CN116023475A

CN116023475A - anti-SAR-COV-2 fully human monoclonal antibody and preparation method and application thereof

Info

Publication number: CN116023475A
Application number: CN202111247420.6A
Authority: CN
Inventors: 万晓春; 李俊鑫; 安倩
Original assignee: Shenzhen Institute of Advanced Technology of CAS
Current assignee: Shenzhen Institute of Advanced Technology of CAS
Priority date: 2021-10-26
Filing date: 2021-10-26
Publication date: 2023-04-28

Abstract

The invention relates to an anti-SAR-COV-2 antibody or an antigen binding fragment thereof and application thereof, and particularly discloses heavy chain and light chain complementarity determining regions and heavy chain and light chain variable region sequences of an anti-SAR-COV-2 antibody 6Y 13. The antibody of the invention is a humanized antibody, and has low side effect and high affinity and specificity.

Description

anti-SAR-COV-2 fully human monoclonal antibody and preparation method and application thereof

Technical Field

The invention belongs to the field of immunology, and particularly relates to an anti-SAR-COV-2 (COVID-19) fully human monoclonal antibody, a preparation method and application thereof.

Background

Of the ten global mass-market drugs in 2018, 8 were fully human or humanized monoclonal antibody drugs. The first anti-TNFa monoclonal antibody Humira of Abwe company for treating arthritis is a fully human monoclonal antibody, which is sold for more than 100 hundred million years. Since the first monoclonal antibody drug was marketed in 1986, the monoclonal antibody drug underwent the stages of murine monoclonal antibody drug (e.g., orth ℃ lane OKT 3), chimeric monoclonal antibody drug (Rituximab), humanized monoclonal antibody drug (Herceptin), and fully human monoclonal antibody drug (Humira). Since the human body has an anti-mouse antibody reaction (HAMA), the mouse monoclonal antibody drug and the chimeric monoclonal antibody drug are gradually eliminated, and the monoclonal antibody drugs currently occupying the market are all humanized monoclonal antibody drugs.

The humanized monoclonal antibody has high specific remarkable curative effect in the aspects of treating inflammation, cancer, influenza, especially coronavirus and the like. Covd-19 is an acute respiratory infectious disease caused by a SAR-COV-2 coronavirus, and so far there is still a lack of effective drugs and vaccines. The new coronavirus needs to rely on specific molecules expressed by the virus itself to bind to receptors on human cells when invading the cells in order to infect the cells and further expand. The humanized antibody for neutralizing the virus is a certain specific antibody generated by human B lymphocytes, and can be combined with antigens on the surface of the virus, so that the virus is prevented from adhering to target cell receptors, the virus is prevented from invading cells, and the SAR-COV-2 influenza can be effectively prevented and treated.

Disclosure of Invention

In order to solve the above problems, the present invention provides an antibody against SAR-COV-2 or an antigen binding fragment thereof, which specifically binds to the S protein of SAR-COV-2.

In one aspect, the invention provides an isolated antibody or antigen-binding fragment thereof directed against SAR-COV-2; it Has Complementarity Determining Regions (HCDR) of three heavy chain variable regions and complementarity determining regions (LCDR) of three light chain variable regions of any one of the following groups:

antibody 6Y13

6Y13-HCDR1：GGSINTYY SEQ ID No：1；

6Y13-HCDR2：ISYSRST SEQ ID No：2；

6Y13-HCDR3：ARRDPQYNLFDH SEQ ID No：3；

6Y13-LCDR1：SGSIASNY SEQ ID No：4；

6Y13-LCDR 2: EDN SEQ ID No:5, a step of; and

6Y13-LCDR3：QSYDSSNLIWV SEQ ID No：6；

in another aspect, the invention provides an isolated antibody or antigen binding fragment thereof against SAR-COV-2, wherein the heavy and light chain variable regions of antibody 6Y13 are:

6Y13 heavy chain variable region:

QVQLQESGPGLVKPSETLSLTCTVSGGSINTYYWSWIRQPPGKGLEYIGHISYSRSTTSNPSLKSRVTISVHTSKNQFSLKLSSVTAADTAVYYCARRDPQYNLFDHWGQGTLVTVSS SEQ ID No：7

6Y13 light chain variable region:

NFMLTQPHSVSESPGKTVTISCTRTSGSIASNYVQWYQQRPGSAPTTVMFEDNQRPSGVPDRFSGSIDSSSNSASLTISGLKTEDEADYYCQSYDSSNLIWVFGGGTKLTVLV SEQ ID No：8；

in the embodiments of the present invention, the antibody or antigen-binding fragment thereof is a humanized antibody, more preferably a fully humanized antibody.

