WO2018140242A1 - Base structurale pour la neutralisation croisée d'anticorps du virus respiratoire syncytial et du métapneumovirus humain - Google Patents

Base structurale pour la neutralisation croisée d'anticorps du virus respiratoire syncytial et du métapneumovirus humain Download PDF

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WO2018140242A1
WO2018140242A1 PCT/US2018/013318 US2018013318W WO2018140242A1 WO 2018140242 A1 WO2018140242 A1 WO 2018140242A1 US 2018013318 W US2018013318 W US 2018013318W WO 2018140242 A1 WO2018140242 A1 WO 2018140242A1
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antibody
heavy
light chain
seq
chain variable
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PCT/US2018/013318
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English (en)
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James E. Crowe, Jr.
Jarrod MOUSA
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Vanderbilt University
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    • 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
    • A61K39/12—Viral antigens
    • 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
    • A61P31/12—Antivirals
    • A61P31/14—Antivirals for RNA viruses
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K16/00—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies
    • C07K16/08—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from viruses
    • C07K16/10—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from viruses from RNA viruses
    • C07K16/1027—Paramyxoviridae, e.g. respiratory syncytial virus
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
    • G01N33/569—Immunoassay; Biospecific binding assay; Materials therefor for microorganisms, e.g. protozoa, bacteria, viruses
    • G01N33/56983—Viruses
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/20—Immunoglobulins specific features characterized by taxonomic origin
    • C07K2317/21—Immunoglobulins specific features characterized by taxonomic origin from primates, e.g. man
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/30—Immunoglobulins specific features characterized by aspects of specificity or valency
    • C07K2317/34—Identification of a linear epitope shorter than 20 amino acid residues or of a conformational epitope defined by amino acid residues
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/60—Immunoglobulins specific features characterized by non-natural combinations of immunoglobulin fragments
    • C07K2317/62—Immunoglobulins specific features characterized by non-natural combinations of immunoglobulin fragments comprising only variable region components
    • C07K2317/622—Single chain antibody (scFv)
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/70—Immunoglobulins specific features characterized by effect upon binding to a cell or to an antigen
    • C07K2317/76—Antagonist effect on antigen, e.g. neutralization or inhibition of binding
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N2760/00—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA ssRNA viruses negative-sense
    • C12N2760/00011—Details
    • C12N2760/18011—Paramyxoviridae
    • C12N2760/18511—Pneumovirus, e.g. human respiratory syncytial virus
    • C12N2760/18534—Use of virus or viral component as vaccine, e.g. live-attenuated or inactivated virus, VLP, viral protein
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2333/00—Assays involving biological materials from specific organisms or of a specific nature
    • G01N2333/005—Assays involving biological materials from specific organisms or of a specific nature from viruses
    • G01N2333/08—RNA viruses
    • G01N2333/115—Paramyxoviridae, e.g. parainfluenza virus
    • G01N2333/135—Respiratory syncytial virus
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2469/00—Immunoassays for the detection of microorganisms
    • G01N2469/10—Detection of antigens from microorganism in sample from host

Definitions

  • the present disclosure relates generally to the fields of medicine, infectious disease, and immunology. More particular, the disclosure relates to human antibodies binding to respiratory syncytial virus (RSV). 2. Background
  • Respiratory syncytial virus (RSV) and human metapneumovirus (HMPV) are two closely related viruses that cause bronchiolitis and pneumonia in infants and the elderly (Collins & Crowe, 2013), with a significant health burden (Hall et al., 2013; Falsey et al., 2005; Hall, 2012; Edwards et al., 2013; Williams et al., 2004).
  • a method of detecting a human respiratory syncytial virus infection in a subject comprising (a) contacting a sample from said subject with an antibody or antibody fragment having heavy chain CDR1 GFTFSSYR (SEQ ID NO: 5), heavy chain CDR2 ITASSSYI (SEQ ID NO: 6), heavy chain CDR3 ARDENTGISHYWFDP (SEQ ID NO: 7), light chain CDR1 GSNLGADYG (SEQ ID NO: 8), light chain CDR2 GDR (SEQ ID NO: 9) and light chain CDR3 QSYDRSLNWV (SEQ ID NO: 10); and (b) detecting human respiratory syncytial virus in said sample by binding of said antibody or antibody fragment to a human respiratory syncytial virus antigen in said sample.
  • the sample maybe a body fluid, such as blood, sputum, tears, saliva, mucous or serum, urine, exudate, transudate, tissue scrapings or feces.
  • Detection may comprise ELISA, RIA or Western blot.
  • the method may further comprise performing steps (a) and (b) a second time and determining a change in human respiratory syncytial virus antigen levels as compared to the first assay.
  • the antibody or antibody fragment may be encoded by heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2, by heavy and light chain variable sequences having 70%, 80%, or 90% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2, or by heavy and light chain variable sequences having 95% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2.
  • the antibody or antibody fragment may comprise heavy and light chain variable sequences heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4, may comprise heavy and light chain variable sequences having 70%, 80% or 90% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4, or may comprise heavy and light chain variable sequences having 95% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4.
  • the antibody fragment may be a recombinant scFv (single chain fragment variable) antibody, Fab fragment, F(ab’) 2 fragment, or Fv fragment.
  • a method of treating a subject infected with human respiratory syncytial virus, or reducing the likelihood of infection of a subject at risk of contracting human respiratory syncytial virus comprising delivering to said subject an antibody or antibody fragment having heavy chain CDR1 GFTFSSYR (SEQ ID NO: 5), heavy chain CDR2 ITASSSYI (SEQ ID NO: 6), heavy chain CDR3 ARDENTGISHYWFDP (SEQ ID NO: 7), light chain CDR1 GSNLGADYG (SEQ ID NO: 8), light chain CDR2 GDR (SEQ ID NO: 9) and light chain CDR3 QSYDRSLNWV (SEQ ID NO: 10).
  • the antibody or antibody fragment may be encoded by heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2, by heavy and light chain variable sequences having 70%, 80%, or 90% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2, or by heavy and light chain variable sequences having 95% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2.
  • the antibody or antibody fragment may comprise heavy and light chain variable sequences heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4, may comprise heavy and light chain variable sequences having 70%, 80% or 90% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4, or may comprise heavy and light chain variable sequences having 95% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4.
  • the antibody fragment may be a recombinant scFv (single chain fragment variable) antibody, Fab fragment, F(ab’)2 fragment, or Fv fragment, a chimeric antibody and/or is an IgG.
  • the antibody or antibody fragment may recognize an epitope on pre-fusion and post- fusion RSV F protein in antigenic sites II (alternatively called site A) and IV, and optionally binds to human metapneumovirus F protein.
  • the antibody or antibody fragment may neutralize RSV and human metapneumovirus.
  • the antibody or antibody fragment may be administered prior to infection or administered after infection. Delivering comprises antibody or antibody fragment administration, or genetic delivery with an RNA or DNA sequence or vector encoding the antibody or antibody fragment.
  • a monoclonal antibody or antibody fragment comprises heavy chain CDR1 GFTFSSYR (SEQ ID NO: 5), heavy chain CDR2 ITASSSYI (SEQ ID NO: 6), heavy chain CDR3 ARDENTGISHYWFDP (SEQ ID NO: 7), light chain CDR1 GSNLGADYG (SEQ ID NO: 8), light chain CDR2 GDR (SEQ ID NO: 9) and light chain CDR3 QSYDRSLNWV (SEQ ID NO: 10).
  • the antibody or antibody fragment may be encoded by heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2, by heavy and light chain variable sequences having 70%, 80%, or 90% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2, or by heavy and light chain variable sequences having 95% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2.
  • the antibody or antibody fragment may comprise heavy and light chain variable sequences heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4, may comprise heavy and light chain variable sequences having 70%, 80% or 90% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4, or may comprise heavy and light chain variable sequences having 95% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4.
  • the antibody fragment may be a recombinant scFv (single chain fragment variable) antibody, Fab fragment, F(ab’)2 fragment, or Fv fragment, or is a chimeric antibody, a bispecific antibody, and/or is an IgG.
  • the antibody or antibody fragment may recognize an epitope on pre-fusion and post-fusion RSV F protein in antigenic sites II (alternatively called A) and IV, and optionally binds to human metapneumovirus F protein, and/or neutralizes RSV and/or human metapneumovirus.
  • the antibody or antibody fragment may further comprise a cell penetrating peptide and/or is an intrabody.
  • a hybridoma or engineered cell encoding an antibody or antibody fragment wherein the antibody or antibody fragment is characterized by heavy chain CDR1 GFTFSSYR (SEQ ID NO: 5), heavy chain CDR2 ITASSSYI (SEQ ID NO: 6), heavy chain CDR3 ARDENTGISHYWFDP (SEQ ID NO: 7), light chain CDR1 GSNLGADYG (SEQ ID NO: 8), light chain CDR2 GDR (SEQ ID NO: 9) and light chain CDR3 QSYDRSLNWV (SEQ ID NO: 10).
  • heavy chain CDR1 GFTFSSYR SEQ ID NO: 5
  • heavy chain CDR2 ITASSSYI SEQ ID NO: 6
  • heavy chain CDR3 ARDENTGISHYWFDP SEQ ID NO: 7
  • light chain CDR1 GSNLGADYG SEQ ID NO: 8
  • light chain CDR2 GDR SEQ ID NO: 9
  • light chain CDR3 QSYDRSLNWV SEQ
  • the antibody or antibody fragment may be encoded by heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2, by heavy and light chain variable sequences having 70%, 80%, or 90% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2, or by heavy and light chain variable sequences having 95% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2.
  • the antibody or antibody fragment may comprise heavy and light chain variable sequences heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4, may comprise heavy and light chain variable sequences having 70%, 80% or 90% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4, or may comprise heavy and light chain variable sequences having 95% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4.
  • the antibody fragment may be a recombinant scFv (single chain fragment variable) antibody, Fab fragment, F(ab’)2 fragment, or Fv fragment.
  • the antibody may be a chimeric antibody, a bispecific antibody, and/or is an IgG.
  • the antibody or antibody fragment may recognize an epitope on pre-fusion and post- fusion RSV F protein in antigenic sites II (alternatively called A) and IV, and optionally binds to human metapneumovirus F protein, and/or neutralizes RSV and/or human metapneumovirus.
  • the antibody or antibody fragment further comprises a cell penetrating peptide and/or is an intrabody.
  • a vaccine formulation comprising one or more antibodies or antibody fragments characterized by heavy chain CDR1 GFTFSSYR (SEQ ID NO: 5), heavy chain CDR2 ITASSSYI (SEQ ID NO: 6), heavy chain CDR3 ARDENTGISHYWFDP (SEQ ID NO: 7), light chain CDR1 GSNLGADYG (SEQ ID NO: 8), light chain CDR2 GDR (SEQ ID NO: 9) and light chain CDR3 QSYDRSLNWV (SEQ ID NO: 10).
  • heavy chain CDR1 GFTFSSYR SEQ ID NO: 5
  • heavy chain CDR2 ITASSSYI SEQ ID NO: 6
  • heavy chain CDR3 ARDENTGISHYWFDP SEQ ID NO: 7
  • light chain CDR1 GSNLGADYG SEQ ID NO: 8
  • light chain CDR2 GDR SEQ ID NO: 9
  • light chain CDR3 QSYDRSLNWV SEQ ID NO: 10
  • the antibody or antibody fragment may be encoded by heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2, by heavy and light chain variable sequences having 70%, 80%, or 90% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2, or by heavy and light chain variable sequences having 95% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2.
  • the antibody or antibody fragment may comprise heavy and light chain variable sequences heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4, may comprise heavy and light chain variable sequences having 70%, 80% or 90% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4, or may comprise heavy and light chain variable sequences having 95% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4.
  • At least one of said antibody fragments may be a recombinant ScFv (single chain fragment variable) antibody, Fab fragment, F(ab’)2 fragment, or Fv fragment, or is a chimeric antibody, is bispecific antibody, and/or is an IgG.
  • the antibody or antibody fragment may recognize an epitope on pre-fusion and post-fusion RSV F protein in antigenic sites II (alternatively called A) and IV, and optionally binds to human metapneumovirus F protein, and/or neutralizes RSV and/or human metapneumovirus.
  • At least one of said antibodies or antibody fragments may further comprise a cell penetrating peptide and/or is an intrabody.
  • An additional embodiment comprises a method of identifying anti-human respiratory syncytial virus (hRSV) protein F site A/IV-specific monoclonal antibody or polyclonal neutralizing antibodies comprising (a) contacting a candidate monoclonal antibody or polyclonal serum with hRSV protein F in the presence of the antibody or antibody fragment as described above; (b)assessing binding of said candidate monoclonal antibody or polyclonal serum to hRSV protein F; and (c) identifying said candidate monoclonal antibody or polyclonal serum as protein F site II (or A)/IV-specific neutralizing when said antibody or antibody fragment as described above blocks binding of said candidate monoclonal antibody or polyclonal serum to hRSV protein F.
  • hRSV anti-human respiratory syncytial virus
  • the method may further comprise performing a control reaction where said candidate monoclonal antibody is contacted with hRSV protein F in the absence of the antibody or antibody fragment as described above.
  • Detection may comprise ELISA, RIA or Western blot.
  • the antibody or antibody fragment may be encoded by heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2, by heavy and light chain variable sequences having 70%, 80%, or 90% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2, or by heavy and light chain variable sequences having 95% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 1 and 2.
