A bispecific antibody and its application

Abstract

The present invention relates to the field of biotechnology, and in particular to a bispecific antibody and its application. The present invention provides a bispecific antibody with neutralizing activity against SARS-CoV-2 mutants (VOCs) and SARS-related coronaviruses (SARSr-CoVs). The bispecific antibody is constructed by fusing the single-chain variable fragments of the two antibodies via a GS linker. The bispecific antibody exhibits high binding ability to S1 and has broad-spectrum and high-efficiency activity against pseudovirus SARS-CoV-2 variants and SARS-related coronaviruses, indicating that the bispecific antibody provided by the present invention has the potential to prevent and treat SARS-CoV-2 and SARS-related coronaviruses.

Description

Technical Field

[0001] The present invention relates to the field of biotechnology, and in particular to a bispecific antibody and applications thereof. Background Art

[0002] The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has inflicted enormous global health and socioeconomic losses. SARS-CoV-2 has evolved rapidly, undergoing multiple lineages and variants. Vaccines and antibodies developed based on the original strain have become less effective against emerging variants. Furthermore, several recently discovered SARS-related coronaviruses (SARSr-CoVs) share significant genetic similarity with SARS-CoV and SARS-CoV-2, increasing their potential for human transmission. Therefore, it is crucial to prepare strategies to address evolving SARS-CoV-2 variants. Vaccination efforts face challenges related to accessibility and unresolved side effects, which may further impact their overall effectiveness. To date, the continued emergence of variants of concern (VOCs) has challenged vaccines developed using sequences from the original SARS-CoV-2 strain (wild-type). For example, the Delta variant (B.1.617.2) and its spread have been largely attributed to its remarkable ability to evade neutralizing antibodies, which are present in recovered and vaccinated individuals. The Omicron variant (BA.1) exhibits a higher propensity to mutate. Subsequently, a series of Omicron subvariants emerged, characterized by a cluster of mutations in the receptor binding domain (RBD) of the spike (S) protein. These mutations result in alterations in the RBD that may affect its binding affinity to human angiotensin-converting enzyme 2 (hACE2). Notably, the Omicron RBD reportedly has lower affinity for ACE2 than the Alpha or Delta variants. The primary factor driving the spread of Omicron is its enhanced ability to evade polyclonal antibodies, which reduces the potency of serum antibody binding and neutralization.

[0003] Although monoclonal antibodies (mAbs) have demonstrated their broad neutralizing activity and efficacy to a certain extent and are considered to be ideal tools for combating coronaviruses, the continuous emergence of mutations poses a major challenge to existing mAbs. Bispecific antibodies (bsAbs) are artificially engineered antibodies that can simultaneously bind to two epitopes of an antigen or two different antigens. In order to construct bsAbs with broad neutralizing activity, a scaffold with the insertion of a natural VH-CH1 switch region is a promising approach. Several bsAb formats targeting SARS-CoV-2 have been developed, including two immunoglobulin G (IgG) single-chain variable fragments and single-chain variable fragments (scFvs) fused to the Fc domain. Although these bsAbs show enhanced neutralization against pseudoviruses and real VOCs, the scope of their efficacy remains unclear. However, the development of bsAbs with strong neutralizing activity and broad spectrum coverage is considered an alternative solution to deal with emerging variants. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a bispecific antibody and its application, which has broad-spectrum neutralizing activity against SARS-CoV-2 mutants and SARS-related coronaviruses.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] In a first aspect, the present invention provides a bispecific antibody, comprising a first antigen-binding arm and a second antigen-binding arm; the first antigen-binding arm comprises a heavy chain variable region VH1 and a light chain variable region VL1; the second antigen-binding arm comprises a heavy chain variable region VH2 and a light chain variable region VL2; the amino acid sequence of VH1 is shown in SEQ ID NO: 1; the amino acid sequence of VL1 is shown in SEQ ID NO: 2; the amino acid sequence of VH2 is shown in SEQ ID NO: 3; and the amino acid sequence of VL2 is shown in SEQ ID NO: 4.

[0007] The first antigen-binding arm of the bispecific antibody designed in the present invention is selected from the heavy chain variable region (H chain FV) sequence of one of the parent antibodies (which can broadly neutralize SARS-related coronaviruses) and the light chain variable region (L chain FV) sequence of the parent antibody SEQ ID NO: 11.