In the technical scheme of the invention, the antibody is an IgG1 antibody.

In the technical scheme of the invention, the antibody or the antigen binding fragment thereof specifically binds to the SAR-COV-2 surface S protein.

In the technical scheme of the invention, the antibody is a monoclonal antibody or a polyclonal antibody, preferably a monoclonal antibody.

In a further aspect the invention provides a nucleotide sequence encoding an antibody or antigen binding fragment thereof as hereinbefore described.

In a further aspect, the invention provides a vector comprising a nucleotide sequence as hereinbefore described.

In a further aspect the invention provides a host cell comprising the aforementioned vector or vector set, preferably the host cell is prokaryotic or eukaryotic, more preferably selected from yeast cells, mammalian cells or other cells suitable for the preparation of antibodies or antigen-binding fragments thereof.

In a further aspect the invention provides a kit comprising an antibody or antigen binding fragment thereof as hereinbefore described.

In a further aspect the invention provides a detection reagent comprising an antibody or antigen-binding fragment thereof as hereinbefore described.

In a further aspect the present invention provides the use of an antibody or antigen binding fragment thereof as described above as a detection reagent for: enzyme-linked immunosorbent assay (ELISA), immunoblotting (Western Blot), flow cytometry (FACS), immunohistochemical (IHC) assay, or immuno-PCR.

In the immunological detection described above, the antibody or antigen-binding fragment thereof may be coupled alone or with a conjugate such as a conjugate of horseradish peroxidase (HRP), alkaline Phosphatase (AP), biotin (Biotin), fluorescein Isothiocyanate (FITC), cy3, cy5, magnetic beads, agarose, etc., by electrostatic adsorption or hydrophilic-hydrophobic adsorption.

In the present embodiment, the detection reagent can be used for detection for non-diagnostic or therapeutic purposes.

In a further aspect the invention provides a pharmaceutical composition comprising an isolated antibody or antigen-binding fragment thereof as hereinbefore described and a pharmaceutically acceptable adjuvant.

In a further aspect of the invention, wherein the antibody or antigen binding fragment thereof blocks or reduces binding of the S protein of SAR-COV-2 to a cell surface receptor of the subject, preferably a cell angiotensin converting enzyme related carboxypeptidase (ACE 2).

In a further aspect, the invention provides the use of an antibody or antigen binding fragment thereof against SAR-COV-2 in the manufacture of a medicament for preventing, treating or alleviating at least one symptom or indication of SAR-COV-2 infection.

In the technical scheme of the invention, the medicine is an oral or injection preparation.

In a further aspect, the invention provides a method of preventing, treating or alleviating at least one symptom or indication of a SAR-COV-2 infection, the method comprising administering to a subject an antibody or antigen-binding fragment thereof of any of the preceding or a pharmaceutical composition of the preceding.

In a further aspect of the invention, wherein the at least one symptom or indication is selected from the group consisting of: pulmonary inflammation, alveolar injury, fever, cough, dyspnea, hypoxia, acute respiratory distress syndrome, septic shock, coagulation dysfunction, metabolic acidosis, nasal obstruction, runny nose, sore throat, diarrhea, organ failure, septic shock and death.

In a further embodiment of the invention, the pharmaceutical composition or the antibody or antigen binding fragment thereof is administered in combination with a second therapeutic agent. Wherein the second therapeutic agent is selected from the group consisting of: anti-inflammatory drugs (e.g., corticosteroids and non-steroidal anti-inflammatory drugs), antiviral drugs, different antibodies to the S protein of SAR-COV-2, vaccines for SAR-COV-2, antibiotics, dietary supplements such as antioxidants, and any other palliative therapy for treating SAR-COV-2 infection, drugs that alleviate the symptoms or indications described above.

In a technical aspect of the invention, wherein the pharmaceutical composition or the antibody or antigen binding fragment thereof is administered subcutaneously, intravenously, intradermally, intraperitoneally, orally, intramuscularly or intracranially.

Advantageous effects

(1) The anti-SAR-COV-2 antibody disclosed by the invention can be used for targeting and combining the S protein of the SAR-COV-2 virus, has high specificity, and can effectively block the combination of the S protein on the surface of the SAR-COV-2 virus and a receptor on the surface of a cell of a subject.

