCGCTGCAACCTCGACGATACCT
    GGGAAGGCAAGATCTACCGGGTGCTCGCCGGCAACCCGGCGAAGCATGACCTGGACATCAAGCCCACGGTC
    ATCAGTCATCGCCTGCATTTCCCCGAGGGCGGCAGCCTGGCCGCGCTGACCGCGCACCAGGCCTGCCACCTG
    CCGCTGGAGGCCTTCACTAAAGATCAGAACGCGACCAAACATCGCCAGCCGCGCGGCTGGGAACAACTGGAG
    CAGTGCGGCTATCCGGTGCAGCGGCTGGTCGCCCTCTACCTGGCGGCGCGACTGTCGTGGAACCAGGTCGA
    CCAGGTGATCCGCAACGCCCTGGCCAGCCCCGGCAGCGGCGGCGACCTGGGCGAAGCGATCCGCGAGCAGC
    CGGAGCAGGCCCGTCTGGCCCTGACCCTGGCCGCCGCCGAGAGCGAGCGCTTCGTCCGGCAGGGCACCGGC
    AACGACGAGGCCGGCGCGGCCAGCGCCGACGTGGTGAGCCTGACCTGCCCGGTCGCCGCCGGTGAATGCGC
    GGGCCCGGCGGACAGCGGCGACGCCCTGCTGGAGCGCAACTATCCCACTGGCGCGGAGTTCCTCGGCGACG
    GCGGCGACGTCAGCTTCAGCACCCGCGGCACGCAGAACTGGACGGTGGAGCGGCTGCTCCAGGCGCACCGC
    CAACTGGAGGAGCGCGGCTATGTGTTCGTCGGCTACCACGGCACCTTCCTCGAAGCGGCGCAAAGCATCGTC
    TTCGGCGGGGTGCGCGCGCGCAGCCAGGACCTCGACGCGATCTGGCGCGGTTTCTATATCGCCGGCGATCC
    GGCGCTGGCCTACGGCTACGCCCAGGACCAGGAACCCGACGCGCGCGGCCGGATCCGCAACGGTGCCCTGC
    TGCGGGTCTATGTGCCGCGCTGGAGTCTGCCGGGCTTCTACCGCACCGGCCTGACCCTGGCCGCGCCGGAG
    GCGGCGGGCGAGGTCGAACGGCTGATCGGCCATCCGCTGCCGCTGCGCCTGGACGCCATCACCGGCCCCGA
    GGAGGAAGGCGGGCGCGTGACCATTCTCGGCTGGCCGCTGGCCGAGCGCACCGTGGTGATTCCCTCGGCGA
    TCCCCACCGACCCGCGCAACGTCGGCGGCGACCTCGACCCGTCCAGCATCCCCGACAAGGAACAGGCGATCA
    GCGCCCTGCCGGACTACGCCAGCCAGCCCGGCAAACCGCCGCGCGAGGACTTGAAGCACCACCACCACCACC
    ACTGA
    SEQ ID NO: 42 Nucleotide sequence EPA with mutation S318 > KDQNATK
    ATGAAAAAGATTTGGCTGGCGCTGGCTGGTTTAGTTTTAGCGTTTAGCGCTAGCGCCGCCGAGGAAGCCTTC
    GACCTCTGGAACGAATGCGCCAAGGCCTGCGTGCTCGACCTCAAGGACGGCGTGCGTTCCAGCCGCATGAG
    CGTCGACCCGGCCATCGCCGACACCAACGGCCAGGGCGTGCTGCACTACTCCATGGTCCTGGAGGGCGGCA
    ACGACGCGCTCAAGCTGGCCATCGACAACGCCCTCAGCATCACCAGCGACGGCCTGACCATCCGCCTCGAAG
    GCGGCGTCGAGCCGAACAAGCCGGTGCGCTACAGCTACACGCGCCAGGCGCGCGGCAGTTGGTCGCTGAAC
    TGGCTGGTACCGATCGGCCACGAGAAGCCCTCGAACATCAAGGTGTTCATCCACGAACTGAACGCCGGTAAC
    CAGCTCAGCCACATGTCGCCGATCTACACCATCGAGATGGGCGACGAGTTGCTGGCGAAGCTGGCGCGCGA
    TGCCACCTTCTTCGTCAGGGCGCACGAGAGCAACGAGATGCAGCCGACGCTCGCCATCAGCCATGCCGGGGT
    CAGCGTGGTCATGGCTCAGGCCCAGCCGCGCCGGGAAAAGCGCTGGAGCGAATGGGCCAGCGGCAAGGTGT
    TGTGCCTGCTCGACCCGCTGGACGGGGTCTACAACTACCTCGCCCAGCAGCGCTGCAACCTCGACGATACCT
    GGGAAGGCAAGATCTACCGGGTGCTCGCCGGCAACCCGGCGAAGCATGACCTGGACATCAAGCCCACGGTC
    ATCAGTCATCGCCTGCATTTCCCCGAGGGCGGCAGCCTGGCCGCGCTGACCGCGCACCAGGCCTGCCACCTG
    CCGCTGGAGGCCTTCACTCGTCATCGCCAGCCGCGCGGCTGGGAACAACTGGAGCAGTGCGGCTATCCGGT
    GCAGCGGCTGGTCGCCCTCTACCTGGCGGCGCGACTGTCGTGGAACCAGGTCGACCAGGTGATCCGCAACG
    CCCTGGCCAAAGATCAGAACGCGACCAAACCCGGCAGCGGCGGCGACCTGGGCGAAGCGATCCGCGAGCAG
    CCGGAGCAGGCCCGTCTGGCCCTGACCCTGGCCGCCGCCGAGAGCGAGCGCTTCGTCCGGCAGGGCACCGG
    CAACGACGAGGCCGGCGCGGCCAGCGCCGACGTGGTGAGCCTGACCTGCCCGGTCGCCGCCGGTGAATGCG
    CGGGCCCGGCGGACAGCGGCGACGCCCTGCTGGAGCGCAACTATCCCACTGGCGCGGAGTTCCTCGGCGAC
    GGCGGCGACGTCAGCTTCAGCACCCGCGGCACGCAGAACTGGACGGTGGAGCGGCTGCTCCAGGCGCACCG