  • the antibody or antibody fragment may comprise heavy and light chain variable sequences heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4, may comprise heavy and light chain variable sequences having 70%, 80% or 90% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4, or may comprise heavy and light chain variable sequences having 95% identity to heavy and light chain variable sequences as set forth in SEQ ID NOS: 3 and 4.
  • the antibody fragment may be a recombinant ScFv (single chain fragment variable) antibody, Fab fragment, F(ab’) 2 fragment, or Fv fragment, or is a chimeric antibody, a bispecific antibody, and/or is an IgG.
  • a further embodiment comprises a monoclonal antibody or fragment thereof, or hybridoma or engineered cell comprising the same, wherein said antibody or fragment thereof recognizes an epitope on pre-fusion and post-fusion RSV F protein in antigenic site II (or A)/IV, and also recognized an epitope on hMPV F protein.
  • Still yet another embodiment comprises a method of determining the antigenic integrity of an antigen comprising (a) contacting a sample comprising said antigen with a first antibody or antibody fragment having clone-paired heavy and light chain CDR sequences from Tables 3 and 4, respectively; and (b) determining antigenic integrity of said antigen by detectable binding of said antibody or antibody fragment to said antigen.
  • the sample may comprise recombinantly produced antigen.
  • the sample may comprise a vaccine formulation or vaccine production batch.
  • Detection may comprise ELISA, RIA, Western blot, a biosensor using surface plasmon resonance or biolayer interferometry, or flow cytometric staining.
  • the first antibody or antibody fragment may be encoded by clone-paired variable sequences as set forth in Table 1, or may be encoded by light and heavy chain variable sequences having 70%, 80%, or 90% identity to clone-paired variable sequences as set forth in Table 1, or may be encoded by light and heavy chain variable sequences having 95% identity to clone-paired sequences as set forth in Table 1.
  • the first antibody or antibody fragment may comprise light and heavy chain variable sequences according to clone-paired sequences from Table 2, or may comprise light and heavy chain variable sequences having 70%, 80% or 90% identity to clone-paired sequences from Table 2, or may comprise light and heavy chain variable sequences having 95% identity to clone-paired sequences from Table 2.
  • the antibody fragment may be a recombinant ScFv (single chain fragment variable) antibody, Fab fragment, F(ab’)2 fragment, or Fv fragment.
  • the method may further comprising performing steps (a) and (b) a second time to determine the antigenic stability of the antigen over time.
  • the method may further comprise (c) contacting a sample comprising said antigen with an antibody or antibody fragment having clone-paired heavy and light chain CDR sequences from Tables 3 and 4, respectively; and (d) determining antigenic integrity of said antigen by detectable binding of said antibody or antibody fragment to said antigen.
  • the second antibody or antibody fragment may be encoded by clone-paired variable sequences as set forth in Table 1, or may be encoded by light and heavy chain variable sequences having 70%, 80%, or 90% identity to clone-paired variable sequences as set forth in Table 1, or may be encoded by light and heavy chain variable sequences having 95% identity to clone-paired sequences as set forth in Table 1.
  • the second antibody or antibody fragment may comprise light and heavy chain variable sequences according to clone-paired sequences from Table 2, or may comprise light and heavy chain variable sequences having 70%, 80% or 90% identity to clone-paired sequences from Table 2, or may comprise light and heavy chain variable sequences having 95% identity to clone-paired sequences from Table 2.
  • the second antibody fragment may be a recombinant ScFv (single chain fragment variable) antibody, Fab fragment, F(ab’)2 fragment, or Fv fragment.
  • the method may further comprise performing steps (c) and (d) a second time to determine the antigenic stability of the antigen over time.
  • the use of the word“a” or“an” when used in conjunction with the term“comprising” in the claims and/or the specification may mean“one,” but it is also consistent with the meaning of“one or more,”“at least one,” and“one or more than one.”
  • the word“about” means plus or minus 5% of the stated number.
  • FIGS. 1A-B Overall structure of the RSV F:MPE8 complex.
  • FIGS. 1A-B Structure of the complex of MPE8 scFv with prefusion RSV F.
  • RSV F subunits are shown in surface format. Two subunits are colored light grey. The third subunit is colored by domain (DI: cyan; DII: green; DIII: magenta: heptad repeat B (HRB): blue).
  • the MPE8 scFvs are shown in cartoon format with VH colored salmon and VL colored yellow.
  • the view in FIG.1B is rotated 90 ⁇ from FIG.1A and oriented down the 3-fold axis of the F trimer.
  • MPE8 binds an epitope in the midsection of the RSV F ectodomain at the intersection of DI, DII and DIII domains from two subunits of the F trimer.
  • FIGS.2A-D The MPE8 epitope and paratope.
  • the MPE8 epitope is formed by residues from two adjacent F subunits. MPE8 is shown in cartoon format, with VH in pink and VL in yellow. The RSV F surface is shown, with interacting residues colored cyan and magenta in the two subunits as indicated.
  • HCDR3 extends into a deep pocket at the F intersubunit interface, making contacts with both chains that are dependent on the prefusion F conformation. The HCDR3 extends underneath the Site A helix-turn-helix motif recognized by palivizumab/motavizumab.
  • MPE8 CDR loops form an extensive interface with RSV F, with HCDR1, HCDR2, LCDR1 and LCDR3 contacting one subunit.
  • LCDR2 contacts a second subunit of F, while HCDR3 interacts with both.
  • LCDR1 interacts with beta strands in HRA that refold to helices in the postfusion conformation.
  • FIG. 2D HCDR3 folds over the surface of the VH and VL interface, covering residues of LCDR2 implicated in cross-reactive recognition of RSV and HMPV F.
  • FIGS. 3A-D Structural basis for MPE8 cross-reactivity.
  • HCDR1, HCDR2 and HCDR3 interact with a contiguous patch of conserved residues within the MPE8 epitope on F.
  • the RSV F epitope is colored by conservation (conserved: light orange; not conserved between RSV/HMPV: medium blue; not conserved between HMPV A/B strains: dark blue)
  • FIGGS.3B Location of predicted somatic mutations in mature MPE8. Somatically mutated residues are shown as spheres. Residue labels with yellow background indicate residues forming contacts with RSV F. The label for LCDR2 residue D50 is highlighted with a red box.
  • VH and VL are shown in cartoon format, colored pink and yellow, respectively.
  • the view in panel (FIG.3C) is rotated 90 ⁇ about the horizontal from FIG.3B.
  • VL D50 within LCDR2 does not directly contact RSV F. D50 makes a hydrogen bond to the sidechain of HCDR3 residue T98, which could impact HCDR3 conformation and HMPV cross-reactivity.
  • FIGS. 4A-E. 25P13 is a unique RSV and HMPV cross-reactive neutralizing antibody that recognizes both the prefusion and postfusion forms of RSV F protein.
  • FIG.4A 25P13 binds both RSV and HMPV F proteins and neutralizes both viruses.
  • FIG.4B Epitope binning using the OctetRed system with anti-penta-HIS biosensors. Sensors were coated with RSV A2 fusion protein (DS-Cav1, prefusion conformation). Horizontal mAbs were loaded first, followed by the vertical mAbs.
  • MAbs were judged to compete for the same site if maximum binding of the competing mAb was reduced to ⁇ 33% of its un-competed binding (black boxes with white numbers). MAbs were considered non-competing if maximum binding of the competing mAb was >66% of its un-competed binding (white boxes with red numbers). Gray boxes with black numbers indicate an intermediate phenotype (between 33 and 66% of un-competed binding).
  • FIG. 4C Epitope binning using OctetRed system with anti-penta-HIS biosensors. Sensors were coated with RSV A2 fusion protein (postfusion conformation, fusion peptide removed). Horizontal mAbs were loaded first, followed by the vertical mAbs.
  • MAbs were judged to compete for the same site if maximum binding of the competing mAb was reduced to ⁇ 33% of its un-competed binding (black boxes with white numbers). MAbs were considered non-competing if maximum binding of the competing mAb was >66% of its un-competed binding (white boxes with red numbers). Gray boxes with black numbers indicate an intermediate phenotype (between 33 and 66% of un-competed binding).
  • FIG.4E Antibody ELISA assays with RSV F mutants that disrupt MPE8 binding (Corti et al., 2013) and lie within the MPE8 epitope (D310A and G307R).
  • FIG. 5 Sequences of the MPE8 VH (SEQ ID NO: 20) and VL (SEQ ID NO: 21) domains. The Chothia numbering scheme for antibodies (used here) is shown above the sequences in single letter amino acid format. The IMGT sequence numbering used previously (Corti et al., 2013) is shown below the sequences.
  • FIG. 6 Schematics of MPE8 scFv constructs.
  • the full mature VH and VL sequences are referred to as VHsm and VLsm, respectively.
  • the inferred unmutated common ancestor sequences are referred to a VHgl and VLgl.
  • the N94S mutation removes an N-linked glycosylation site and was previously shown not to affect MPE8 neutralization and is used here as the mature MPE8 sequence (Corti et al., 2013).
  • Other mutations of the mature sequence are shown above the diagrams, with residues labeled in the Chothia numbering scheme (FIG.5).
  • GT(GGSGG)3GAS SEQ ID NO:23) FIGS. 7A-B.
  • FIG. 7A Gel filtration profiles of the purified RSV F DS-CAV1 and DS-CAV1:MPE8 complex.
  • FIG.7B SDS-PAGE analysis of purified F:MPE8 complexes and a dissolved crystal.
  • FIGS.8A-D Superposition of the postfusion RSV F onto the DS-CAV1:MPE8 complex.
  • FIG. 8A The DSCAV1:MPE8 complex structure is shown with a single subunit of the F trimer represented in cartoon format in grey. The MPE8 scFv is shown as a semitransparent surface with VL in yellow and VH in pink. Residues that contact MPE8 in the two RSV F HRA ⁇ -strands are shown as blue spheres.
  • FIG. 8B Superposition of a single subunit of the postfusion RSV F trimer (Swanson et al., 2011; McLellan et al., 2011) onto the DSCAV1:MPE8 complex.
  • the postfusion RSV F is shown in cartoon format in grey with the translocated HRA ⁇ -strand residues shown as blue spheres.
  • FIG. 8CC The DS-CAV1:MPE8 trimer structure is shown in cartoon format with two subunits of the F trimer colored grey and one colored blue.
  • the F DII domain makes contacts to MPE8 VL in the prefusion conformation.
  • FIG. 8D The postfusion RSV F trimer structure is shown in cartoon format with two subunits of the F trimer colored grey and one colored blue. In the postfusion conformation, the F DII domain makes significant clashes with the MPE8 VL, contributing to the prefusion specificity.
  • FIGS 9A-B Mutations in F that disrupt MPE8 binding map to the interface.
  • FIG.9A Surface representation of F showing the location of residues within the MPE8 epitope that disrupt MPE8 binding (Corti et al., 2013). The epitope is colored light purple, with magenta indicating the positions of residues R49, T50, L305, G307, I309 and D310 that selectively reduce MPE8 binding to RSV F.
  • FIG.9B Close-up view of the F residues implicated in MPE8 binding, showing the positions of MPE8 HCDR2, HCDR3 and LCDR1. The F residues are shown in stick representation and colored magenta. The turn and C-terminal helix of the site A epitope are labeled.
  • FIGS. 11A-D The MPE8 epitope is distinct from other structurally characterized anti-RSV F neutralizing antibodies. RSV F is shown in surface representation with antibodies shown in cartoon format, colored from N- (blue) to C- (red) termini for each chain.
  • FIG.11A MPE8:RSV F complex determined here.
  • FIG. 11B D25:F complex (3).
  • FIG.11C Low resolution motavizumab:F complex (Gilman et al., 2015).
  • FIG.11D Low resolution AM14:F complex (Gilman et al., 2015).
  • Respiratory syncytial virus remains a major human pathogen, infecting the majority of infants before age two and causing reinfection throughout life.
  • RSV Respiratory syncytial virus
  • F RSV fusion
  • the inventors examine the structural basis for cross-reactive antibody neutralization of the RSV and HMPV fusion (F) protein by two related, independently isolated antibodies, MPE8 that was previously reported and a new antibody designated 25P13. They solved the structure of the MPE8 antibody bound to RSV F and identified a related antibody (25P13) from an independent blood donor.
  • the 25P13 antibody not only recognizes both RSV and HMPV, but also this antibody recognizes both the prefusion and post-fusion forms of the F proteins; MPE8 recognizes only the prefusion form of F.
  • RSV Human respiratory syncytial virus
  • palivizumab can be employed to prevent human RSV in preterm (under 35 weeks gestation) infants, infants with certain congenital heart defects (CHD) or bronchopulmonary dysplasia (BPD), and infants with congenital malformations of the airway. Treatment is limited to supportive care (e.g., C-PAP), including oxygen therapy.
  • supportive care e.g., C-PAP
  • Human RSV is a negative-sense, single-stranded RNA virus of the family Pneumoviridae. Its name comes from the fact that F proteins on the surface of the virus cause the cell membranes on nearby cells to merge, forming syncytia. It was first isolated in 1956 from a chimpanzee, and called Chimpanzee Coryza Agent (CCA). Also in 1956, a new type of cytopathogenic myxovirus was isolated from a group of human infants with infantile croup. In temperate climates there is an annual epidemic during the winter months. In tropical climates, infection is most common during the rainy season.
  • CCA Chimpanzee Coryza Agent
  • HRSV human immunocompromised virus
  • the incubation time is 4–5 days.
