Disclosure of Invention
The present disclosure provides antibodies and antigen-binding fragments thereof that specifically bind to human IL-33, nucleic acid molecules encoding the antibodies or fragments, vectors and host cells comprising the nucleic acid molecules, methods of making the antibodies or fragments, pharmaceutical compositions comprising the antibodies or fragments, and methods of treating disorders associated with allergic diseases (including treating atopic dermatitis) or related pharmaceutical uses of the antibodies or fragments.
Combined person
IL-33
And antigen binding fragments thereof
In some embodiments, in a first aspect, the present application provides an antibody or antigen-binding portion thereof that specifically binds IL-33 comprising a heavy chain variable region comprising an HCDR3 sequence, optionally further comprising an HCDR1 and/or HCDR2 sequence. In some embodiments, the HCDR1 sequence described above comprises a sequence selected from SEQ ID NOs: 33, 39, 45, 51, 57, 63, 69 and 75. In some embodiments, the HCDR2 sequence described above comprises a sequence selected from SEQ ID NOs: 34, 40, 46, 52, 58, 64, 70 and 76. In some embodiments, the HCDR3 sequence described above comprises a sequence selected from SEQ ID NOs: 35, 41, 47, 53, 59, 65, 71 and 77.
In some embodiments, the heavy chain variable region comprises a heavy chain variable region that is substantially identical to a light chain variable region selected from SEQ ID NOs: 2, 6, 10, 14, 18, 22, 26 and 30, or the heavy chain variable region comprises an amino acid sequence having at least 80% homology to the amino acid sequence selected from the group consisting of SEQ ID NOs: 2, 6, 10, 14, 18, 22, 26 and 30.
In some embodiments, the antibody or antigen-binding portion thereof that specifically binds IL-33 further comprises a light chain variable region, wherein the light chain variable region comprises an LCDR1, LCDR2, and/or LCDR3 sequence. In certain embodiments, the LCDR1 sequence comprises a sequence selected from SEQ ID NOs: 36, 42, 48, 54, 60, 66, 72 and 78. In certain embodiments, the LCDR2 sequence comprises a sequence selected from SEQ ID NOs: 37, 43, 49, 55, 61, 67, 73 and 79. In certain embodiments, the LCDR3 sequence comprises a sequence selected from SEQ ID NOs: 38, 44, 50, 56, 62, 68, 74 and 80.
In some embodiments, the light chain variable region comprises a heavy chain variable region substantially identical to a light chain variable region selected from SEQ ID NOs: 4, 8, 12, 16, 20, 24, 28 and 32, having an amino acid sequence at least 80% homologous; or the light chain variable region comprises a sequence selected from the group consisting of SEQ ID NOs: 4, 8, 12, 16, 20, 24, 28 and 32.
In some embodiments, the heavy chain of an antibody, or antigen-binding portion thereof, that specifically binds IL-33 comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 83, 89, 95, 101 and 107 or an amino acid sequence having at least 80% homology to the above sequences. Optionally, the light chain of the antibody, or antigen-binding portion thereof, comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 86, 92, 98, 104 and 110 or an amino acid sequence having at least 80% homology to the above sequences.
In some embodiments, the antibody that specifically binds IL-33 of the first aspect is a monoclonal antibody.
In some embodiments, the antibody that specifically binds IL-33 of the first aspect is a humanized antibody.
In some embodiments, an IL-33 antibody or antigen-binding portion thereof disclosed herein binds to the same epitope on antibody 20H, 127H, 177H, 219H, 309H or IL-33, or competes with 20H, 127H, 177H, 219H, 309H for binding to IL-33. Wherein the heavy chain sequence of the antibody 20H is as shown in SEQ ID NO: 83 and the light chain sequence is shown in SEQ ID NO: 86, respectively; and the heavy chain sequence of the antibody 127H is set forth in SEQ ID NO: 89 and a light chain sequence is shown as SEQ ID NO: 92, respectively; and the heavy chain sequence of the antibody 177H is as set forth in SEQ ID NO: 95, and the light chain sequence is shown as SEQ ID NO: 98 is shown; and the heavy chain sequence of the antibody 219H is set forth in SEQ ID NO: 101, and the light chain sequence is shown as SEQ ID NO: 104 is shown; and the heavy chain sequence of the antibody 309H is set forth in SEQ ID NO: 107, and the light chain sequence is shown as SEQ ID NO: 110.
In some embodiments, an antibody or antigen-binding portion thereof disclosed herein is capable of inhibiting IL-5 secretion by KU812 cells.
In a second aspect, the present application provides a nucleotide molecule encoding an antibody or antigen-binding portion thereof that specifically binds IL-33 as described above.
In a third aspect, the present application provides an expression vector comprising a nucleotide molecule as described above.
In some embodiments, the expression vector is pTT5, pUC57, pDR1, pcdna3.1(+), pDHFF, or pCHO 1.0, and the like.
In a fourth aspect, the present application provides a host cell comprising an expression vector as described above. In some embodiments, the host cell is HEK293, COS, CHO, NS0, sf9, sf21, DH5 α, BL21(DE3), TG1, or the like.
In a fifth aspect, the present application provides a method of making an antibody or antigen-binding portion thereof of the first aspect that specifically binds IL-33, the method comprising the steps of:
a) culturing said host cell of the fourth aspect under expression conditions such that said antibody, or antigen-binding portion thereof, is produced by said host cell, thereby expressing said antibody, or antigen-binding portion thereof; and
b) isolating and purifying the antibody or antigen-binding portion thereof expressed by a).