(2) Compared with the murine antibody, the gene of the fully human antibody is fully derived from human genes, has no other species components, does not generate toxic or side effects such as anti-mouse anti-antibody and the like in human body, has better biocompatibility, and is more suitable and potential to become a macromolecular medicament for treating influenza virus.

(3) Compared with the method for preparing the SAR-COV-2 virus-resistant humanized monoclonal antibody by using the phage display technology provided by the prior art, the method for developing the SAR-COV-2 virus-resistant antibody by using the single B cell has the advantages of simplicity and rapidness in operation, high affinity and specificity of the produced humanized antibody and the like.

Drawings

FIG. 1 is a graph showing ELISA results of example 1.

Detailed Description

The following detailed description of the present invention will be made in detail to make the above objects, features and advantages of the present invention more apparent, but should not be construed to limit the scope of the present invention.

In order to more clearly understand the technical features, objects and advantages of the present invention, the following detailed description of the technical solution of the present invention will be made with reference to specific embodiments, and it should be understood that these examples are only for illustrating the present invention and are not intended to limit the scope of the present invention. In the examples, each of the starting reagent materials is commercially available, and the experimental methods without specifying the specific conditions are conventional methods and conventional conditions well known in the art, or according to the conditions recommended by the instrument manufacturer.

As used herein, the term "antibody" refers to a molecule comprising at least one antigen binding site that immunospecifically binds to a particular antigen target of interest. Thus, the term "antibody" includes, but is not limited to, full length antibodies and/or variants thereof, fragments, peptibodies, and variants thereof, monoclonal antibodies (including full length monoclonal antibodies), polyclonal antibodies, multispecific antibodies (e.g., bispecific antibodies) formed from at least two intact antibodies, human antibodies, humanized antibodies, and antibody mimics of the structure and/or function of an antibody or designated fragments or portions thereof, including single chain antibodies and fragments thereof. Binding of an antibody to a target may cause a variety of effects, such as, but not limited to, modulation, reduction, increase, antagonism, agonism, alleviation, slowing, blocking, inhibition, elimination and/or interference with at least one target activity or binding, or receptor activity or binding, in vitro, in situ and/or in vivo. Thus, antibodies of the present disclosure encompass antibody fragments capable of binding to a biomolecule (e.g., an antigen or receptor) or portion thereof, including but not limited to Fab, fab ' and F (ab ') 2, pFc ', fd, single domain antibodies (sdAb), variable fragments (Fv), single chain variable fragments (scFv), or disulfide-linked Fv (sdFv); a bifunctional antibody or a bivalent bifunctional antibody; a linear antibody; a single chain antibody molecule; multispecific antibodies formed from antibody fragments. Antibodies may be of any type (e.g., igG, igE, igM, igD, igA and IgY), class (e.g., igG1, igG2, igG3, igG4, igA1, and IgA 2) or subclass.

As used herein, the term "monoclonal antibody" refers to an antibody obtained from a population of substantially homogeneous antibodies, i.e., the individual antibodies comprising the population are identical except for the possible presence of small amounts of mutations that may occur naturally. Monoclonal antibodies are highly specific, being directed against a single antigenic site. Furthermore, in contrast to polyclonal antibody preparations that include different antibodies directed against different determinants (epitopes), each monoclonal antibody is directed against a single determinant on the antigen. In addition to its specificity, monoclonal antibodies have the advantage that they can be synthesized without contaminating other antibodies. The modifier "monoclonal" is not to be construed as requiring antibody production by any particular method.

As used herein, the term HCDR is synonymous with heavy chain complementarity determining region and LCDR is synonymous with light chain complementarity determining region.

As used herein, monoclonal antibodies include "chimeric" antibodies in which a portion of the heavy and/or light chain is identical or homologous to corresponding sequences in antibodies derived from a particular species or belonging to a particular class or subclass of antibody, while the remainder of the chain is identical or homologous to corresponding sequences in antibodies derived from another species or belonging to another class or subclass of antibody, and fragments of such antibodies exhibit the desired biological activity.

As used herein, the term "SAR-COV-2" also referred to as "novel coronavirus" refers to a newly occurring virus that causes novel coronavirus pneumonia (COVID-19).

As used herein, S protein refers to Spike protein (Spike protein) on coronaviruses, and SARS-CoV-2 recognizes ACE2 on the surface of cells in humans through Spike protein on the surface of the virus and infects host cells. The S protein on the surface of coronavirus SARS-CoV-2 can inhibit the adhesion of virus to target cell receptor effectively to prevent virus from invading cell.