  • HRSV produces mainly mild symptoms, often indistinguishable from common colds and minor illnesses.
  • the Centers for Disease Control consider HRSV to be the“most common cause of bronchiolitis (inflammation of the small airways in the lung) and pneumonia in children under 1 year of age in the United States.”
  • RSV can cause bronchiolitis, leading to severe respiratory illness requiring hospitalization and, rarely, causing death. This is more likely to occur in patients that are immunocompromised or infants born prematurely.
  • Other HRSV symptoms common among infants include listlessness, poor or diminished appetite, and a possible fever.
  • Recurrent wheezing and asthma are more common among individuals who suffered severe HRSV infection during the first few months of life than among controls; whether HRSV infection sets up a process that leads to recurrent wheezing or whether those already predisposed to asthma are more likely to become severely ill with HRSV has yet to be determined.
  • Symptoms of pneumonia in immuno-compromised patients such as in transplant patients and especially bone marrow transplant patients should be evaluated to rule out HRSV infection. This can be done by means of polymerase chain reaction (PCR) testing for HRSV nucleic acids in peripheral blood samples if all other infectious processes have been ruled out or if it is highly suspicious for RSV such as a recent exposure to a known source of HRSV infection.
  • PCR polymerase chain reaction
  • Complications include bronchiolitis or pneumonia, asthma, recurring infections, and acute otitis media.
  • Transmission. The incubation period is 2–8 days, but is usually 4–6 days.
  • RSV spreads easily by direct contact, and can remain viable for a half an hour or more on hands or for up to 5 hours on countertops.
  • Childcare facilities allow for rapid child-to-child transmission in a short period of time.
  • RSV can last 2–8 days, but symptoms may persist for up to three weeks.
  • the human RSV is virtually the same as chimpanzee coryza virus and can be transmitted from apes to humans, although transmission from humans to apes is more common.
  • the virus has also been recovered from cattle, goats and sheep, but these are not regarded as major vectors of transmission and there is no animal reservoir of the virus.
  • Human RSV is a medium-sized (120-200 nm) enveloped virus that contains a lipoprotein coat and a linear negative-sense RNA genome (must be converted to an anti-sense genome prior to translation).
  • the former contains virally encoded F, G, and SH lipoproteins.
  • the F and G lipoproteins are the only two that target the cell membrane, and are highly conserved among RSV isolates.
  • HRSV is divided into two antigenic subgroups, A and B, on the basis of the reactivity of the virus with monoclonal antibodies against the attachment (G) and fusion (F) glycoproteins.
  • Subtype B is characterized as the asymptomatic strains of the virus that the majority of the population experiences. The more severe clinical illnesses involve subtype A strains, which tend to predominate in most outbreaks.
  • the genome is ⁇ 15,000 nucleotides in length and is composed of a single strand of RNA with negative polarity. It has 10 genes encoding 11 proteins. To date, 10 HRSV-A genotypes have been designated, GA1 to GA7, SAA1, NA1, and NA2.
  • the HRSV-B genotypes include GB1 to GB4, SAB1 to SAB3, and BA1 to BA6. The genome of HRSV was completely sequenced in 1997.
  • Diagnosis Human respiratory syncytial virus may be suspected based on the time of year of the infection; prevalence usually coincides with the winter flu season. Tests include (a) chest X-rays to check for typical bilateral perihilar fullness of bronchiolitis induced by the virus, (b) skin monitoring to check for hypoxemia, a lower than usual level of oxygen in the bloodstream, (c) blood tests to check white cell counts or to look for the presence of viruses, bacteria or other organisms, and (d) lab testing of respiratory secretions.
  • RT-PCR assays are now commercially available. The sensitivity of these assays is equal to or exceeds the sensitivity of virus isolation and antigen detections methods. Highly sensitive RT-PCR assays should be considered when testing adults, because they may have low viral loads in their respiratory specimens.
  • Serologic tests are less frequently used for diagnosis. Although useful for research, a diagnosis using a collection of paired acute and convalescent sera to demonstrate a significant rise in antibody titer to HRSV cannot be made in time to guide care of the patient. On top of that, the antibody level does not always correlate with the acuteness or activity level of the infection.
  • RSV infection can be confirmed using tests for antigens or antibodies, or viral RNA by reverse transcription PCR. Quantification of viral load can be determined by various assay tests.
  • palivizumab brand name Synagis manufactured by MedImmune
  • Palivizumab is a monoclonal antibody directed against RSV surface fusion protein. It is given by monthly injections, which are begun just prior to the RSV season and are usually continued for five months.
  • HRSV prophylaxis is indicated for infants that are premature or have either cardiac or lung disease, but the cost of prevention limits use in many parts of the world.
  • Vaccine Research A vaccine trial in 1960s using a formalin-inactivated vaccine (FI- RSV) increased disease severity in children who had been vaccinated. There is much active investigation into the development of a new vaccine, but at present no vaccine exists. Some of the most promising candidates are based on temperature sensitive mutants which have targeted genetic mutations to reduce virulence.
  • FI- RSV formalin-inactivated vaccine
  • nebulized hypertonic saline has shown that the use of nebulized 3% HS is a safe, inexpensive, and effective treatment for infants hospitalized with moderately severe viral bronchiolitis where respiratory syncytial virus (RSV) accounts for the majority of viral bronchiolitis cases.
  • RSV respiratory syncytial virus
  • One study noted a 26% reduction in length of stay: 2.6 ⁇ 1.9 days, compared with 3.5 ⁇ 2.9 days in the normal-saline treated group (p 0.05).
  • Supportive care includes fluids and oxygen until the illness runs its course.
  • Salbutamol may be used in an attempt to relieve any bronchospasm if present. Increased airflow, humidified and delivered via nasal cannula, may be supplied in order to reduce the effort required for respiration.
  • monoclonal antibodies binding to human respiratory syncytial virus will have several applications. These include the production of diagnostic kits for use in detecting and diagnosing human respiratory syncytial virus infection, as well as for treating the same. In these contexts, one may link such antibodies to diagnostic or therapeutic agents, use them as capture agents or competitors in competitive assays, or use them individually without additional agents being attached thereto. The antibodies may be mutated or modified, as discussed further below. Methods for preparing and characterizing antibodies are well known in the art (see, e.g., Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory, 1988; U.S. Patent 4,196,265).
  • the methods for generating monoclonal antibodies generally begin along the same lines as those for preparing polyclonal antibodies.
  • the first step for both these methods is immunization of an appropriate host or identification of subjects who are immune due to prior natural infection.
  • a given composition for immunization may vary in its immunogenicity. It is often necessary therefore to boost the host immune system, as may be achieved by coupling a peptide or polypeptide immunogen to a carrier.
  • exemplary and preferred carriers are keyhole limpet hemocyanin (KLH) and bovine serum albumin (BSA).
  • KLH keyhole limpet hemocyanin
  • BSA bovine serum albumin
  • Other albumins such as ovalbumin, mouse serum albumin or rabbit serum albumin can also be used as carriers.
  • Means for conjugating a polypeptide to a carrier protein are well known in the art and include glutaraldehyde, m-maleimidobencoyl-N-hydroxysuccinimide ester, carbodiimyde and bis-biazotized benzidine.
  • the immunogenicity of a particular immunogen composition can be enhanced by the use of non-specific stimulators of the immune response, known as adjuvants.
  • adjuvants include complete Freund’s adjuvant (a non-specific stimulator of the immune response containing killed Mycobacterium tuberculosis), incomplete Freund’s adjuvants and aluminum hydroxide adjuvant.
  • a suitable approach is to identify subjects that have been exposed to the pathogens, such as those who have been diagnosed as having contracted the disease, or those who have been vaccinated to generate protective immunity against the pathogen. Circulating anti-pathogen antibodies can be detected, and antibody producing B cells from the antibody-positive subject may then be obtained.
  • the amount of immunogen composition used in the production of polyclonal antibodies varies upon the nature of the immunogen as well as the animal used for immunization.
  • a variety of routes can be used to administer the immunogen (subcutaneous, intramuscular, intradermal, intravenous and intraperitoneal).
  • the production of polyclonal antibodies may be monitored by sampling blood of the immunized animal at various points following immunization. A second, booster injection, also may be given. The process of boosting and titering is repeated until a suitable titer is achieved.
  • the immunized animal can be bled and the serum isolated and stored, and/or the animal can be used to generate MAbs.
  • somatic cells with the potential for producing antibodies, specifically B lymphocytes (B cells), are selected for use in the MAb generating protocol. These cells may be obtained from biopsied spleens or lymph nodes, or from circulating blood. The antibody-producing B lymphocytes from the immunized animal are then fused with cells of an immortal myeloma cell, generally one of the same species as the animal that was immunized or human or human/mouse chimeric cells.
  • B lymphocytes B lymphocytes
  • Myeloma cell lines suited for use in hybridoma-producing fusion procedures preferably are non-antibody-producing, have high fusion efficiency, and enzyme deficiencies that render then incapable of growing in certain selective media which support the growth of only the desired fused cells (hybridomas). Any one of a number of myeloma cells may be used, as are known to those of skill in the art (Goding, pp.65-66, 1986; Campbell, pp.75-83, 1984).
  • Methods for generating hybrids of antibody-producing spleen or lymph node cells and myeloma cells usually comprise mixing somatic cells with myeloma cells in a 2:1 proportion, though the proportion may vary from about 20:1 to about 1:1, respectively, in the presence of an agent or agents (chemical or electrical) that promote the fusion of cell membranes.
  • Fusion methods using Sendai virus have been described by Kohler and Milstein (1975; 1976), and those using polyethylene glycol (PEG), such as 37% (v/v) PEG, by Gefter et al. (1977).
  • PEG polyethylene glycol
  • the use of electrically induced fusion methods also is appropriate (Goding, pp. 71-74, 1986).
  • Fusion procedures usually produce viable hybrids at low frequencies, about 1 x 10 -6 to 1 x 10- 8 . However, this does not pose a problem, as the viable, fused hybrids are differentiated from the parental, infused cells (particularly the infused myeloma cells that would normally continue to divide indefinitely) by culturing in a selective medium.
  • the selective medium is generally one that contains an agent that blocks the de novo synthesis of nucleotides in the tissue culture media.
  • Exemplary and preferred agents are aminopterin, methotrexate, and azaserine. Aminopterin and methotrexate block de novo synthesis of both purines and pyrimidines, whereas azaserine blocks only purine synthesis.
  • the media is supplemented with hypoxanthine and thymidine as a source of nucleotides (HAT medium).
  • HAT medium a source of nucleotides
  • azaserine is used, the media is supplemented with hypoxanthine.
  • Ouabain is added if the B cell source is an Epstein Barr virus (EBV) transformed human B cell line, in order to eliminate EBV transformed lines that have not fused to the myeloma.
  • EBV Epstein Barr virus
  • the preferred selection medium is HAT or HAT with ouabain. Only cells capable of operating nucleotide salvage pathways are able to survive in HAT medium.
  • the myeloma cells are defective in key enzymes of the salvage pathway, e.g., hypoxanthine phosphoribosyl transferase (HPRT), and they cannot survive.
  • HPRT hypoxanthine phosphoribosyl transferase
  • the B cells can operate this pathway, but they have a limited life span in culture and generally die within about two weeks. Therefore, the only cells that can survive in the selective media are those hybrids formed from myeloma and B cells.
  • ouabain may also be used for drug selection of hybrids as EBV-transformed B cells are susceptible to drug killing, whereas the myeloma partner used is chosen to be ouabain resistant.
  • Culturing provides a population of hybridomas from which specific hybridomas are selected. Typically, selection of hybridomas is performed by culturing the cells by single-clone dilution in microtiter plates, followed by testing the individual clonal supernatants (after about two to three weeks) for the desired reactivity.
  • the assay should be sensitive, simple and rapid, such as radioimmunoassays, enzyme immunoassays, cytotoxicity assays, plaque assays dot immunobinding assays, and the like.
  • the selected hybridomas are then serially diluted or single-cell sorted by flow cytometric sorting and cloned into individual antibody-producing cell lines, which clones can then be propagated indefinitely to provide mAbs.
  • the cell lines may be exploited for MAb production in two basic ways.
  • a sample of the hybridoma can be injected (often into the peritoneal cavity) into an animal (e.g., a mouse).
  • the animals are primed with a hydrocarbon, especially oils such as pristane (tetramethylpentadecane) prior to injection.
  • pristane tetramethylpentadecane
  • the injected animal develops tumors secreting the specific monoclonal antibody produced by the fused cell hybrid.
  • the body fluids of the animal such as serum or ascites fluid, can then be tapped to provide MAbs in high concentration.
  • the individual cell lines could also be cultured in vitro, where the MAbs are naturally secreted into the culture medium from which they can be readily obtained in high concentrations.
  • human hybridoma cells lines can be used in vitro to produce immunoglobulins in cell supernatant.
  • the cell lines can be adapted for growth in serum-free medium to optimize the ability to recover human monoclonal immunoglobulins of high purity.
  • MAbs produced by either means may be further purified, if desired, using filtration, centrifugation and various chromatographic methods such as FPLC or affinity chromatography.
  • Fragments of the monoclonal antibodies of the disclosure can be obtained from the purified monoclonal antibodies by methods which include digestion with enzymes, such as pepsin or papain, and/or by cleavage of disulfide bonds by chemical reduction.
  • monoclonal antibody fragments encompassed by the present disclosure can be synthesized using an automated peptide synthesizer.
  • RNA can be isolated from the hybridoma line and the antibody genes obtained by RT-PCR and cloned into an immunoglobulin expression vector.