In a sixth aspect, the present application provides a pharmaceutical composition comprising the anti-IL-33 antibody, or antigen-binding portion thereof, of the first aspect and a pharmaceutically acceptable carrier.
In some embodiments, the compositions are used to treat IL-33-associated diseases.
In a seventh aspect, the application provides the use of an anti-IL-33 antibody or antigen-binding portion thereof according to the first aspect, or a composition according to the sixth aspect, in the manufacture of a medicament for the prevention or treatment of an IL-33-associated disease, such as an immune-mediated inflammatory response or an inflammatory disease.
The anti-IL-33 antibodies or antigen-binding portions thereof of the present application are capable of specifically binding to IL-33, with one or more of the following effects: blocking the binding of IL-33 to IL-33R; inhibits IL-5 secretion from KU812 cells. The anti-IL-33 antibodies, or antigen-binding portions thereof, of the present application can be used to prevent or treat IL-33-associated diseases, such as immune-mediated inflammatory diseases.
The inventors of the present application have conducted extensive experiments to obtain a group of monoclonal antibodies capable of blocking IL33 signaling by specifically blocking IL-33 binding to a cell surface IL-33 receptor (IL-33R), which are capable of blocking IL-33 mediated biological activity.
Detailed Description
The present application provides novel anti-IL-33 antibodies, or antigen-binding portions thereof, that specifically bind to IL-33. In preferred embodiments, the antibodies of the present application, or antigen-binding portions thereof, bind to human IL-33 with high affinity and inhibit the activity of IL-33. Also provided are polynucleotides encoding the antibodies or antigen-binding fragments thereof, vectors comprising the polynucleotides, host cells comprising the polynucleotides or vectors, methods of making and purifying the antibodies, and medical and biological applications of the antibodies or antigen-binding fragments thereof, such as preventing or treating IL-33-associated diseases or disorders. Methods of using the antibodies or antigen-binding fragments thereof to detect IL-33 and modulate IL-33 activity are also contemplated.
To facilitate understanding of the present application, certain terms used herein are first defined.
The term "antibody" as used herein refers to an immunoglobulin molecule comprising four polypeptide chains, two heavy (H) chains and two light (L) chains interconnected by a disulfide bond, as well as multimers thereof (e.g., IgM). Each heavy chain comprises a heavy chain variable region (abbreviated VH) and a heavy chain constant region (abbreviated CH). The heavy chain constant region comprises three domains, CH1, CH2, and CH 3. Each light chain comprises a light chain variable region (abbreviated VL) and a light chain constant region (abbreviated CL). The light chain constant region comprises a domain (CL 1). The VH and VL regions can be further subdivided into hypervariable regions known as Complementarity Determining Regions (CDRs) into which conserved regions known as Framework Regions (FRs) are interspersed.
As used herein, the term "antigen-binding portion" of an antibody refers to a portion or segment of an intact antibody molecule that is responsible for binding to an antigen. The antigen binding domain may comprise a heavy chain variable region (VH), a light chain variable region (VL), or both. Antigen-binding fragments of antibodies can be prepared from intact antibody molecules using any suitable standard technique, including proteolytic digestion or recombinant genetic engineering techniques, among others. Non-limiting examples of antigen-binding moieties include: a Fab fragment; a F (ab') 2 fragment; (ii) a fragment of Fd; (iv) an Fv fragment; single chain fv (scFv) molecules; a single domain antibody; a dAb fragment and the smallest recognition unit (e.g., an isolated CDR) that consists of amino acid residues that mimic a hypervariable region of an antibody. The term "antigen-binding portion" also includes other engineered molecules, such as diabodies, triabodies, tetrabodies, minibodies, and the like.
As used herein, the terms "heavy chain variable region (VH)" and "light chain variable region (VL)" refer to single antibody variable heavy and light chain regions, respectively, that comprise FR1, 2, 3, and 4 and CDR1, 2, and 3.
It is well known to those skilled in the art that the complementarity determining regions (CDRs, usually CDR1, CDR2, and CDR3) are the regions of the variable region that have the greatest impact on the affinity and specificity of an antibody. There are two common definitions of CDR Sequences for VH or VL, namely the Kabat definition and Chothia definition, see, for example, Kabat et al, "Sequences of Proteins of Immunological Interest", National Institutes of Health, Bethesda, Md. (1991); A1-Lazikani et al, J.mol.biol.273: 927-; and Martin et al, proc. natl.acad.sci.usa86: 9268-9272(1989). For a given antibody variable region sequence, can according to Kabat definition or Chothia definition to determine VH and VL sequence in CDR region sequence. In embodiments of the present application, the CDR sequences are defined using Kabat. Herein, CDR1, CDR2 and CDR3 of the heavy chain variable region are abbreviated as HCDR1, HCDR2 and HCDR3, respectively; CDR1, CDR2, and CDR3 of the light chain variable region are abbreviated as LCDR1, LCDR2, and LCDR3, respectively.
The CDR region sequences in the variable region sequences can be analyzed in a variety of ways for the variable region sequences of a given antibody, such as can be determined using the online software Abysis (http:// www.abysis.org /).
The term "specific binding" as used herein refers to a non-random binding reaction between two molecules, e.g. binding of an antibody to an epitope of an antigen, e.g. the ability of an antibody to bind to a specific antigen with an affinity that is at least two times greater than its affinity for a non-specific antigen. It will be appreciated, however, that an antibody is capable of specifically binding to two or more antigens whose sequences are related. For example, an antibody of the invention can specifically bind to IL-33 in humans and non-humans (e.g., non-human primates).
