Anti-novel coronavirus XBB variant antibody and application thereof

Abstract

The invention provides an antibody or an antigen binding fragment. The antibody or the antigen binding fragment comprises an HCDR1 sequence, an HCDR2 sequence and an HCDR3 sequence which are respectively shown as amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2 and SEQ ID NO: 3; and LCDR1, LCDR2 and LCDR3 sequences shown as amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5 and SEQ ID NO: 6 respectively. Compared with a natural antibody, the antibody containing the novel coronavirus XBB has better novel coronavirus XBB affinity and novel coronavirus XBB neutralizing capacity, and can effectively detect the novel coronavirus XBB and diagnose related diseases caused by the novel coronavirus XBB, or effectively prevent and / or treat the related diseases caused by the novel coronavirus XBB.

Description

Technical Field

[0001] The present invention belongs to the field of biopharmaceutical technology, and specifically relates to antibodies against the novel coronavirus XBB variant and applications thereof. Background Art

[0002] The new coronavirus XBB is a recombinant strain of BJ.1 (BA.2.10.1.1) and BM.1.1.1 (BA.2.75.3.1.1.1), and its recombination site is located in the RBD domain. After that, the XBB mutant strain gradually evolved into the Omicron sub-branch, including XBB.1 and XBB.1.5. XBB.1.5 is the new coronavirus strain with the fastest transmission speed and the strongest immune evasion and infection capabilities. Andrew Pecos, a virologist at Johns Hopkins University, said that XBB.1.5 is different from strains of the same family. It has an additional key mutation F486P, which can better bind to human cells. This site is the most critical site for antibody neutralization, so the mutation of this site may be closely related to immune escape. Therefore, it is urgent to develop an antibody with a stronger affinity for the new coronavirus XBB. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art to at least a certain extent. To this end, the present invention provides an anti-new coronavirus XBB variant antibody, which has a high binding affinity to the S protein of the new coronavirus XBB.

[0004] The present invention is accomplished based on the following findings of the inventors:

[0005] The existing new coronavirus antibodies are all natural antibody sequences isolated from organisms. They have been modified through dry and wet experimental screening, humanization and affinity optimization to improve their affinity and neutralization ability for antigens, thereby meeting the clinical demand for new coronavirus antibodies, especially antibodies against mutant viruses. However, the existing technology is highly dependent on natural antibody sequences. However, among the currently known antibody sequences, the antigen affinity and virus neutralization ability of many natural antibodies against the new coronavirus XBB variant need to be improved, making it difficult to meet clinical needs.

[0006] Based on this, the present invention provides an antibody against the XBB variant of the new coronavirus generated by an artificial intelligence method (see CN116959576A for the specific method), which has better antigen affinity and virus neutralization ability than natural antibodies.

[0007] Therefore, in the first aspect of the present invention, the present invention proposes an antibody or antigen-binding fragment. According to an embodiment of the present invention, the antibody or antigen-binding fragment comprises a HCDR3 having an amino acid sequence as shown in SEQ ID NO: 3 or a conservatively modified form thereof. Compared with natural antibodies, antibodies containing the HCDR3 of the present invention have better affinity for the new coronavirus XBB and the ability to neutralize the new coronavirus XBB, and can effectively detect the new coronavirus XBB, diagnose related diseases caused by the new coronavirus XBB, or effectively prevent and / or treat related diseases caused by the new coronavirus XBB.

[0008] According to an embodiment of the present invention, the antibody or antigen-binding fragment may further include at least one of the following technical features:

[0009] According to an embodiment of the present invention, the antibody or antigen-binding fragment further includes a CDR selected from at least one of the following: heavy chain variable region CDR: amino acid sequence of SEQ ID NO: 1-2 or a conservatively modified form thereof; light chain variable region CDR: amino acid sequence of SEQ ID NO: 4-6 or a conservatively modified form thereof.

[0010] According to an embodiment of the present invention, the antibody or antigen-binding fragment comprises: HCDR1, HCDR2, HCDR3 as shown in the amino acid sequences of SEQ ID NOs: 1, 2 and 3, respectively; and LCDR1, LCDR2, LCDR3 as shown in the amino acid sequences of SEQ ID NOs: 4, 5 and 6, respectively.

[0011] According to an embodiment of the present invention, the antibody or antigen-binding fragment comprises a heavy chain framework region.

[0012] According to an embodiment of the present invention, at least a portion of the heavy chain framework region is derived from at least one of a mouse antibody, a primate antibody, a bovine antibody, a horse antibody, a dairy cow antibody, a porcine antibody, a sheep antibody, a goat antibody, a dog antibody, a cat antibody, a rabbit antibody, a camel antibody, a donkey antibody, a deer antibody, a mink antibody, a chicken antibody, a duck antibody, a goose antibody, a turkey antibody, a fighting cock antibody or a mutant thereof.

[0013] According to an embodiment of the present invention, at least a portion of the heavy chain framework region is derived from at least one of a murine antibody and a human antibody.

[0014] According to an embodiment of the present invention, the antibody or antigen-binding fragment comprises a light chain framework region.

[0015] According to an embodiment of the present invention, at least a portion of the light chain framework region is derived from at least one of a mouse antibody, a primate antibody, a bovine antibody, a horse antibody, a dairy cow antibody, a porcine antibody, a sheep antibody, a goat antibody, a dog antibody, a cat antibody, a rabbit antibody, a camel antibody, a donkey antibody, a deer antibody, a mink antibody, a chicken antibody, a duck antibody, a goose antibody, a turkey antibody, a fighting cock antibody or a mutant thereof.

[0016] According to an embodiment of the present invention, at least a portion of the light chain framework region is derived from at least one of a murine antibody and a human antibody.

[0017] According to an embodiment of the present invention, the antibody or antigen-binding fragment comprises: a heavy chain variable region having an amino acid sequence as shown in SEQ ID NO:7 or an amino acid sequence having at least 90% homology thereto; and a light chain variable region having an amino acid sequence as shown in SEQ ID NO:8 or an amino acid sequence having at least 90% homology thereto.

[0018] According to an embodiment of the present invention, the antibody or antigen-binding fragment further comprises a heavy chain constant region.

[0019] According to an embodiment of the present invention, the antibody or antigen-binding fragment further comprises a light chain constant region.

[0020] According to an embodiment of the present invention, at least a portion of at least one of the heavy chain constant region and the light chain constant region is from at least one of a mouse antibody, a primate antibody, a bovine antibody, a horse antibody, a dairy cow antibody, a porcine antibody, a sheep antibody, a goat antibody, a dog antibody, a cat antibody, a rabbit antibody, a camel antibody, a donkey antibody, a deer antibody, a mink antibody, a chicken antibody, a duck antibody, a goose antibody, a turkey antibody, a fighting cock antibody or a mutant thereof.

[0021] According to an embodiment of the present invention, the heavy chain constant region includes a heavy chain constant region selected from IgG1, IgG2, IgG3, IgG4, IgA, IgM, IgE or IgD; or the light chain constant region includes a light chain constant region selected from κ type or λ type.

[0022] According to an embodiment of the present invention, the light chain constant region and the heavy chain constant region are both derived from a murine antibody or a mutant thereof, or a human antibody or a mutant thereof.

[0023] According to an embodiment of the present invention, the N-terminus of the heavy chain constant region is connected to the C-terminus of the heavy chain variable region.

[0024] According to an embodiment of the present invention, the N-terminus of the light chain constant region is connected to the C-terminus of the light chain variable region.

[0025] According to an embodiment of the present invention, the heavy chain constant region includes the heavy chain constant region shown in SEQ ID NO: 9 or an amino acid sequence having at least 80% identity thereto.

[0026] According to an embodiment of the present invention, the light chain constant region includes the light chain constant region shown in SEQ ID NO: 10 or an amino acid sequence having at least 80% identity thereto.

[0027] According to an embodiment of the present invention, the antibodies include polyclonal antibodies, full-length monoclonal antibodies, Fab antibodies, Fab' antibodies, F(ab') 2 At least one of an antibody, an Fv antibody, a single-chain antibody, a single-domain antibody, and a minimum recognition unit; or the antigen-binding fragment includes F(ab') 2 fragment, Fab' fragment, Fab fragment, F(ab) 2 At least one of a fragment, an Fv fragment, a scFv fragment, a scFv-Fc fusion protein, a scFv-Fv fusion protein and a minimum recognition unit.

[0028] According to an embodiment of the present invention, the antibody or antigen-binding fragment comprises: a heavy chain having an amino acid sequence as shown in SEQ ID NO: 11 or an amino acid sequence having at least 80% homology thereto; and a light chain having an amino acid sequence as shown in SEQ ID NO: 12 or an amino acid sequence having at least 80% homology thereto.

[0029] In the second aspect of the present invention, the present invention proposes a recombinant protein. According to an embodiment of the present invention, the recombinant protein includes: the antibody or antigen-binding fragment described in the first aspect. The recombinant protein of the present invention has better affinity for the new coronavirus XBB and neutralization ability of the new coronavirus XBB, and can effectively detect the new coronavirus XBB, diagnose related diseases caused by the new coronavirus XBB, or effectively prevent and / or treat related diseases caused by the new coronavirus XBB.

[0030] According to an embodiment of the present invention, the recombinant protein further includes at least one of a biologically active protein or a fragment thereof, a biologically active polypeptide or a fragment thereof.

[0031] According to an embodiment of the present invention, the biologically active protein or fragment thereof includes at least one selected from a protein tag, a protein toxin or a fragment thereof, an interferon or a fragment thereof, a biological response regulator or a fragment thereof and an Fc fragment.