  • combinatorial immunoglobulin phagemid libraries are prepared from RNA isolated from the cell lines and phagemids expressing appropriate antibodies are selected by panning using viral antigens.
  • the antibody according to the present disclosure may be defined, in the first instance, by binding specificity.
  • Those of skill in the art by assessing the binding specificity/affinity of a given antibody using techniques well known to those of skill in the art, can determine whether such antibodies fall within the scope of the instant claims.
  • monoclonal antibodies having clone-paired CDRs from the heavy and light chains as illustrated in Tables 3 and 4, respectively. Such antibodies may be produced by the clones discussed below in the Examples section using methods described herein.
  • the antibodies of the present disclosure relate to the identification, through their binding specificity, of a previously unrecognized complex epitope that comprises elements of the previously designated antigenic site A (also called site II) and elements of site IV.
  • the antibodies may be defined by their variable sequence, which include additional“framework” regions. These are provided in Tables 1 and 2 that encode or represent full variable regions. Furthermore, the antibodies sequences may vary from these sequences, optionally using methods discussed in greater detail below.
  • nucleic acid sequences may vary from those set out above in that (a) the variable regions may be segregated away from the constant domains of the light and heavy chains, (b) the nucleic acids may vary from those set out above while not affecting the residues encoded thereby, (c) the nucleic acids may vary from those set out above by a given percentage, e.g., 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% homology, (d) the nucleic acids may vary from those set out above by virtue of the ability to hybridize under high stringency conditions, as exemplified by low salt and/or high temperature conditions, such as provided by about 0.02 M to about 0.15 M NaCl at temperatures of about 50°C to about 70°C, (e) the amino acids may vary from those set out above by a given percentage, e.g., 80%, 85%, 90%, 91%, 92%, 93%, 9
  • Hybridomas may be cultured, then cells lysed, and total RNA extracted. Random hexamers may be used with RT to generate cDNA copies of RNA, and then PCR performed using a multiplex mixture of PCR primers expected to amplify all human variable gene sequences. PCR product can be cloned into pGEM-T Easy vector, then sequenced by automated DNA sequencing using standard vector primers. Assay of binding and neutralization may be performed using antibodies collected from hybridoma supernatants and purified by FPLC, using Protein G columns.
  • Recombinant full length IgG antibodies were generated by subcloning heavy and light chain Fv DNAs from the cloning vector into an IgG plasmid vector, transfected into 293 Freestyle cells or CHO cells, and antibodies were collected an purified from the 293 or CHO cell supernatant.
  • Lonza has developed a generic method using pooled transfectants grown in CDACF medium, for the rapid production of small quantities (up to 50 g) of antibodies in CHO cells. Although slightly slower than a true transient system, the advantages include a higher product concentration and use of the same host and process as the production cell line.
  • Antibody molecules will comprise fragments (such as F(ab’), F(ab’)2) that are produced, for example, by the proteolytic cleavage of the mAbs, or single-chain immunoglobulins producible, for example, via recombinant means. Such antibody derivatives are monovalent. In one embodiment, such fragments can be combined with one another, or with other antibody fragments or receptor ligands to form“chimeric” binding molecules. Significantly, such chimeric molecules may contain substituents capable of binding to different epitopes of the same molecule.
  • the antibody is a derivative of the disclosed antibodies, e.g., an antibody comprising the CDR sequences identical to those in the disclosed antibodies (e.g., a chimeric, or CDR-grafted antibody).
  • an antibody comprising the CDR sequences identical to those in the disclosed antibodies (e.g., a chimeric, or CDR-grafted antibody).
  • modifications such as introducing conservative changes into an antibody molecule.
  • the hydropathic index of amino acids may be considered.
  • the importance of the hydropathic amino acid index in conferring interactive biologic function on a protein is generally understood in the art (Kyte and Doolittle, 1982). It is accepted that the relative hydropathic character of the amino acid contributes to the secondary structure of the resultant protein, which in turn defines the interaction of the protein with other molecules, for example, enzymes, substrates, receptors, DNA, antibodies, antigens, and the like.
  • Patent 4,554,101 the following hydrophilicity values have been assigned to amino acid residues: basic amino acids: arginine (+3.0), lysine (+3.0), and histidine (-0.5); acidic amino acids: aspartate (+3.0 ⁇ 1), glutamate (+3.0 ⁇ 1), asparagine (+0.2), and glutamine (+0.2); hydrophilic, nonionic amino acids: serine (+0.3), asparagine (+0.2), glutamine (+0.2), and threonine (-0.4), sulfur containing amino acids: cysteine (-1.0) and methionine (-1.3); hydrophobic, nonaromatic amino acids: valine (-1.5), leucine (-1.8), isoleucine (-1.8), proline (-0.5 ⁇ 1), alanine (-0.5), and glycine (0); hydrophobic, aromatic amino acids: tryptophan (- 3.4), phenylalanine (-2.5), and tyrosine (-2.3).
  • an amino acid can be substituted for another having a similar hydrophilicity and produce a biologically or immunologically modified protein.
  • substitution of amino acids whose hydrophilicity values are within ⁇ 2 is preferred, those that are within ⁇ 1 are particularly preferred, and those within ⁇ 0.5 are even more particularly preferred.
  • amino acid substitutions generally are based on the relative similarity of the amino acid side-chain substituents, for example, their hydrophobicity, hydrophilicity, charge, size, and the like.
  • Exemplary substitutions that take into consideration the various foregoing characteristics are well known to those of skill in the art and include: arginine and lysine; glutamate and aspartate; serine and threonine; glutamine and asparagine; and valine, leucine and isoleucine.
  • the present disclosure also contemplates isotype modification.
  • isotype modification By modifying the Fc region to have a different isotype, different functionalities can be achieved. For example, changing to IgG1 can increase antibody dependent cell cytotoxicity, switching to class A can improve tissue distribution, and switching to class M can improve valency.
  • Modifications in the Fc region can be introduced to extend the in vivo half-life of the antibody, or to alter Fc mediated fucntions such as complement activation, antibody dependent cellular cytotoxicity (ADCC), and FcR mediated phagocytosis.
  • Other types of modifications include residue modification designed to reduce oxidation, aggregation, deamidation, and immunogenicity in humans. Other changes can lead to an increase in manufacturability or yield, or reduced tissue cross-reactivity in humans.
  • Modified antibodies may be made by any technique known to those of skill in the art, including expression through standard molecular biological techniques, or the chemical synthesis of polypeptides. Methods for recombinant expression are addressed elsewhere in this document.
  • a Single Chain Variable Fragment is a fusion of the variable regions of the heavy and light chains of immunoglobulins, linked together with a short (usually serine, glycine) linker.
  • This chimeric molecule retains the specificity of the original immunoglobulin, despite removal of the constant regions and the introduction of a linker peptide. This modification usually leaves the specificity unaltered.
  • These molecules were created historically to facilitate phage display where it is highly convenient to express the antigen binding domain as a single peptide.
  • scFv can be created directly from subcloned heavy and light chains derived from a hybridoma.
  • Single chain variable fragments lack the constant Fc region found in complete antibody molecules, and thus, the common binding sites (e.g., protein A/G) used to purify antibodies. These fragments can often be purified/immobilized using Protein L since Protein L interacts with the variable region of kappa light chains.
  • Flexible linkers generally are comprised of helix- and turn-promoting amino acid residues such as alaine, serine and glycine. However, other residues can function as well.
  • Tang et al. (1996) used phage display as a means of rapidly selecting tailored linkers for single-chain antibodies (scFvs) from protein linker libraries.
  • a random linker library was constructed in which the genes for the heavy and light chain variable domains were linked by a segment encoding an 18-amino acid polypeptide of variable composition.
  • the scFv repertoire (approx. 5 ⁇ 10 6 different members) was displayed on filamentous phage and subjected to affinity selection with hapten. The population of selected variants exhibited significant increases in binding activity but retained considerable sequence diversity.
  • scFv catalytically active scFv that was produced efficiently in soluble form.
  • Sequence analysis revealed a conserved proline in the linker two residues after the VH C terminus and an abundance of arginines and prolines at other positions as the only common features of the selected tethers.
  • the recombinant antibodies of the present disclosure may also involve sequences or moieties that permit dimerization or multimerization of the receptors. Such sequences include those derived from IgA, which permit formation of multimers in conjunction with the J-chain. Another multimerization domain is the Gal4 dimerization domain.
  • the chains may be modified with agents such as biotin/avidin, which permit the combination of two antibodies.
  • a single-chain antibody can be created by joining receptor light and heavy chains using a non-peptide linker or chemical unit.
  • the light and heavy chains will be produced in distinct cells, purified, and subsequently linked together in an appropriate fashion (i.e., the N-terminus of the heavy chain being attached to the C-terminus of the light chain via an appropriate chemical bridge).
  • Cross-linking reagents are used to form molecular bridges that tie functional groups of two different molecules, e.g., a stablizing and coagulating agent.
  • a stablizing and coagulating agent e.g., a stablizing and coagulating agent.
  • dimers or multimers of the same analog or heteromeric complexes comprised of different analogs can be created.
  • hetero- bifunctional cross-linkers can be used that eliminate unwanted homopolymer formation.
  • An exemplary hetero-bifunctional cross-linker contains two reactive groups: one reacting with primary amine group (e.g., N-hydroxy succinimide) and the other reacting with a thiol group (e.g., pyridyl disulfide, maleimides, halogens, etc.).
  • primary amine group e.g., N-hydroxy succinimide
  • a thiol group e.g., pyridyl disulfide, maleimides, halogens, etc.
  • the cross-linker may react with the lysine residue(s) of one protein (e.g., the selected antibody or fragment) and through the thiol reactive group, the cross-linker, already tied up to the first protein, reacts with the cysteine residue (free sulfhydryl group) of the other protein (e.g., the selective agent).
  • cross-linker having reasonable stability in blood will be employed.
  • Numerous types of disulfide-bond containing linkers are known that can be successfully employed to conjugate targeting and therapeutic/preventative agents. Linkers that contain a disulfide bond that is sterically hindered may prove to give greater stability in vivo, preventing release of the targeting peptide prior to reaching the site of action. These linkers are thus one group of linking agents.
  • SMPT cross-linking reagent
  • Another cross-linking reagent is SMPT, which is a bifunctional cross-linker containing a disulfide bond that is“sterically hindered” by an adjacent benzene ring and methyl groups. It is believed that steric hindrance of the disulfide bond serves a function of protecting the bond from attack by thiolate anions such as glutathione which can be present in tissues and blood, and thereby help in preventing decoupling of the conjugate prior to the delivery of the attached agent to the target site.
  • thiolate anions such as glutathione which can be present in tissues and blood
  • the SMPT cross-linking reagent lends the ability to cross-link functional groups such as the SH of cysteine or primary amines (e.g., the epsilon amino group of lysine).
  • Another possible type of cross-linker includes the hetero-bifunctional photoreactive phenylazides containing a cleavable disulfide bond such as sulfosuccinimidyl-2-(p-azido salicylamido) ethyl-1,3'-dithiopropionate.
  • the N-hydroxy- succinimidyl group reacts with primary amino groups and the phenylazide (upon photolysis) reacts non-selectively with any amino acid residue.
  • non-hindered linkers also can be employed in accordance herewith.
  • Other useful cross-linkers include SATA, SPDP and 2-iminothiolane (Wawrzynczak & Thorpe, 1987). The use of such cross-linkers is well understood in the art. Another embodiment involves the use of flexible linkers.
  • U.S. Patent 4,680,3308 describes bifunctional linkers useful for producing conjugates of ligands with amine-containing polymers and/or proteins, especially for forming antibody conjugates with chelators, drugs, enzymes, detectable labels and the like.
  • U.S. Patents 5,141,648 and 5,563,250 disclose cleavable conjugates containing a labile bond that is cleavable under a variety of mild conditions. This linker is particularly useful in that the agent of interest may be bonded directly to the linker, with cleavage resulting in release of the active agent. Particular uses include adding a free amino or free sulfhydryl group to a protein, such as an antibody, or a drug.
  • U.S. Patent 5,856,456 provides peptide linkers for use in connecting polypeptide constituents to make fusion proteins, e.g., single chain antibodies.
  • the linker is up to about 50 amino acids in length, contains at least one occurrence of a charged amino acid (preferably arginine or lysine) followed by a proline, and is characterized by greater stability and reduced aggregation.
  • U.S. Patent 5,880,270 discloses aminooxy-containing linkers useful in a variety of immunodiagnostic and separative techniques. E. Intrabodies
  • the antibody is a recombinant antibody that is suitable for action inside of a cell— such antibodies are known as“intrabodies.”
  • These antibodies may interfere with target function by a variety of mechanism, such as by altering intracellular protein trafficking, interfering with enzymatic function, and blocking protein-protein or protein-DNA interactions.
  • their structures mimic or parallel those of single chain and single domain antibodies, discussed above. Indeed, single-transcript/single-chain is an important feature that permits intracellular expression in a target cell, and also makes protein transit across cell membranes more feasible. However, additional features are required.
  • the two major issues impacting the implementation of intrabody therapeutic are delivery, including cell/tissue targeting, and stability.
  • delivery a variety of approaches have been employed, such as tissue-directed delivery, use of cell-type specific promoters, viral-based delivery and use of cell-permeability/membrane translocating peptides.