The term "monoclonal antibody" as used herein refers to an antibody obtained from a substantially homogeneous population of antibodies, i.e., the individual antibodies comprising the population are identical except for the possible presence of naturally occurring mutations in a small number of individuals. The monoclonal antibodies described herein specifically include "chimeric" antibodies in which a portion of the heavy and/or light chain is identical or homologous to corresponding sequences in antibodies derived from a particular species or belonging to a particular antibody class or subclass, while the remainder of the heavy and/or light chain is identical or homologous to corresponding sequences in antibodies derived from another species or belonging to another antibody class or subclass, and also include fragments of such antibodies, so long as they exhibit the desired biological activity.
The term "homology", as used herein, is defined as the percentage of residues in an amino acid or nucleotide sequence variant that are identical, if necessary to the maximum percentage, after alignment and the introduction of gaps in the sequence. Methods and computer programs for alignment are well known in the art. "at least 80% homology" as used herein means homology of any value from 80% to 100%, e.g., 85%, 90%, 95%, 99%, etc.
As used herein, the term "IL-33 associated disease" includes diseases and/or symptoms associated with activation of the IL-33 signaling pathway. Exemplary IL-33-associated diseases or disorders include immune-mediated inflammatory responses, such as atopic dermatitis, asthma, and the like.
In one aspect, the present application provides an antibody, or antigen-binding portion thereof, that specifically binds IL-33, comprising a heavy chain variable region and/or a light chain variable region. The CDR, VH, VL, heavy and light chain amino acid sequences and corresponding nucleotide sequences suitable for use in the antibodies disclosed herein are exemplified in tables 3-7 below. In certain embodiments, the anti-IL-33 antibody or antigen-binding portion thereof comprises an HCDR3, HCDR2, or HCDR1 sequence independently selected from any one of the HCDR3, HCDR2, or HCDR1 sequences set forth in table 4. In certain embodiments, an anti-IL-33 antibody of the present application may further comprise a light chain CDR independently selected from any one of the light chain CDR1, CDR2, or CDR3 sequences shown in table 5. For example, an anti-IL-33 antibody of the present application may comprise any of the heavy chain variable domains shown in tables 3 and 4, optionally paired with any of the light chain variable domains shown in tables 3 and 5.
In some embodiments, the HCDR1 sequence described above comprises a sequence selected from SEQ ID NOs: 33, 39, 45, 51, 57, 63, 69 and 75. In some embodiments, the HCDR2 sequence described above comprises a sequence selected from SEQ ID NOs: 34, 40, 46, 52, 58, 64, 70 and 76. In some embodiments, the HCDR3 sequence described above comprises a sequence selected from SEQ ID NOs: 35, 41, 47, 53, 59, 65, 71 and 77.
In specific embodiments, HCDR3 is selected from SEQ ID NOs: 35, 41, 47, 53, 59, 65, 71 and 77. In a preferred embodiment, HCDR3 is selected from the group consisting of the amino acid sequences set forth in 47, 71 and 77.
In specific embodiments, HCDR2 is selected from SEQ ID NOs: 34, 40, 46, 52, 58, 64, 70 and 76. In a preferred embodiment, the HCDR2 is selected from the group consisting of amino acid sequences set forth in 46, 70 and 76.
In specific embodiments, HCDR1 is selected from SEQ ID NOs: 33, 39, 45, 51, 57, 63, 69 and 75. In a preferred embodiment, the HCDR1 is selected from the group consisting of the amino acid sequences set forth in 45, 69 and 75.
In some embodiments, an antibody heavy chain variable region disclosed herein comprises a heavy chain variable region selected from the group consisting of SEQ ID NOs: 2, 6, 10, 14, 18, 22, 26 and 30. In specific embodiments, the heavy chain variable region is encoded by a sequence selected from the group consisting of SEQ ID NOs: 2, 6, 10, 14, 18, 22, 26 and 30.
In some embodiments, the amino acid sequence of an antibody heavy chain variable region disclosed herein is identical to SEQ ID NOs: 2, 6, 10, 14, 18, 22, 26 and 30 have at least 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more homology. In preferred embodiments, the heavy chain variable region is identical to SEQ ID NOs: 88, 100 or 106 has a homology of 99% or more.
The antibodies or antigen-binding portions thereof disclosed herein may further comprise a light chain variable region in addition to the heavy chain variable region.
In some embodiments, the LCDR3 of the light chain variable region is selected from SEQ ID NOs: 74 and 80, or an amino acid sequence selected from the group consisting of SEQ ID NOs: 38, 44, 50, 56, 62 and 68. In a preferred embodiment, LCDR3 is selected from SEQ ID NOs: 50, 74 and 80.
In some embodiments, LCDR2 is selected from SEQ ID NOs: 73 and 79, or an amino acid sequence selected from the group consisting of SEQ ID NOs: 37, 43, 49, 55, 61 and 67. In a preferred embodiment, LCDR2 is selected from SEQ ID NOs: 49, 73 and 79.
In some embodiments, LCDR1 is selected from SEQ ID NOs: 72 and 78, or an amino acid sequence selected from SEQ ID NOs: 36, 42, 48, 54, 60 and 66. In a preferred embodiment, LCDR1 is selected from SEQ ID NOs: 48, 72 and 78.
