CN118307667A

CN118307667A - Anti-respiratory syncytial virus antibody and application thereof

Info

Publication number: CN118307667A
Application number: CN202410166293.4A
Authority: CN
Inventors: 王健伟; 张乔; 郭丽; 钟景川; 任丽丽
Original assignee: Institute of Pathogen Biology of CAMS
Current assignee: Institute of Pathogen Biology of CAMS
Priority date: 2024-02-05
Filing date: 2024-02-05
Publication date: 2024-07-09

Abstract

The invention relates to an anti-respiratory syncytial virus antibody and application thereof, wherein the antibody comprises a heavy chain variable region and a light chain variable region, and the heavy chain variable region comprises HCDR1, HCDR2 and HCDR3 with amino acid sequences shown as SEQ ID NO 1-3, 7-9 or 13-15 respectively; and the light chain variable region comprises LCDR1, LCDR2 and LCDR3 with amino acid sequences shown in SEQ ID NO 4-6, 10-12 or 16-18 respectively. The antibody provided by the invention has high-efficiency neutralization activity on respiratory syncytial virus.

Description

Anti-respiratory syncytial virus antibody and application thereof

Technical Field

The invention relates to the fields of immunology and molecular biology, in particular to an anti-respiratory syncytial virus antibody and application thereof.

Background

Respiratory syncytial virus (Respiratory syncytial virus, RSV) is a single-stranded negative strand RNA virus belonging to the genus paramyxoviridae, pneumovirus. The genome is about 15.2kb in length, and encodes 11 proteins, namely nonstructural proteins NS1, NS2, nucleocapsid protein N, phosphoprotein P, matrix protein M, small hydrophobin SH, adhesion protein G, fusion proteins F, M-1, M2-2, and polymerase subunit protein L.

The development of antibodies against respiratory syncytial virus is also greatly driven, and several tens of respiratory syncytial virus vaccines and neutralizing antibody projects are currently being developed. Up to now, the FDA has approved 2 RSV vaccines for marketing, along with Arexvy of GSK available in batch at 5 months of 2023, in addition to Abrysvo for the best. In addition to vaccines, two prophylactic monoclonal antibodies against respiratory syncytial virus have also been FDA approved, i.e., palivizumab (Palivizumab) approved in 1998, as well as nisavizumab (Nirsevimab) co-developed by aslican and celecoxib. In addition, the human monoclonal antibodies MK-1654 and RI-002 of ADMA biologics from Merck have entered phase II and phase III clinical trials, respectively.

With the progress of single-cell PCR technology, the development of respiratory syncytial virus neutralizing antibodies is greatly promoted. However, there are few existing prophylactic and therapeutic monoclonal antibodies against respiratory syncytial virus, and the global disease burden caused by respiratory syncytial virus is very serious every year. In order to alleviate and reduce the high mortality of children, the elderly and immunocompromised persons caused by respiratory syncytial virus, there is a need for an antibody having a highly potent neutralizing activity against respiratory syncytial virus.

Disclosure of Invention

In view of the above, the present invention provides an anti-respiratory syncytial virus antibody and its use, which has high neutralizing activity against respiratory syncytial virus.

In view of the above objects, a first aspect of the present invention provides an antibody against respiratory syncytial virus, comprising a heavy chain variable region and a light chain variable region, wherein:

The heavy chain variable region comprises HCDR1 with an amino acid sequence shown as SEQ ID NO. 1, HCDR2 with an amino acid sequence shown as SEQ ID NO. 2 and HCDR3 with an amino acid sequence shown as SEQ ID NO. 3; and

The light chain variable region comprises LCDR1 with an amino acid sequence shown as SEQ ID NO. 4, LCDR2 with an amino acid sequence shown as SEQ ID NO. 5 and LCDR3 with an amino acid sequence shown as SEQ ID NO. 6;

or alternatively

The heavy chain variable region comprises HCDR1 with an amino acid sequence shown as SEQ ID NO. 7, HCDR2 with an amino acid sequence shown as SEQ ID NO. 8 and HCDR3 with an amino acid sequence shown as SEQ ID NO. 9; and

The light chain variable region comprises LCDR1 with an amino acid sequence shown as SEQ ID NO. 10, LCDR2 with an amino acid sequence shown as SEQ ID NO. 11 and LCDR3 with an amino acid sequence shown as SEQ ID NO. 12;

or alternatively

The heavy chain variable region comprises HCDR1 with an amino acid sequence shown as SEQ ID NO. 13, HCDR2 with an amino acid sequence shown as SEQ ID NO. 14 and HCDR3 with an amino acid sequence shown as SEQ ID NO. 15; and

The light chain variable region comprises LCDR1 with an amino acid sequence shown as SEQ ID NO. 16, LCDR2 with an amino acid sequence shown as SEQ ID NO. 17 and LCDR3 with an amino acid sequence shown as SEQ ID NO. 18.

In the present application, HCDR means one Complementarity Determining Region (CDR) in a heavy chain Variable Region (HEAVY CHAIN Variable Region), for example HCDR1 means CDR1 in the heavy chain Variable Region; LCDR refers to one Complementarity Determining Region (CDR) in the light chain Variable Region (LIGHT CHAIN Variable Region), e.g., LCDR1 refers to CDR1 in the light chain Variable Region.