  • the approach is generally to either screen by brute force, including methods that involve phage diplay and may include sequence maturation or development of consensus sequences, or more directed modifications such as insertion stabilizing sequences (e.g., Fc regions, chaperone protein sequences, leucine zippers) and disulfide replacement/modification.
  • insertion stabilizing sequences e.g., Fc regions, chaperone protein sequences, leucine zippers
  • intrabodies may require is a signal for intracellular targeting.
  • Vectors that can target intrabodies (or other proteins) to subcellular regions such as the cytoplasm, nucleus, mitochondria and ER have been designed and are commercially available (Invitrogen Corp.; Persic et al., 1997).
  • the antibodies of the present disclosure may be purified.
  • the term“purified,” as used herein, is intended to refer to a composition, isolatable from other components, wherein the protein is purified to any degree relative to its naturally-obtainable state.
  • a purified protein therefore also refers to a protein, free from the environment in which it may naturally occur.
  • this designation will refer to a composition in which the protein or peptide forms the major component of the composition, such as constituting about 50%, about 60%, about 70%, about 80%, about 90%, about 95% or more of the proteins in the composition.
  • Protein purification techniques are well known to those of skill in the art. These techniques involve, at one level, the crude fractionation of the cellular milieu to polypeptide and non-polypeptide fractions. Having separated the polypeptide from other proteins, the polypeptide of interest may be further purified using chromatographic and electrophoretic techniques to achieve partial or complete purification (or purification to homogeneity). Analytical methods particularly suited to the preparation of a pure peptide are ion-exchange chromatography, exclusion chromatography; polyacrylamide gel electrophoresis; isoelectric focusing.
  • protein purification include, precipitation with ammonium sulfate, PEG, antibodies and the like or by heat denaturation, followed by centrifugation; gel filtration, reverse phase, hydroxylapatite and affinity chromatography; and combinations of such and other techniques.
  • polypeptide In purifying an antibody of the present disclosure, it may be desirable to express the polypeptide in a prokaryotic or eukaryotic expression system and extract the protein using denaturing conditions.
  • the polypeptide may be purified from other cellular components using an affinity column, which binds to a tagged portion of the polypeptide.
  • affinity column which binds to a tagged portion of the polypeptide.
  • antibodies are fractionated utilizing agents (i.e., protein A) that bind the Fc portion of the antibody.
  • agents i.e., protein A
  • antigens may be used to simultaneously purify and select appropriate antibodies.
  • Such methods often utilize the selection agent bound to a support, such as a column, filter or bead.
  • the antibodies is bound to a support, contaminants removed (e.g., washed away), and the antibodies released by applying conditions (salt, heat, etc.).
  • compositions comprising anti-human respiratory syncytial virus antibodies and antigens for generating the same.
  • Such compositions comprise a prophylactically or therapeutically effective amount of an antibody or a fragment thereof, or a peptide immunogen, and a pharmaceutically acceptable carrier.
  • pharmaceutically acceptable means approved by a regulatory agency of the Federal or a state government or listed in the U.S. Pharmacopeia or other generally recognized pharmacopeia for use in animals, and more particularly in humans.
  • carrier refers to a diluent, excipient, or vehicle with which the therapeutic is administered.
  • Such pharmaceutical carriers can be sterile liquids, such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil and the like. Water is a particular carrier when the pharmaceutical composition is administered intravenously. Saline solutions and aqueous dextrose and glycerol solutions can also be employed as liquid carriers, particularly for injectable solutions.
  • suitable pharmaceutical excipients include starch, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene, glycol, water, ethanol and the like.
  • compositions can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents.
  • These compositions can take the form of solutions, suspensions, emulsion, tablets, pills, capsules, powders, sustained-release formulations and the like.
  • Oral formulations can include standard carriers such as pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharine, cellulose, magnesium carbonate, etc. Examples of suitable pharmaceutical agents are described in“Remington's Pharmaceutical Sciences.”
  • Such compositions will contain a prophylactically or therapeutically effective amount of the antibody or fragment thereof, preferably in purified form, together with a suitable amount of carrier so as to provide the form for proper administration to the patient.
  • the formulation should suit the mode of administration, which can be oral, intravenous, intraarterial, intrabuccal, intranasal, nebulized, bronchial inhalation, or delivered by mechanical ventilation.
  • Active vaccines are also envisioned where antibodies like those disclosed are produced in vivo in a subject at risk of Human respiratory syncytial virus infection.
  • Such vaccines can be formulated for parenteral administration, e.g., formulated for injection via the intradermal, intravenous, intramuscular, subcutaneous, or even intraperitoneal routes. Administration by intradermal and intramuscular routes are contemplated.
  • the vaccine could alternatively be administered by a topical route directly to the mucosa, for example by nasal drops, inhalation, or by nebulizer.
  • Pharmaceutically acceptable salts include the acid salts and those which are formed with inorganic acids such as, for example, hydrochloric or phosphoric acids, or such organic acids as acetic, oxalic, tartaric, mandelic, and the like. Salts formed with the free carboxyl groups may also be derived from inorganic bases such as, for example, sodium, potassium, ammonium, calcium, or ferric hydroxides, and such organic bases as isopropylamine, trimethylamine, 2-ethylamino ethanol, histidine, procaine, and the like.
  • inorganic acids such as, for example, hydrochloric or phosphoric acids, or such organic acids as acetic, oxalic, tartaric, mandelic, and the like.
  • Salts formed with the free carboxyl groups may also be derived from inorganic bases such as, for example, sodium, potassium, ammonium, calcium, or ferric hydroxides, and such organic bases as isopropylamine, trimethylamine,
  • Passive transfer of antibodies generally will involve the use of intravenous or intramuscular injections.
  • the forms of antibody can be human or animal blood plasma or serum, as pooled human immunoglobulin for intravenous (IVIG) or intramuscular (IG) use, as high-titer human IVIG or IG from immunized or from donors recovering from disease, and as monoclonal antibodies (MAb).
  • IVIG intravenous
  • IG intramuscular
  • MAb monoclonal antibodies
  • Such immunity generally lasts for only a short period of time, and there is also a potential risk for hypersensitivity reactions, and serum sickness, especially from gamma globulin of non-human origin.
  • passive immunity provides immediate protection.
  • the antibodies will be formulated in a carrier suitable for injection, i.e., sterile and syringeable.
  • compositions of the disclosure are supplied either separately or mixed together in unit dosage form, for example, as a dry lyophilized powder or water-free concentrate in a hermetically sealed container such as an ampoule or sachette indicating the quantity of active agent.
  • a hermetically sealed container such as an ampoule or sachette indicating the quantity of active agent.
  • the composition is to be administered by infusion, it can be dispensed with an infusion bottle containing sterile pharmaceutical grade water or saline.
  • an ampoule of sterile water for injection or saline can be provided so that the ingredients may be mixed prior to administration.
  • compositions of the disclosure can be formulated as neutral or salt forms.
  • Pharmaceutically acceptable salts include those formed with anions such as those derived from hydrochloric, phosphoric, acetic, oxalic, tartaric acids, etc., and those formed with cations such as those derived from sodium, potassium, ammonium, calcium, ferric hydroxides, isopropylamine, triethylamine, 2-ethylamino ethanol, histidine, procaine, etc. IV.
  • Antibody Conjugates include those formed with anions such as those derived from hydrochloric, phosphoric, acetic, oxalic, tartaric acids, etc., and those formed with cations such as those derived from sodium, potassium, ammonium, calcium, ferric hydroxides, isopropylamine, triethylamine, 2-ethylamino ethanol, histidine, procaine, etc. IV. Antibody Conjugates
  • Antibodies of the present disclosure may be linked to at least one agent to from an antibody conjugate.
  • it is conventional to link or covalently bind or complex at least one desired molecule or moiety.
  • a molecule or moiety may be, but is not limited to, at least one effector or reporter molecule.
  • Effector molecules comprise molecules having a desired activity, e.g., cytotoxic activity.
  • Non-limiting examples of effector molecules which have been attached to antibodies include toxins, anti-tumor agents, therapeutic enzymes, radionuclides, antiviral agents, chelating agents, cytokines, growth factors, and oligo- or polynucleotides.
  • reporter molecule is defined as any moiety which may be detected using an assay.
  • reporter molecules which have been conjugated to antibodies include enzymes, radiolabels, haptens, fluorescent labels, phosphorescent molecules, chemiluminescent molecules, chromophores, photoaffinity molecules, colored particles or ligands, such as biotin.
  • Antibody conjugates are generally preferred for use as diagnostic agents.
  • Antibody diagnostics generally fall within two classes, those for use in in vitro diagnostics, such as in a variety of immunoassays, and those for use in vivo diagnostic protocols, generally known as "antibody-directed imaging.”
  • Many appropriate imaging agents are known in the art, as are methods for their attachment to antibodies (see, for e.g., U.S. Patents 5,021,236, 4,938,948, and 4,472,509).
  • the imaging moieties used can be paramagnetic ions, radioactive isotopes, fluorochromes, NMR-detectable substances, and X-ray imaging agents.
  • paramagnetic ions such as chromium (III), manganese (II), iron (III), iron (II), cobalt (II), nickel (II), copper (II), neodymium (III), samarium (III), ytterbium (III), gadolinium (III), vanadium (II), terbium (III), dysprosium (III), holmium (III) and/or erbium (III), with gadolinium being particularly preferred.
  • Ions useful in other contexts, such as X-ray imaging include but are not limited to lanthanum (III), gold (III), lead (II), and especially bismuth (III).
  • radioactive isotopes for therapeutic and/or diagnostic application, one might mention astatine 211 , 14 carbon, 51 chromium, 36 chlorine, 57 cobalt, 58 cobalt, copper 67 , 152 Eu, gallium 67 , 3 hydrogen, iodine 123 , iodine 125 , iodine 131 , indium 111 , 59 iron, 32 phosphorus, rhenium 186 , rhenium 188 , 75 selenium, 35 sulphur, technicium 99m and/or yttrium 90 .
  • Radioactively labeled monoclonal antibodies of the present disclosure may be produced according to well-known methods in the art. For instance, monoclonal antibodies can be iodinated by contact with sodium and/or potassium iodide and a chemical oxidizing agent such as sodium hypochlorite, or an enzymatic oxidizing agent, such as lactoperoxidase.
  • Monoclonal antibodies according to the disclosure may be labeled with technetium 99m by ligand exchange process, for example, by reducing pertechnate with stannous solution, chelating the reduced technetium onto a Sephadex column and applying the antibody to this column.
  • direct labeling techniques may be used, e.g., by incubating pertechnate, a reducing agent such as SNCl2, a buffer solution such as sodium-potassium phthalate solution, and the antibody.
  • Intermediary functional groups which are often used to bind radioisotopes which exist as metallic ions to antibody are diethylenetriaminepentaacetic acid (DTPA) or ethylene diaminetetracetic acid (EDTA).
  • fluorescent labels contemplated for use as conjugates include Alexa 350, Alexa 430, AMCA, BODIPY 630/650, BODIPY 650/665, BODIPY-FL, BODIPY-R6G, BODIPY-TMR, BODIPY-TRX, Cascade Blue, Cy3, Cy5,6-FAM, Fluorescein Isothiocyanate, HEX, 6-JOE, Oregon Green 488, Oregon Green 500, Oregon Green 514, Pacific Blue, REG, Rhodamine Green, Rhodamine Red, Renographin, ROX, TAMRA, TET, Tetramethylrhodamine, and/or Texas Red.
  • antibody conjugates contemplated in the present disclosure are those intended primarily for use in vitro, where the antibody is linked to a secondary binding ligand and/or to an enzyme (an enzyme tag) that will generate a colored product upon contact with a chromogenic substrate.
  • suitable enzymes include urease, alkaline phosphatase, (horseradish) hydrogen peroxidase or glucose oxidase.
  • Preferred secondary binding ligands are biotin and avidin and streptavidin compounds. The use of such labels is well known to those of skill in the art and are described, for example, in U.S. Patents 3,817,837, 3,850,752, 3,939,350, 3,996,345, 4,277,437, 4,275,149 and 4,366,241.
  • hapten-based affinity labels react with amino acids in the antigen binding site, thereby destroying this site and blocking specific antigen reaction.
  • this may not be advantageous since it results in loss of antigen binding by the antibody conjugate.
  • Molecules containing azido groups may also be used to form covalent bonds to proteins through reactive nitrene intermediates that are generated by low intensity ultraviolet light (Potter and Haley, 1983).
  • 2- and 8-azido analogues of purine nucleotides have been used as site-directed photoprobes to identify nucleotide binding proteins in crude cell extracts (Owens & Haley, 1987; Atherton et al., 1985).
  • the 2- and 8-azido nucleotides have also been used to map nucleotide binding domains of purified proteins (Khatoon et al., 1989; King et al., 1989; Dholakia et al., 1989) and may be used as antibody binding agents.
  • Some attachment methods involve the use of a metal chelate complex employing, for example, an organic chelating agent such as diethylenetriaminepentaacetic acid anhydride (DTPA); ethylenetriaminetetraacetic acid; N-chloro-p-toluenesulfonamide; and/or tetrachloro-3 ⁇ -6 ⁇ -diphenylglycouril-3 attached to the antibody (U.S. Patents 4,472,509 and 4,938,948).
  • DTPA diethylenetriaminepentaacetic acid anhydride
  • ethylenetriaminetetraacetic acid N-chloro-p-toluenesulfonamide
  • tetrachloro-3 ⁇ -6 ⁇ -diphenylglycouril-3 attached to the antibody
  • Monoclonal antibodies may also be reacted with an enzyme in the presence of a coupling agent such as glutaraldehyde or periodate.