The term "humanized antibody" as used herein includes antibodies having variable and constant regions derived from human germline immunoglobulin sequences. The humanized antibodies of the invention may comprise amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by random or in vitro site-specific mutagenesis or by in vivo somatic mutation).

The term "antigen-binding fragment" or the like as used herein includes any naturally occurring, enzymatically available, synthetic or genetically engineered polypeptide or glycoprotein that specifically binds an antigen to form a complex. The term "antigen binding fragment" of an antibody as used herein has the ability to bind to one or more fragments of the S protein of SAR-COV-2.

In one aspect, the invention provides an anti-SAR-COV-2 fully human monoclonal antibody or a biologically active fragment derived from the monoclonal antibody capable of specifically binding SAR-COV-2, wherein the amino acid sequences of the heavy and light chain CDR1, CDR2 and CDR3 regions of the antibody are as follows:

antibody 6Y13

6Y13-HCDR1：GGSINTYY SEQ ID No：1；

6Y13-HCDR2：ISYSRST SEQ ID No：2；

6Y13-HCDR3：ARRDPQYNLFDH SEQ ID No：3；

6Y13-LCDR1：SGSIASNY SEQ ID No：4；

6Y13-LCDR 2: EDN SEQ ID No:5, a step of; and

6Y13-LCDR3：QSYDSSNLIWV SEQ ID No：6；

in some embodiments, the heavy chain variable region amino acid sequence of the antibody 6Y13 is shown as SEQ ID NO. 7, or the sequence is replaced, deleted or added with one or more amino acids to form an amino acid sequence with the same function;

and is also provided with

The amino acid sequence of the light chain variable region of the antibody is shown as SEQ ID NO. 8, or the amino acid sequence NFMLTQPHSVSESPGKTVTISCTRTSGSIASNYVQWYQQRPGSAPTTVMFEDNQRPSGVPDRFSGSIDSSSNSASLTISGLKTEDEADYYCQSYDSSNLIWVFGGGTKLTVLV SEQ ID No. with the same function is formed by replacing, deleting or adding one or more amino acids in the sequence: 8.

ELISA experiments prove that the anti-SAR-COV-2 fully human monoclonal antibody can target and bind the S protein of SAR-COV-2 virus. Compared with the murine antibody, the gene of the fully human antibody is fully derived from human genes, has no other species components, does not generate toxic or side effects such as anti-mouse anti-antibody and the like in human body, has better biocompatibility, and is more suitable and potential to become a macromolecular medicament for treating influenza virus.

In another aspect, the invention provides a gene encoding an anti-SAR-COV-2 fully human monoclonal antibody of the invention. In some embodiments, the gene comprises a nucleotide sequence encoding an amino acid having the above-described amino acids.

In some embodiments, the nucleotide sequence is as follows (the following sequences are merely exemplary, and one skilled in the art can design other nucleotide sequences that can be translated into the desired amino acid sequence depending on the particular amino acid sequence):

the nucleotide sequence encoding the heavy chain variable region of antibody 6Y13 is:

Caggtgcagctgcaggagtcgggcccaggactggtgaagccttcggagaccctgtccctcacctgcactgtctctggtggctccatcaatacttactactggagctggatccggcagcccccagggaagggactggagtacattgggcatatctcttacagtcggagcaccacctccaacccctccctcaagagtcgagtcaccatatcagtacacacgtccaagaaccagttctccctgaagctgagctctgtgaccgctgcggacacggccgtgtattactgtgcgaggcgagacccccaatataatttgttcgaccactggggccagggaaccctggtcaccgtctcctca SEQ ID No：9

the nucleotide sequence encoding the antibody 6Y13 light chain variable region is:

aattttatgctgactcagccccactctgtgtcggagtctccggggaagacggtaaccatctcctgcacccgcaccagtggcagcattgccagcaactatgtgcagtggtaccagcagcgcccgggcagtgcccccaccactgtgatgtttgaggataaccaaagaccctctggggtccctgatcggttctctggctccatcgacagctcctccaactctgcctccctcaccatctctggactgaagactgaggacgaggctgattactactgtcagtcttatgatagcagcaatcttatttgggtgttcggcggagggaccaagctgaccgtcctaGTA SEQ ID No：10。

in the heavy chain variable region and light chain variable region sequences of the antibodies of the invention, CDR regions are shown in the underlined regions.