In a preferred embodiment of the present invention, the heavy chain variable region further comprises HFR1 having an amino acid sequence shown as SEQ ID NO. 19, HFR2 having an amino acid sequence shown as SEQ ID NO. 20, HFR3 having an amino acid sequence shown as SEQ ID NO. 21, and HFR4 having an amino acid sequence shown as SEQ ID NO. 22; and

The light chain variable region also comprises LFR1 with an amino acid sequence shown as SEQ ID NO. 23, LFR2 with an amino acid sequence shown as SEQ ID NO. 24, LFR3 with an amino acid sequence shown as SEQ ID NO. 25 and LFR4 with an amino acid sequence shown as SEQ ID NO. 26;

or alternatively

The heavy chain variable region also comprises HFR1 with an amino acid sequence shown as SEQ ID NO. 27, HFR2 with an amino acid sequence shown as SEQ ID NO. 28, HFR3 with an amino acid sequence shown as SEQ ID NO. 29 and HFR4 with an amino acid sequence shown as SEQ ID NO. 22; and

The light chain variable region also comprises LFR1 with an amino acid sequence shown as SEQ ID NO. 30, LFR2 with an amino acid sequence shown as SEQ ID NO. 31, LFR3 with an amino acid sequence shown as SEQ ID NO. 32 and LFR4 with an amino acid sequence shown as SEQ ID NO. 33;

or alternatively

The heavy chain variable region also comprises HFR1 with an amino acid sequence shown as SEQ ID NO. 34, HFR2 with an amino acid sequence shown as SEQ ID NO. 35, HFR3 with an amino acid sequence shown as SEQ ID NO. 36 and HFR4 with an amino acid sequence shown as SEQ ID NO. 37; and

The light chain variable region also comprises LFR1 with an amino acid sequence shown as SEQ ID NO. 38, LFR2 with an amino acid sequence shown as SEQ ID NO. 39, LFR3 with an amino acid sequence shown as SEQ ID NO. 40 and LFR4 with an amino acid sequence shown as SEQ ID NO. 26.

In the present application, HFR means one Framework Region (FR) in the heavy chain Variable Region (HEAVY CHAIN Variable Region), for example HFR1 refers to FR1 in the heavy chain Variable Region; LFR means one Framework Region (FR) in the light chain Variable Region (LIGHT CHAIN Variable Region), for example LFR1 refers to FR1 in the light chain Variable Region.

In the present application, each heavy chain variable region and light chain variable region typically comprises 3 CDRs and up to 4 FRs, which are arranged from amino-terminus to carboxy-terminus in, for example, the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. The CDRs and FRs in the heavy chain variable region of the antibody of the application are arranged from amino-terminus to carboxy-terminus in the following order: HFR1, HCDR1, HFR2, HCDR2, HFR3, HCDR3, HFR4; the CDRs and FRs in the light chain variable region of the antibody of the application are arranged from amino-terminus to carboxy-terminus in the following order: LFR1, LCDR1, LFR2, LCDR2, LFR3, LCDR3, LFR4.

In a preferred embodiment of the invention, the amino acid sequence of the heavy chain variable region is shown as SEQ ID NO. 41 and the amino acid sequence of the light chain variable region is shown as SEQ ID NO. 42; or alternatively

The amino acid sequence of the heavy chain variable region is shown as SEQ ID NO. 43, and the amino acid sequence of the light chain variable region is shown as SEQ ID NO. 44; or alternatively

The amino acid sequence of the heavy chain variable region is shown as SEQ ID NO. 45, and the amino acid sequence of the light chain variable region is shown as SEQ ID NO. 46.

In a preferred embodiment of the invention, the antibody is a humanized monoclonal antibody.

In a second aspect the invention provides a nucleic acid molecule comprising a nucleotide sequence encoding an antibody as described above.

In a preferred embodiment of the invention, the nucleotide sequence encoding the antibody comprises:

1) A nucleotide sequence encoding the heavy chain variable region as shown in SEQ ID NO. 47; and a nucleotide sequence encoding the light chain variable region as set forth in SEQ ID NO. 48;

or alternatively

2) A nucleotide sequence encoding the heavy chain variable region as set forth in SEQ ID NO. 49; and a nucleotide sequence encoding the light chain variable region as set forth in SEQ ID NO. 50;

or alternatively

3) A nucleotide sequence encoding the heavy chain variable region as shown in SEQ ID NO. 51; and a nucleotide sequence encoding the light chain variable region as set forth in SEQ ID NO. 52.

In a third aspect the invention provides a vector comprising a nucleic acid molecule as described above.

In a fourth aspect the invention provides a cell comprising a nucleic acid molecule as described above or a vector as described above.

In a fifth aspect the invention provides a pharmaceutical composition comprising an antibody as described above, a nucleic acid molecule as described above, a vector as described above or a cell as described above, and a pharmaceutically acceptable carrier.

In a sixth aspect, the present invention provides the use of an antibody as defined above, a nucleic acid molecule as defined above, a vector as defined above, a cell as defined above or a pharmaceutical composition as defined above for the manufacture of a medicament for the prophylaxis and/or treatment of respiratory syncytial virus or for the manufacture of a respiratory syncytial virus detection reagent.

The beneficial effects of the invention are as follows:

The anti-respiratory syncytial virus antibody has a unique CDR region, can effectively neutralize respiratory syncytial virus, particularly has high-efficiency neutralization activity on an A strain of respiratory syncytial virus, and has IC ₅₀ of 0.01-4.0 mug/mL. Thus, the antibodies of the invention can be used in the preparation of medicaments for the prophylaxis and/or treatment of respiratory syncytial virus. In addition, the antibodies of the invention can be used to prepare respiratory syncytial virus detection reagents for the detection of viral antigens and for the discovery of effective neutralizing epitopes.

Drawings

Fig. 1: flow cell sorting schematic.

Fig. 2: RSV F binding antibody screening concentration response curve; (a) RSFP B6; (B) RSFP D9; (C) RSFP G7.

Fig. 3: (1) Graph of binding capacity of RSV antibodies to RSV fusion proteins; (A) RSFP2B6, RSFP2D9, and RSFP G7 binding capacity profiles for RSV a pre-F, respectively; (B) RSFP2B6, RSFP2D9, and RSFP G7 binding capacity profiles for RSV a post-F, respectively; (C) RSFP2B6, RSFP2D9, and RSFP G7 binding capacity profiles for RSV B pre-F, respectively; (D) RSFP2B6, RSFP2D9 and RSFP G7 binding capacity profiles for RSV B post-F, respectively.