[0032] In the third aspect of the present invention, the present invention proposes a multispecific antibody. According to an embodiment of the present invention, the multispecific antibody comprises: a first binding region, the first binding region comprises the antibody or antigen binding fragment described in the first aspect; a second binding region, the second binding region has a first molecule binding activity. The multispecific antibody of the present invention has better affinity for the new coronavirus XBB and neutralization ability of the new coronavirus XBB, and can effectively detect the new coronavirus XBB, diagnose related diseases caused by the new coronavirus XBB, or effectively prevent and / or treat related diseases caused by the new coronavirus XBB.

[0033] According to an embodiment of the present invention, the first molecule includes at least one of an antigen, a virus, a bacterium, an endotoxin, a cytokine, and a cytokine receptor.

[0034] In a fourth aspect of the present invention, the present invention provides a nucleic acid molecule. According to an embodiment of the present invention, the nucleic acid molecule encodes the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, or the multispecific antibody described in the third aspect. The nucleic acid molecule of the present invention may encode the antibody or antigen-binding fragment of the first aspect, the recombinant protein described in the second aspect, or the multispecific antibody described in the third aspect.

[0035] According to an embodiment of the present invention, the nucleic acid molecule is DNA.

[0036] In the fifth aspect of the present invention, the present invention provides an expression vector. According to an embodiment of the present invention, the expression vector carries the nucleic acid molecule described in the fourth aspect. Thus, the expression vector of the present invention can effectively achieve the expression of the antibody or antigen-binding fragment of the first aspect, the recombinant protein of the second aspect, or the multi-specific antibody of the third aspect, thereby achieving the in vitro mass acquisition of the antibody or antigen-binding fragment, the recombinant protein, or the multi-specific antibody.

[0037] According to an embodiment of the present invention, the expression vector comprises a vector selected from a eukaryotic expression vector or a prokaryotic expression vector.

[0038] In the sixth aspect of the present invention, the present invention provides a recombinant cell. According to an embodiment of the present invention, the recombinant cell includes carrying the nucleic acid molecule described in the fourth aspect or the expression vector described in the fifth aspect; or expressing the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, or the multispecific antibody described in the third aspect. The recombinant cell can effectively express the aforementioned antibody or antigen-binding fragment, recombinant protein or multispecific antibody in the cell under suitable conditions.

[0039] According to an embodiment of the present invention, the recombinant cell is obtained by introducing the expression vector described in the fifth aspect into a host cell.

[0040] In the seventh aspect of the present invention, the present invention proposes a conjugate. According to an embodiment of the present invention, the conjugate comprises the antibody or antigen binding fragment described in the first aspect, the recombinant protein described in the second aspect, or the multispecific antibody described in the third aspect; and a coupling portion, wherein the coupling portion is connected to the antibody or antigen binding fragment, the recombinant protein or the multispecific antibody. The conjugate of the present invention can bind to the new coronavirus XBB, has better affinity for the new coronavirus XBB and neutralization ability of the new coronavirus XBB, can effectively detect the new coronavirus XBB, diagnose related diseases caused by the new coronavirus XBB, or effectively prevent and / or treat related diseases caused by the new coronavirus XBB.

[0041] According to an embodiment of the present invention, the coupling part includes at least one selected from a carrier, a drug, a toxin, a cytokine, a protein tag and a modifier.

[0042] In the eighth aspect of the present invention, the present invention proposes a pharmaceutical composition. According to an embodiment of the present invention, the pharmaceutical composition includes the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, the multispecific antibody described in the third aspect, the nucleic acid molecule described in the fourth aspect, the expression vector described in the fifth aspect, the recombinant cell described in the sixth aspect, or the conjugate described in the seventh aspect. The pharmaceutical composition of the present invention can bind to the new coronavirus XBB, has better affinity for the new coronavirus XBB and neutralization ability of the new coronavirus XBB, and can effectively prevent and / or treat related diseases caused by the new coronavirus XBB.

[0043] According to an embodiment of the present invention, the pharmaceutical composition further comprises a pharmaceutically acceptable excipient.

[0044] In the ninth aspect of the present invention, the present invention proposes a kit. According to an embodiment of the present invention, the kit includes the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, the multispecific antibody described in the third aspect, the nucleic acid molecule described in the fourth aspect, the expression vector described in the fifth aspect, the recombinant cell described in the sixth aspect, or the conjugate described in the seventh aspect. The kit of the present invention can bind to the new coronavirus XBB and has a strong affinity for the new coronavirus XBB, and can effectively detect the new coronavirus XBB and diagnose related diseases caused by the new coronavirus XBB.

[0045] In the tenth aspect of the present invention, the present invention proposes a use of the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, the multispecific antibody described in the third aspect, the nucleic acid molecule described in the fourth aspect, the expression vector described in the fifth aspect, the recombinant cell described in the sixth aspect, or the conjugate described in the seventh aspect in the preparation of a drug, wherein the drug is used to prevent and / or treat related diseases caused by the new coronavirus XBB.

[0046] In the eleventh aspect of the present invention, the present invention proposes a use of the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, the multispecific antibody described in the third aspect, the nucleic acid molecule described in the fourth aspect, the expression vector described in the fifth aspect, the recombinant cell described in the sixth aspect, or the conjugate described in the seventh aspect in the preparation of a kit for detecting the new coronavirus XBB, diagnosing related diseases caused by the new coronavirus XBB, or evaluating the prognosis of related diseases caused by the new coronavirus XBB.

[0047] In the twelfth aspect of the present invention, the present invention proposes a method for detecting the novel coronavirus XBB. According to an embodiment of the present invention, the method comprises: contacting the sample to be detected with the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, the multispecific antibody described in the third aspect, or the conjugate described in the seventh aspect to form an immune complex. The method of the present invention has the advantages of detecting the novel coronavirus XBB, especially for in vitro detection, and has the advantages of high detection accuracy.

[0048] According to an embodiment of the present invention, based on the signal of the immune complex, it is determined whether the sample to be tested contains the content of the new coronavirus XBB.

[0049] According to an embodiment of the present invention, the immune complex further comprises a second antibody, which binds to the antibody or antigen-binding fragment.

[0050] According to an embodiment of the present invention, the immune complex also includes a second antibody, which binds to the new coronavirus XBB.

[0051] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0053] Figure 1 This is a schematic diagram of the pre-training of the Roformer model in Example 1 of the present invention;

[0054] Figure 2 Schematic diagram of the process of generating an antigen epitope sequence to an antibody sequence in Example 1 of the present invention;

[0055] Figure 3 A comparison between the artificial intelligence generated antibody and the natural antibody in Example 1 of the present invention;

[0056] Figure 4 This is a graph showing the results of a protein blotting experiment of natural antibodies and artificial intelligence-generated antibodies binding to the S protein of the new coronavirus XBB variant in Example 2 of the present invention. DETAILED DESCRIPTION

[0057] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.

[0058] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Further, in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0059] Detailed description of the invention

[0060] Definitions and general terms

[0061] In this document, the terms “include” or “comprising” are open expressions, that is, including the contents specified in the present invention but not excluding other contents.

[0062] As used herein, the terms "optionally", "optional" or "optionally" generally mean that the subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0063] Herein, the term "fragment" refers to a target protein or polypeptide, and a target protein or polypeptide having an N-terminal (N-terminus) or C-terminal (C-terminus) truncation, and / or internal deletion.

[0064] As used herein, the terms "identity", "homology" or "similarity" are used to describe an amino acid sequence or a nucleic acid sequence relative to a reference sequence, and the percentage of identical amino acids or nucleotides between two amino acid sequences or nucleic acid sequences is determined by conventional methods, for example, see Ausubel et al., eds. (1995), Current Protocols in Molecular Biology, Chapter 19 (Greene Publishing and Wiley-Interscience, New York); and the ALIGN program (Dayhoff (1978), Atlas of Protein Sequence and Structure 5: Suppl. 3 (National Biomedical Research There are many algorithms for aligning sequences and determining sequence identity, including the homology alignment algorithm of Needleman et al. (1970) J. Mol. Biol. 48:443; the local homology algorithm of Smith et al. (1981) Adv. Appl. Math. 2:482; the similarity search method of Pearson et al. (1988) Proc. Natl. Acad. Sci. 85:2444; the Smith-Waterman algorithm (Meth. Mol. Biol. 48:443); the local homology algorithm of Smith et al. (1981) Adv. Appl. Math. 2:482; the similarity search method of Pearson et al. (1988) Proc. Natl. Acad. Sci. 85:24 ... .70:173-187 (1997); and BLASTP, BLASTN, and BLASTX algorithms (see Altschul et al. (1990) J. Mol. Biol. 215:403-410). Computer programs that utilize these algorithms are also available, and include, but are not limited to: ALIGN or Megalign (DNASTAR) software, or WU-BLAST-2 (Altschul et al., Meth. Enzym., 266:460-480 (1996)); or GAP, BESTFIT, BLAST Altschul et al., supra, FASTA, and TFASTA, available in the Genetics Computing Group (GCG) package, Version 8, Madison, Wisconsin, USA; and CLUSTAL in the PC / Gene program provided by Intelligenetics, Mountain View, California.

[0065] As used herein, the term "at least 80% identity" refers to at least 80%, and may be 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9% identity to each reference sequence.

[0066] As used herein, the term "at least 90% identity" refers to at least 90%, and may be 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9% identity to each reference sequence.