  • Conjugates with fluorescein markers are prepared in the presence of these coupling agents or by reaction with an isothiocyanate.
  • imaging of breast tumors is achieved using monoclonal antibodies and the detectable imaging moieties are bound to the antibody using linkers such as methyl-p- hydroxybenzimidate or N-succinimidyl-3-(4-hydroxyphenyl)propionate.
  • derivatization of immunoglobulins by selectively introducing sulfhydryl groups in the Fc region of an immunoglobulin, using reaction conditions that do not alter the antibody combining site are contemplated.
  • Antibody conjugates produced according to this methodology are disclosed to exhibit improved longevity, specificity and sensitivity (U.S. Patent 5,196,066, incorporated herein by reference).
  • Site-specific attachment of effector or reporter molecules, wherein the reporter or effector molecule is conjugated to a carbohydrate residue in the Fc region have also been disclosed in the literature (O’Shannessy et al., 1987). This approach has been reported to produce diagnostically and therapeutically promising antibodies which are currently in clinical evaluation. V. Immunodetection Methods
  • the present disclosure concerns immunodetection methods for binding, purifying, removing, quantifying and otherwise generally detecting Human respiratory syncytial virus and its associated antigens. While such methods can be applied in a traditional sense, another use will be in quality control and monitoring of vaccine and other virus stocks, where antibodies according to the present disclosure can be used to assess the amount or integrity (i.e., long term stability) of H1 antigens in viruses. Alternatively, the methods may be used to screen various antibodies for appropriate/desired reactivity profiles.
  • immunodetection methods include enzyme linked immunosorbent assay (ELISA), radioimmunoassay (RIA), immunoradiometric assay, fluoroimmunoassay, chemiluminescent assay, bioluminescent assay, and Western blot to mention a few.
  • ELISA enzyme linked immunosorbent assay
  • RIA radioimmunoassay
  • immunoradiometric assay fluoroimmunoassay
  • fluoroimmunoassay chemiluminescent assay
  • bioluminescent assay bioluminescent assay
  • Western blot to mention a few.
  • a competitive assay for the detection and quantitation of human respiratory syncytial virus antibodies directed to specific viral epitopes in samples also is provided.
  • the steps of various useful immunodetection methods have been described in the scientific literature, such as, e.g., Doolittle and Ben-Zeev (1999), Gulbis and Galand (1993), De Jag
  • the immunobinding methods include obtaining a sample suspected of containing Human respiratory syncytial virus, and contacting the sample with a first antibody in accordance with the present disclosure, as the case may be, under conditions effective to allow the formation of immunocomplexes.
  • These methods include methods for purifying human respiratory syncytial virus or related antigens from a sample.
  • the antibody will preferably be linked to a solid support, such as in the form of a column matrix, and the sample suspected of containing the Human respiratory syncytial virus or antigenic component will be applied to the immobilized antibody. The unwanted components will be washed from the column, leaving the human respiratory syncytial virus antigen immunocomplexed to the immobilized antibody, which is then collected by removing the organism or antigen from the column.
  • the immunobinding methods also include methods for detecting and quantifying the amount of human respiratory syncytial virus or related components in a sample and the detection and quantification of any immune complexes formed during the binding process.
  • a sample suspected of containing human respiratory syncytial virus or its antigens and contact the sample with an antibody that binds Human respiratory syncytial virus or components thereof, followed by detecting and quantifying the amount of immune complexes formed under the specific conditions.
  • the biological sample analyzed may be any sample that is suspected of containing human respiratory syncytial virus or Human respiratory syncytial virus antigen, such as a tissue section or specimen, a homogenized tissue extract, a biological fluid, including blood and serum, or a secretion, such as feces or urine.
  • the chosen biological sample with the antibody under effective conditions and for a period of time sufficient to allow the formation of immune complexes is generally a matter of simply adding the antibody composition to the sample and incubating the mixture for a period of time long enough for the antibodies to form immune complexes with, i.e., to bind to Human respiratory syncytial virus or antigens present.
  • the sample-antibody composition such as a tissue section, ELISA plate, dot blot or Western blot, will generally be washed to remove any non-specifically bound antibody species, allowing only those antibodies specifically bound within the primary immune complexes to be detected.
  • the antibody employed in the detection may itself be linked to a detectable label, wherein one would then simply detect this label, thereby allowing the amount of the primary immune complexes in the composition to be determined.
  • the first antibody that becomes bound within the primary immune complexes may be detected by means of a second binding ligand that has binding affinity for the antibody.
  • the second binding ligand may be linked to a detectable label.
  • the second binding ligand is itself often an antibody, which may thus be termed a“secondary” antibody.
  • the primary immune complexes are contacted with the labeled, secondary binding ligand, or antibody, under effective conditions and for a period of time sufficient to allow the formation of secondary immune complexes.
  • the secondary immune complexes are then generally washed to remove any non-specifically bound labeled secondary antibodies or ligands, and the remaining label in the secondary immune complexes is then detected.
  • Further methods include the detection of primary immune complexes by a two-step approach.
  • a second binding ligand such as an antibody that has binding affinity for the antibody, is used to form secondary immune complexes, as described above.
  • the secondary immune complexes are contacted with a third binding ligand or antibody that has binding affinity for the second antibody, again under effective conditions and for a period of time sufficient to allow the formation of immune complexes (tertiary immune complexes).
  • the third ligand or antibody is linked to a detectable label, allowing detection of the tertiary immune complexes thus formed. This system may provide for signal amplification if this is desired.
  • One method of immunodetection uses two different antibodies.
  • a first biotinylated antibody is used to detect the target antigen, and a second antibody is then used to detect the biotin attached to the complexed biotin.
  • the sample to be tested is first incubated in a solution containing the first step antibody. If the target antigen is present, some of the antibody binds to the antigen to form a biotinylated antibody/antigen complex.
  • the antibody/antigen complex is then amplified by incubation in successive solutions of streptavidin (or avidin), biotinylated DNA, and/or complementary biotinylated DNA, with each step adding additional biotin sites to the antibody/antigen complex.
  • the amplification steps are repeated until a suitable level of amplification is achieved, at which point the sample is incubated in a solution containing the second step antibody against biotin.
  • This second step antibody is labeled, as for example with an enzyme that can be used to detect the presence of the antibody/antigen complex by histoenzymology using a chromogen substrate.
  • a conjugate can be produced which is macroscopically visible.
  • PCR Polymerase Chain Reaction
  • the PCR method is similar to the Cantor method up to the incubation with biotinylated DNA, however, instead of using multiple rounds of streptavidin and biotinylated DNA incubation, the DNA/biotin/streptavidin/antibody complex is washed out with a low pH or high salt buffer that releases the antibody. The resulting wash solution is then used to carry out a PCR reaction with suitable primers with appropriate controls. At least in theory, the enormous amplification capability and specificity of PCR can be utilized to detect a single antigen molecule.
  • A. ELISAs Polymerase Chain Reaction
  • Immunoassays in their most simple and direct sense, are binding assays. Certain preferred immunoassays are the various types of enzyme linked immunosorbent assays (ELISAs) and radioimmunoassays (RIA) known in the art. Immunohistochemical detection using tissue sections is also particularly useful. However, it will be readily appreciated that detection is not limited to such techniques, and western blotting, dot blotting, FACS analyses, and the like may also be used.
  • the antibodies of the disclosure are immobilized onto a selected surface exhibiting protein affinity, such as a well in a polystyrene microtiter plate. Then, a test composition suspected of containing the Human respiratory syncytial virus or Human respiratory syncytial virus antigen is added to the wells. After binding and washing to remove non-specifically bound immune complexes, the bound antigen may be detected. Detection may be achieved by the addition of another anti-Human respiratory syncytial virus antibody that is linked to a detectable label.
  • ELISA is a simple“sandwich ELISA.” Detection may also be achieved by the addition of a second anti-Human respiratory syncytial virus antibody, followed by the addition of a third antibody that has binding affinity for the second antibody, with the third antibody being linked to a detectable label.
  • the samples suspected of containing the Human respiratory syncytial virus or Human respiratory syncytial virus antigen are immobilized onto the well surface and then contacted with the anti-Human respiratory syncytial virus antibodies of the disclosure. After binding and washing to remove non-specifically bound immune complexes, the bound anti-Human respiratory syncytial virus antibodies are detected. Where the initial anti-Human respiratory syncytial virus antibodies are linked to a detectable label, the immune complexes may be detected directly. Again, the immune complexes may be detected using a second antibody that has binding affinity for the first anti-Human respiratory syncytial virus antibody, with the second antibody being linked to a detectable label.
  • ELISAs have certain features in common, such as coating, incubating and binding, washing to remove non-specifically bound species, and detecting the bound immune complexes. These are described below.
  • a plate with either antigen or antibody In coating a plate with either antigen or antibody, one will generally incubate the wells of the plate with a solution of the antigen or antibody, either overnight or for a specified period of hours. The wells of the plate will then be washed to remove incompletely adsorbed material. Any remaining available surfaces of the wells are then“coated” with a nonspecific protein that is antigenically neutral with regard to the test antisera. These include bovine serum albumin (BSA), casein or solutions of milk powder.
  • BSA bovine serum albumin
  • the coating allows for blocking of nonspecific adsorption sites on the immobilizing surface and thus reduces the background caused by nonspecific binding of antisera onto the surface.
  • a secondary or tertiary detection means rather than a direct procedure.
  • the immobilizing surface is contacted with the biological sample to be tested under conditions effective to allow immune complex (antigen/antibody) formation. Detection of the immune complex then requires a labeled secondary binding ligand or antibody, and a secondary binding ligand or antibody in conjunction with a labeled tertiary antibody or a third binding ligand.
  • Under conditions effective to allow immune complex (antigen/antibody) formation means that the conditions preferably include diluting the antigens and/or antibodies with solutions such as BSA, bovine gamma globulin (BGG) or phosphate buffered saline (PBS)/Tween. These added agents also tend to assist in the reduction of nonspecific background.
  • The“suitable” conditions also mean that the incubation is at a temperature or for a period of time sufficient to allow effective binding. Incubation steps are typically from about 1 to 2 to 4 hours or so, at temperatures preferably on the order of 25°C to 27°C, or may be overnight at about 4°C or so. Following all incubation steps in an ELISA, the contacted surface is washed so as to remove non-complexed material. A preferred washing procedure includes washing with a solution such as PBS/Tween, or borate buffer. Following the formation of specific immune complexes between the test sample and the originally bound material, and subsequent washing, the occurrence of even minute amounts of immune complexes may be determined.
  • a solution such as PBS/Tween, or borate buffer.
  • the second or third antibody will have an associated label to allow detection.
  • this will be an enzyme that will generate color development upon incubating with an appropriate chromogenic substrate.
  • a urease, glucose oxidase, alkaline phosphatase or hydrogen peroxidase-conjugated antibody for a period of time and under conditions that favor the development of further immune complex formation (e.g., incubation for 2 hours at room temperature in a PBS-containing solution such as PBS-Tween).
  • the amount of label is quantified, e.g., by incubation with a chromogenic substrate such as urea, or bromocresol purple, or 2,2'-azino-di-(3-ethyl-benzthiazoline-6- sulfonic acid (ABTS), or H2O2, in the case of peroxidase as the enzyme label. Quantification is then achieved by measuring the degree of color generated, e.g., using a visible spectra spectrophotometer.
  • a chromogenic substrate such as urea, or bromocresol purple, or 2,2'-azino-di-(3-ethyl-benzthiazoline-6- sulfonic acid (ABTS), or H2O2
  • Quantification is then achieved by measuring the degree of color generated, e.g., using a visible spectra spectrophotometer.
  • the present disclosure contemplates the use of competitive formats. This is particularly useful in the detection of Human respiratory syncytial virus antibodies in sample.
  • competition based assays an unknown amount of analyte or antibody is determined by its ability to displace a known amount of labeled antibody or analyte.
  • the quantifiable loss of a signal is an indication of the amount of unknown antibody or analyte in a sample.
  • the inventors propose the use of labeled Human respiratory syncytial virus monoclonal antibodies to determine the amount of Human respiratory syncytial virus antibodies in a sample.
  • the basic format would include contacting a known amount of Human respiratory syncytial virus monoclonal antibody (linked to a detectable label) with Human respiratory syncytial virus antigen or particle.
  • the Human respiratory syncytial virus antigen or organism is preferably attached to a support. After binding of the labeled monoclonal antibody to the support, the sample is added and incubated under conditions permitting any unlabeled antibody in the sample to compete with, and hence displace, the labeled monoclonal antibody. By measuring either the lost label or the label remaining (and subtracting that from the original amount of bound label), one can determine how much non-labeled antibody is bound to the support, and thus how much antibody was present in the sample.
  • the Western blot is an analytical technique used to detect specific proteins in a given sample of tissue homogenate or extract. It uses gel electrophoresis to separate native or denatured proteins by the length of the polypeptide (denaturing conditions) or by the 3-D structure of the protein (native/ non-denaturing conditions). The proteins are then transferred to a membrane (typically nitrocellulose or PVDF), where they are probed (detected) using antibodies specific to the target protein.