Fig. 4: neutralization concentration response curve of RSV F antibody against pseudovirus; (a) RSFP B6; (B) RSFP D9; (C) RSFP G7.

Fig. 5: neutralization concentration response curve of RSV F antibody against RSV (strain A2) virus; (a) RSFP B6; (B) RSFP D9; (C) RSFP G7.

Detailed Description

It is to be noted that unless otherwise defined, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art.

The experimental methods in the following examples are conventional methods unless otherwise specified. The raw materials and reagent materials used in the examples below are all commercially available products unless otherwise specified.

As used herein and in the appended claims, the singular forms "a," "an," "the," and "the" include plural referents unless the context clearly dictates otherwise.

In the present application, the term "comprising" is generally intended to include the explicitly specified features, but not to exclude other elements.

In the present application, the term "antibody" has the meaning conventional in the art and refers to an immunoglobulin molecule composed of four polypeptide chains, which refer to two heavy (H) chains and two light (L) chains that are interconnected by disulfide bonds. By analyzing the amino acid sequences of the heavy and light chains of different antibodies, it was found that the amino acid sequences of the heavy and light chains near the N-terminus varied widely, with the other portions of the amino acid sequences being relatively constant. Thus, regions of the antibody light and heavy chains that vary greatly near the N-terminal amino acid sequence are referred to as variable regions (V), regions near the C-terminal amino acid sequence are referred to as constant regions (C), V regions of the heavy and light chains are abbreviated as VH and VL, respectively, and C regions of the heavy and light chains are abbreviated as CH and CL, respectively. The variable regions of antibodies are particularly strongly varied by a small percentage of amino acid residues whose composition and sequence are more prone to mutation (hypervariable regions, HVR); three hypervariable regions are present in each of the V regions of the L and H chains, and are also known as complementarity determining regions (complementarity determining region, CDRs) because of their spatial structure which can form a precise complement with an epitope. In antibodies, there are Kabat, abM, chothia, contact, IMGT common rules for CDR partitioning, which are well known to those skilled in the art, and when a website for executing these rules is applied, the VH and VL sequences are simply inputted and the corresponding rules are selected, so that CDR sequences according to different rules can be obtained. It will be appreciated by those skilled in the art that the scope of the present application encompasses combinations of CDR sequences obtained by analysis using different rules. The 6 CDR regions of an antibody together determine the ability and specificity of the antibody to recognize the corresponding antigen. It will be appreciated by those skilled in the art that when the application defines an amino acid sequence of 6 CDR regions, the ability of an antibody to recognize and to specifically identify the corresponding antigen is contemplated.

In the present application, the term "variable region" refers to the domain of an antibody that is involved in binding an antigen in the heavy or light chain of the antibody. The variable regions of the heavy and light chains of natural antibodies (VH and VL, respectively) generally have similar structures and can be further subdivided into regions of hypervariability (called Complementarity Determining Regions (CDRs)) interspersed with regions that are more conserved, called Framework Regions (FR).

In the present application, the term "complementarity determining regions" (CDRs, e.g., CDR1, CDR2, and CDR 3) refers to amino acid residues of an antibody variable region whose presence is essential for antigen binding. Each variable region typically has 3 CDR regions identified as CDR1, CDR2, and CDR 3. Each complementarity determining region may comprise amino acid residues (Kabat et al.,Sequences of Proteins of Immulological Interest,5th Ed.Public Health Service,National Institutes of Health,Bethesda,MD.1991)) from a "complementarity determining region" as defined by Kabat and/or those residues from a "hypervariable loop" (Chothia and Lesk; J Mol Biol 196:901-917 (1987)).

In the present application, the Complementarity Determining Regions (CDRs) and Framework Regions (FRs) of a given antibody may be identified using the Kabat system (Kabat et al Sequences of Proteins of Immunological Interest, 5 th edition, U.S. department of health and public service, PHS, NIH, NIH publication No. 91-3242, 1991).

In the present application, the term "fully humanized antibody" refers to an antibody obtained by transferring all genes encoding human antibodies into genetically engineered animals with deleted antibody genes by transgenic or transchromosomal techniques, so that the animals express human antibodies and the purpose of fully humanizing the antibodies is achieved. The purpose of "fully humanization" is to eliminate the immunogenicity of antibodies of non-human origin in humans while at the same time retaining the affinity as much as possible. It may be advantageous to select human framework sequences most similar to those of antibodies of non-human origin as templates for humanization engineering. In some cases, it may be desirable to replace one or more amino acids in a human framework sequence with corresponding residues in a non-human framework to avoid loss of affinity.

In the present application, "monoclonal antibody" refers to an antibody obtained from a substantially homogeneous population of antibodies, i.e., the population comprising a single antibody is identical except for possible mutations (e.g., natural mutations) that may be present in minor amounts. Thus, the term "monoclonal" indicates the nature of the antibody, i.e., not a mixture of unrelated antibodies. In contrast to polyclonal antibody preparations, which typically include different antibodies directed against different determinants (epitopes), each monoclonal antibody of a monoclonal antibody preparation is directed against a separate one of the determinants on the antigen. In addition to their specificity, monoclonal antibody preparations have the advantage that they are generally not contaminated with other antibodies. The term "monoclonal" is not to be construed as requiring production of the antibody by any particular method. The term monoclonal antibody specifically includes chimeric, humanized and human antibodies.