[0008] The second antigen-binding arm is selected from the heavy chain variable region (H chain FV) sequence of another parent antibody (which can neutralize a wide range of SARS-CoV-2 variants): SEQ ID NO: 12; and the light chain variable region (L chain FV) sequence of the parent antibody: SEQ ID NO: 13. The first binding arm of the designed bispecific antibody targets the RBD binding domain of SARS-CoV-2, and the second binding arm targets a shared antigenic epitope of SARS-related coronaviruses. This specific antibody improves neutralization ability by simultaneously binding to key regions of both viruses, preventing the viruses from entering host cells.

[0009] Preferably, the first antigen-binding arm of the bispecific antibody specifically binds to the RBD receptor binding domain of SARS-CoV-2, and the second antigen-binding arm specifically binds to a shared antigenic epitope of SARS-related coronaviruses.

[0010] Preferably, the amino acid sequence of the heavy chain constant region of the bispecific antibody is shown in SEQ ID NO: 5, and the amino acid sequence of the light chain constant region is shown in SEQ ID NO: 6.

[0011] Preferably, the heavy chain amino acid sequence of the bispecific antibody is shown in SEQ ID NO: 7, and the light chain amino acid sequence is shown in SEQ ID NO: 8.

[0012] Preferably, the heavy chain variable regions VH1 and VH2, and the light chain variable regions VL1 and VL2 of the bispecific antibody are respectively connected by a GS linker.

[0013] Preferably, the amino acid sequence of the GS linker is shown in SEQ ID NO:9.

[0014] Preferably, the method for preparing the bispecific antibody comprises the following steps:

[0015] (a) Designing the nucleic acid sequences of the light chain and heavy chain of a bispecific antibody comprising a first antigen-binding arm and a second antigen-binding arm, and connecting the Fv fragment via a GS linker;

[0016] (b) inserting the nucleic acid sequence into an expression vector;

[0017] (c) transferring the expression vector into 293F cells;

[0018] (d) culturing the host cell to express the bispecific antibody;

[0019] (e) purifying the bispecific antibody.

[0020] The construction strategy of the bispecific antibody is as follows: the light chain and heavy chain of the bispecific antibody comprising a first antigen-binding arm and a second antigen-binding arm are constructed, and inserted into the expression vector pCDNA3.1, transfected into HEK293 cells, and the culture supernatant is collected and purified using a Protein A column.

[0021] In a second aspect, the present invention provides a nucleic acid molecule encoding the above-mentioned bispecific antibody.

[0022] In a third aspect, the present invention provides a vector comprising the above-mentioned nucleic acid molecule.

[0023] In a fourth aspect, the present invention provides a host cell comprising the aforementioned nucleic acid molecule or the aforementioned vector.

[0024] Preferably, the host cell is a 293F cell.

[0025] In a fifth aspect, the present invention provides a pharmaceutical composition comprising the above-mentioned bispecific antibody and a pharmaceutically acceptable carrier.

[0026] In a sixth aspect, the present invention provides the use of the above-mentioned bispecific antibodies or a combination of the bispecific antibodies in the preparation of a medicament for preventing and / or treating SARS-CoV-2 mutants and / or SARS-related coronavirus infections.

[0027] The bispecific antibodies provided by the present invention exhibit high binding ability to S1 and have broad-spectrum and high-efficiency activity against pseudovirus SARS-CoV-2 variants (VOCs) and SARS-related coronaviruses (SARSr-CoVs), indicating that the bispecific antibodies provided by the present invention have the potential to prevent and treat SARS-CoV-2 and SARS-related coronaviruses, and can be used to prevent and / or treat SARS-CoV-2 mutants and / or SARS-related coronavirus infections.

[0028] The present invention is beneficial in that:

[0029] The present invention provides a bispecific antibody with neutralizing activity against SARS-CoV-2 mutants and SARS-related coronaviruses. The bispecific antibody is constructed by fusing the single-chain variable fragments of the bispecific antibody via a GS linker. The bispecific antibody exhibits high binding ability to S1 and has broad-spectrum and high-efficiency activity against pseudovirus SARS-CoV-2 variants (VOCs) and SARS-related coronaviruses (SARSr-CoVs), indicating that the bispecific antibody provided by the present invention has the potential to prevent and treat SARS-CoV-2 and SARS-related coronaviruses. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structural composition of the bispecific antibody 5-HI protein.