In some embodiments, the antibody light chain variable region disclosed herein comprises a heavy chain variable region selected from the group consisting of SEQ ID NOs: 4, 8, 12, 16, 20, 24, 28 and 32. In specific embodiments, the light chain variable region is encoded by a sequence selected from the group consisting of SEQ ID NOs: 4, 8, 12, 16, 20, 24, 28 and 32.
In some embodiments, the amino acid sequence of the antibody light chain variable region disclosed herein is identical to SEQ ID NOs: 4, 8, 12, 16, 20, 24, 28 or 32 has at least 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more homology. In preferred embodiments, the light chain variable region is identical to SEQ ID NOs: 91, 103 or 109 has a homology of more than 99%.
In some embodiments, the heavy or heavy chain variable region, the light or light chain variable region of the antibodies disclosed herein can be substituted, deleted or added with at least one amino acid based on the respective corresponding specific amino acid sequences listed above, and the resulting mutants still retain the activity of binding to IL-33.
In certain embodiments, the number of amino acid substitutions, deletions or additions is 1 to 30, preferably 1 to 20, more preferably 1 to 10. In preferred embodiments, the sequence variant differs from the original amino acid sequence by substitutions, deletions and/or additions of about 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acids. In more preferred embodiments, the sequence variant differs from the original amino acid sequence by a substitution, deletion or addition of about 1, 2, 3, 4 or 5 amino acids. In particular embodiments, the amino acid substitution is a conservative substitution.
In preferred embodiments, the antibody disclosed herein is antibody 127H, 219H or 309H. Wherein the heavy chain sequence of the antibody 127H is as shown in SEQ ID NO: 89 and a light chain sequence is shown as SEQ ID NO: 92, respectively; and the heavy chain sequence of the antibody 219H is set forth in SEQ ID NO: 101, and the light chain sequence is shown as SEQ ID NO: 104 is shown; and the heavy chain sequence of the antibody 309H is set forth in SEQ ID NO: 107, and the light chain sequence is shown as SEQ ID NO: 110.
In some embodiments, an antibody or antigen-binding portion thereof disclosed herein binds to the same epitope on interleukin-33 as antibody 20H, 127H, 177H, 219H, 309H, or competes with 20H, 127H, 177H, 219H, 309H for binding to interleukin-33.
In some embodiments, the antibodies disclosed herein are monoclonal antibodies. In particular embodiments, the antibodies disclosed herein are humanized antibodies.
The antibodies, or antigen-binding portions thereof, disclosed herein are capable of specifically binding IL-33. In specific embodiments, the antibody or antigen binding portion thereof specifically binds to human IL-33 or monkey IL-33. In a preferred embodiment, the antibody, or antigen binding portion thereof, specifically binds to human IL-33.
In some embodiments, an antibody or antigen-binding portion thereof disclosed herein is capable of inhibiting IL-5 secretion by KU 812.
For example, the inventors of the present application performed in vitro and in vivo biological experiments on the anti-human IL-33 monoclonal antibody disclosed herein, and the results showed that the antibody binds well to IL-33.
Specifically, the inventors of the present application carried out experiments such as binding detection, experimental analysis for blocking the binding of IL-33 to IL-33R, and in vitro cell function detection of an anti-human IL-33 monoclonal antibody. The experimental results show that the anti-human IL-33 monoclonal antibody disclosed by the invention can be combined with IL-33, block the signal conduction between IL-33 and IL-33R and inhibit the generation of inflammatory reaction.
The present application also provides nucleotide molecules encoding the antibodies disclosed herein, or antigen-binding portions thereof, vectors comprising the polynucleotides, host cells comprising the polynucleotides or vectors, and methods of making and purifying the antibodies.
In some embodiments, the nucleotide molecule encoding the antibody, or antigen-binding portion thereof, is operably linked to a control sequence that is recognized by a host cell transformed with the vector.
In some embodiments, any suitable expression vector may be used in the present application. For example, the expression vector may be one of pTT5, pUC57, pDR1, pcDNA3.1(+), pDFHF and pCHO 1.0. Expression vectors may include fusion DNA sequences with appropriate transcriptional and translational regulatory sequences attached.
In some embodiments, useful host cells are cells containing the above-described expression vectors, which may be eukaryotic cells, such as mammalian or insect host cell culture systems, may be used for expression of the antibodies or antigen-binding portions thereof of the present application. For example, HEK293 cells, COS, CHO, NS0, sf9, sf21, and the like, can be used in the present invention. The host cell may be a prokaryotic cell containing the above expression vector, and may be, for example, DH5 α, BL21(DE3), TG1 or the like.
In some embodiments, the methods of preparing an anti-human IL-33 monoclonal antibody disclosed herein comprise: culturing the host cell under expression conditions such that the anti-human IL-33 monoclonal antibody is expressed; isolating and purifying the expressed anti-human IL-33 monoclonal antibody. Using the above method, the recombinant protein can be purified as a substantially homogeneous substance, for example, as a single band on SDS-PAGE electrophoresis.
In some embodiments, the anti-IL-33 antibodies disclosed herein can be isolated and purified using affinity chromatography, and the anti-IL-33 antibodies bound to the affinity column can be eluted using conventional methods, such as high salt buffers, pH changes, and the like, depending on the nature of the affinity column being used.