In the present application, the terms "pseudovirus" and "viroid" are used interchangeably with the same meaning; it is meant a virus-like particle formed by the self-assembly of viral proteins that does not encapsulate nucleic acids or encapsulate other nucleic acids, such that the pseudovirus or viroid, while capable of infecting a host cell, does not have autonomous replication capacity. Therefore, it is highly biosafety compared to a genuine virus. Packaging systems for pseudoviruses are generally composed of two parts, namely a packaging component and an expression component. The packaging component is constructed from the viral (e.g., HIV-1) genome, with the genetic information required for packaging, reverse transcription, and integration removed, providing the proteins necessary for the pseudoviral particle; the expression component is complementary to the packaging component and contains the genetic information required for packaging, reverse transcription and integration, as well as the exogenous gene of interest. The packaging component and the carrier component are transfected together into host cells, and the pseudoviral particles can be harvested in the cell supernatant.

In the present application, the term "neutralizing antibody" refers to an antibody having neutralizing activity. The term "neutralizing activity" refers to an immunoglobulin having antiviral activity, which can specifically recognize a virus autoantigen, and can effectively bind to and neutralize the virus activity, prevent the virus from invading a target cell, and block the replication of the virus in the target cell to play an important role in antiviral.

In the present application, the binding of antibodies to antigens can be determined by methods commonly used in the art, such as ELISA methods, generally indicated by EC ₅₀ and IC ₅₀. EC ₅₀ refers to the half-maximal effect concentration, which is the concentration of antibody that can reach 50% of the maximal biological effect; IC ₅₀ refers to the half inhibition concentration, concentration of antibody required to inhibit half of a particular biological process (e.g., ACE2 binding to RBD protein). The smaller the values of EC ₅₀ and IC ₅₀, the greater the binding capacity of the antibody to the antigen.

In the present application, the term "vector" generally refers to a nucleic acid vector into which a polynucleotide encoding a protein can be inserted and the protein expressed. The vector may be transformed, transduced or transfected into a host cell to allow expression of the genetic material elements carried thereby within the host cell. For example, the carrier comprises: a plasmid; phagemid; a cosmid; artificial chromosomes such as Yeast Artificial Chromosome (YAC), bacterial Artificial Chromosome (BAC) or P1-derived artificial chromosome (PAC); phages such as lambda phage or M13 phage, animal viruses, etc. A vector may contain a variety of elements for controlling expression, including promoter sequences, transcription initiation sequences, enhancer sequences, selection elements, and reporter genes. In addition, the vector may also contain a replication origin. It is also possible for the vector to include components that assist it in entering the cell, such as viral particles, liposomes or protein shells, but not just these.

In the present application, the term "pharmaceutical composition" generally refers to a pharmaceutical composition suitable for administration to a patient, which may comprise an antibody, nucleic acid molecule, vector or cell according to the present application, and may further comprise one or more pharmaceutically acceptable excipients, such as: one or more of a carrier, a protective agent, a stabilizer, an excipient, a diluent, a solubilizer, a surfactant, an emulsifier, and a preservative.

As described in the background section, the present invention has been made to solve the technical problem of providing an antibody having a high neutralizing activity against respiratory syncytial virus. In order to solve the technical problem, 3 strains of fully humanized monoclonal antibodies RSFP D9, RSFP2B6 and RSFP G7 of the respiratory syncytial virus are obtained by screening through a single B cell flow sorting-antibody gene amplification pairing expression technology.

The fusion protein F protein and the adhesion protein G protein of the respiratory syncytial virus are key to virus invasion to human bodies, and the F protein becomes a good target for scientists to develop respiratory syncytial virus neutralizing antibodies because the G protein is easy to mutate and relatively conservative. The F glycoprotein exists in two forms, a Pre-fusion conformation (Pre-F) and a post-fusion conformation (post-F). Studies have shown that only a portion of specific epitopes acting in the Pre-F conformation are more effective in neutralizing respiratory syncytial virus, so Pre-F is the preferred antigen for respiratory syncytial virus vaccines. The antibodies RSFP D9, RSFP B6 and RSFP G7 obtained by screening belong to neutralizing antibodies, and have strong binding capacity to Pre-F glycoprotein.

In addition, antibodies RSFP D9, RSFP2B6, RSFP G7 screened in the present invention are fully humanized antibodies that eliminate the immunogenicity of non-human antibodies in humans while retaining the affinity to the greatest extent possible.

Examples 2-4 of the present invention demonstrate that:

RSFP2D9 antibody has good broad-spectrum binding capacity to RSV A/B strain fusion protein, the binding capacity (EC ₅₀) is less than 30ng/mL, RSFP G7 antibody tends to bind to post-fusion conformation of RSV A/B strain fusion protein, the binding capacity (EC ₅₀) is less than 70ng/mL, the RSFP B6 antibody has pre-fusion and post-fusion conformation of RSV A/B strain fusion protein, and the binding capacity (EC ₅₀) is 292.2-602.7ng/mL.

RSFP2D9 antibody neutralized RSV pseudovirus IC ₅₀ was 0.5319 μg/mL, RSFP B6 antibody neutralized RSV pseudovirus IC ₅₀ was 3.89 μg/mL and RSFP2G7 antibody neutralized RSV pseudovirus IC ₅₀ was 1.704 μg/mL.

The IC ₅₀ for RSFP D9 antibody-neutralized RSV strain A2 was 0.054 μg/mL, the IC ₅₀ for RSFP B6 antibody-neutralized RSV strain A2 was 1.003 μg/mL and the IC ₅₀ for RSFP G7 antibody-neutralized RSV strain A2 was 0.734 μg/mL.

From this, it can be seen that these three antibodies have unique CDR regions, can specifically bind to the fusion protein of respiratory syncytial virus, in particular to the fusion protein of respiratory syncytial virus A/B strain, and the binding capacity (EC ₅₀) is 13.6 ng/mL-602.7 ng/mL; and can effectively neutralize respiratory syncytial virus, in particular to an A strain of respiratory syncytial virus, and the IC ₅₀ is 0.01 mug/mL-4.0 mug/mL.