    CCAACTGGAGGAGCGCGGCTATGTGTTCGTCGGCTACCACGGCACCTTCCTCGAAGCGGCGCAAAGCATCGT
    CTTCGGCGGGGTGCGCGCGCGCAGCCAGGACCTCGACGCGATCTGGCGCGGTTTCTATATCGCCGGCGATC
    CGGCGCTGGCCTACGGCTACGCCCAGGACCAGGAACCCGACGCGCGCGGCCGGATCCGCAACGGTGCCCTG
    CTGCGGGTCTATGTGCCGCGCTGGAGTCTGCCGGGCTTCTACCGCACCGGCCTGACCCTGGCCGCGCCGGA
    GGCGGCGGGCGAGGTCGAACGGCTGATCGGCCATCCGCTGCCGCTGCGCCTGGACGCCATCACCGGCCCCG
    AGGAGGAAGGCGGGCGCGTGACCATTCTCGGCTGGCCGCTGGCCGAGCGCACCGTGGTGATTCCCTCGGCG
    ATCCCCACCGACCCGCGCAACGTCGGCGGCGACCTCGACCCGTCCAGCATCCCCGACAAGGAACAGGCGATC
    AGCGCCCTGCCGGACTACGCCAGCCAGCCCGGCAAACCGCCGCGCGAGGACTTGAAGCACCACCACCACCAC
    CACTGA
    SEQ ID NO: 43 Nucleotide sequence EPA with mutation A519 > KDQNATK
    ATGAAAAAGATTTGGCTGGCGCTGGCTGGTTTAGTTTTAGCGTTTAGCGCTAGCGCCGCCGAGGAAGCCTT-
    GACCTCTGGAACGAATGCGCCAAGGCCTGCGTGCTCGACCTCAAGGACGGCGTGCGTTCCAGCCGCATGAG
    CGTCGACCCGGCCATCGCCGACACCAACGGCCAGGGCGTGCTGCACTACTCCATGGTCCTGGAGGGCGGCA
    ACGACGCGCTCAAGCTGGCCATCGACAACGCCCTCAGCATCACCAGCGACGGCCTGACCATCCGCCTCGAAG
    GCGGCGTCGAGCCGAACAAGCCGGTGCGCTACAGCTACACGCGCCAGGCGCGCGGCAGTTGGTCGCTGAAC
    TGGCTGGTACCGATCGGCCACGAGAAGCCCTCGAACATCAAGGTGTTCATCCACGAACTGAACGCCGGTAAC
    CAGCTCAGCCACATGTCGCCGATCTACACCATCGAGATGGGCGACGAGTTGCTGGCGAAGCTGGCGCGCGA
    TGCCACCTTCTTCGTCAGGGCGCACGAGAGCAACGAGATGCAGCCGACGCTCGCCATCAGCCATGCCGGGGT
    CAGCGTGGTCATGGCTCAGGCCCAGCCGCGCCGGGAAAAGCGCTGGAGCGAATGGGCCAGCGGCAAGGTGT
    TGTGCCTGCTCGACCCGCTGGACGGGGTCTACAACTACCTCGCCCAGCAGCGCTGCAACCTCGACGATACCT
    GGGAAGGCAAGATCTACCGGGTGCTCGCCGGCAACCCGGCGAAGCATGACCTGGACATCAAGCCCACGGTC
    ATCAGTCATCGCCTGCATTTCCCCGAGGGCGGCAGCCTGGCCGCGCTGACCGCGCACCAGGCCTGCCACCTG
    CCGCTGGAGGCCTTCACTCGTCATCGCCAGCCGCGCGGCTGGGAACAACTGGAGCAGTGCGGCTATCCGGT
    GCAGCGGCTGGTCGCCCTCTACCTGGCGGCGCGACTGTCGTGGAACCAGGTCGACCAGGTGATCCGCAACG
    CCCTGGCCAGCCCCGGCAGCGGCGGCGACCTGGGCGAAGCGATCCGCGAGCAGCCGGAGCAGGCCCGTCTG
    GCCCTGACCCTGGCCGCCGCCGAGAGCGAGCGCTTCGTCCGGCAGGGCACCGGCAACGACGAGGCCGGCGC
    GGCCAGCGCCGACGTGGTGAGCCTGACCTGCCCGGTCGCCGCCGGTGAATGCGCGGGCCCGGCGGACAGCG
    GCGACGCCCTGCTGGAGCGCAACTATCCCACTGGCGCGGAGTTCCTCGGCGACGGCGGCGACGTCAGCTTC
    AGCACCCGCGGCACGCAGAACTGGACGGTGGAGCGGCTGCTCCAGGCGCACCGCCAACTGGAGGAGCGCGG
    CTATGTGTTCGTCGGCTACCACGGCACCTTCCTCGAAGCGGCGCAAAGCATCGTCTTCGGCGGGGTGCGCGC
    GCGCAGCCAGGACCTCGACGCGATCTGGCGCGGTTTCTATATCGCCGGCGATCCGGCGCTGGCCTACGGCT
    ACGCCCAGGACCAGGAACCCGACGCGCGCGGCCGGATCCGCAACGGTGCCCTGCTGCGGGTCTATGTGCCG
    CGCTGGAGTCTGCCGGGCTTCTACCGCACCGGCCTGACCCTGAAAGATCAGAACGCGACCAAAGCGCCGGA
    GGCGGCGGGCGAGGTCGAACGGCTGATCGGCCATCCGCTGCCGCTGCGCCTGGACGCCATCACCGGCCCCG
    AGGAGGAAGGCGGGCGCGTGACCATTCTCGGCTGGCCGCTGGCCGAGCGCACCGTGGTGATTCCCTCGGCG
    ATCCCCACCGACCCGCGCAACGTCGGCGGCGACCTCGACCCGTCCAGCATCCCCGACAAGGAACAGGCGATC
    AGCGCCCTGCCGGACTACGCCAGCCAGCCCGGCAAACCGCCGCGCGAGGACTTGAAGCACCACCACCACCAC
    CACTGA

Claims (17)

1-15. (canceled)