In some embodiments, the humanized anti-human IL-33 monoclonal antibodies disclosed herein are obtained by the following method: IL-33 antigen prepared in a laboratory is used for immunizing a Balb/c mouse, and after the titer of the immunized mouse is higher for multiple times, spleen cells of the mouse are taken to be fused with hybridoma cells, and hybridoma cell strains with the IL-33 inhibition functional activity are screened out. More specifically, the inventors of the present invention have made extensive experiments to express IL-33 antigen and IL-33R separately, and then immunized mice with IL-33 antigen mixed with different adjuvants, and further fused splenocytes of the mice with hybridoma cell line sp2/0, and then screened positive cell lines using IL-33 antigen from the fused hybridomas, and verified that the binding of IL-33 to IL-33R is blocked and the function of IL-33 is surely inhibited, thereby obtaining target cell lines. After the target molecule is subjected to humanization transformation, the light chain and heavy chain genes are simultaneously cloned into a eukaryotic expression vector pTT 5. The expression vector is transiently transfected into HEK293 cells, antibodies are produced by serum-free medium culture, and humanized anti-human IL-33 monoclonal antibodies are separated or purified by a Protein A affinity column.
In other embodiments, the parent antibody of murine origin may be further altered using techniques conventional in the art, such as PCR mutagenesis, to produce chimeric or humanized or other variant forms of the antibody. Parent antibodies of the present application can be mutagenized, for example, within the Complementarity Determining Regions (CDR) domains of an antigen to produce variant antibodies, which can be screened for the presence of properties of interest, such as binding affinity (lower KD), IC50, specificity, preferential binding, and the like. Preferably, the property of interest in the variant antibody is an improvement over the property in the parent antibody. Amino acid substitution variant antibodies are preferred, and at least 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid residues of the parent antibody molecule are removed and a different residue is inserted in its position. The most interesting sites for substitutional mutagenesis are one or more CDR regions, but Framework Region (FR) alterations are also contemplated. Conservative amino acid substitutions are preferred, and non-conservative amino acid changes can also be introduced and the resulting variant antibodies screened for properties of interest.
The application also provides the use of an anti-IL-33 antibody, or a composition comprising an anti-IL-33 antibody, in the manufacture of a medicament for preventing or treating an IL-33-associated disease or condition. In some embodiments, the IL-33-associated disease or condition is an immune-mediated inflammatory response or an immune-mediated inflammatory disease.
In some embodiments, the anti-IL-33 antibodies disclosed herein can be used as anti-immune-mediated inflammatory response agents. An anti-immune-mediated inflammatory response agent, as referred to herein, refers to an agent that inhibits and/or treats an immune-mediated inflammatory response, e.g., it may delay the development of and/or reduce the severity of symptoms associated with an immune-mediated inflammatory response. In some embodiments, the medicament may reduce an existing inflammatory response with symptoms and prevent the appearance of other symptoms. In some embodiments, the medicament may also reduce or prevent the transfer of an inflammatory response.
In this specification and claims, the words "comprise", "comprising" and "contain" mean "including but not limited to", and are not intended to exclude other moieties, additives, components, or steps.
It should be understood that features, characteristics, components or steps described in a particular aspect, embodiment or example of the present application may be applied to any other aspect, embodiment or example described herein unless incompatible therewith.
The above disclosure generally describes the present application and the following examples are further illustrative of the present application and are not to be construed as limiting the present application. The examples do not include detailed descriptions of conventional methods such as those for constructing vectors and plasmids, methods for inserting genes encoding proteins into vectors and plasmids, or methods for introducing plasmids into host cells. Such methods are well known to those of ordinary skill in the art and are described in numerous publications.
Examples
The present disclosure is further described below in conjunction with the following examples, which are not intended to limit the scope of the present disclosure. Experimental procedures for conditions not specified in the examples are generally carried out according to conventional conditions, or according to conditions recommended by the manufacturers of the raw materials or the commercial products (see Sambrook et al, molecular cloning, A laboratory Manual, Cold spring harbor laboratory; Ausubel et al, contemporary methods of molecular biology, Greene publishing Association, Wiley Interscience, N.Y.). Reagents of specific sources are not indicated, and conventional reagents are purchased in the market.
Example 1Preparation of human IL-33 antigen, human IL-33R extracellular protein and reference antibody pf158
The human IL-33 antigen sequence was derived from UniProt (UniProtKB-O95760), codon-optimized according to the codon usage bias of Criceulus griseus by Biotech, and the 112-position 270-amino acid fragment was synthesized and cloned into pET-28a (+) vector (from Biotech) to obtain pET-hIL-33-His. Using pET-hIL-33-His as a template, respectively inserting a His tag (HHHHHHHHHH) and a Flag tag (DYKDDDDK) into the N end and the C end of the hIL-33 fragment by a PCR method to respectively obtain N-His-hIL-33 and hIL-33-Flag fragments, constructing the fragments on a pET-28a (+) expression vector, verifying sequencing, and selecting a clone with a completely correct sequence for prokaryotic expression production. Proteins were purified from E.coli supernatants using nickel columns (purchased from GE) and Flag affinity chromatography (purchased from Sigma) for the following immunization of mice and further analysis and study.
The human IL-33R sequence was from UniProt (UniProtKB-Q01638), and the cloning vector for this gene was purchased from Chinesia Forsythia (Cat: HG 10105-M). The vector is used as a template, and an hfc fragment and a Flag tag (DYKDDDDK) are respectively inserted into the C end of an extracellular segment (amino acids 19 to 328) of the hIL-33R by a PCR method to obtain the hIL-33R-ECD-hfc and the hIL-33R-ECD-Flag fragment. And recombining the hIL-33R-ECD-hfc and the hIL-33R-ECD-flag fragment to connect into a pTT5 vector, verifying sequencing, and selecting a clone with a completely correct sequence for eukaryotic expression production. The hIL-33R-ECD-hfc-pTT5 and hIL-33R-ECD-flag-pTT5 vectors were transfected into HEK293E cell lines (laboratory preservation) by the PEI method, respectively. After 5 days of culture in Freestyle293 medium (from Gibco) containing 3mM valproic acid, the protein was purified from the cell culture supernatant by protein a (from GE) and Flag affinity chromatography (from Sigma) for further analysis and study as follows.