In summary, antibodies RSFP D9, RSFP B6, RSFP G7 screened in the present invention are fully humanized and have highly neutralizing activity.

RSFP2B6 antibodies

RSFP2B6 antibodies comprise a heavy chain variable region and a light chain variable region.

1.1 RSFP2 heavy chain Variable Region of antibody 2B6 (HEAVY CHAIN Variable Region)

The heavy chain variable region of RSFP B6 antibody comprises 3 complementarity determining regions HCDR1, HCDR2 and HCDR3; and 4 frame regions HFR1, HFR2, HFR3, and HFR4, respectively, are as follows:

HFR1:QVQLVQSGGALAQPGRSLRLSCTTS(SEQ ID NO:19)

HCDR1:GFTFGDYA(SEQ ID NO:1)

HFR2:VNWVRQAPGKGLEWVGI(SEQ ID NO:20)

HCDR2:VRTEPYGGTT(SEQ ID NO:2)

HFR3:EYSASVKGRFIISRDDSKGIAYLQMNSLKTEDTGVYYC(SEQ ID NO:21)

HCDR3:SQPILNVDV(SEQ ID NO:3)

HFR4:WGQGTTVTVSS(SEQ ID NO:22)

the amino acid sequence of the heavy chain Variable Region (Amino Acid Sequence of HEAVY CHAIN Variable Region) is:

QVQLVQSGGALAQPGRSLRLSCTTSGFTFGDYAVNWVRQAPGKGLEWVGIVRTEPYGGTTEYSASVKGRFIISRDDSKGIAYLQMNSLKTEDTGVYYCSQPILNVDVWGQGTTVTVSS(SEQ ID NO:41)

the nucleotide sequence (Nucleotide Sequence) encoding the heavy chain Variable Region (HEAVY CHAIN Variable Region) is:

gtgcagctggtgcagtctgggggagccttggcacagccagggcggtccctgagactctcctgtacaacctctggattcacctttggtgattatgctgtgaactgggtccgccaggctccagggaaggggctggagtgggtaggcatcgttagaaccgaaccttatggtgggacaacagaatacagcgcgtctgtgaaaggcagattcatcatctcaagagatgattccaaaggcatcgcctatctgcaaatgaacagcctgaaaaccgaggacacaggcgtgtattactgttctcagccgattctcaatgtagacgtctggggccaagggaccacggtcaccgtctcctc(SEQ ID NO:47)

1.2 RSFP 2A 2B6 antibody light chain Variable Region (LIGHT CHAIN Variable Region)

The light chain variable region of the RSFP B6 antibody comprises 3 complementarity determining regions LCDR1, LCDR2 and LCDR3; and 4 frame regions LFR1, LFR2, LFR3, and LFR4, respectively, as follows:

LFR1:NFMLTQPHSVSESPGKTVTISCTRS(SEQ ID NO:23)

LCDR1:SGSFGSDY(SEQ ID NO:4)

LFR2:VQWYQQRPGSAPNTVIY(SEQ ID NO:24)

LCDR2:ENN(SEQ ID NO:5)

LFR3:QRPSGVPDRFSGSIDSSSNSASLTISGLKTEDEADYYC(SEQ ID NO:25)

LCDR3:QSYDDNTPWV(SEQ ID NO:6)

LFR4:FGGGTELTVL(SEQ ID NO:26)

The amino acid sequence of the light chain Variable Region (Amino Acid Sequence of LIGHT CHAIN Variable Region) is:

NFMLTQPHSVSESPGKTVTISCTRSSGSFGSDYVQWYQQRPGSAPNTVIYENNQRPSGVPDRFSGSIDSSSNSASLTISGLKTEDEADYYCQSYDDNTPWVFGGGTELTVL(SEQ ID NO:42)

The nucleotide sequence (Nucleotide Sequence) encoding the light chain Variable Region (LIGHT CHAIN Variable Region) is:

aattttatgctgactcagccccactctgtgtcggagtctccggggaagacagtaaccatctcctgcacccgcagcagtggcagctttggcagcgactatgtgcagtggtaccagcagcgcccgggcagtgcccccaacactgtgatctatgagaataaccaaagaccctctggggtccctgatcgattctctggctccatcgacagctcctccaactctgcctccctcaccatctctggactgaagactgaggacgaggctgactactactgtcagtcttatgatgacaacaccccttgggtgttcggcggagggaccgagctgaccgtccta(SEQ ID NO:48)

RSFP2D9 antibodies

RSFP2D9 antibodies comprise a heavy chain variable region and a light chain variable region.

2.1 Heavy chain Variable Region of RSFP D9 antibody (HEAVY CHAIN Variable Region)

The heavy chain variable region of RSFP D9 antibody comprises 3 complementarity determining regions HCDR1, HCDR2 and HCDR3; and 4 frame regions HFR1, HFR2, HFR3, and HFR4, respectively, are as follows:

HFR1:EVQLVESGGGLVQPGGSLRLSCAAS(SEQ ID NO:27)

HCDR1:GFTFSTYE(SEQ ID NO:7)

HFR2:MNWVRQAPGKGLEWISY(SEQ ID NO:28)

HCDR2:ISVSGATI(SEQ ID NO:8)

HFR3:YYADSVKGRFTISRDNAKSSVYLQMTSLRPEDTAIYYC(SEQ ID NO:29)

HCDR3:ARDNSLTDYGSGLY(SEQ ID NO:9)

HFR4:WGQGTTVTVSS(SEQ ID NO:22)