[0067] In this article, the term "expression vector" generally refers to a nucleic acid molecule that can be inserted into a suitable host and replicates itself, the nucleic acid molecule comprises a nucleotide sequence that can express a target protein, and the nucleic acid molecule can be transferred into a host cell and / or between host cells. The expression vector may include a vector that is mainly used to insert DNA or RNA into a cell, a vector that is mainly used to replicate DNA or RNA, and a vector that is mainly used for the expression of transcription and / or translation of DNA or RNA. The expression vector also includes vectors with a variety of the above functions. The expression vector can be a polynucleotide that can be transcribed and translated into a polypeptide when introduced into a suitable host cell. Typically, the expression vector can produce a desired expression product by culturing a suitable host cell containing the expression vector.

[0068] In this article, the term "recombinant cell" generally refers to the use of genetic engineering technology or cell fusion technology to modify or reorganize the genetic material of the host cell to obtain a cell with a unique trait of stable inheritance. Among them, the term "host cell" refers to a prokaryotic cell or eukaryotic cell that can be introduced into a recombinant expression vector. The terms "transformed" or "transfected" used herein refer to the introduction of nucleic acids (such as vectors) into cells by various techniques known in the art. Suitable host cells can be transformed or transfected with the DNA sequence of the present invention, and can be used for the expression and / or secretion of target proteins. Examples of suitable host cells that can be used in the present invention include immortalized hybridoma cells, NS / 0 myeloma cells, 293 cells, Chinese hamster ovary (CHO) cells, HeLa cells, Cap cells (cells derived from human amniotic fluid) and CoS cells.

[0069] As used herein, the term "pharmaceutical composition" generally refers to a unit dosage form and can be prepared by any of the methods well known in the pharmaceutical art. All methods include the step of combining the active ingredient with a carrier that constitutes one or more accessory ingredients. Typically, the composition is prepared by uniformly and thoroughly combining the active antibody or antigen-binding fragment with a liquid carrier, a finely divided solid carrier, or both.

[0070] In this article, the term "pharmaceutically acceptable excipient" may include any solvent, solid excipient, diluent or other liquid excipient, etc., suitable for a specific target dosage form. Except for any conventional excipients that are incompatible with the antibody or antigen-binding fragment of the present invention, such as any adverse biological effects produced or interactions with any other components of the pharmaceutically acceptable composition in a harmful manner, their use is also within the scope of the present invention.

[0071] In this article, the term "administration" refers to the introduction of a predetermined amount of a substance into a patient by a suitable method. The antibody or antigen-binding fragment, recombinant protein, multispecific antibody or pharmaceutical composition of the present invention can be administered by any common route as long as it can reach the desired tissue. Various modes of administration are contemplated, including peritoneal, intravenous, intramuscular, subcutaneous injection, etc., but the present invention is not limited to these exemplified modes of administration. Preferably, the composition of the present invention is administered by intravenous or subcutaneous injection.

[0072] As used herein, the term "treatment" refers to the use of drugs to obtain the desired pharmacological and / or physiological effects. The effect may be preventive in terms of completely or partially preventing a disease or its symptoms, and / or may be therapeutic in terms of partially or completely curing a disease and / or the adverse effects caused by the disease. "Treatment" as used herein covers diseases in mammals, particularly humans, and includes: (a) preventing the occurrence of a disease or condition in an individual who is susceptible to the disease but has not yet been diagnosed with the disease; (b) inhibiting the disease, such as blocking the progression of the disease; or (c) alleviating the disease, such as alleviating symptoms associated with the disease. "Treatment" as used herein covers any medication that administers a drug or antibody or antigen-binding fragment to an individual to treat, cure, alleviate, improve, reduce or inhibit the individual's disease, including but not limited to administering a drug containing the antibody or antigen-binding fragment described herein to an individual in need.

[0073] Detailed description of the anti-novel coronavirus XBB variant antibody and its application

[0074] The present invention proposes an antibody or antigen-binding fragment, a recombinant protein, a multispecific antibody, a nucleic acid molecule, an expression vector, a recombinant cell, a conjugate, a pharmaceutical composition, a kit and their uses, and a method for detecting the novel coronavirus XBB, which will be described in detail below.

[0075] Antibodies or antigen-binding fragments

[0076] In one aspect of the present invention, the present invention provides an antibody or antigen-binding fragment. According to an embodiment of the present invention, the antibody or antigen-binding fragment comprises a HCDR3 having an amino acid sequence as shown in SEQ ID NO: 3 or a conservatively modified form thereof. Compared with natural antibodies, antibodies containing the HCDR3 of the present invention have better affinity for the new coronavirus XBB and the ability to neutralize the new coronavirus XBB, and can effectively detect the new coronavirus XBB, diagnose related diseases caused by the new coronavirus XBB, or effectively prevent and / or treat related diseases caused by the new coronavirus XBB.

[0077] In this article, the term "antibody" is used in the broadest sense, which can include full-length monoclonal antibodies, multispecific antibodies, and chimeric antibodies, and the specific structure is not limited as long as they show the desired biological activity. It usually includes a light chain with a lighter molecular weight and a heavy chain with a heavier molecular weight, and the heavy chain (H chain) and the light chain (L chain) are connected by a disulfide bond to form an antibody molecule. Among them, the amino acid sequence of the amino terminal (N terminal) of the peptide chain varies greatly, which is called the variable region (V region); the carboxyl terminal (C terminal) is relatively stable and varies little, which is called the constant region (C region). The V regions of the L chain and the H chain are called VL and VH, respectively.

[0078] In this article, the heavy chain complementary determining region (heavy chain variable region CDR) is represented by "HCDRs" or "HCDR", which includes HCDR1 (also known as CDR-H1), HCDR2 (also known as CDR-H2) and HCDR3 (also known as CDR-H3); the light chain complementary determining region (light chain variable region CDR) is represented by "LCDRs" or "LCDR", which includes LCDR1 (also known as CDR-L1), LCDR2 (also known as CDR-L2) and LCDR3 (also known as CDR-L3). Commonly used CDR definition schemes in the art include: Kabat definition, Chothia definition, IMGT definition, Contact definition and AbM definition.

[0079] As described herein, the "Kabat definition" refers to the definition system described by Kabat et al., U. S. Patent. of Health and Human Services, "Sequence of Proteins of Immunological Interest" (1983). For the "Chothia definition", see Chothia et al., J Mol Biol 196:901-917 (1987). Exemplary defined CDRs are listed in Table A below. The definitions in different documents are slightly different. Given the variable region amino acid sequence of an antibody, a person skilled in the art can routinely determine which residues contain a specific CDR. It should be noted that the CDRs in the present invention include but are not limited to CDRs defined by other methods in Table A. CDRs determined based on the heavy chain variable region and light chain variable region disclosed in this application using other rules disclosed in the art also fall within the scope of protection of the present disclosure.

[0080] Table A: CDR Definition 1

[0081] CDR Kabat <![CDATA[AbM 2 ]]> IMGT Chothia HCDR1 <![CDATA[H31~H35 3 ]]> <![CDATA[H26~H35 3 ]]> <![CDATA[H26~H33 5 ]]> <![CDATA[H26~H32..34 4 ]]> HCDR2 H50~H65 H50~H58 H51~H57 H52~H56 HCDR3 H95~H102 H95~H102 H93~H102 H95~H102 LCDR1 L24~L34 L24~L34 L27~L32 L24~L34 LCDR2 L50~L56 L50~L56 L50~L51 L50~L56 LCDR3 L89~L97 L89~L97 L89~L97 L89~L97

[0082] 1 The numbering of all CDR definitions in Table A is based on the Kabat numbering system (see below), with amino acid numbers on the heavy chain represented by "H+numbers" and amino acid numbers on the light chain represented by "L+numbers".

[0083] 2 "AbM" as used in Table A with a lowercase "b" refers to CDRs defined by Oxford Molecular's "AbM" antibody modeling software.

[0084] 3 If both H35A and H35B are absent, CDR-H1 ends at position 35; if only H35A is present, CDR-H1 ends at position 35A; if both H35A and H35B are present, CDR-H1 ends at position 35B.

[0085] 4 If both H35A and H35B are absent, CDR-H1 ends at position 32; if only H35A is present, CDR-H1 ends at position 33; if both H35A and H35B are present, CDR-H1 ends at position 34.

[0086] 5If both H35A and H35B are absent, CDR-H1 ends at position 33; if only H35A is present, CDR-H1 ends at position 34; if both H35A and H35B are present, CDR-H1 ends at position 35.

[0087] Kabat et al. also defined a numbering system applicable to the variable region sequence of any antibody. A person of ordinary skill in the art can clearly correspond the Kabat numbering system to any variable region sequence without relying on any experimental data outside the sequence itself. As described herein, "Kabat numbering" refers to the numbering system described in "Kabat et al., U. S. Patent. of Health and Human Services, "Sequence of Proteins of Immunological Interest" (1983)", and the HCDRs and LCDRs of the antibodies or antigen-binding fragments of the present invention are numbered using the above numbering system. For specific numbering results, see Table A. It should be noted that the polypeptide sequences in the sequence table and Table B of the present invention are numbered according to the Kabat numbering system. However, a person of ordinary skill in the art is fully capable of converting the sequence Kabat numbering of the sequence table into "HCDRs" and / or "LCDRs" under other numbering systems, which are all within the scope of protection of the present invention.

[0088] As used herein, the term "antigen-binding fragment" is a fragment comprising part or all of an antibody, which lacks at least some of the amino acids present in the full-length chain but is still capable of specifically binding to an antigen, for example, the fragment may comprise part or all of an antibody CDR. Such fragments are biologically active because they bind to an antigen and can compete with other antigen-binding molecules (including intact antibodies) for binding to a given epitope. Such fragments are selected from Fab, Fv, scFv or single domain antibodies. Such fragments can be produced by recombinant nucleic acid technology, or can be produced by enzymatic cleavage or chemical cleavage of antigen-binding molecules (including intact antibodies).