16. A modified EPA (Exotoxin A of Pseudomonas aeruginosa) protein having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises at least one consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the at least one consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218, (ii) one or more amino acids between amino acid residues 264-284, (iii) one or more amino acids between amino acid residues 308-328, and (iv) one or more amino acids between amino acid residues 509-529 of SEQ ID NO: 1 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
17. The modified EPA (Exotoxin A of Pseudomonas aeruginosa) of claim 16 having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises at least two consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the at least two consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218, (ii) one or more amino acids between amino acid residues 264-284, (iii) one or more amino acids between amino acid residues 308-328, (iv) one or more amino acids between amino acid residues 509-529, and (v) one or more amino acids between amino acid residues 230-250, of SEQ ID NO: 1 or at equivalent position(s) within an amino acid 5 sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
18. A modified EPA (Exotoxin A of Pseudomonas aeruginosa) protein of claim 16 having an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1, modified in that the amino acid sequence comprises at least three consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, wherein the at least three consensus sequences have each been added next to or substituted for one or more amino acids, independently selected from: (i) one or more amino acids between amino acid residues 198-218, (ii) one or more amino acids between amino acid residues 264-284, (iii) one or more amino acids between amino acid residues 308-328, (iv) one or more amino acids between amino acid residues 509-529 of SEQ ID NO: 1, and (v) one or more amino acids between amino acid residues 230-250 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
19. The modified EPA protein of claim 16, wherein the consensus sequence(s) selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3) have each been independently substituted for one or more amino acids of the amino acid sequence of SEQ ID NO: 1 or an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
20. The modified EPA protein of claim 16, wherein a further consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5), wherein X and Z are independently any amino acid except proline and J and U are independently 1 to 5 naturally occurring amino acid residues, has been added next to, or substituted for, one or more amino acids, at the N-terminus of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