EVQLVESGGGLVQPGGSLRLSCAASGFTFSTYEMNWVRQAPGKGLEWISYISVSGATIYYADSVKGRFTISRDNAKSSVYLQMTSLRPEDTAIYYCARDNSLTDYGSGLYWGQGTTVTVSS(SEQ ID NO:43)

gaggtgcaactggtggagtctgggggaggcttggtacagcctggagggtccctgagactctcctgtgcagcctctggattcaccttcagtacttacgaaatgaactgggtccgccaggctccagggaaggggctggagtggatctcgtatattagtgtaagtggcgcgaccatatactacgcagactctgtgaagggccgattcaccatctccagagacaacgccaagagctcagtgtatctgcaaatgaccagcctgagacccgaggacacggctatttattactgtgcgagagataattctctcaccgattatggatcgggcttgtactggggccaggggaccacggtcaccgtctcctcag(SEQ ID NO:49)

2.2 RSFP2 light chain Variable Region of 2D9 antibody (LIGHT CHAIN Variable Region)

The light chain variable region of RSFP D9 antibody comprises 3 complementarity determining regions LCDR1, LCDR2 and LCDR3; and 4 frame regions LFR1, LFR2, LFR3, and LFR4, respectively, as follows:

LFR1:DIVMTQSPSSLSASVGDRVTITCRAS(SEQ ID NO:30)

LCDR1:QSISSY(SEQ ID NO:10)

LFR2:LNWYQQKPGKAPKLLIY(SEQ ID NO:31)

LCDR2:DAS(SEQ ID NO:11)

LFR3:SLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYC(SEQ ID NO:32)

LCDR3:QQSYSTPPT(SEQ ID NO:12)

LFR4:FGQGTKVEIK(SEQ ID NO:33)

DIVMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYDASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQSYSTPPTFGQGTKVEIK(SEQ ID NO:44)

gacatcgtgatgacccagtctccatcctccctgtctgcatctgtaggagacagagtcaccatcacttgccgggcaagtcagagcattagcagctatttaaattggtatcagcagaaaccagggaaagcccctaagctcctgatctatgatgcatccagtttgcaaagtggggtcccatcaaggttcagtggcagtggatctgggacagatttcactctcaccatcagcagtctgcaacctgaagattttgcaacttactactgtcaacagagttacagtacccctccaacgttcggccaagggaccaaggtggagatcaaa(SEQ ID NO:50)

RSFP2G7 antibodies

RSFP2G7 antibodies comprise a heavy chain variable region and a light chain variable region.

3.1 Heavy chain Variable Region of RSFP G7 antibody (HEAVY CHAIN Variable Region)

The heavy chain variable region of RSFP G7 antibody comprises 3 complementarity determining regions HCDR1, HCDR2 and HCDR3; and 4 frame regions HFR1, HFR2, HFR3, and HFR4, respectively, are as follows:

HFR1:QVQLVQSGTEVRKPGSSVKVSCTAS(SEQ ID NO:34)

HCDR1:GGTFSIYD(SEQ ID NO:13)

HFR2:IFWVRQAPGQGLEWMGR(SEQ ID NO:35)

HCDR2:IIPILDQI(SEQ ID NO:14)

HFR3:DYAQKFEGRVTITADKGRKTVYMELSSLRSDDTAVYYC(SEQ ID NO:36)

HCDR3:ARPPDTYDNIER(SEQ ID NO:15)

HFR4:WGPGTLVTVSS(SEQ ID NO:37)

QVQLVQSGTEVRKPGSSVKVSCTASGGTFSIYDIFWVRQAPGQGLEWMGRIIPILDQIDYAQKFEGRVTITADKGRKTVYMELSSLRSDDTAVYYCARPPDTYDNIERWGPGTLVTVSS(SEQ ID NO:45)

caggtccagcttgtgcagtctgggactgaggtgaggaagcctgggtcctcggtgaaggtctcctgtacggcttctggaggcaccttcagcatttatgatatcttctgggtgcgacaggcccctggacaaggccttgagtggatgggacggatcatcccaattcttgatcaaatagactacgcccaaaagtttgagggcagagtcaccattaccgcggacaaaggcaggaaaacagtctacatggagttgagcagcctgagatctgacgacacggccgtgtactactgtgcgagacccccagacacctatgacaacatcgagcggtggggcccgggcaccctggtcaccgtctcctca(SEQ ID NO:51)

3.2 Light chain Variable Region of RSFP G7 antibody (LIGHT CHAIN Variable Region)

LFR1:SYVLTQPPSASGTPGQRVTISCSGS(SEQ ID NO:38)

LCDR1:SSNIGSNY(SEQ ID NO:16)

LFR2:VYWYQQLPGTAPKLLIY(SEQ ID NO:39)

LCDR2:RNN(SEQ ID NO:17)

LFR3:QRPSGVPDRFSGSKSGTSASLAISGLRSEDEADYYC(SEQ ID NO:40)

LCDR3:AAWDDSLSGWV(SEQ ID NO:18)

LFR4:FGGGTELTVL(SEQ ID NO:26)

SYVLTQPPSASGTPGQRVTISCSGSSSNIGSNYVYWYQQLPGTAPKLLIYRNNQRPSGVPDRFSGSKSGTSASLAISGLRSEDEADYYCAAWDDSLSGWVFGGGTELTVL(SEQ ID NO:46)

cctatgtgctgactcagccaccctcagcgtctgggacccccgggcagagggtcaccatctcttgttctggaagcagctccaacatcggaagtaattatgtatactggtaccaacaactcccaggaacggcccccaaactcctcatctataggaataatcagcggccctcaggggtccctgaccgattctctggctccaagtctggcacctcagcctccctggccatcagtgggctccggtccgaggatgaggctgattattactgcgcagcatgggatgacagcctgagtggttgggtgttcggcggagggaccgagctgaccgtccta(SEQ ID NO:52)

the invention also relates to nucleic acid molecules comprising nucleotide sequences encoding the antibodies of the invention. The nucleotide sequence encoding the antibody comprises:

or alternatively

2) A nucleotide sequence encoding the heavy chain variable region as shown in SEQ ID NO. 51; and a nucleotide sequence encoding the light chain variable region as set forth in SEQ ID NO. 52.