[0089] As used herein, "conservatively modified forms of an amino acid sequence" refers to amino acid modifications that do not significantly affect or alter the binding properties of an antibody comprising the amino acid sequence, including amino acid substitutions, additions, and deletions. Modifications can be introduced into the antibodies of the invention by standard techniques such as site-directed mutagenesis and PCR-mediated mutagenesis. Conservative amino acid substitutions are substitutions in which an amino acid residue is replaced by an amino acid residue with a similar side chain. Families of amino acid residues with similar side chains have been identified in the art. These families include amino acids with basic side chains (e.g., lysine, arginine, histidine), amino acids with acidic side chains (e.g., aspartic acid, glutamic acid), amino acids with uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine, tryptophan), amino acids with non-polar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine), amino acids with beta-branched side chains (e.g., threonine, valine, isoleucine), and amino acids with aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine). Thus, one or more amino acid residues in the CDR region of an antibody of the invention may be replaced by other amino acid residues from the same side chain family, and the retained function of the altered antibody may be tested using the functional assays described herein. Preferably, conservative modifications are no more than 1 or 2 in number.

[0090] According to an embodiment of the present invention, the antibody or antigen-binding fragment may further include at least one of the following technical features:

[0091] According to an embodiment of the present invention, the antibody or antigen-binding fragment further includes a CDR selected from at least one of the following: heavy chain variable region CDR: amino acid sequence of SEQ ID NO: 1-2 or a conservatively modified form thereof; light chain variable region CDR: amino acid sequence of SEQ ID NO: 4-6 or a conservatively modified form thereof.

[0092] According to an embodiment of the present invention, the antibody or antigen-binding fragment comprises: HCDR1, HCDR2, HCDR3 as shown in the amino acid sequences of SEQ ID NOs: 1, 2 and 3, respectively; and LCDR1, LCDR2, LCDR3 as shown in the amino acid sequences of SEQ ID NOs: 4, 5 and 6, respectively.

[0093] According to an embodiment of the present invention, the antibody or antigen-binding fragment comprises a heavy chain framework region.

[0094] According to an embodiment of the present invention, at least a portion of the heavy chain framework region is derived from at least one of a mouse antibody, a primate antibody, a bovine antibody, a horse antibody, a dairy cow antibody, a porcine antibody, a sheep antibody, a goat antibody, a dog antibody, a cat antibody, a rabbit antibody, a camel antibody, a donkey antibody, a deer antibody, a mink antibody, a chicken antibody, a duck antibody, a goose antibody, a turkey antibody, a fighting cock antibody or a mutant thereof.

[0095] According to an embodiment of the present invention, at least a portion of the heavy chain framework region is derived from at least one of a murine antibody and a human antibody.

[0096] According to an embodiment of the present invention, the antibody or antigen-binding fragment comprises a light chain framework region.

[0097] According to an embodiment of the present invention, at least a portion of the light chain framework region is derived from at least one of a mouse antibody, a primate antibody, a bovine antibody, a horse antibody, a dairy cow antibody, a porcine antibody, a sheep antibody, a goat antibody, a dog antibody, a cat antibody, a rabbit antibody, a camel antibody, a donkey antibody, a deer antibody, a mink antibody, a chicken antibody, a duck antibody, a goose antibody, a turkey antibody, a fighting cock antibody or a mutant thereof.

[0098] According to an embodiment of the present invention, at least a portion of the light chain framework region is derived from at least one of a murine antibody and a human antibody.

[0099] According to an embodiment of the present invention, the antibody or antigen-binding fragment comprises: a heavy chain variable region having an amino acid sequence as shown in SEQ ID NO:7 or an amino acid sequence having at least 90% homology thereto; and a light chain variable region having an amino acid sequence as shown in SEQ ID NO:8 or an amino acid sequence having at least 90% homology thereto.

[0100] According to an embodiment of the present invention, the antibody or antigen-binding fragment further comprises a heavy chain constant region.

[0101] According to an embodiment of the present invention, the antibody or antigen-binding fragment further comprises a light chain constant region.

[0102] According to an embodiment of the present invention, at least a portion of at least one of the heavy chain constant region and the light chain constant region is from at least one of a mouse antibody, a primate antibody, a bovine antibody, a horse antibody, a dairy cow antibody, a porcine antibody, a sheep antibody, a goat antibody, a dog antibody, a cat antibody, a rabbit antibody, a camel antibody, a donkey antibody, a deer antibody, a mink antibody, a chicken antibody, a duck antibody, a goose antibody, a turkey antibody, a fighting cock antibody or a mutant thereof.

[0103] According to an embodiment of the present invention, the heavy chain constant region includes a heavy chain constant region selected from IgG1, IgG2, IgG3, IgG4, IgA, IgM, IgE or IgD; or the light chain constant region includes a light chain constant region selected from κ type or λ type.

[0104] According to an embodiment of the present invention, the light chain constant region and the heavy chain constant region are both derived from a murine antibody or a mutant thereof, and / or a human antibody or a mutant thereof.

[0105] According to an embodiment of the present invention, the N-terminus of the heavy chain constant region is connected to the C-terminus of the heavy chain variable region.

[0106] According to an embodiment of the present invention, the N-terminus of the light chain constant region is connected to the C-terminus of the light chain variable region.

[0107] According to an embodiment of the present invention, the heavy chain constant region includes the heavy chain constant region shown in SEQ ID NO: 9 or an amino acid sequence having at least 80% identity thereto.

[0108] According to an embodiment of the present invention, the light chain constant region includes the light chain constant region shown in SEQ ID NO: 10 or an amino acid sequence having at least 80% identity thereto.

[0109] According to an embodiment of the present invention, the antibodies include polyclonal antibodies, full-length monoclonal antibodies, Fab antibodies, Fab' antibodies, F(ab') 2 At least one of an antibody, an Fv antibody, a single-chain antibody, a single-domain antibody, and a minimum recognition unit; or the antigen-binding fragment includes F(ab') 2 fragment, Fab' fragment, Fab fragment, F(ab) 2 At least one of a fragment, an Fv fragment, a scFv fragment, a scFv-Fc fusion protein, a scFv-Fv fusion protein and a minimum recognition unit.

[0110] As used herein, the terms "full-length antibody", "full-length monoclonal antibody" or "full-length monoclonal antibody" are composed of at least two identical light chains and at least two identical heavy chains connected by interchain disulfide bonds, such as immunoglobulin G (IgG), immunoglobulin A (IgA), immunoglobulin M (IgM), immunoglobulin D (IgD) or immunoglobulin E (IgE).

[0111] In this article, the terms "polyantibody" and "multispecific antibody" are synonymous, both referring to antibodies that can recognize multiple antigenic epitopes, such as antibodies that can recognize two antigenic epitopes (bispecific antibodies, referred to as bispecific antibodies), antibodies that recognize three antigenic epitopes, or antibodies that recognize four antigenic epitopes. They are understood in a broad sense, and the specific structure is not limited, as long as they can recognize multiple antigenic epitopes. In the present invention, at least one of the multiple antigenic epitopes is derived from the new coronavirus XBB.

[0112] In this article, the terms "single-domain antibody", "nanoantibody" and "VHH antibody" are used interchangeably, which were originally described as antigen-binding immunoglobulin (variable) domains of "heavy chain antibodies" (i.e., "antibodies lacking light chains") (Hamers-Casterman C, Atarhouch T, Muyldermans S, Robinson G, Hamers C, Songa EB, Bendahman N, Hamers R.: "Naturally occurring antibodies devoid of light chains"; Nature 363, 446-448 (1993)), comprising a heavy chain variable region (VH) and conventional CH2 and CH3 regions, which specifically bind to antigenic proteins (e.g., the S protein of the new coronavirus XBB) through the heavy chain variable region.

[0113] As used herein, the term "Fab antibody" or "Fab fragment" generally refers to an antibody or fragment containing only the Fab molecule, which is composed of the VH and CH1 of the heavy chain and a complete light chain, with the light chain and the heavy chain connected by a disulfide bond.

[0114] As used herein, the term "F(ab') 2 Antibody" or "F(ab') 2 A "fragment" has two antigen-binding F(ab') portions linked together by a disulfide bond.

[0115] As used herein, the term "Fv antibody" or "Fv fragment" generally refers to an antibody or fragment consisting only of a light chain variable region (VL) and a heavy chain variable region (VH) connected by non-covalent bonds, and is the smallest functional fragment of an antibody that retains a complete antigen binding site.

[0116] As used herein, the terms "single-chain antibody" and "scFv fragment" refer to antibodies or fragments formed by connecting the heavy chain variable region and the light chain variable region of an antibody via a short peptide.

[0117] In this article, the terms "minimum recognition unit" and "MRU" both refer to antibodies or fragments consisting of only one CDR, and their molecular weight is very small, accounting for only about 1% of the complete antibody.

[0118] According to an embodiment of the present invention, the antibody or antigen-binding fragment comprises: a heavy chain having an amino acid sequence as shown in SEQ ID NO: 11 or an amino acid sequence having at least 80% homology thereto; and a light chain having an amino acid sequence as shown in SEQ ID NO: 12 or an amino acid sequence having at least 80% homology thereto.

[0119] Recombinant proteins and multispecific antibodies

[0120] In the second aspect of the present invention, the present invention proposes a recombinant protein. According to an embodiment of the present invention, the recombinant protein includes: the antibody or antigen-binding fragment described in the first aspect. The recombinant protein of the present invention has better affinity for the new coronavirus XBB and neutralization ability of the new coronavirus XBB, and can effectively detect the new coronavirus XBB, diagnose related diseases caused by the new coronavirus XBB, or effectively prevent and / or treat related diseases caused by the new coronavirus XBB.