The amino acid sequence of the reference antibody pf158 is derived from patent WO2017187307A 1. The constant region of the antibody was IgG 1. After codon optimization, nucleotide sequences were synthesized from the whole gene, and the sequences were subcloned into pUC57 vector (from Biochemical Co., Ltd.) to obtain pUC57-pf158-VH, pUC57-pf158-VL, pUC57-IgG1-CH, and pUC57-IgG 1-CL. The variable regions VH and VL of pf158 are spliced with IgG1-CH and IgG1-CL by a PCR method to obtain pf158-HC and pf158-LC fragments which are cloned to pTT5 expression vectors, and the correct cloning vectors marked as pf158-HC-pTT5 and pf158-LC-pTT5 are obtained through sequencing verification. Both vectors were transiently transfected into a HEK293E cell line, and after 5 days of culture in Freestyle293 medium containing 3mM valproic acid, the pf158 antibody Protein was purified from the cell culture supernatant using a Protein a affinity column (purchased from GE).
Example 2Human IL-33 antigen immunized mice
The hIL-33-his antigen (at a dose of 100. mu.g/mouse) was diluted to 75. mu.l with physiological saline, mixed with equal volume of Freund's complete adjuvant, and subjected to ultrasonic emulsification to complete the complete 4-5 week-old Balb/c mice (purchased from Shanghai Ling Biotech Co., Ltd., animal production license number: SCXK 2013-. Three weeks later, the same antigen (at a dose of 50. mu.g/mouse) was diluted to 75. mu.l with the same physiological saline and mixed with an equal volume of Freund's incomplete adjuvant, and after completion of the ultrasonication, the mice were subjected to subcutaneous multiple immunizations, and these immunizations were repeated two weeks later. All mice were tail trimmed one week after the third immunization, bled and sera were isolated and tested for serum titer using ELISA coated with hIL-33-his antigen. For mice with serum antibody titers > 10000, shock immunization was performed one week after blood draw: tail vein injection of 10 u g antigen protein/100 u l normal saline/mouse.
The detection of the titres was carried out by ELISA: ELISA plates were coated with hIL-33-his antigen at a concentration of 1. mu.g/ml, 100. mu.l per well, overnight at 4 ℃. PBST (PBS containing 0.5% Tween-20) plates were washed 2 times and then blotted dry. Adding coating solution containing 1% BSA into each well, sealing for 200 μ l, sealing for 4 hr at normal temperature, draining, and storing in refrigerator at-20 deg.C. In the detection process, 100 mu l of mouse serum with different concentrations is added into each hole of an ELISA plate, 2 multiple holes are arranged, and the mixture is incubated for 1.5 hours at room temperature. PBST was washed 3 times and then patted dry. Mu.l of HRP-labeled rabbit anti-mouse Ig antibody (purchased from Sigma) diluted 1: 10000 times in PBST was added and incubated at room temperature for 1 hour. PBST was washed 3 times and then patted dry. Adding 100 μ l of developing solution into each well (mixing ELISA developing solution A and developing solution B at a volume ratio of 1: 1 before use) for developing, and adding 100 μ l of 2M H into each well2SO4The reaction was terminated by the stop solution. OD values of each well were immediately measured at a wavelength of 450nm with a microplate reader (Molecular Device).
Example 3Hybridoma cell fusion and screening
Splenocytes were taken three days after the mice were shock immunized for fusion.
Collecting hybridoma sp2/0 cells (from China academy of sciences type culture Collection cell Bank, accession number TCM-18) with good growth state at 37 deg.C and 5% CO2Culturing in incubator, and changing liquid one day before fusion. The fusion and selection process was as follows: the spleen of the mouse is taken, ground, washed and counted. The spleen cells and sp2/0 cells were mixed at a ratio of 10: 1 and centrifuged at 1500rpm for 7 minutes. The supernatant was washed off. Adding 1ml PEG (1450) within 1 min, shaking gently for 90 s, adding 5ml serum-free DMEM culture solution (from Gibco) within 2.5 min, adding 5ml serum-free culture solution once again to terminate the reaction, standing for 5 min, and centrifuging at 1280rpmFor 8 minutes. Cells were seeded evenly into 96-well plates at 200. mu.l per well, in the number of two million sp2/0 cells per 96-well plate. Firstly, HAT culture medium containing hypoxanthine (H), methotrexate (A) and thymidine (T) is used for screening, half amount of liquid is changed every 3-4 days, and HT culture medium is changed on the 10 th day. After 10 days, when the hybridoma cells are more than 10% of the bottom of the 96-well plate, taking the supernatant and carrying out ELISA detection by using an ELISA plate coated by hIL-33-his antigen. The ELISA detection method was the same as described in example 2. Meanwhile, the antibody is subjected to secondary screening by using the hIL-33-flag by using the same ELISA detection method so as to remove the anti-His positive antibody. The hu-IL-33 positive hybridoma clones were selected for expansion in 24-well plates and subcloned by limiting dilution. Obtaining the hybridoma strain which stably expresses the target antibody, and then preserving and building a library.