In another aspect, the invention provides a vector comprising a gene as described above.

In a further aspect, the invention provides a cell comprising a gene as described above or a vector as described above.

In still another aspect, the present invention provides a method for producing the anti-SAR-COV-2 fully human monoclonal antibody or a biologically active fragment derived from the monoclonal antibody capable of specifically binding SAR-COV-2, the method comprising culturing genetically engineered cells containing the above gene encoding the heavy and light chain of the anti-SAR-COV-2 fully human monoclonal antibody or the above vector or directly culturing the above cells, collecting and purifying the anti-SAR-COV-2 fully human monoclonal antibody.

In the prior art, a method for preparing the anti-SAR-COV-2 virus humanized monoclonal antibody by adopting a phage display technology has the advantages of low production cost, no complicated work such as immunization and cell fusion, and the like, but has obvious disadvantages that the antibodies obtained from a non-immune antibody library often have insufficient affinity, are limited by the conversion rate of exogenous genes, have insufficient library capacity of the antibody library to cover the antibody diversity of animals, and the like. The invention separates the B cell secreting functional antibody from the blood of patient, then extracts RNA and synthesizes cDNA, clones the gene secreting target antibody from it, and finally recombines and expresses fully human monoclonal antibody. The technology is simple and quick to operate, the produced humanized antibody has high affinity and specificity, and in addition, the improved monoclonal antibody technology with the virus neutralization function or tumor killing function can be further separated from memory B cells, so that complicated operation and cost are greatly reduced.

In another aspect, the invention provides a pharmaceutical composition comprising an anti-SAR-COV-2 fully human monoclonal antibody or a biologically active fragment derived from the monoclonal antibody capable of specifically binding SAR-COV-2.

In another aspect, the invention provides the use of said anti-SAR-COV-2 fully human monoclonal antibody or a biologically active fragment derived from said monoclonal antibody capable of specifically binding SAR-COV-2 or said pharmaceutical composition in the manufacture of a medicament for the treatment of a disease caused by SAR-COV-2 virus.

In another aspect, the invention provides a kit for detecting SAR-COV-2 virus levels, comprising the anti-SAR-COV-2 fully human monoclonal antibody or a biologically active fragment derived from the monoclonal antibody capable of specifically binding SAR-COV-2; in some embodiments, the kit further comprises a second antibody and an enzyme or fluorescent or radiolabel for detection, and a buffer; the second antibody is, for example, an anti-antibody against the monoclonal antibody of the invention.

Example 1

(1) Construction of NTH-3T3 cell line stably expressing CD40L (3T 3-CD 40L)

3T3-CD40L feeder cells were established using lentiviruses. The lentiviral expression vector pLVX-CD40L was constructed, 293T cells were transfected, and viral supernatants were collected on day four of transfection. NIH-3T3 cells were activated, cultured for 3 passages, infected with lentivirus, and cultured and passaged 3 additional times. Sorting cells with FITC fluorescence intensity near MFI by flow cytometry, re-adding to culture flask at 37deg.C, 5% CO ₂ The 3T3 cells expressing CD40L and 3T3 cells transfected with empty vector pLVX (with ZxGreen) were stained with anti-CD 40L with APC, respectively, and then analyzed by an up-flow cytometer. As a result, it was found that all 3T3-CD40L feeder cells expressed CD40L. When fineWhen the cell grows to 80% -90%, the cells are digested and collected, and the concentration is 1×10 per milliliter ⁷ And (3) cells. Placing into a radiometer for 5000rads radiation, and re-suspending cells in frozen solution with concentration of 3.5X10 per ml ⁷ Cells were aliquoted into 1mL frozen vials and stored in liquid nitrogen (2 years of storage).

(2) Sorting and activation of memory B cells

Separating and cryopreserving PBMC of recovered patient infected with SAR-COV-2 virus with 10-50×10 per tube ⁶ Cells were frozen in a liquid nitrogen tank. PBMC flow-type staining solution was prepared, and the composition thereof is shown in Table 1 below

TABLE 1 PBMC flow staining solution

Antibodies to	Volume (mu L)
		CD19-PE-Cy7	0.5
IgM-PE	1.0
		IgA-APC	2.5
IgD-FITC	2.5
		PBS-1％(wt/vol)BSA	43.5

Thawing PBMC, adding the PBMC flow-type staining solution, and sorting on flow cytometrySelecting CD19 ⁺ IgM ^– IgA ^– IgD ^– The purity of the memory B cells is more than 90%, if the purity is less than 90%, the sorting process is repeated. A mixed medium for activating B cells was prepared as shown in table 2 below:

TABLE 2

Component (A)	Volume of
		Complete IMDM medium	336mL
IL-2(10,000U mL ^-1 )	3.5mL
		IL-21(100μg mL ^-1 )	175μL
3T3-CD40L obtained in step (1)	10mL

Adding memory B cells into mixed culture medium, mixing, limiting dilution in 384 well plate, 1 cell per well, 50 μl volume, placing at 37deg.C, 5% CO ₂ And (5) standing and culturing in an incubator. After 13 days, the supernatant was subjected to ELISA to obtain a humanized monoclonal antibody.

(3) Surface antigen S protein experiment of human monoclonal antibody combined with SAR-COV-2 virus

The surface antigen S protein is purchased from Yinqiao Shenzhou company, has immunogenicity, and the anti-S protein antibody can be used for SAR-COV-2 influenza virus. ELISA experiments were performed on the supernatant humanized monoclonal antibodies obtained above, specifically:

(1) 100ng/100 μl of HA protein of SAR-COV-2 virus was coated in 96-well ELISA plates, 100 μl per well;

(2) Placing in a refrigerator at 4 ℃ overnight;

(3) Washing with PBST solution three times, adding 200 μl of 5% skimmed milk powder solution into each well, and incubating at 37deg.C for 1 hr;

(4) Three times with PBST solution, 100. Mu.l of normal human serum (negative control) or supernatant without virus infection was added, each three replicates;

(5) After incubation for 1 hour at 37 ℃ the cells were washed three times with PBST solution;

(6) HRP-loaded anti-human IgG antibody (abcam) was diluted 1:5000 and added to the microplate at 100. Mu.L per well;

(7) After incubation for 1 hour at 37 ℃ the cells were washed three times with PBST solution;

(8) mu.L of TMB substrate solution (Thermo Scientific) was added to each well, at 37℃for 5 minutes;

(9) 100 μl of 2M sulfuric acid was added to each well, and the absorbance was immediately measured at 450nm in a microplate reader. The results are shown in figure 1, and ELISA experiments show that the human monoclonal antibody obtained by the invention can target and bind the S protein of SAR-COV-2 virus.

EXAMPLE 2 cloning of humanized monoclonal antibody Gene

The B cells obtained in example 1 capable of secreting an antibody binding to SAR-COV-2 virus were lysed, and the lysate was subjected to reverse transcription of RNA to obtain PCR template cDNA of the humanized antibody gene. Primers for cloning antibody genes were designed and synthesized, and the heavy and light chain genes of the antibodies were cloned using cDNA as a template, and sequenced by Jinwei corporation. Specifically:

(1) The lysed B cell fluid was transferred to a 96-well plate (Eppendorf, 030133366).

(2) Reverse transcription system: 150ng of random primer (Invitrogen, 481190-011), 0.5. Mu.L of 10mM dNTP (Invitrogen, 18497-088), 1. Mu.L of 0.1M DTT (Invitrogen, 18080-044), 0.5% v/v Igepal CA-630 (Sigma, I3021-50 ML), 4U RNAsin (Promega), 6U Prime RNAse Inhibitor (Eppendorf) and 50U

III reverse transcriptase (Invitrogen, 18080-044) DEPC water was added to 14. Mu.L/well.

(3) Reverse transcription reaction procedure: 42 ℃ for 10min;25 ℃ for 10min;50 ℃ for 60min;94℃for 5min.

(4) The cDNA was stored at-20 ℃.

(5) Primer design and synthesis:

(6) Heavy and light chains of antibody genes were amplified by PCR using KOD-Plus-Neo (TOYOBO, KOD 401) kit, 40. Mu.L system: 3.5. Mu.L cDNA,20nM mixed primer, 4. Mu.L buffer, 4. Mu.L 2mM dNTPs, 2.4. Mu.L MgSO ₄ ，1μL KOD。

(7) The reaction procedure: 94 ℃ for 2min;45 cycles: 98 ℃ for 10s;58 ℃ for 30s;68℃for 28s.

(8) Agarose gel was performed on the amplified product.