21. The modified EPA protein of claim 16, wherein a further consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and J-D/E-X-N-Z-S/T-U (SEQ ID NO: 5), wherein X and Z are independently any amino acid except proline and J and U are independently 1 to 5 naturally occurring amino acid residues, has been added next to, or substituted for, one or more amino acids, at the C-terminus of SEQ ID NO: 1 or at an equivalent position within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
22. The modified EPA protein of claim 16, wherein at least one consensus sequence selected from: D/E-X-N-Z-S/T (SEQ ID NO: 2) and K-D/E-X-N-Z-S/T-K (SEQ ID NO: 3), wherein X and Z are independently any amino acid except proline, has been added next to, or substituted for: (i) one or more amino acids between amino acid residues 198-218, (ii) one or more amino acids between amino acid residues 308-328, or (iii) one or more amino acids between amino acid residues 509-529 of SEQ ID NO: 1 or at equivalent position(s) within an amino acid sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to SEQ ID NO: 1.
23. The modified EPA protein of claim 16, wherein the amino acid sequence comprises substitution of leucine 552 to valine (L552V) (or at a position equivalent to L552 of SEQ ID NO:1) and deletion of glutamine 553 (4E553) (or at a position equivalent to E553 of SEQ ID NO:1).
24. A conjugate comprising a modified EPA protein of claim 16 covalently linked to an antigen.
25. The conjugate of claim 24, wherein the antigen is a saccharide.
26. A host cell comprising:
i) one or more nucleotide sequences comprising polysaccharide synthesis genes, for producing a bacterial polysaccharide antigen or a yeast polysaccharide antigen or a mammalian polysaccharide antigen, integrated into the host cell genome;
ii) a nucleotide sequence encoding a heterologous oligosaccharyl transferase, within a plasmid;
iii) a nucleotide sequence that encodes a modified EPA protein according to claim 16, within a plasmid.
27. A process for producing a bioconjugate that comprises a modified EPA protein linked to a polysaccharide, said process comprising (i) culturing the host cell of claim 26 under conditions suitable for the production of glycoproteins and (ii) isolating the bioconjugate, isolating the bioconjugate from a periplasmic extract from the host cell.
28. An immunogenic composition comprising a conjugate of claim 24, and at least one of a pharmaceutically acceptable excipient or carrier.
29. A vaccine comprising the immunogenic composition of claim 28 and an adjuvant.
30. A method of inducing an immune response in a subject, the method comprising administering a therapeutically or prophylactically effective amount of the conjugate of claim 24 to a subject in need thereof.
31. A method of inducing an immune response in a subject, the method comprising administering a therapeutically or prophylactically effective amount of the immunogenic composition of claim 28, to a subject in need thereof.
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