[0031] Figure 2 This is a graph showing the binding activity of the bispecific antibody 5-HI against SARS-related coronaviruses.

[0032] Figure 3 This is a graph showing the binding activity of the bispecific antibody 5-HI against the mutant strain (VOC).

[0033] Figure 4 This is a graph showing the neutralizing activity of the bispecific antibody 5-HI against SARS-related coronaviruses.

[0034] Figure 5 This is a graph showing the neutralizing activity of the bispecific antibody 5-HI against the mutant strain (VOC).

[0035] Figure 6 This is a graph showing the neutralization activity of the bispecific antibody 5-HI against live viruses. DETAILED DESCRIPTION

[0036] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0037] In the following examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0038] The amino acid sequences involved in the present invention are shown in the following table:

[0039]

[0040]

[0041]

[0042] Example 1: Construction of bispecific antibodies

[0043] DVD-Ig is an engineered bispecific antibody composed of two variable domains, each of which can recognize and bind to different antigens. This design enables DVD-Ig to simultaneously target two different antigens or epitopes, enhancing its therapeutic efficacy, particularly in complex diseases that require simultaneous regulation of multiple targets, such as cancer, autoimmune diseases, or inflammatory diseases. In this example, bispecific antibodies (bsAbs) were constructed by combining a modified DVD-Ig with the fragment variable regions (Fv) from two different antibodies, mAb1 and mAb2 (monoclonal antibodies SCM 15-45 and SCM 13-65).

[0044] Construction strategy: The light chain and heavy chain of a bispecific antibody containing a first antigen-binding arm and a second antigen-binding arm were constructed and inserted into the expression vector pCDNA3.1. HEK293 cells were transfected, and the culture supernatant was collected and purified using a Protein A column.

[0045] 1. Construction of expression plasmids for the heavy and light chains of bispecific antibodies (bsAbs) (hereinafter referred to as 5-HI)

[0046] The nucleic acid sequences of the light chain and heavy chain of the bispecific antibody comprising the first antigen-binding arm and the second antigen-binding arm are designed respectively.

[0047] The heavy chain amino acid sequence of the bispecific antibody is shown in SEQ ID NO: 7, and the light chain amino acid sequence is shown in SEQ ID NO: 8.

[0048] The first antigen-binding arm can neutralize the SARS-related coronavirus, and the second antigen-binding arm can neutralize mutant strains of SARS-CoV-2. The first antigen-binding arm comprises a heavy chain variable region VH1 and a light chain variable region VL1; the second antigen-binding arm comprises a heavy chain variable region VH2 and a light chain variable region VL2. The amino acid sequence of VH1 is shown in SEQ ID NO: 1; the amino acid sequence of VL1 is shown in SEQ ID NO: 2; the amino acid sequence of VH2 is shown in SEQ ID NO: 3; and the amino acid sequence of VL2 is shown in SEQ ID NO: 4. The 5-HI heavy chain plasmid and light chain plasmid were synthesized and constructed by Nanjing GenScript. Among them, VH was cloned into the AbVec2.0-hIgG1 vector (addgene, #80795), and VL lambda (VL lambda chain was synthesized and constructed by Nanjing GenScript, lambda gene (AFR33667.1)) was cloned into the MapAbVec1.1-IGLC (addgene, #99575) vector.

[0049] 2. Expression of bispecific antibody 5-HI in 293F eukaryotic cell expression system

[0050] (1) Use FreeStyle the day before transfection TM 293 expression medium (Gibco, catalog number: 12338018) was used to adjust the 293F cell density to 1×10 6 / mL; count the cells on the day of transfection and use fresh FreeStyle TM 293 expression medium was used to adjust the 293F cell density to 2 × 10 6 pieces / mL.

[0051] (2) Prepare PEI mixture: Add Polyethylenimine (PEI) (Polysciences, Cat. No. 23996-2) to OptiPRO TM SMF medium (ThermoFisher, catalog number: 12309019) was added to the transfection concentration of 4 μg / mL; the plasmid mixture was prepared by adding the extracted paired heavy chain plasmid and light chain plasmid at a mass ratio of 1:2 to OptiPRO TM Mix well in SFM medium so that the total plasmid concentration during transfection is 1 μg / mL.