(9) The sequencing result of the antibody gene heavy chain variable region PCR product is as follows, wherein:

the heavy chain variable region nucleotide sequence of the antibody 6Y13 is shown as SEQ ID No. 9:

Caggtgcagctgcaggagtcgggcccaggactggtgaagccttcggagaccctgtccctcacctgcactgtctctggtggctccatcaatacttactactggagctggatccggcagcccccagggaagggactggagtacattgggcatatctcttacagtcggagcaccacctccaacccctccctcaagagtcgagtcaccatatcagtacacacgtccaagaaccagttctccctgaagctgagctctgtgaccgctgcggacacggccgtgtattactgtgcgaggcgagacccccaatataatttgttcgaccactggggccagggaaccctggtcaccgtctcctca SEQ ID No：9；

the amino acid sequence of the heavy chain variable region of the antibody 6Y13 is shown as SEQ ID No. 7:

QVQLQESGPGLVKPSETLSLTCTVSGGSINTYYWSWIRQPPGKGLEYIGHISYSRSTTSNPSLKSRVTISVHTSKNQFSLKLSSVTAADTAVYYCARRDPQYNLFDHWGQGTLVTVSS SEQ ID No：7；

the nucleotide sequence of the light chain variable region of the antibody 6Y13 is shown as SEQ ID No. 10,

aattttatgctgactcagccccactctgtgtcggagtctccggggaagacggtaaccatctcctgcacccgcaccagtggcagcattgccagcaactatgtgcagtggtaccagcagcgcccgggcagtgcccccaccactgtgatgtttgaggataaccaaagaccctctggggtccctgatcggttctctggctccatcgacagctcctccaactctgcctccctcaccatctctggactgaagactgaggacgaggctgattactactgtcagtcttatgatagcagcaatcttatttgggtgttcggcggagggaccaagctgaccgtcctaGTA SEQ ID No：10；

the amino acid sequence of the antibody 6Y13 light chain variable region is shown as SEQ ID No. 8

NFMLTQPHSVSESPGKTVTISCTRTSGSIASNYVQWYQQRPGSAPTTVMFEDNQRPSGVPDRFSGSIDSSSNSASLTISGLKTEDEADYYCQSYDSSNLIWVFGGGTKLTVLV SEQ ID No：8。

Correspondingly, the CDR region sequences of each antibody are as follows:

antibody 6Y13

6Y13-HCDR1：GGSINTYY SEQ ID No：1；

6Y13-HCDR2：ISYSRST SEQ ID No：2；

6Y13-HCDR3：ARRDPQYNLFDH SEQ ID No：3；

6Y13-LCDR1：SGSIASNY SEQ ID No：4；

6Y13-LCDR 2: EDN SEQ ID No:5, a step of; and

6Y13-LCDR3：QSYDSSNLIWV SEQ ID No：6；

the above results show that the supernatant contains an antibody capable of binding SAR-COV-2 virus.

The last explanation is: the above embodiments are only for illustrating the implementation procedure and features of the present invention, and not for limiting the technical solution of the present invention, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those of ordinary skill in the art that: modifications and equivalents may be made thereto without departing from the spirit and scope of the invention, and any modifications and equivalents are intended to be included within the scope of the present invention.

SEQUENCE LISTING

<110> Shenzhen advanced technology research institute of China academy of sciences

<120> anti-SAR-COV-2 fully human monoclonal antibody, preparation method and application thereof