[0121] According to an embodiment of the present invention, the recombinant protein further includes at least one of a biologically active protein or a fragment thereof, a biologically active polypeptide or a fragment thereof.

[0122] According to an embodiment of the present invention, the biologically active protein or fragment thereof includes at least one selected from a protein tag, a protein toxin or a fragment thereof, an interferon or a fragment thereof, a biological response regulator or a fragment thereof and an Fc fragment.

[0123] In this article, "protein tag" generally refers to a polypeptide or protein fused with a target protein (antibody or antigen-binding fragment), which can be used for the expression, detection, disappearance or purification of the target protein, etc., including but not limited to His tag (also known as His-Tag, sequence HHHHHH), Flag tag (also known as Flag-Tag, sequence DYKDDDDK), GST tag (also known as GST-Tag, glutathione sulfhydryl transferase tag), MBP tag (also known as MBP-Tag, maltose binding protein tag), SUMO tag and C-Myc tag, etc.

[0124] In this article, "toxin" generally refers to a substance that is toxic to the host, including protein toxins and non-protein toxins. Among them, protein toxins include but are not limited to abrin, ricin A, Pseudomonas exotoxin and diphtheria toxin. In the present invention, the protein toxin is preferably a protein toxin with enzymatic activity.

[0125] In this article, "interferon" generally refers to a glycoprotein that has the ability to directly kill or inhibit viruses, including but not limited to IFN-α, INF-β and IFN-γ.

[0126] In this article, "biological response modifiers" generally refer to a class of protein substances that directly or indirectly enhance the body's anti-tumor effect through the immune system, including but not limited to lymphokines, IL-2, IL-6, IL-10 and GM-CSF.

[0127] Herein, "Fc fragment" generally refers to the Fc region from IgG (e.g., IgG1, IgG2, IgG3 or IgG4 subtype), IgA1, IgA2, IgD, IgE or IgM, including CH2, CH3 region and optionally hinge region. Preferably, IgG, IgA1, IgA2, IgD, IgE or IgM is derived from mouse, human, primate or alpaca.

[0128] In the third aspect of the present invention, the present invention proposes a multispecific antibody. According to an embodiment of the present invention, the multispecific antibody comprises: a first binding region, the first binding region comprises the antibody or antigen binding fragment described in the first aspect; a second binding region, the second binding region has a first molecule binding activity. The multispecific antibody of the present invention has better affinity for the new coronavirus XBB and neutralization ability of the new coronavirus XBB, and can effectively detect the new coronavirus XBB, diagnose related diseases caused by the new coronavirus XBB, or effectively prevent and / or treat related diseases caused by the new coronavirus XBB.

[0129] According to an embodiment of the present invention, the first molecule includes at least one of an antigen, a virus, a bacterium, an endotoxin, a cytokine, and a cytokine receptor.

[0130] Nucleic acid molecules, expression vectors and recombinant cells

[0131] In a fourth aspect of the present invention, the present invention provides a nucleic acid molecule. According to an embodiment of the present invention, the nucleic acid molecule encodes the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, or the multispecific antibody described in the third aspect. The nucleic acid molecule of the present invention may encode the antibody or antigen-binding fragment of the first aspect, the recombinant protein described in the second aspect, or the multispecific antibody described in the third aspect.

[0132] According to an embodiment of the present invention, the nucleic acid molecule is DNA.

[0133] It should be noted that, for the nucleic acid molecules mentioned herein, those skilled in the art will understand that they actually include any one or both of the complementary double strands. For convenience, in this specification and claims, although only one strand is given in most cases, the other strand complementary thereto is actually disclosed. In addition, the nucleic acid sequence in this application includes a DNA form or an RNA form, and disclosing one of them means that the other is also disclosed.

[0134] In the fifth aspect of the present invention, the present invention proposes an expression vector. According to an embodiment of the present invention, the expression vector carries the nucleic acid molecule described in the fourth aspect. When the above-mentioned nucleic acid molecule is connected to the expression vector, the nucleic acid molecule can be directly or indirectly connected to the control element on the expression vector, as long as these control elements can control the translation and expression of the nucleic acid molecule. Of course, these control elements can come directly from the expression vector itself, or they can be exogenous, that is, not from the expression vector itself. Of course, the nucleic acid molecule can be operably connected to the control element.

[0135] Herein, "operably linked" means connecting the foreign gene to the expression vector so that the control elements in the expression vector, such as transcription control sequences and translation control sequences, can play their intended functions of regulating the transcription and translation of the foreign gene. Commonly used expression vectors can be, for example, plasmids, bacteriophages, and the like.

[0136] According to some specific embodiments of the present invention, after the expression vector is introduced into a suitable recipient cell, the expression of the aforementioned antibody or antigen-binding fragment, the aforementioned recombinant protein or the aforementioned multi-specific antibody can be effectively achieved under the mediation of the regulatory system, thereby achieving large-scale in vitro acquisition of the antibody or antigen-binding fragment, recombinant protein or multi-specific antibody.

[0137] According to an embodiment of the present invention, the expression vector comprises a vector selected from a eukaryotic expression vector or a prokaryotic expression vector.

[0138] In an optional embodiment of the present invention, the expression vector is a plasmid expression vector, a viral expression vector, such as a lentiviral expression vector.

[0139] In the sixth aspect of the present invention, the present invention provides a recombinant cell. According to an embodiment of the present invention, the recombinant cell includes carrying the nucleic acid molecule described in the fourth aspect or the expression vector described in the fifth aspect; or expressing the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, or the multispecific antibody described in the third aspect. The recombinant cell can effectively express the aforementioned antibody or antigen-binding fragment, recombinant protein or multispecific antibody in the cell under suitable conditions.

[0140] It should be noted that "suitable conditions" refer to conditions suitable for the expression of the antibody or antigen-binding fragment, recombinant protein or multi-specific antibody of the present invention. It is easy for those skilled in the art to understand that conditions suitable for the expression of the antibody or antigen-binding fragment, recombinant protein or multi-specific antibody include but are not limited to suitable transformation or transfection methods, suitable transformation or transfection conditions, healthy host cell state, suitable host cell density, suitable cell culture environment, and suitable cell culture time. "Suitable conditions" are not particularly limited, and those skilled in the art can optimize the most suitable conditions for the expression of the above-mentioned antibodies or antigen-binding fragments, recombinant proteins or multi-specific antibodies according to the specific environment of the laboratory.

[0141] According to an embodiment of the present invention, the recombinant cell is obtained by introducing the expression vector described in the fifth aspect into a host cell.

[0142] According to an embodiment of the present invention, the recombinant cell is a eukaryotic cell, preferably a mammalian cell.

[0143] Conjugates, pharmaceutical compositions and kits

[0144] In the seventh aspect of the present invention, the present invention proposes a conjugate. According to an embodiment of the present invention, the conjugate comprises the antibody or antigen binding fragment described in the first aspect, the recombinant protein described in the second aspect, or the multispecific antibody described in the third aspect; and a coupling portion, wherein the coupling portion is connected to the antibody or antigen binding fragment, the recombinant protein or the multispecific antibody. The conjugate of the present invention can bind to the new coronavirus XBB, has better affinity for the new coronavirus XBB and neutralization ability of the new coronavirus XBB, and can effectively detect the new coronavirus XBB, diagnose related diseases caused by the new coronavirus XBB, or prevent and / or treat related diseases caused by the new coronavirus XBB.

[0145] According to an embodiment of the present invention, the coupling part includes at least one selected from a carrier, a drug, a toxin, a cytokine, a protein tag and a modifier.

[0146] In this article, the carrier can be a substance that can be suspended or dispersed in a liquid phase (for example, solid phase carriers such as particles and magnetic beads), or a solid phase that can contain or carry a liquid phase (for example, a support such as a plate, a membrane, a test tube, and a container such as a well plate, a microfluidic channel, a glass capillary, a nanocolumn, a monolithic column, etc.); it can also be a labeling carrier for labeling an antibody or antigen-binding fragment, a recombinant protein or a multispecific antibody, such as an enzyme (for example, peroxidase, alkaline phosphatase, luciferin, β-galactosidase, etc.). glycosidase), affinity substances (for example, one of streptavidin and biotin, one of the positive and antisense nucleic acids complementary to each other), fluorescent substances (for example, fluorescein, fluorescein isothiocyanate, rhodamine, green fluorescent protein, red fluorescent protein), luminescent substances (for example, luciferin, aequorin, acridinium ester, tris(2,2'-bipyridine)ruthenium, luminol), radioactive isotopes (for example, 3H, 14C, 32P, 35S, 125I) and gold colloid, etc.

[0147] According to an embodiment of the present invention, the drug is a small molecule drug that can bind to an antibody or antigen-binding fragment, a recombinant protein or a multi-specific antibody.

[0148] According to an embodiment of the present invention, the protein tag includes but is not limited to a His tag, a Flag tag, a GST tag, an MBP tag, a SUMO tag, a C-Myc tag, and the like.

[0149] According to the embodiments of the present invention, the modifier should be understood in a broad sense, and may refer to a substance used to modify a protein. For example, it may be polyethylene glycol or a derivative thereof.

[0150] It should be noted that the binding method of the coupling part and the antibody or antigen-binding fragment, recombinant protein or multispecific antibody can be a method known in the art, for example, physical adsorption, covalent binding, methods using affinity substances (e.g., biotin, streptavidin) and ion binding methods.