The invention also provides vectors, such as plasmid, phagemid, phage or viral vectors, comprising one or more nucleic acid molecules of the invention into which the nucleic acid molecules encoding the antibodies of the invention are inserted.

Antibodies provided herein can be prepared by recombinant expression of nucleotide sequences encoding light and heavy chains or portions thereof in a cell (e.g., a host cell). To express antibodies recombinantly, a host cell may be transfected with one or more recombinant expression vectors carrying nucleotide sequences encoding light and/or heavy chains or portions thereof, such that the light and heavy chains are expressed in the host cell. Standard recombinant DNA methodologies are used to prepare and/or obtain nucleic acids encoding heavy and light chains, incorporate these nucleic acids into recombinant expression vectors, and introduce the vectors into host cells, such as those described in U.S. Pat. No.4,816,397 to Sambrook,Fritsch and Maniatis(eds.),Molecular Cloning;ALaboratory Manual,Second Edition,Cold Spring Harbor,N.Y.,(1989)、Ausubel,F.M.etal.(eds.)Current Protocols in Molecular Biology,Greene Publishing Associates,(1989) and to Boss et al.

Furthermore, the nucleotide sequence encoding the variable region of the heavy and/or light chain may be converted into, for example, a nucleotide sequence encoding a full length antibody chain, fab fragment or ScFv: for example, a DNA fragment encoding a light chain variable region or a heavy chain variable region may be operably linked (such that the amino acid sequences encoded by both DNA fragments are in frame) to another DNA fragment encoding, for example, an antibody constant region or a flexible linker. The sequences of the human heavy and light chain constant regions are known in the art (see, e.g., Kabat,E.A.,el al.(1991)Sequences of Proteins of Immunological Interest,Fifth Edition,U.S.Department of Health and Human Services,NIH Publication No.91-3242), for DNA fragments comprising these regions, which can be obtained by standard PCR amplification.

Thus, embodiments of the invention are also host cells comprising the vector or nucleic acid molecule, wherein the host cells may be higher eukaryotic host cells, e.g., mammalian cells, lower eukaryotic host cells, e.g., yeast cells, and may be prokaryotic cells, e.g., bacterial cells.

The antibodies of the invention may be formulated with at least one other agent (e.g., a stabilizing compound) into a pharmaceutical composition comprising an antibody of the invention and one or more pharmaceutically acceptable carriers, diluents, or excipients.

The antibody provided by the invention can be used for preparing respiratory syncytial virus preventive and/or therapeutic drugs, has the characteristics of full humanization, high expression and good stability, and is suitable for industrialization. In addition, the antibody can be used for preparing respiratory syncytial virus detection reagents, detecting virus antigens and finding effective neutralization antigen epitopes.

The technical scheme provided by the invention is further described below with reference to specific embodiments. The following examples are given for illustration of the invention and are not intended to limit the scope of the invention.

EXAMPLE 1 screening of anti-RSV fully human monoclonal antibodies

1.1 Sample preparation

(1) Donor PBMC cells (peripheral blood mononuclear cells) were resuscitated: after the frozen cells were taken out, they were placed in a 37℃water bath, thawed, transferred to a centrifuge tube containing 1640 medium (containing 10% fetal bovine serum), centrifuged at 300g for 5 minutes, the supernatant was discarded, and the cell concentration was adjusted to 1X 10 ⁸ cells/mL per 100. Mu.L in PBS containing 2mM EDTA and 0.5% Bovine Serum Albumin (BSA) (hereinafter referred to as LB solution).

(2) Isolation of Pan B cells: using MojoSort ^TM Human Pan B Cell Isolation Kit kit, 3 μl of biotinylated antibody mixture was added to each tube, mixed well and incubated at 4deg.C for 15 minutes. 5 mu L of streptavidin nano magnetic beads are added into each tube, and the mixture is fully and uniformly mixed and placed at 4 ℃ for 15 minutes of incubation. LB solution was added to 500. Mu.L, transferred to Miltenyi ^TM MS Columns, the filtrate was collected, the magnetic column was washed once with 500. Mu.L LB solution, the two cell filtrates were combined, placed in a centrifuge tube, and the number of cells was adjusted to 5X 10 ⁵ cells/tube.

(3) Activity staining of isolated cells: the B cells were centrifuged at 300g for 5 minutes at 4℃and the supernatant was discarded. Preparing Zombie NIR ^TM Fixable Viability working solution: the Zombie NIR ^TM Fixable Viability stock solution was diluted 1:200 with PBS to obtain a cell viability staining solution, 100. Mu.L of the cell viability staining solution was added to each tube of the centrifuge tube, incubated at room temperature for 10 minutes in the absence of light, 1mL of PBS solution was added to each tube to terminate the reaction, and the supernatant was discarded after centrifugation at 300g for 5 minutes at 4 ℃.

(4) Preparing PE marked Spike protein and FITC marked RBD: taking 1.5mL centrifuge tube, adding 89 mu L PBS solution, adding 1 mu L BioLegend ^TM PE-strepitavidin, adding 2 mu gACROBiosystems ^TM Biotinylated RSV pre-F protein, and placing on ice for 40 minutes to obtain PE marked RSV F protein; a1.5 mL centrifuge tube was taken, 89. Mu.L of PBS solution was added, 1. Mu.L of BioLegend ^TM FITC-strepitavidin was added, 2. Mu. g ACROBiosystems ^TM Biotinylated RSV pre-F protein was added, and the mixture was kept on ice for 40 minutes to obtain FITC-labeled RSV F protein.