Example 4Mouse anti-human IL-33 monoclonal antibody blocks the combination of human IL-33 and IL-33R extracellular region protein
The blocking of IL-33 binding to hIL-33R-ECD-hfc by murine anti-human hIL-33 monoclonal antibodies was investigated by ELISA. hIL-33-his antigen coated enzyme label plate, after sealing, hIL-33R-ECD-hfc and 300. mu.l mouse source anti-human hIL-33 monoclonal antibody hybridoma cell culture supernatant in subclone are added simultaneously, and finally HRP antibody is added for color development detection. The cell line that blocked hIL-33 and hIL-33R-ECD-hfc binding was retained for the next round of subcloning.
A preferred murine anti-human IL-33 monoclonal antibody was affinity purified by Protein G affinity chromatography and then quantified by BCA method (reagents from Thermo). The blocking of IL-33 binding to hIL-33R-ECD-hfc by murine anti-human hIL-33 monoclonal antibodies was investigated by ELISA. 307 monoclonal antibodies were analyzed, and FIG. 1 shows representative experimental results. Table 1 lists the IC's of partially preferred antibodies50Data, IC50All are below 63 ng/ml.
Table 1: exemplary murine anti-human IL-33 monoclonal antibodies block hIL-33 binding to hIL-33R-ECD-hfc
Antibody numbering
|
IC50(ng/ml)
|
5
|
61.53
|
20
|
41.15
|
76
|
43.79
|
96
|
39.08
|
97
|
39.98
|
113
|
39.04
|
119
|
39.12
|
127
|
37.74
|
130
|
33.17
|
158
|
45.99
|
174
|
49.64
|
177
|
62.66
|
205
|
50.21
|
209
|
50.2
|
219
|
61.33
|
223
|
52.18
|
258
|
49.12
|
260
|
51.92
|
309
|
30.23 |
Example 5Affinity detection of murine anti-human IL-33 monoclonal antibody binding to human IL-33
A preferred murine anti-human IL-33 monoclonal antibody was affinity purified by Protein G affinity chromatography and then quantified by BCA method. EC for binding of anti-human IL-33 monoclonal antibody to hIL-33-his50Detection was performed by ELISA. The detection method was as in example 3.1 u g/ml hIL-33-his antigen coated ELISA plate, adding different concentrations of murine anti-human IL-33 monoclonal antibody for detection.
307 monoclonal antibodies were analyzed, and FIG. 2 shows representative experimental results. Table 2 lists the EC for partially preferred antibodies50Data, higher affinity of these antibodies to human IL-33, EC50Are all atLess than 66 ng/ml.
Table 2: exemplary murine anti-human hIL-33 monoclonal antibodies have affinity for human IL-33-his
Antibody numbering
|
EC50(ng/ml)
|
5
|
36.58
|
20
|
41.08
|
76
|
51.98
|
96
|
57.38
|
97
|
65.11
|
113
|
55.90
|
119
|
56.51
|
127
|
43.92
|
130
|
45.57
|
158
|
49.51
|
174
|
50.81
|
177
|
44.37
|
205
|
40.42
|
209
|
33.25
|
219
|
35.69
|
223
|
45.66
|
258
|
41.54
|
260
|
39.88
|
309
|
52.31 |
Example 6Determination of mouse source anti-human IL-33 monoclonal antibody sequence
Total RNA of each hybridoma cell line was extracted using Trizol (purchased from Shanghai Probiotics), mRNA was reverse-transcribed into cDNA using a reverse transcription kit (purchased from Thermo), light chain variable region and heavy chain variable region genes of Mouse-derived anti-human hIL-33 monoclonal antibody were amplified by PCR using Mouse Ig-Primer Set (purchased from Novagen) as primers, and then the PCR products were cloned into pMD18-T vector, sequenced and the variable region gene sequences were analyzed. According to the results of various functional experiments and early druggability analysis, 8 antibodies shown in the table 3 are finally selected as lead antibodies, and the nucleotide sequences of the light chain variable regions of the antibodies are obtained by sequencing. The amino acid sequences obtained by transformation were analyzed in GenBank by alignment, and all the sequences were consistent with the characteristics of the mouse IgG variable region genes. The amino acid sequences of the light chain variable region and the heavy chain variable region of the murine anti-human IL-33 monoclonal antibody were analyzed according to the Kabat's rule and 3 CDRs were determined, as detailed in tables 4 and 5.
Table 3: nucleotide sequence and amino acid sequence of mouse IL-33 antibody heavy chain variable region and light chain variable region
Table 4: heavy chain CDR amino acid sequence of murine IL-33 antibody
Table 5: light chain CDR amino acid sequence of murine IL-33 antibody
Example 7Humanization of murine anti-human IL-33 monoclonal antibodies
Based on the results of sequence analysis, antibodies 20, 127, 177, 219 and 309 were picked and chimeric antibodies and humanized antibodies were constructed, and the amino acid sequences of the humanized antibodies are detailed in tables 6 and 7. The chimeric antibody was constructed by intercepting the heavy chain variable region and light chain variable region of a murine antibody and linking them to the light and heavy chain constant regions of human IgG1, respectively, using overlapping PCR.