  • a membrane typically nitrocellulose or PVDF
  • Samples may be taken from whole tissue or from cell culture. In most cases, solid tissues are first broken down mechanically using a blender (for larger sample volumes), using a homogenizer (smaller volumes), or by sonication. Cells may also be broken open by one of the above mechanical methods. However, it should be noted that bacteria, virus or environmental samples can be the source of protein and thus Western blotting is not restricted to cellular studies only. Assorted detergents, salts, and buffers may be employed to encourage lysis of cells and to solubilize proteins. Protease and phosphatase inhibitors are often added to prevent the digestion of the sample by its own enzymes. Tissue preparation is often done at cold temperatures to avoid protein denaturing.
  • the proteins of the sample are separated using gel electrophoresis. Separation of proteins may be by isoelectric point (pI), molecular weight, electric charge, or a combination of these factors. The nature of the separation depends on the treatment of the sample and the nature of the gel. This is a very useful way to determine a protein. It is also possible to use a two-dimensional (2-D) gel which spreads the proteins from a single sample out in two dimensions. Proteins are separated according to isoelectric point (pH at which they have neutral net charge) in the first dimension, and according to their molecular weight in the second dimension.
  • isoelectric point pH at which they have neutral net charge
  • the proteins In order to make the proteins accessible to antibody detection, they are moved from within the gel onto a membrane made of nitrocellulose or polyvinylidene difluoride (PVDF).
  • PVDF polyvinylidene difluoride
  • the membrane is placed on top of the gel, and a stack of filter papers placed on top of that. The entire stack is placed in a buffer solution which moves up the paper by capillary action, bringing the proteins with it.
  • Another method for transferring the proteins is called electroblotting and uses an electric current to pull proteins from the gel into the PVDF or nitrocellulose membrane.
  • the proteins move from within the gel onto the membrane while maintaining the organization they had within the gel. As a result of this blotting process, the proteins are exposed on a thin surface layer for detection (see below).
  • the antibodies of the present disclosure may also be used in conjunction with both fresh-frozen and/or formalin-fixed, paraffin-embedded tissue blocks prepared for study by immunohistochemistry (IHC).
  • IHC immunohistochemistry
  • the method of preparing tissue blocks from these particulate specimens has been successfully used in previous IHC studies of various prognostic factors, and is well known to those of skill in the art (Brown et al., 1990; Abbondanzo et al., 1990; Allred et al., 1990).
  • frozen-sections may be prepared by rehydrating 50 ng of frozen“pulverized” tissue at room temperature in phosphate buffered saline (PBS) in small plastic capsules; pelleting the particles by centrifugation; resuspending them in a viscous embedding medium (OCT); inverting the capsule and/or pelleting again by centrifugation; snap-freezing in -70°C isopentane; cutting the plastic capsule and/or removing the frozen cylinder of tissue; securing the tissue cylinder on a cryostat microtome chuck; and/or cutting 25-50 serial sections from the capsule.
  • whole frozen tissue samples may be used for serial section cuttings.
  • Permanent-sections may be prepared by a similar method involving rehydration of the 50 mg sample in a plastic microfuge tube; pelleting; resuspending in 10% formalin for 4 hours fixation; washing/pelleting; resuspending in warm 2.5% agar; pelleting; cooling in ice water to harden the agar; removing the tissue/agar block from the tube; infiltrating and/or embedding the block in paraffin; and/or cutting up to 50 serial permanent sections. Again, whole tissue samples may be substituted.
  • the present disclosure concerns immunodetection kits for use with the immunodetection methods described above.
  • the antibodies may be used to detect Human respiratory syncytial virus or Human respiratory syncytial virus antigens, the antibodies may be included in the kit.
  • the immunodetection kits will thus comprise, in suitable container means, a first antibody that binds to Human respiratory syncytial virus or Human respiratory syncytial virus antigen, and optionally an immunodetection reagent.
  • the Human respiratory syncytial virus antibody may be pre- bound to a solid support, such as a column matrix and/or well of a microtitre plate.
  • the immunodetection reagents of the kit may take any one of a variety of forms, including those detectable labels that are associated with or linked to the given antibody. Detectable labels that are associated with or attached to a secondary binding ligand are also contemplated. Exemplary secondary ligands are those secondary antibodies that have binding affinity for the first antibody.
  • suitable immunodetection reagents for use in the present kits include the two- component reagent that comprises a secondary antibody that has binding affinity for the first antibody, along with a third antibody that has binding affinity for the second antibody, the third antibody being linked to a detectable label.
  • a number of exemplary labels are known in the art and all such labels may be employed in connection with the present disclosure.
  • kits may further comprise a suitably aliquoted composition of the Human respiratory syncytial virus or Human respiratory syncytial virus antigens, whether labeled or unlabeled, as may be used to prepare a standard curve for a detection assay.
  • the kits may contain antibody-label conjugates either in fully conjugated form, in the form of intermediates, or as separate moieties to be conjugated by the user of the kit.
  • the components of the kits may be packaged either in aqueous media or in lyophilized form.
  • the container means of the kits will generally include at least one vial, test tube, flask, bottle, syringe or other container means, into which the antibody may be placed, or preferably, suitably aliquoted.
  • the kits of the present disclosure will also typically include a means for containing the antibody, antigen, and any other reagent containers in close confinement for commercial sale. Such containers may include injection or blow-molded plastic containers into which the desired vials are retained.
  • the present disclosure also contemplates the use of antibodies and antibody fragments as described herein for use in assessing the antigenic integrity of a viral antigen in a sample.
  • Biological medicinal products like vaccines differ from chemical drugs in that they cannot normally be characterized molecularly; antibodies are large molecules of significant complexity, and have the capacity to vary widely from preparation to preparation. They are also administered to healthy individuals, including children at the start of their lives, and thus a strong emphasis must be placed on their quality to ensure, to the greatest extent possible, that they are efficacious in preventing or treating life-threatening disease, without themselves causing harm.
  • an antigen or vaccine from any source or at any point during a manufacturing process.
  • the quality control processes may therefore begin with preparing a sample for an immunoassay that identifies binding of an antibody or fragment disclosed herein to a viral antigen.
  • immunoassays are disclosed elsewhere in this document, and any of these may be used to assess the structural/antigenic integrity of the antigen. Standards for finding the sample to contain acceptable amounts of antigenically intact antigen may be established by regulatory agencies.
  • antigen integrity is assessed is in determining shelf-life and storage stability. Most medicines, including vaccines, can deteriorate over time. Therefore, it is critical to determine whether, over time, the degree to which an antigen, such as in a vaccine, degrades or destabilizes such that is it no longer antigenic and/or capable of generating an immune response when administered to a subject. Again, standards for finding the sample to contain acceptable amounts of antigenically intact antigen may be established by regulatory agencies.
  • viral antigens may contain more than one protective epitope.
  • assays that look at the binding of more than one antibody, such as 2, 3, 4, 5 or even more antibodies.
  • These antibodies bind to closely related epitopes, such that they are adjacent or even overlap each other.
  • they may represent distinct epitopes from disparate parts of the antigen.
  • the gene encoding the stabilized prefusion DS-CAV1 RSV F trimer (McLellan et al., 2013a) was synthesized (GeneWiz ) and cloned into the PTT5 expression vector (National Research Council (NRC), Canada) with a T4-fibritin trimerization domain in-frame with the heptad repeat of the C-terminal HRB, and with Thrombin cleavage site.
  • the wt MPE8 single chain Fv (scFv) gene was synthesized by Life Technologies as a GeneArt® StringsTM DNA Fragment, was cloned into the pCEP4 expression vector (Invitrogen) and contains a C-terminal TEV cleavage site and His6 tag.
  • the RSV F and scFv expression plasmids were prepared using the Plasmid Mega® Kit (Qiagen) and transfected into suspension 293-6E cells (NRC) at a density of 1.8 to 2.0 million cells/mL using 25-kDa linear polyethylenimine (Polysciences), (PEI) following 293-6E cell protocols.
  • Supernatants were harvested five days post-transfection by centrifugation (20 min at 8,000 x g at room temperature), filtered through 0.45 ⁇ m filters and dialyzed against 200 mM NaCl, 50 mM Na2HPO4 pH 7.4.
  • the RSV F protein was purified by Co 2+ affinity chromatography (TALON Resin, BD Biosciences) and size exclusion chromatography using a Superdex-200 column equilibrated in 25 mM sodium phosphate, pH 7.4, and 100 mM NaCl, 100 mM imidazole.
  • the purified protein was concentrated with Amicon Ultra centrifugal filters with a 10 kD molecular weight cut-off (Millipore).
  • RSV F mutants L305R, G307R and D310A were prepared from the DS-CAV1 RSV F construct (Biozilla– Mutagenesis). Additional MPE8 variants were synthesized and cloned into the PTT5 expression vector corresponding to hGL- lGL, hGL-lSM, hSM-lSM D50G and hGL-lGL G56D. The MPE8 mutant proteins were expressed similarly to wild-type MPE8 in 293-6E cells, with supernatants harvested five days post-transfection. The MPE8 proteins were purified by Co 2+ affinity chromatography and size exclusion chromatography and concentrated as with wild-type MPE8.
  • RSV F DS-CAV1 mutants L305R, G307R, and D310A were expressed in expiCHO cells following the manufacturer’s protocol, harvested after six days, and purified by HiTrap TALON crude columns (GE Healthcare).
  • cDNAs encoding the published variable gene sequences encoding the mAbs motavizumab, 101F, and D25 were synthesized (Genscript), and heavy and light chain sequences were cloned into vectors encoding human IgG1 and lambda or kappa light chain constant regions, respectively.
  • Plasmids encoding the heavy and light chains of mAb 54G10 were a gift from Dr. Dennis Burton (Scripps Research Institute). Mab 131-2a protein was obtained from Sigma (MAB8599).
  • palivizumab Medimmune
  • mAbs were expressed in HEK293F cells for 5 days following the manufacturer’s protocol and purified by HiTrap MabSelectSure columns (GE Healthcare).
  • Crystals were grown from hanging drops with a well solution containing 0.1M Potassium Nitrate, 0.1M Citrate Phosphate pH 4.2, 1% Tacsimate pH 7.0, 14% PEG 6000. Crystals appeared after 3–10 days.
  • Crystals were transferred to a cryoprotectant solution of 0.1M Potassium Nitrate, 0.1M Citrate Phosphate pH 4.2, 1% Tacsimate pH 7.0, 14% PEG 6000 and 15% glycerol, followed by flash cooling in liquid nitrogen. Data were collected at LS-CAT 21-ID-F beamline at the Advanced Photon Source (APS) - Argonne National Laboratory. Crystals belong to space group P3121 and exhibited significant diffraction anisotropy.
  • the native data were initially processed to 3.1 ⁇ with XDS and then submitted to the Diffraction Anisotropy Server, which truncated the data to 3.1 ⁇ along the c* axis and 3.6 ⁇ along the a*/b* axes (Table S1).
  • the F model starts with residue 25 and ends with residue 509 (of 562 in the ectodomain construct).
  • the Fv VH model starts with residue E1 and ends with residue S113
  • the Fv VL model starts with residue V3 and ends with residue L127 with one additional glycine derived from the construct.
  • the final refinement statistics, native data, and phasing statistics are summarized in Table S1. Figures were generated with the program Pymol (world-wide-web at pymol.org).
  • Enzyme linked immunosorbent assay for binding to RSV F protein. 384- well plates were coated with 2 ⁇ g/mL of antigen overnight at 4 °C. Plates were blocked for with 2% milk supplemented with 2% goat serum for one hour, followed by three washes with PBS-T. Primary mAbs or B cell culture supernatants were applied to wells for two hours. Plates were washed with PBS-T four times before applying secondary antibody (goat anti-human IgG Fc, Meridian Life Science) at a dilution of 1:4,000 in blocking solution.
  • secondary antibody goat anti-human IgG Fc, Meridian Life Science
  • phosphatase substrate solution (1 mg/mL phosphatase substrate in 1M Tris aminomethane, Sigma) was added to each well.
  • the plates were incubated at room temperature before reading the optical density at 405 nm on a Biotek plate reader.
  • 25P13 was isolated from the PBMCs of a Nashville Red Cross donor. PBMCs were isolated from human donor blood samples using Ficoll- Histopaque density gradient centrifugation. PBMCs were transformed with Epstein-Barr virus as described previously (Smith et al., 2012). Cells were screened by ELISA for binding to post- fusion RSV F, and positive wells were fused with HMMA2.5 myeloma cells using the previously published protocol (Smith et al., 2012. The 25P13 hybridoma was biologically cloned by single-cell fluorescence-activated sorting.
  • the 25P13 hybridoma was expanded step- wise into 48-well and 12-well plates followed by 75-cm 2 flask in Media E (StemCell Technologies).
  • Antibody production was accomplished by expanding the hybridoma to four 225-cm 2 cell culture flasks in serum-free medium (Hybridoma-SFM, GIBCO). After 21 days, supernatants were sterile filtered using 0.45 ⁇ m pore size filter devices.
  • HiTrap MabSelectSure columns GE Healthcare Life Sciences
  • Virus was grown in Vero cells with Opti-MEM I+ GlutaMAX medium (Fisher) 37 °C in a CO2 incubator. The medium for cell propagation was supplemented with 2% fetal bovine serum. Confluent Vero cell monolayer cultures in 24-well plates were washed once with Opti-MEM I+GlutaMAX to remove serum, and then incubated with HMPV:mAb mixtures for one hour.
  • the cells were overlaid with 0.75% methylcellulose in Opti-MEM I+GlutaMAX containing 5 ⁇ g/mL trypsin.