<130> CP121011051C

<160> 10

<170> PatentIn version 3.3

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65 70 75 80

Lys Leu Ser Ser Val Thr Ala Ala Asp Thr Ala Val Tyr Tyr Cys Ala

85 90 95

Arg Arg Asp Pro Gln Tyr Asn Leu Phe Asp His Trp Gly Gln Gly Thr

100 105 110

Leu Val Thr Val Ser Ser

115

<210> 8

<211> 113

<212> PRT

<213> artificial sequence

<400> 8

Asn Phe Met Leu Thr Gln Pro His Ser Val Ser Glu Ser Pro Gly Lys

1 5 10 15

Thr Val Thr Ile Ser Cys Thr Arg Thr Ser Gly Ser Ile Ala Ser Asn

20 25 30

Tyr Val Gln Trp Tyr Gln Gln Arg Pro Gly Ser Ala Pro Thr Thr Val

35 40 45

Met Phe Glu Asp Asn Gln Arg Pro Ser Gly Val Pro Asp Arg Phe Ser

50 55 60

Gly Ser Ile Asp Ser Ser Ser Asn Ser Ala Ser Leu Thr Ile Ser Gly

65 70 75 80

Leu Lys Thr Glu Asp Glu Ala Asp Tyr Tyr Cys Gln Ser Tyr Asp Ser

85 90 95

Ser Asn Leu Ile Trp Val Phe Gly Gly Gly Thr Lys Leu Thr Val Leu

100 105 110

Val

<210> 9

<211> 354

<212> DNA

<213> artificial sequence

<400> 9

caggtgcagc tgcaggagtc gggcccagga ctggtgaagc cttcggagac cctgtccctc 60

acctgcactg tctctggtgg ctccatcaat acttactact ggagctggat ccggcagccc 120

ccagggaagg gactggagta cattgggcat atctcttaca gtcggagcac cacctccaac 180

ccctccctca agagtcgagt caccatatca gtacacacgt ccaagaacca gttctccctg 240

aagctgagct ctgtgaccgc tgcggacacg gccgtgtatt actgtgcgag gcgagacccc 300

caatataatt tgttcgacca ctggggccag ggaaccctgg tcaccgtctc ctca 354

<210> 10

<211> 339

<212> DNA

<213> artificial sequence

<400> 10

aattttatgc tgactcagcc ccactctgtg tcggagtctc cggggaagac ggtaaccatc 60

tcctgcaccc gcaccagtgg cagcattgcc agcaactatg tgcagtggta ccagcagcgc 120

ccgggcagtg cccccaccac tgtgatgttt gaggataacc aaagaccctc tggggtccct 180

gatcggttct ctggctccat cgacagctcc tccaactctg cctccctcac catctctgga 240

ctgaagactg aggacgaggc tgattactac tgtcagtctt atgatagcag caatcttatt 300

tgggtgttcg gcggagggac caagctgacc gtcctagta 339

Claims

1. An isolated antibody against SAR-COV-2, or an antigen-binding fragment thereof, having three heavy chain complementarity determining regions and three light chain complementarity determining regions of any one of the following sets:

antibody 6Y13

6Y13-HCDR1：GGSINTYY SEQ ID No：1；

6Y13-HCDR2：ISYSRST SEQ ID No：2；

6Y13-HCDR3：ARRDPQYNLFDH SEQ ID No：3；

6Y13-LCDR1：SGSIASNY SEQ ID No：4；

6Y13-LCDR 2: EDN SEQ ID No:5, a step of; and

6Y13-LCDR3：QSYDSSNLIWV SEQ ID No：6。

2. the isolated anti-SAR-COV-2 antibody or antigen-binding fragment thereof according to claim 1, the heavy chain variable region and the light chain variable region of antibody 6Y13 having the sequence, respectively;

6Y13 heavy chain variable region:

QVQLQESGPGLVKPSETLSLTCTVSGGSINTYYWSWIRQPPGKGLEYIGHISYSRSTTSNPSLKSRVTISVHTSKNQFSLKLSSVTAADTAVYYCARRDPQYNLFDHWGQGTLVTVSSSEQ ID No：7，

6Y13 light chain variable region:

3. the antibody or antigen-binding fragment thereof of any one of claim 1 or claim 2, which is a humanized antibody or antigen-binding fragment thereof.

4. A nucleotide sequence characterized by: encoding the antibody or antigen binding fragment thereof of any one of claims 1-3.

5. A carrier, characterized in that: comprising the nucleotide sequence of claim 4.

6. A host cell, characterized in that: comprising the vector of claim 5.

7. A kit comprising the antibody or antigen-binding fragment thereof of any one of claims 1-3.

8. A detection reagent comprising the antibody or antigen-binding fragment thereof of any one of claims 1-3.

9. Use of the antibody or antigen binding fragment thereof of any one of claims 1-3 as a detection reagent for: enzyme-linked immunosorbent assay, immunoblotting, flow cytometry, immunohistochemical assay, or immuno-PCR.

10. A pharmaceutical composition comprising the isolated antibody or antigen-binding fragment thereof of any one of claims 1-3 and a pharmaceutically acceptable adjuvant.

11. Use of an antibody or antigen-binding fragment thereof against SAR-COV-2 according to any one of claims 1-3, or a pharmaceutical composition according to claim 10, in the manufacture of a medicament for preventing, treating or alleviating at least one symptom or indication of SAR-COV-2 infection;

preferably, the at least one symptom or indication is selected from the group consisting of: novel coronavirus pneumonia, pulmonary inflammation, alveolar injury, fever, cough, dyspnea, hypoxia, acute respiratory distress syndrome, septic shock, coagulation dysfunction, metabolic acidosis, nasal obstruction, runny nose, pharyngalgia, diarrhea, organ failure, septic shock and death.