The amino acid sequences of the light chain variable region and the heavy chain variable region of the mouse-derived anti-human IL-33 monoclonal antibody were analyzed according to Kabat's rule and 3 CDRs and 4 FRs were determined. Taking the antibody No. 309 as an example, a heavy chain CDR-grafted antibody was constructed by performing homology comparison between NCBI IgBlast and human IgG Germline sequences (Germinne), selecting IGHV1-46 x 01 as a heavy chain CDR-grafted template, and grafting the heavy chain CDR region of a mouse-derived anti-human IL-33 monoclonal antibody 309 into IGHV1-46 x 01 framework region. Similarly, by comparing the sequence homology with human IgG germline, IGKV1-39 x 01 was selected as a light chain CDR-grafted template, and the light chain CDR region of the murine anti-human IL-33 monoclonal antibody 309 was grafted into the framework region of IGKV1-39 x 01 to construct a light chain CDR-grafted antibody, which was defined as 309-Gr (309-Grafting). Meanwhile, on the basis, the amino acid sites of some framework regions are subjected to back mutation. In the case of back-mutation, the amino acid sequence is Kabat-encoded and the position of the site is indicated by the Kabat code. Preferably, for the heavy chain variable region, M at position 48 is returned to I, M at position 70 is returned to L, R at position 72 is returned to V, T at position 74 is returned to K, S at position 77 is returned to N, and V at position 79 is returned to A; for the light chain variable region sequence, L at position 46 was returned to V and Y at position 49 was returned to S (the above heavy and light chain encodings are all based on Kabat). The above-mentioned variable region gene sequence was codon-optimized and synthesized by an organism according to the codon usage preference of Cricetulus griseus. The synthetic humanized variable region sequences were ligated to the human IgG1 constant region, which was defined as a humanized antibody to antibody No. 309 (309-Humanization, 309H).
The remaining 5 antibodies were also humanized using the same principles described above. Transient expression vectors of humanized heavy chains and light chains are respectively constructed by utilizing pTT5 vector, and the light chains and the heavy chains are combined to be transiently transfected by utilizing HEK293 system and express antibody. HEK293 cells in Free Style293 Expression Medium (purchased from Gibco company) Medium culture, using PEI transfection method to plasmid transfer into cells for 5 days after cell supernatant, using Protein A purification to obtain antibody.
Table 6: nucleotide sequence and amino acid sequence of heavy chain variable region and light chain variable region of humanized anti-IL-33 antibody
Table 7: amino acid sequences of heavy and light chains of exemplary humanized anti-IL-33 antibodies
Example 8Humanized anti-human IL-33 monoclonal antibody blocks the binding of human IL-33 and extracellular region protein
The humanized anti-human IL-33 monoclonal antibody was affinity-purified by Protein A affinity column, and then quantified by BCA method. Blocking of IL-33 binding to hIL-33R-ECD-hfc by humanized anti-human hIL-33 monoclonal antibodies was investigated by ELISA. The detection method was as in example 4. FIG. 3 shows representative experimental results, and Table 8 lists the IC of partial antibodies50And (4) data. The experimental result shows that the blocking capability of the humanized anti-human IL-33 monoclonal antibody on hIL-33 binding to hIL-33R-ECD-hfc is obviously higher than that of the reference antibody pf 158.
Table 8: humanized antibody against hIL-33 binding hIL-33R-ECD-hfc positive
Antibody numbering
|
IC50(ng/ml)
|
pf158
|
139.60
|
127H
|
49.95
|
219H
|
93.53
|
309H
|
65.93 |
Example 9Humanized anti-human IL-33 monoclonal antibody inhibits the secretion of IL-5 by KU812 cells
KU812 cells (ATCC, CRL-2099) with good growth status were taken, counted and resuspended at 5 × 10 with recombinant hIL-33 at a final concentration of 50ng/ml5Cell suspension in ml. The medium was RPMI1640 medium (purchased from Gibco), which contained 10% fetal bovine serum (purchased from Sigma), 100U/ml penicillin (purchased from Gibco) and 100mg/ml streptomycin (purchased from Gibco), and was called RPMI-1640 complete medium. 37 ℃ and 5% CO2After 0.5 hour of incubation, different concentrations of antibody were added. Different concentrations of humanized anti-human IL-33 monoclonal antibody (250. mu.g/ml, 3-fold dilution, 9 different concentrations) were diluted with medium solution, 100. mu.l per well, added to a 96-well flat-bottom cell culture plate (purchased from Corning), and then 100. mu.l of cell suspension was added per well. Each group was set with 2 multiple wells at 37 deg.C and 5% CO2And (5) performing medium incubation for 24 hours. Taking the supernatant and detecting according to IL-5 kit (R)&D, Cat: S5000B) instructions for the operation of detecting IL-5 secretion, the OD value of each well was measured at a wavelength of 450nm using a microplate reader (Molecular Device).
The humanized anti-human IL-33 monoclonal antibody was analyzed for the inhibitory activity of KU812 to secrete IL-5 (FIG. 4), and the data of 3 antibodies 127H, 219H, 309H are shown in Table 9. The result shows that 127H and 309H have stronger inhibition effect on the IL-5 secretion of KU812 cells, and the functional activity of the antibody is obviously superior to that of a reference antibody pf 158.
Table 9: inhibition of IL-5 secretion by KU812 by different humanized antibodies
Antibody numbering
|
IC50(ng/ml)
|
pf158
|
658.00
|
127H
|
108.00
|
219H
|
2261.00
|
309H
|
16.45 |
It is to be understood that while the present disclosure is illustrated in some form, it is not to be limited to what is shown and described herein. It will be apparent to those skilled in the art that various changes can be made in the embodiments and/or in a feature or parameter without departing from the scope of the application. Such variations are within the scope of the disclosure as claimed.