[0052] (3) Finally, the PEI mixture was added to the plasmid mixture and gently mixed to prepare a transfection mixture system, and the mixture was allowed to stand at room temperature for 20 minutes; the transfection mixture system was added to the 293F cells prepared in step (1), and gently shaken to mix; the cells were placed in a 37°C suspension incubator containing 8% CO2 and suspended at 125 rpm for 7 days to obtain a suspension culture solution.

[0053] 3. Bispecific Antibody Purification

[0054] The above suspension culture solution was centrifuged at 4000 rpm for 15 min to collect the expression supernatant; the supernatant was filtered using a 0.22 μm filter (JET, catalog number: FPE204030); The protein purifier was used to balance the Protein A column with PBS at a flow rate of 3 mL / min. The filtered expression supernatant was then loaded onto the Protein A column at a flow rate of 3 mL / min. Non-specific binding proteins on the Protein A column were washed away with PBS at a flow rate of 3 mL / min. Antibodies bound to the Protein A column were eluted with a glycine buffer at pH 3.0 at a flow rate of 1 mL / min. The eluate was collected to obtain the purified bispecific antibody 5-HI, which has the following structure: Figure 1 shown.

[0055] Example 2: Detection of the Binding Activity of Bispecific Antibody 5-HI to Viral Protein S1

[0056] (1) Expression and purification of viral protein S1

[0057] The S1 gene with a Flag tag (located at the C-terminus) was cloned into the pVAX1 vector to obtain a plasmid encoding S1, which was then transiently expressed in 293F cells.

[0058] S1 sequences were selected from the following coronaviruses:

[0059] (a) SARS-related coronaviruses: SARS-CoV-2WT (wild type, QHD43416.1), SARS-CoV (AAP13567.1), bat-RaTG13 (QHR63300.2), pangolin-GD18 (QLR06867.1), pangolin-GX-P5L (QIA48632.1), bat-WIV1 (AGZ48828.1), civet-007 (AAU04646.1), civet-SZ3 (AY304486.1);

[0060] (b) Mutant strains VOC: Omicron mutant strains: including BA.1 (B.1.1.529, UGY75354.1), BA.2 (UHU97100.1), BA.3 (UNH00890.1), BA.5 (UYO86297.1), BQ.1 (UUN09240.1), BF.7 (UST29212.1) and BA.2.75 (UYM51877.1).

[0061] During transfection, the plasmid encoding S1 (30 μg) was mixed with PEI reagent (the mass ratio of plasmid to PEI was 1:3), incubated at room temperature for 15 minutes, and then transfected into 293F cells (30 mL, 2 × 10 6 The transfected cells were maintained for 5 days, and the supernatant was collected and filtered (0.22 μm). Then, the purified S1 protein was purified using Anti-DYKDDDDK G1 affinity resin (GenScript, L00432).

[0062] Purification process is: resin wash buffer (formula: 50mM Tris-HCl, 150mM NaCl, pH=7.4) wash three times, and with elution buffer (formula 0.1M Tris, 0.5M NaCl, pH=12) protein is eluted into the bottle containing 1 / 20 volume of 1M HCl of eluent.With PBS and Amicon tube, the eluted protein is concentrated and stored at-80 ℃.

[0063] (2) ELISA detection of the half-maximal effective concentration (EC50) of the bispecific antibody 5-HI and viral protein S1

[0064] The purified SARS-like S1 protein, SARS-CoV-2 S1 protein, or SARS-CoV S1 protein was coated onto an ELISA plate at a concentration of 2 μg / mL (100 μL / well). After incubation at 4°C overnight, unbound proteins were washed away with 1×PBST. The plate was blocked at room temperature for 2 h using a blocking solution containing 2% FBS (Gibco, Catalog No. 10270-106) and 2% BSA (Sigma, Catalog No. V900933). After washing away the blocking solution with 1×PBST, the bispecific antibody purified in Example 1 was diluted (using a solution containing 2% FBS (Gibco, Catalog No. 10270-106) and 2% BSA (Sigma, Catalog No. V900933). The antibody was diluted with BSA (Sigma, catalog number: V900933) blocking buffer to obtain antibody solutions with concentrations of 10, 3.33, 1.11, 0.37, 0.123, 0.041, 0.0137, 0.0046, 0.0015, 0.0005, 0.0017 and 0 μg / mL, respectively.