  • Cells were incubated for four days before being fixed with neutral buffered formalin. Plaques were visualized by immunoperoxidase staining where anti-HMPV F guinea pig serum (or a mouse mAb targeting the HMPV nucleoprotein (Meridian Life Science) was used at 1:1,000 dilution in milk to overlay the cells for one hour, followed by incubation with 1:1,000 diluted goat anti-guinea pig IgG or anti-mouse IgG coupled to horseradish peroxidase (Meridian Life Science) for one hour. TrueBlue peroxidase substrate (Kirkegaard and Perry) then was added to visualize plaques. Plaques were counted and compared to the virus control. Data were analyzed with Prism software (GraphPad) to obtain IC50 values.
  • Competition binding was conducted on an OctetRed system (ForteBio) using anti-penta-HIS biosensors (ForteBio) and kinetics buffer (ForteBio). After obtaining an initial baseline in kinetics buffer, 10 ⁇ g/mL of his-tagged RSV F postfusion or prefusion (DSCAV1) protein was immobilized onto anti-penta-HIS biosensor tips for 120 s. The baseline signal was measured again for 60 s before biosensor tips were immersed into wells containing 100 ⁇ g/mL primary antibody for 300 s. Following this, biosensors were immersed into wells containing 100 ⁇ g/mL of a second mAb for 300 s.
  • Percent binding of a second mAbs in the presence of the first mAb was determined by comparing the maximal signal of the second mAb after the first mAb was added to the maximum signal of the second mAb alone. MAbs were considered non-competing if maximum binding of the second mAb was ⁇ 66% of its un-competed binding. A level between 33%–66% of its uncompeted binding was considered intermediate competition, and ⁇ 33% was considered competing.
  • the RSV/HMPV F protein is a class I viral fusion protein that refolds to drive membrane fusion and virus entry (Jardetzky & Lamb, 2014; Wen et al., 2012; McLellan et al., 2013a; McLellan et al., 2011; Swanson et al., 2011; Yin et al., 2006; Mas et al., 2016), and it is the major target of the neutralizing antibody response.
  • MPE8 was isolated from human B cells based on its ability to cross-neutralize a panel of RSV and HMPV strains (Corti et al., 2013).
  • the inventors determined the crystal structure of an MPE8 variant in complex with a stabilized prefusion RSV F trimer (DS-CAV1) (Joyce et al., 2016; Boyington et al., 2016; Stewart-Jones et al., 2015; McLellan et al., 2013b). They generated single chain Fv (scFv) constructs for MPE8 and predicted unmutated common ancestor (UCA) variants that retain RSV F binding and neutralization (Corti et al., 2013) (FIGS. 5-6).
  • scFv single chain Fv constructs for MPE8 and predicted unmutated common ancestor (UCA) variants that retain RSV F binding and neutralization
  • MPE8 binds an epitope near the midsection of the RSV F ectodomain (FIGS. 1A and 1B, consistent with previous mapping studies (Corti et al., 2013).
  • the interface buries ⁇ 1,100 ⁇ 2 of surface on each of the proteins (2,200 ⁇ 2 total).
  • the three scFvs are positioned with VH and VL domains aligned nearly perpendicular to the long axis of the F trimer and parallel to the predicted plane of the viral membrane.
  • the MPE8 V domains radiate horizontally outwards from three apices of the F subunits, engaging the widest section of the F head domain (FIGS. 1B).
  • MPE8 binds preferentially to prefusion F. Its conformational specificity has three apparent structural determinants. First, MPE8 engages RSV F residues located spanning two neighboring subunits of the trimer (FIGS. 1A-B), defining an intersubunit epitope present only in the prefusion conformation. Second, MPE8 contacts two ⁇ -strands of the prefusion heptad repeat A (HRA), which refold into a long helix and move away from the MPE8 interface in the postfusion form (McLellan et al., 2013a; Yin et al., 2006) (FIGS. 8A-B). Third, docking of MPE8 onto the post-fusion F structure indicates that steric clashes between F DII and the MPE8 VL domain could interfere with binding (FIGS.8C-D).
  • HRA prefusion heptad repeat A
  • MPE8 epitope lies within 1 subunit of the F trimer, involving residues in DI and DIII, with a smaller contact area in DII of the neighboring subunit (FIG.2A).
  • the DIII contacts overlap the helix-turn-helix motif of the palivizumab/motavizumab site A epitope (FIGS.2A-B).
  • the VH domain lies distal to the F trimer interface, primarily contacting the F surface below and to one edge of site A (FIGS.2A-C).
  • the HCDR3 loop extends underneath the site A motif in DIII to insert its tip into a pocket formed at the intersubunit interface (FIGS.
  • HCDR3 residues (100B-100G) interact with the turn residues within site A (FIG. 2B).
  • HCDR2 also forms interactions with the second helix of site A and with residues in DI, while HCDR1 contacts F below site A in DI (FIG.2C).
  • RSV F mutations that have been shown previously to affect MPE8 binding also map to the structural interface (FIGS. 9A-B). The mutation of D310A would disrupt interactions with HCDR2 and many of these previously identified mutations line the groove along which HCDR3 extends (L305R, G307R, R49D and T50A).
  • the VL domain is positioned near the trimer interface with LCDR2 contacting DII of the adjacent subunit (FIG.2C). LCDR2 interactions across the trimer, together with HCDR3, would contribute to preferential binding to prefusion F. LCDR1 and LCDR3 interact with the first helix of site A (FIGS. 2A-D). LCDR1 also contacts two beta strands of the DIII HRA motif (F residues 178, 180 and 184-187), present only in the prefusion conformation (FIGS. 8A-D).
  • the MPE8 paratope is a relatively flat surface comprised of the 6 CDR loops, with the heavy chain HCDR3 wrapping across the front of the VH domains and covering LCDR2 (FIG. 2D).
  • HCDR1, HCDR2 and HCDR3 form an L-shaped surface that defines the majority of the MPE8 binding surface, with HCDR3 inserting into the F intersubunit groove.
  • the MPE8 epitope is only partially conserved in HMPV (FIG. 3A and Table S2).
  • HCDR1 and HCDR2 anchor the antibody to the largest contiguous surface of conserved residues (FIG.3A).
  • HCDR3 extends along a narrower conserved segment to contact additional, more fragmented patches of surface residue conservation.
  • the light chain, particularly LCDR1 also contacts smaller, more isolated islands of conserved residues (FIG. 3A).
  • MPE8 crossreactivity appears to be achieved by the formation of a large interface with a mosaic patchwork of conservation rather than by a narrow focus on a single conserved site.
  • the predicted MPE8 UCA selectively neutralizes RSV, but not HMPV (Corti et al., 2013), indicating that cross-reactivity emerges as a result of somatic hypermutation that broadens its reactivity to HMPV.
  • MPE8 9 in VH and 5 in VL, are mutated in mature MPE8.
  • VL residues play a major role in HMPV cross-reactivity (Corti et al., 2013).
  • three of the five VL residues (D50, N52 and R93) are located in or near the RSV F interface (FIGS.3B-C).
  • VL D50 is a major determinant of cross-reactivity to HMPV F (Corti et al., 2013). Mutation of D50 to glycine, representing a reversion to the UCA, ablates HMPV F binding. D50 is located behind HCDR3 and does not directly contact F, but forms a hydrogen bond to HCDR3 residue T98 (FIG.3D). D50 may therefore indirectly stabilize an HCDR3 conformation that can bind both RSV and HMPV F, similar to somatic mutations observed in other antibodies.
  • VL R93S in LCDR3 reduces MPE8 binding to HMPV B strains (Corti et al., 2013).
  • R93 lies above antigenic site A and forms a hydrogen bond with the main chain of RSV F residue 263 (FIGS. 3B-C).
  • somatically mutated residues in VH have also been shown to influence MPE8 cross-reactivity (Corti et al., 2013).
  • the structure indicates that these effects are likely due to VH residues Y58 and N100A in HCDR2 and HCDR3, respectively.
  • Y58 the predicted germline residue, forms contacts to RSV F D310, an F residue important for MPE8 binding.
  • N100A is at the tip of HCDR3 and is mutated to serine in the mature MPE8 sequence (FIGS.2B-C).
  • LCDR3 is also well conserved (7 out of 10 residues), including two key residues (Y107 and R93) that are buried in the MPE8 complex with RSV F.
  • HCDR3 exhibits the largest differences ( ⁇ 50% identity) and is shorter by two residues, indicating that the 25P13 HCDR3 would not insert as deeply into the intersubunit crevice in F and may not engage two subunits of F as observed for MPE8 (FIGS. 2A-D).
  • a G307R mutation was previously shown to disrupt MPE8 binding (Corti et al., 2013). This mutation significantly reduces but does not eliminate 25P13 binding, consistent with interaction differences of its shorter HCDR3 loop (FIG.4E and FIGS.9A-B). Together, these data indicate that related cross-reactive neutralizing antibodies can be readily identified, which utilize germline HCDR1 and HCDR2 sequences to anchor interactions with F through a conserved surface determinant present in RSV and HMPV F proteins.
  • the MPE8 and 25P13 epitopes are distinct from other structurally characterized anti-F antibodies (FIGS.11A-D).
  • D25 (McLellan et al., 2013a) and AM14 (Gilman et al., 2015) are two neutralizing antibodies specific for the prefusion F conformation, while motavizumab can bind both pre and post-fusion RSV F.
  • D25 binds an epitope in the top of DIII that does not have any overlap with MPE8 (McLellan et al., 2013a).
  • Low-resolution structures of AM14 and motavizumab with RSV F have been determined (Gilman et al., 2015) and binding of both of these antibodies would be sterically blocked by MPE8.
  • the epitopes of AM14 and motavizumab partially overlap that of MPE8. However, only MPE8 engages the larger patch of conserved residues lying below the site A epitope that provides its nascent cross-reactivity (FIG. 3A).
  • the newly isolated 25P13 antibody disclosed here is the only antibody that recognizes both HMPV and RSV F and also recognizes both prefusion and postfusion F of both viruses, thus it is the first member of a new class of RSV human antibodies developed.
  • MPE8 and 25P13 appear to achieve their cross-reactivity through an anchoring interaction mediated by germline HCDR1 & HCDR2 loops with a conserved F surface within DI, while fine tuning interactions across a patchwork of conserved and non-conserved epitope residues.
  • the mode of binding of 25P13 can be distinguished from that of MPE8 because it recognizes both prefusion and postfusion F.
  • compositions and methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this disclosure have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the disclosure. More specifically, it will be apparent that certain agents which are both chemically and physiologically related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the disclosure as defined by the appended claims.

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Abstract

La présente invention concerne des anticorps se liant à des formes de pré-fusion et de post-fusion des deux protéines F du virus respiratoire syncytial humain et du métapneumovirus humain, y compris des anticorps neutralisants, et des procédés d'utilisation de ceux-ci.
PCT/US2018/013318 2017-01-27 2018-01-11 Base structurale pour la neutralisation croisée d'anticorps du virus respiratoire syncytial et du métapneumovirus humain WO2018140242A1 (fr)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023061264A1 (fr) * 2021-10-12 2023-04-20 中国科学院分子细胞科学卓越创新中心 Conception et utilisation d'un anticorps entièrement humain pour neutraliser le virus respiratoire syncytial

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110189171A1 (en) * 2007-03-06 2011-08-04 Symphogen A/S Recombinant antibodies for treatment of respiratory syncytial virus infections
US20120070447A1 (en) * 2000-11-28 2012-03-22 Medimmune, Llc Methods of administering / dosing anti-rsv antibodies for prophylaxis and treatment
US20130336923A1 (en) * 2005-12-02 2013-12-19 Dana-Farber Cancer Institute, Inc. Carbonic Anhydrase IX (G250) Antibodies and Methods of Use Thereof
WO2014037419A1 (fr) * 2012-09-04 2014-03-13 Vib Vzw Domaines variables simples d'immunoglobuline dirigés contre le cd74 et leurs utilisations dérivées

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120070447A1 (en) * 2000-11-28 2012-03-22 Medimmune, Llc Methods of administering / dosing anti-rsv antibodies for prophylaxis and treatment
US20130336923A1 (en) * 2005-12-02 2013-12-19 Dana-Farber Cancer Institute, Inc. Carbonic Anhydrase IX (G250) Antibodies and Methods of Use Thereof
US20110189171A1 (en) * 2007-03-06 2011-08-04 Symphogen A/S Recombinant antibodies for treatment of respiratory syncytial virus infections
WO2014037419A1 (fr) * 2012-09-04 2014-03-13 Vib Vzw Domaines variables simples d'immunoglobuline dirigés contre le cd74 et leurs utilisations dérivées

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
DATABASE UniProtKB 11 May 2016 (2016-05-11), "Uncharacterized protein", XP055531263, Database accession no. A0A140T466_CITAM *
DATABASE UniProtKB 16 November 2011 (2011-11-16), "ABC-type multidrug transport system, ATPase component", XP055531267, Database accession no. G2LFC5_CHLTF *
DATABASE UniProtKB 18 September 2013 (2013-09-18), XP055531254, Database accession no. S1R577_9ENTE *
WEN ET AL.: "Structural basis for antibody cross-neutralization of respiratory syncytial virus and human metapneumovirus", NATURE MICROBIOLOGY, vol. 2, no. 4, 30 January 2017 (2017-01-30), pages 1 - 14, XP055531271 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023061264A1 (fr) * 2021-10-12 2023-04-20 中国科学院分子细胞科学卓越创新中心 Conception et utilisation d'un anticorps entièrement humain pour neutraliser le virus respiratoire syncytial

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