[0151] In the eighth aspect of the present invention, the present invention proposes a pharmaceutical composition. According to an embodiment of the present invention, the pharmaceutical composition includes the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, the multispecific antibody described in the third aspect, the nucleic acid molecule described in the fourth aspect, the expression vector described in the fifth aspect, the recombinant cell described in the sixth aspect, or the conjugate described in the seventh aspect. The pharmaceutical composition of the present invention can bind to the new coronavirus XBB, has better affinity for the new coronavirus XBB and neutralization ability of the new coronavirus XBB, and can effectively prevent and / or treat related diseases caused by the new coronavirus XBB.

[0152] According to an embodiment of the present invention, the pharmaceutical composition further comprises a pharmaceutically acceptable excipient.

[0153] The administration of the pharmaceutical composition of the present invention can be carried out by any acceptable mode of administration. The pharmaceutical composition of the present invention can be formulated into a solid, semisolid, liquid or gaseous form of preparation, such as an injection, a lyophilized powder, and the current methods for preparing these dosage forms are known or obvious to those skilled in the art. Typical routes of administration of such pharmaceutical compositions include, but are not limited to, subcutaneous injection, intravenous, intramuscular, intradermal, intrasternal injection or infusion techniques. The pharmaceutical composition of the present invention is formulated so as to allow the biologically active ingredients contained therein to be bioavailable after the composition is administered to a patient.

[0154] In the ninth aspect of the present invention, the present invention proposes a kit. According to an embodiment of the present invention, the kit includes the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, the multispecific antibody described in the third aspect, the nucleic acid molecule described in the fourth aspect, the expression vector described in the fifth aspect, the recombinant cell described in the sixth aspect, or the conjugate described in the seventh aspect. The kit of the present invention can bind to the new coronavirus XBB and has a strong affinity for the new coronavirus XBB, and can effectively detect the new coronavirus XBB or diagnose related diseases caused by the new coronavirus XBB.

[0155] use

[0156] In the tenth aspect of the present invention, the present invention proposes a use of the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, the multispecific antibody described in the third aspect, the nucleic acid molecule described in the fourth aspect, the expression vector described in the fifth aspect, the recombinant cell described in the sixth aspect, or the conjugate described in the seventh aspect in the preparation of a drug, wherein the drug is used to prevent and / or treat related diseases caused by the new coronavirus XBB.

[0157] In the eleventh aspect of the present invention, the present invention proposes a use of the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, the multispecific antibody described in the third aspect, the nucleic acid molecule described in the fourth aspect, the expression vector described in the fifth aspect, the recombinant cell described in the sixth aspect, or the conjugate described in the seventh aspect in the preparation of a kit for detecting the new coronavirus XBB, diagnosing related diseases caused by the new coronavirus XBB, or evaluating the prognosis of related diseases caused by the new coronavirus XBB.

[0158] method

[0159] In the twelfth aspect of the present invention, the present invention proposes a method for detecting the novel coronavirus XBB. According to an embodiment of the present invention, the method comprises: contacting the sample to be detected with the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, the multispecific antibody described in the third aspect, or the conjugate described in the seventh aspect to form an immune complex. The method of the present invention has the advantages of detecting the novel coronavirus XBB, especially for in vitro detection, and has the advantages of high detection accuracy.

[0160] According to an embodiment of the present invention, based on the signal of the immune complex, it is determined whether the sample to be tested contains the content of the new coronavirus XBB.

[0161] According to an embodiment of the present invention, the immune complex further comprises a second antibody, which binds to the antibody or antigen-binding fragment.

[0162] According to an embodiment of the present invention, the immune complex also includes a second antibody, which binds to the new coronavirus XBB.

[0163] In the thirteenth aspect of the present invention, the present invention proposes a method for preventing and / or treating related diseases caused by the new coronavirus XBB. According to an embodiment of the present invention, the method comprises: administering a pharmaceutically acceptable amount of the aforementioned antibody or antigen-binding fragment, the aforementioned recombinant protein, the aforementioned multispecific antibody, the aforementioned pharmaceutical composition or the aforementioned conjugate to a subject. The method of the present invention can effectively treat or prevent related diseases caused by the new coronavirus XBB.

[0164] The effective amount of the antibody or antigen-binding fragment, recombinant protein, multispecific antibody, pharmaceutical composition or conjugate of the present invention may vary depending on the mode of administration and the severity of the disease to be treated. The selection of the preferred effective amount can be determined by a person of ordinary skill in the art based on various factors (e.g., through clinical trials). The factors include, but are not limited to: pharmacokinetic parameters of the active ingredient such as bioavailability, metabolism, half-life, etc.; the severity of the disease to be treated, the patient's weight, the patient's immune status, the route of administration, etc. For example, depending on the urgency of the treatment situation, several divided doses may be administered daily, or the dose may be reduced proportionally.

[0165] The antibodies or antigen binding fragments, recombinant proteins, multispecific antibodies, pharmaceutical compositions or conjugates of the present invention can be incorporated into drugs suitable for parenteral administration (e.g., intravenous, subcutaneous, intraperitoneal, intramuscular). These drugs can be prepared in various forms. For example, liquid, semisolid and solid dosage forms, including but not limited to liquid solutions (e.g., injection solutions and infusion solutions) or lyophilized powders. Typical drugs are in the form of injection solutions or infusion solutions. The aforementioned antibodies or antigen binding fragments, recombinant proteins, multispecific antibodies, pharmaceutical compositions or conjugates can be administered by intravenous infusion or injection or intramuscular or subcutaneous injection.

[0166] In this article, the term "subject" refers to a vertebrate, preferably a mammal, most preferably a human. Mammals include, but are not limited to, rodents, apes, humans, livestock, competitive animals, and pets. Tissues, cells, and progeny of biological entities obtained in vivo or cultured in vitro are also included.

[0167] According to an embodiment of the present invention, the administration route of the method is subcutaneous injection or intravenous injection.

[0168] In the fourteenth aspect of the present invention, the present invention proposes a method for diagnosing related diseases caused by the new coronavirus XBB. According to an embodiment of the present invention, the method comprises: using the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, the multispecific antibody described in the third aspect, or the conjugate described in the seventh aspect to detect the sample to be tested, and based on the test results, determining the content of the new coronavirus XBB in the sample to be tested. The method of the present invention can effectively diagnose related diseases caused by the new coronavirus XBB.

[0169] According to an embodiment of the present invention, the sample to be tested is blood.

[0170] In the fifteenth aspect of the present invention, the present invention proposes a method for evaluating the prognosis of related diseases caused by the new coronavirus XBB. According to an embodiment of the present invention, the method comprises: using the antibody or antigen-binding fragment described in the first aspect, the recombinant protein described in the second aspect, the multispecific antibody described in the third aspect, or the conjugate described in the seventh aspect to detect the sample to be tested, and based on the test results, determining the content of the new coronavirus XBB in the sample to be tested. The method of the present invention can effectively evaluate the prognosis of related diseases caused by the new coronavirus XBB.

[0171] According to an embodiment of the present invention, the sample to be tested is derived from a patient suffering from a disease related to the novel coronavirus XBB before or after treatment.

[0172] According to an embodiment of the present invention, the prognosis effect of the related diseases caused by the new coronavirus XBB is determined based on the content of the new coronavirus XBB in the test sample of the patient suffering from the related diseases caused by the new coronavirus XBB before or after treatment.

[0173] According to an embodiment of the present invention, a decrease in the content of the new coronavirus XBB in the test sample of a patient suffering from a disease related to the new coronavirus XBB after treatment is an indication of a good prognosis for the patient.

[0174] According to an embodiment of the present invention, the sample to be tested is blood.

[0175] The amino acid sequences involved in this article are shown in Table B:

[0176] Table B: Amino Acid Sequences

[0177]

[0178]

[0179]

[0180] The scheme of the present invention will be explained below in conjunction with the embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Where specific techniques or conditions are not indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used are not indicated by the manufacturer and are all conventional products that can be obtained commercially.

[0181] The present invention will be described in detail below through examples. In the examples or test examples, experimental methods without specific conditions are all carried out under conventional conditions.

[0182] Practice of the present disclosure will employ, unless otherwise indicated, conventional techniques of cell biology, molecular biology (including recombinant techniques), microbiology, biochemistry, and immunology, which are within the capabilities of a skilled artisan.

[0183] In the embodiments of the present invention, the nucleotide sequence used to prepare the expression vector can be obtained according to its amino acid sequence using conventional methods or conventional software (such as the online program Vectorbuilder (website: https: / / www.vectorbuilder.cn / tool / codon-optimization.html), GeneOptimizer online program, etc.).

[0184] Example 1: Generation of novel coronavirus antibodies based on artificial intelligence

[0185] The specific screening method of this embodiment is shown in the patent application publication number CN116959576A, wherein the main steps are as follows:

[0186] The Roformer (Su, Jianlin, Yu Lu, Shengfeng Pan, Ahmed Murtadha, Bo Wen, and Yunfeng Liu. 2021. "RoFormer: Enhanced Transformer with Rotary Position Embedding." ArXiv [Cs.CL]. arXiv. http: / / arxiv.org / abs / 2104.09864.) model was used to pre-train more than 100 million antibody sequences in the Antibody Observation Space (OAS) dataset to learn the sequence characteristics of the light and heavy chains of antibodies, and the Antibody Roformer pre-training model was established. The specific process of pre-training includes the following steps:

[0187] 1) Randomly select some words or characters for masking: Randomly select some words or characters in the training data for masking. Specifically, take each amino acid in the antibody sequence as a token and randomly select 15% of the tokens for masking.

[0188] 2) Replace the masked words or characters: The masked words or characters are replaced with a special marker [MASK]. For example, the sequence

[0189] After "MDVLY" is segmented, some characters will be masked and it will become "MD[MASK]L[MASK]".