[0065] The above-mentioned antibody solutions of different concentrations were added to the ELISA plate and incubated at 37°C for 1 hour; 1×PBST was used to wash away unbound antibodies, and then RHP-labeled anti-human IgG antibody (Jackson ImmunoResearch, Catalog No.: 109-035-003) was added and incubated at 37°C for 1 hour; after washing away unbound anti-human IgG antibody with 1×PBST, 100 μL TMB colorimetric solution (ThermoFisher, Catalog No.: 002023) was added and incubated at room temperature for 5 minutes; finally, 50 μL 1M sulfuric acid was added to terminate the reaction; the OD value was measured using a Varioskan Flash full-wavelength scanning multi-function reader (ThermoFisher); the data were calculated using Prism8.0 software (GraphPad) to obtain the half-maximal effective concentration (EC50) of the bispecific antibody against the new coronavirus SARS-CoV-2 Wuhan-Hu-1 and Omicron mutants.

[0066] The results are as follows Figure 2-3 As shown, the bispecific antibody 5-HI has good binding activity against mutant strains and SARS-Related coronaviruses.

[0067] Example 3: Detection of Bispecific Antibody 5-HI Pseudovirus Neutralization Activity

[0068] (1) Pseudovirus coating

[0069] The S protein coding sequences of coronaviruses (CoVs), including SARS-CoV2 WT, SARS-CoV, Pangolin-GD18, Pangolin-GX-P5L, Bat-RaTG13, Bat-WIV1, Civet-007, Civet-SZ3, and Omicron (BA.1, BA.2, BA.3, BA.5, BQ.1, BF.7, BA.2.75, XBB 1.5 (YP_009724390.1), EG.5.1 (YP_009724390.1), and JN.1 (YP_009724390.1), were cloned into the pcDNA3.1 vector.

[0070] To generate pseudoviruses, 293T cells were grown to 70% confluence and co-transfected with the packaging plasmid pNL4-3.Luc.RE and a plasmid expressing the S protein (mass ratio of packaging plasmid to S protein expression plasmid was 3:1). Six hours later, the transfection supernatant was replaced with fresh DMEM supplemented with 10% fetal bovine serum (FBS) and allowed to stand for 48 hours. The culture supernatant was collected, centrifuged at 1500 × g for 15 minutes, and filtered (0.45 μm) to obtain the pseudovirus supernatant. The supernatant was stored at -80°C and subsequently diluted for titer determination and neutralization experiments.

[0071] (2) Pseudovirus neutralization experiment

[0072] One day before infection, 0.8×10 5 293T / hACE2 cells were seeded into 96-well plates (using DMEM supplemented with 10% FBS) at a density of 100 μL per well at 400 μg / mL. On the day of infection, the bispecific antibody purified in Example 1 was diluted in complete medium (DMEM supplemented with 10% FBS) according to a concentration gradient, and then an equal amount of pseudovirus supernatant was added to prepare multiple mixtures. Each mixture contained antibody at concentrations of 100, 33.3, 11.1, 3.7, 1.23, 0.41, 0.137, 0.046, 0.015, 0.005, 0.017, and 0 μg / mL.

[0073] The mixture of the antibody obtained above and the pseudovirus was incubated at 37°C for 1 hour. The culture medium in the 96-well plate was discarded, the treated mixture was added, and the cells were centrifuged at 800×g for 30 minutes. After incubation at 37°C for 6-8 hours, the mixture was discarded and freshly prepared DMEM medium (Gibco, Catalog No.: 11995065) containing 10% FBS (Gibco, Catalog No.: 10270-106) was added. After the cells were cultured for 48 hours, 50 μL of cell lysis buffer (Promega, Catalog No.: E153A) was added to each well of the 96-well culture plate and lysed at 37°C for 2 minutes. The 96-well culture plate was then frozen at -40°C for 30 minutes. After freezing, the 96-well culture plate was taken out and lysed at 37°C for 3 minutes. The cells were centrifuged at 2000 rpm for 1 minute to obtain cell lysate. 40 μL of the above cell lysate was aspirated and added to the 96-well black flat plate. 50 μL of luciferase detection reagent (Promega, Catalog No.: E1501) was added and the cells were detected by Varioskan. OD values ​​were measured using a Flash full-wavelength scanning multi-function reader (ThermoFisher). Neutralization inhibition rate was calculated as follows: Neutralization inhibition rate = [1 - (OD value of the well with the antibody and virus mixture - OD value of the blank well) / (OD value of the well with virus only but no antibody added - OD value of the blank well)] × 100%. Based on the neutralization inhibition rate results, the IC50 value of the antibody was calculated using Prism 8.0 software (GraphPad).

[0074] The results are as follows Figure 4-5 As shown, the bispecific antibody 5-HI has good neutralizing activity against mutant strains and SARS-Related coronaviruses.

[0075] Example 4: Detection of live virus neutralization activity of bispecific antibody 5-HI against SARS-CoV-2 WT and mutant strains

[0076] 50 μL of the bispecific antibody 5-HI at different antibody dilutions (antibody concentrations of 100, 33.3, 11.1, 3.7, 1.23, 0.41, 0.137, 0.046, 0.015, 0.005, 0.017, and 0 μg / mL; diluted in DMEM medium (Gibco, Cat. No. 11995065) containing 10% FBS (Gibco, Cat. No. 10270-106)) was mixed with 50 μL of live SARS-CoV-2, XBB.5.1, EG.5.1, and JN.1 viruses (200 focus-forming units), incubated at 37°C for 1 hour, and then transferred to a 96-well plate seeded with Vero E6 cells and incubated at 37°C for 1 hour for viral infection. After infection, the virus solution was discarded and replaced with DMEM virus maintenance medium containing 1.2% (v / v) sodium carboxymethylcellulose. After 24 h, the cells were fixed with 4% (v / v) paraformaldehyde and 0.2% (v / v) TritonX-100 was used to increase cell permeability. Immunostaining was performed using a SARS-CoV-2 S protein rabbit monoclonal antibody (China Biological, 40143-T62) and a peroxidase-labeled goat anti-rabbit antibody (H+L) (Jackson, 111-035-144), respectively. Finally, KPL TrueBle peroxidase substrate (SeraCare Life Science, 5510-0030) was used to visualize virally infected lesions, and viral lesion units were counted using CTL Immuno Spot S6 (Ccell Technology Limited).

[0077] The results are as follows Figure 6 As shown, the bispecific antibody 5-HI exhibited good neutralizing activity against live viruses of SARS-CoV-2 WT and mutant strains.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A bispecific antibody, characterized in that: The bispecific antibody comprises a first antigen-binding arm and a second antigen-binding arm; the first antigen-binding arm comprises a heavy chain variable region VH1 and a light chain variable region VL1; the second antigen-binding arm comprises a heavy chain variable region VH2 and a light chain variable region VL2; the amino acid sequence of VH1 is shown in SEQ ID NO: 1; the amino acid sequence of VL1 is shown in SEQ ID NO: 2; the amino acid sequence of VH2 is shown in SEQ ID NO: 3; and the amino acid sequence of VL2 is shown in SEQ ID NO:

4.

2. The bispecific antibody according to claim 1, wherein The first antigen-binding arm of the bispecific antibody specifically binds to the RBD receptor binding domain of SARS-CoV-2, and the second antigen-binding arm specifically binds to the shared antigenic epitope of SARS-related coronaviruses.

3. The bispecific antibody according to claim 1, wherein The amino acid sequence of the heavy chain constant region of the bispecific antibody is shown in SEQ ID NO: 5, and the amino acid sequence of the light chain constant region is shown in SEQ ID NO:

6.

4. The bispecific antibody according to claim 1, wherein The heavy chain amino acid sequence of the bispecific antibody is shown in SEQ ID NO: 7, and the light chain amino acid sequence is shown in SEQ ID NO:

8.

5. The bispecific antibody according to claim 1, wherein The heavy chain variable regions VH1 and VH2, and the light chain variable regions VL1 and VL2 of the bispecific antibody are respectively connected by a GS linker. A nucleic acid molecule encoding the bispecific antibody according to any one of claims 1 to 5.

7. A carrier, characterized in that The vector comprises the nucleic acid molecule according to claim 6.

8. A host cell, characterized in that The host cell comprises the nucleic acid molecule of claim 6 or the vector of claim 7.

9. A pharmaceutical composition, characterized in that The pharmaceutical composition contains the bispecific antibody according to any one of claims 1 to 5 and a pharmaceutically acceptable carrier.

10. Use of the bispecific antibody according to any one of claims 1 to 5 or a combination of bispecific antibodies in the preparation of a medicament for preventing and / or treating SARS-CoV-2 mutants and / or SARS-related coronavirus infection.

Images