[0190] 3) Input into the model: Input the masked and replaced text sequence into the model for training. The model needs to combine the context to predict the masked words or characters.

[0191] 4) Calculate the loss function: The model outputs the predicted word or character probability distribution, uses the cross entropy loss function to calculate the difference between the model prediction result and the actual result, and performs back propagation to update the model parameters. The cross entropy loss function formula is as follows:

[0192]

[0193] The Roformer model is a variant of the BERT (Devlin, Jacob, Ming-Wei Chang, Kenton Lee, and Kristina Toutanova. 2018. "BERT: Pre-Training of Deep Bidirectional Transformers for Language Understanding." ArXiv [Cs.CL]. arXiv. http: / / arxiv.org / abs / 1810.04805.) model that uses rotational position encoding. The BERT model architecture is mainly composed of a multi-layer Transformer (Vaswani, Ashish, Noam Shazeer, Niki Parmar, Jakob Uszkoreit, Llion Jones, Aidan N. Gomez, Kaiser, and Illia Polosukhin. 2017. “Attention Is All You Need.” Advances in Neural Information Processing Systems 30. https: / / proceedings.neurips.cc / paper / 7181-attention-is-all.) encoder, each Transformer block contains two parts: self-attention and feed-forward neural network.

[0194] The self-attention mechanism is used to learn the dependencies between positions in the input sequence. In BERT, each word is represented as a vector, and the self-attention mechanism can calculate the weight of each word to other words, and then use these weights to calculate the weighted average vector representation, thereby achieving the effect of paying attention to each part of the sequence. By obtaining the Queue (Q), Key (K) and Value (V) matrices, and then calculating the attention weight matrix A:

[0195]

[0196] Feedforward neural network layer is a basic neural network structure in deep learning. Input Z into a feedforward neural network layer as follows:

[0197] FFN(A)=max(0,AW1+b1)W 2 +b 2 , (3)

[0198] Then, if Figure 2 As shown, ESM2 (Lin, Zeming, Halil Akin, Roshan Rao, Brian Hie, Zhongkai Zhu, Wenting Lu, Nikita Smetanin, et al. 2022. "Evolutionary-Scale Prediction of Atomic Level Protein Structure with a Language Model." BioRxiv. https: / / doi.org / 10.1101 / 2022.07.20.500902.) pre-trained on large-scale protein sequence data is used as an encoder to encode the input antigen epitope sequence, which is called Antigen model; the pre-trained HeavyRoformer is used as a decoder to decode the encoding input by the encoder to generate an antibody sequence, and finally the generation process from antigen epitope sequence to antibody sequence is realized. Specifically, the parameters of the previously pre-trained Antigen model and AntibodyRoformer are directly used in the construction of encoder and decoder. For the encoder, it contains multiple Antigen layers, and the self-attention parameter weights of each Antigen layer are derived from the ESM2 model. Similarly, the Self-attention parameter weights of the Antibody Layer in the decoder are also inherited from AntibodyRoformer. The Cross-attention layer in the decoder is randomly initialized. Then, the antigen-CDRH3 sequence of the Cov-AbDab dataset is used to train the data generation model.

[0199] The S protein sequence of the novel coronavirus XBB variant was used as an antigen to input the AI-generated model to generate the corresponding antibody. SnugDock (Sircar, Aroop, and Jeffrey J. Gray. 2010. “SnugDock: Paratope Structural Optimization during Antibody-Antigen Docking Compensates for Errors in Antibody Homology Models.” PLoS Computational Biology 6(1): e1000644.) was used to evaluate the postures of the antibody-antigen complexes of the AI-generated antibody and the natural antibody, and the binding surface energy and binding surface RMSD of each posture were obtained. The results are shown in the figure below. Figure 3 As shown in a, the antibody generated by the model has smaller binding surface energy and binding surface RMSD than the natural antibody in the evaluation of 1000 postures of SnugDock, which indicates that the antibody generated by the present invention has a higher affinity for the antibody. Figure 3 b and Figure 3 c shows the structure of the model-generated antibody and the natural antibody and XBB complex. The generated antibody mainly binds to a continuous region of the light chain, while the natural antibody has discontinuous partial binding sites on both the light chain and the heavy chain. The results show that this method can quickly generate potential high-affinity antibody sequences for new antigen variants, which is of great significance for the design of antibody vaccines and drugs for viruses such as the new coronavirus that mutate at a high rate.

[0200] Example 2: Preparation of Antibodies

[0201] 1. Using genetic engineering technology, the nucleotide sequence encoding the heavy chain (amino acid sequence as shown in SEQ ID NO: 11) and the nucleotide sequence encoding the light chain (amino acid sequence as shown in SEQ ID NO: 12) were cloned into the pCMV3 expression vector, and the above expression vector was amplified to obtain the corresponding expression vector. Then, the obtained expression vector was transfected into the HEK-293 cell line using the chemical transfection reagent PEI, and the cell strain that can stably express the antibody sequence was obtained by pressure screening.

[0202] 2. Use protein purification technology to extract and purify the new coronavirus XBB variant antibody sequence from the above cell lines.

[0203] Example 3: Detection of antibody binding ability to the S protein of the novel coronavirus XBB variant and the novel coronavirus neutralization efficacy

[0204] In order to determine the binding ability of the artificial intelligence-generated antibody prepared in Example 2 to the S protein of the new coronavirus XBB variant (amino acid sequence as shown in SEQ ID NO: 14), in vitro experimental methods such as Western blot, surface plasmon resonance analysis and pseudovirus neutralization assay in the new coronavirus antibody evaluation study were used (see He, Qingwen, Lili Wu, Zepeng Xu, Xiaoyun Wang, Yufeng Xie, Yan Chai, Anqi Zheng, et al. 2023. "An Updated Atlas of Antibody Evasion by SARS-CoV-2 Omicron Sub-Variants Including BQ.1.1 and XBB." Cell Reports. Medicine 4(4): 100991.; Qu, Panke, Julia N. Faraone, John P. Evans, Yi-Min Zheng, Claire Carlin, Mirela Anghelina, Patrick Stevens, et al. 2023. "Enhanced Evasion of Neutralizing Antibody Response by Omicron XBB.1.5, CH.1.1, and CA.3.1 Variants." Cell Reports 42 (5): 112443.) The artificial intelligence-generated antibody (i.e., artificial) and the natural antibody (i.e., natural, wherein the amino acid sequence of the heavy chain is shown in SEQ ID NO: 15, and the amino acid sequence of the light chain is shown in SEQ ID NO: 12, purchased from ACROBiosystems) prepared in Example 2 were evaluated. Among them, the protein blotting results of the natural antibody (natural) and the artificial intelligence-generated antibody (artificial) binding to the S protein of the new coronavirus XBB variant are shown in Figure 4The results of surface plasmon resonance analysis of natural antibodies (natural) and artificial antibodies (artificial) binding to the S protein of the new coronavirus XBB variant are shown in Table 1. The results of the Western blot experiment showed that the artificial intelligence-generated antibodies and two natural antibodies used as controls can bind to the new coronavirus XBB variant S protein; compared with natural antibodies, artificial intelligence-generated antibodies show high binding affinity to the new coronavirus XBB variant S protein and superior new coronavirus neutralization efficacy.

[0205] Table 1

[0206]

[0207] Example 4: Application of artificial antibodies in the treatment, prevention and diagnosis of diseases related to the novel coronavirus XBB variant

[0208] The purified antibody sequences were used in experimental animal models for treatment and prevention of the novel coronavirus XBB variant to observe its inhibitory effect on viral replication and infection process and its effect on normal tissues. The specific schemes that can be used are as follows:

[0209] 1) Selection of experimental animal models: Rhesus monkeys (Cynomolgus macaque), mice and rats were used as experimental animal models.

[0210] 2) Design of experimental and control groups: Four groups were set for different species, namely: Group A (antibody treatment group, using the artificial intelligence generated antibodies prepared in Example 2), Group B (antibody prevention group, using the artificial intelligence generated antibodies prepared in Example 2), Group C (negative control group, not infected with the new coronavirus, no antibody treatment) and Group D (positive control group, infected with the new coronavirus, no antibody treatment). The number of animals in each group was 6.

[0211] The novel coronavirus XBB variant was infected in each group of animals. Except for group B, the animals in other groups were not treated before infection. The dosage of each group was the same. The respiratory secretions of the animals in each group were collected every day for viral load detection. On the 7th day after infection, the experimental animals were killed and the lung tissues were taken for pathological section observation. The serum of the experimental animals was collected for cytokine levels, antibody levels and safety assessment.

[0212] 3) Administration: Group A: The purified antibody sequences were administered on the 1st and 3rd day after infection, respectively; Group B: The purified antibody sequences were administered 1 day before infection for prevention; Group C: No antibody sequences were administered as a negative control; Group D: No antibody sequences were administered after infection as a positive control.

[0213] 4) Detection indicators and methods: a) Viral load: Real-time fluorescence quantitative PCR (RT-qPCR) was used to detect the viral load in the respiratory secretions of each group of animals; b) Pathological changes: The pathological changes in the lung tissue of each group of animals were observed through pathological sections; c) Cytokine levels: The levels of cytokines in the serum of each group of animals were detected by enzyme-linked immunosorbent assay (ELISA); d) Antibody levels: The antibody levels in the serum of each group of animals were detected by ELISA; e) Safety assessment: The effects of antibody sequences on normal tissues were detected through blood routine tests, liver and kidney function and other indicators.

[0214] The test results found that by comparing the viral load, pathological changes, cytokine levels and antibody levels of each group of animals, the artificial antibody sequence can effectively treat and prevent infection with the new coronavirus XBB variant; through testing of blood routine, liver and kidney function and other indicators, it was found that the artificial antibody sequence has no effect on normal tissues and is safe.

[0215] In summary, the novel coronavirus XBB variant antibody sequence of the present invention is effective and safe in the treatment and prevention of novel coronavirus XBB variant, and provides a theoretical basis for further clinical trials.

[0216] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0217] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. An antibody or antigen-binding fragment, It is characterized in that It includes a HCDR3 having an amino acid sequence as shown in SEQ ID NO: 3 or a conservatively modified form thereof.

2. The antibody or antigen-binding fragment according to claim 1, It is characterized in that Further comprising at least one CDR selected from the group consisting of: Heavy chain variable region CDR: amino acid sequence of SEQ ID NO: 1-2 or conservatively modified forms thereof; Light chain variable region CDR: amino acid sequence of SEQ ID NO: 4-6 or conservatively modified forms thereof; Optionally, the antibody or antigen-binding fragment comprises: HCDR1, HCDR2, HCDR3 as shown in the amino acid sequences of SEQ ID NOs: 1, 2 and 3, respectively; and LCDR1, LCDR2, LCDR3 are shown in the amino acid sequences of SEQ ID NO: 4, 5 and 6 respectively.

3. The antibody or antigen-binding fragment according to claim 2, It is characterized in that The antibody or antigen-binding fragment comprises a heavy chain framework region; Optionally, at least a portion of the heavy chain framework region is from at least one of a mouse antibody, a primate antibody, a bovine antibody, a horse antibody, a dairy cow antibody, a porcine antibody, a sheep antibody, a goat antibody, a dog antibody, a cat antibody, a rabbit antibody, a camel antibody, a donkey antibody, a deer antibody, a mink antibody, a chicken antibody, a duck antibody, a goose antibody, a turkey antibody, a fighting cock antibody, or a mutant thereof; Optionally, at least a portion of the heavy chain framework region is derived from at least one of a murine antibody and a human antibody; Optionally, the antibody or antigen-binding fragment comprises a light chain framework region; Optionally, at least a portion of the light chain framework region is derived from at least one of a mouse antibody, a primate antibody, a bovine antibody, a horse antibody, a dairy cow antibody, a porcine antibody, a sheep antibody, a goat antibody, a dog antibody, a cat antibody, a rabbit antibody, a camel antibody, a donkey antibody, a deer antibody, a mink antibody, a chicken antibody, a duck antibody, a goose antibody, a turkey antibody, a fighting cock antibody, or a mutant thereof; Optionally, at least a portion of the light chain framework region is from at least one of a murine antibody and a human antibody.

4. The antibody or antigen-binding fragment according to claim 1, It is characterized in that The antibody or antigen-binding fragment comprises: A heavy chain variable region having an amino acid sequence as shown in SEQ ID NO: 7, or an amino acid sequence having at least 90% homology thereto; and The light chain variable region has an amino acid sequence as shown in SEQ ID NO: 8, or an amino acid sequence having at least 90% homology thereto.

5. The antibody or antigen-binding fragment according to any one of claims 1 to 4, It is characterized in that The antibody or antigen-binding fragment further comprises a heavy chain constant region; Optionally, the antibody or antigen-binding fragment further comprises a light chain constant region; Optionally, at least a portion of at least one of the heavy chain constant region and the light chain constant region is from at least one of a mouse antibody, a primate antibody, a bovine antibody, a horse antibody, a dairy cow antibody, a porcine antibody, a sheep antibody, a goat antibody, a dog antibody, a cat antibody, a rabbit antibody, a camel antibody, a donkey antibody, a deer antibody, a mink antibody, a chicken antibody, a duck antibody, a goose antibody, a turkey antibody, a fighting cock antibody, or a mutant thereof; Optionally, the heavy chain constant region comprises a heavy chain constant region selected from IgG1, IgG2, IgG3, IgG4, IgA, IgM, IgE or IgD; or The light chain constant region comprises a light chain constant region selected from a κ type or a λ type; Optionally, the light chain constant region and the heavy chain constant region are both from a murine antibody or a mutant thereof, or a human antibody or a mutant thereof; Optionally, the N-terminus of the heavy chain constant region is connected to the C-terminus of the heavy chain variable region; Optionally, the N-terminus of the light chain constant region is linked to the C-terminus of the light chain variable region; Optionally, the heavy chain constant region comprises the heavy chain constant region set forth in SEQ ID NO:9, or an amino acid sequence having at least 80% identity thereto; Optionally, the light chain constant region comprises the light chain constant region set forth in SEQ ID NO: 10, or an amino acid sequence at least 80% identical thereto.

6. The antibody or antigen-binding fragment according to any one of claims 1 to 4, It is characterized in that The antibodies include polyclonal antibodies, full-length monoclonal antibodies, Fab antibodies, Fab' antibodies, F(ab') 2 At least one of an antibody, an Fv antibody, a single-chain antibody, a single-domain antibody, and a minimum recognition unit; or The antigen-binding fragments include F(ab') 2 fragment, Fab' fragment, Fab fragment, F(ab) 2 At least one of a fragment, an Fv fragment, an scFv fragment, an scFv-Fc fusion protein, an scFv-Fv fusion protein, and a minimum recognition unit; Optionally, the antibody or antigen-binding fragment comprises: The heavy chain of the amino acid sequence shown in SEQ ID NO: 11 or an amino acid sequence having at least 80% homology thereto; and The light chain of the amino acid sequence shown in SEQ ID NO: 12 or an amino acid sequence having at least 80% homology thereto.

7. A recombinant protein, It is characterized in that include: The antibody or antigen-binding fragment according to any one of claims 1 to 6; Optionally, further comprising at least one of a biologically active protein or a fragment thereof, a biologically active polypeptide or a fragment thereof; Optionally, the biologically active protein or fragment thereof comprises at least one selected from the group consisting of a protein tag, a protein toxin or a fragment thereof, an interferon or a fragment thereof, a biological response modifier or a fragment thereof, and an Fc fragment.

8. A multispecific antibody, It is characterized in that include: A first binding region, the first binding region comprising the antibody or antigen-binding fragment of any one of claims 1 to 6; a second binding region, the second binding region having a first molecule binding activity; Optionally, the first molecule comprises at least one of an antigen, a virus, a bacterium, an endotoxin, a cytokine, and a cytokine receptor.

9. A nucleic acid molecule, It is characterized in that The nucleic acid molecule encodes the antibody or antigen-binding fragment of any one of claims 1 to 6, the recombinant protein of claim 7, or the multispecific antibody of claim 8; Optionally, the nucleic acid molecule is DNA.

10. An expression vector, It is characterized in that Carrying the nucleic acid molecule according to claim 9; Optionally, the expression vector comprises a vector selected from a eukaryotic expression vector or a prokaryotic expression vector.

11. A recombinant cell, It is characterized in that include: Carrying the nucleic acid molecule according to claim 9 or the expression vector according to claim 10; or, Expressing the antibody or antigen-binding fragment of any one of claims 1 to 6, the recombinant protein of claim 7, or the multispecific antibody of claim 8; Optionally, the recombinant cell is obtained by introducing the expression vector of claim 10 into a host cell.

12. A conjugate, It is characterized in that Include: The antibody or antigen-binding fragment of any one of claims 1 to 6, the recombinant protein of claim 7, or the multispecific antibody of claim 8; and a coupling moiety, which is connected to the antibody or antigen-binding fragment, recombinant protein or multispecific antibody; Optionally, the coupling moiety comprises at least one selected from a carrier, a drug, a toxin, a cytokine, a protein tag and a modifier.

13. A pharmaceutical composition, It is characterized in that include: The antibody or antigen-binding fragment of any one of claims 1 to 6, the recombinant protein of claim 7, the multispecific antibody of claim 8, the nucleic acid molecule of claim 9, the expression vector of claim 10, the recombinant cell of claim 11 or the conjugate of claim 12; Optionally, a pharmaceutically acceptable excipient is further included.

14. A kit, It is characterized in that include: The antibody or antigen-binding fragment of any one of claims 1 to 6, the recombinant protein of claim 7, the multispecific antibody of claim 8, the nucleic acid molecule of claim 9, the expression vector of claim 10, the recombinant cell of claim 11 or the conjugate of claim 12.

15. Use of the antibody or antigen-binding fragment of any one of claims 1 to 6, the recombinant protein of claim 7, the multispecific antibody of claim 8, the nucleic acid molecule of claim 9, the expression vector of claim 10, the recombinant cell of claim 11 or the conjugate of claim 12 in the preparation of a drug for preventing and treating diseases related to the novel coronavirus XBB.

16. Use of the antibody or antigen-binding fragment of any one of claims 1 to 6, the recombinant protein of claim 7, the multispecific antibody of claim 8, the nucleic acid molecule of claim 9, the expression vector of claim 10, the recombinant cell of claim 11 or the conjugate of claim 12 in the preparation of a kit for detecting the new coronavirus XBB, diagnosing related diseases caused by the new coronavirus XBB, or evaluating the prognosis of related diseases caused by the new coronavirus XBB.

17. A method for detecting the novel coronavirus XBB, It is characterized in that include: The antibody or antigen-binding fragment of any one of claims 1 to 6, the recombinant protein of claim 7, the multispecific antibody of claim 8 or the conjugate of claim 12 is contacted with a sample to be detected to form an immune complex; Optionally, based on the signal of the immune complex, determining whether the sample to be tested contains the content of the new coronavirus XBB; Optionally, the immune complex further comprises a second antibody that binds to the antibody or antigen-binding fragment; Optionally, the immune complex also includes a second antibody that binds to the new coronavirus XBB.

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