(5) Surface staining of isolated cells: mu.L of a fluorescent-labeled flow-through antibody mixture (containing 5. Mu.L of BioLegend ^TM anti-human CD19-APC, 5. Mu.L of BioLegend ^TM anti-human CD27-BV510, 5. Mu.L of BioLegend ^TM anti-human IgD-BV421, 5. Mu.L of BioLegend ^TM anti-human IgG-PerCP/Cy5.5, 5. Mu.L of RSV F-PE (prepared in step (4)), 5. Mu.L of RSV F-FITC (prepared in step (4)) was added, and after mixing, incubated for 40 minutes on ice in the dark. 1mL of LB was added to each tube, centrifuged at 300g for 5 minutes at 4℃and the supernatant was discarded, and the above procedure was repeated once to resuspend the cells in 200. Mu.L of LB solution, thereby preparing a flow sort.

1.2 Single B cell flow sorting

The cells of live+/CD19+/CD27+/IgG+/IgD-/RSVF+ were selected and sorted according to the loop gate strategy as follows: the single lymphocyte population was first circled, live+ cells were circled, CD19+ B cells were circled, CD27+ memory B cells were circled, igG+/IgD-B cells were circled, and memory B cells bound to probe RSV F were circled (results are shown in FIG. 1). B cells were sorted 1 per well into 96-well plates containing PBS. After the sorting is finished, the 96-well plate is sealed by a sealing film immediately and is placed on dry ice for solidification, and then the dried ice is transferred into a refrigerator at the temperature of minus 80 ℃ for RT-PCR operation in the next day.

1.3 Cloning of Single B cell VDJ RT-PCR and BCR heavy and light chains

Single B cell VDJ RT-PCR was performed according to the method provided in reference 【Gieselmann L,Kreer C,Ercanoglu MS,et al.Effective high-throughput isolation of fully human antibodies targeting infectious pathogens.Nat Protoc.2021;16(7):3639-3671.】, amplifying the BCR heavy and light chain variable region sequences and aligning the VDJ sequences by IMGT. The aligned correct BCR heavy and light chain variable region sequences were cloned into heavy chain expression vector IgGvec-Hb and light chain expression vector IgGvec-L, respectively, according to the molecular cloning protocol.

1.4 Expression and purification of antibodies

The concentration of the Expi 293 cells was adjusted to 3X 10 ⁶/mL, and the transfection reagent was prepared as follows, and A solution was prepared: 50 μg of antibody plasmid was added to 3mL of Gibco ^TM Opti-MEM, solution B: 180uL Expi Fectamine of the mixture was added to 3mL of Opti-MEM, and the mixture was thoroughly mixed by shaking. The solutions A and B were mixed, allowed to stand at room temperature for 20min after being thoroughly mixed, added to 50mL of the Expi 293 cells, and incubated in an incubator at 37℃for 5 days at 120rpm in 8% CO ₂.

The collected cell supernatants were purified using Protein A affinity beads to obtain antibodies, and the antibody concentrations were determined using a NanoDrop2000 micro-spectrophotometer, using the procedure described in the manufacturer's instructions.

1.5 Screening for antibodies that bind to RSV F protein

1.5.1 Dilution of fusion protein Pre-F glycoprotein (Baiposis RSF-V52H 7) with coating buffer, addition to 96-well ELISA plates, 50ng of fusion glycoprotein Pre-F protein per well, and incubation at 4deg.C overnight in a refrigerator.

The supernatant was discarded the next 1.5.2 days, 300. Mu.L of 5% BSA blocking solution was added to each well, incubated in an incubator at 37℃for 2 hours, the blocking solution was discarded, and the wells were washed once with PBST solution.

1.5.3 Gradient diluting the antibody to be tested to 10. Mu.g/mL with PBS containing 0.5% BSA, sequentially diluting 6 gradients with PBS 10 times, adding to the blocked ELISA plate, incubating in an incubator at 37℃for 1h, discarding the solution, washing 3 times with PBST solution, and drying on absorbent paper.

1.5.4 Sigma-Aldrich ^TM HRP conjugated anti-human IgG-Fc antibody (1:10000, diluted in PBS containing 0.5% BSA) was added, 100. Mu.L per well, incubated in 37℃incubator for 1h, the solution was discarded, washed 3 times with PBST solution and blotted dry on absorbent paper.

1.5.5 Adding 100. Mu.L TMB color developing solution to each well, standing at room temperature for reaction for 10min, and adding 50. Mu.L stop solution to each well. Absorbance was read in a microplate reader at a wavelength of 450 nm. From the 48 antibodies tested, we selected 3 antibodies RSFP D9, RSFP B6, RSFP G7 (see fig. 2) with strong binding capacity to RSV F protein.

The invention screens to obtain 3 strains of fully human respiratory syncytial virus monoclonal antibodies, and sequences the gene amplification products of the heavy chain and the light chain to obtain the gene coding sequences and the amino acid sequences of the heavy chain and the light chain of the antibodies as follows:

The nucleotide sequence of the heavy chain variable region of RSFP B2B 6 antibody is shown as SEQ ID NO. 47, the amino acid sequence is shown as SEQ ID NO. 41, the amino acid sequences of CDR1, CDR2 and CDR3 of the heavy chain variable region are shown as amino acids 26-33, 51-60 and 99-107 of SEQ ID NO. 41, respectively shown as SEQ ID NO. 1-3; the nucleotide sequence of the light chain variable region is shown as SEQ ID NO. 48, the amino acid sequence is shown as SEQ ID NO. 42, the amino acid sequences of CDR1, CDR2 and CDR3 of the light chain variable region are shown as amino acids 26-33, 51-53 and 92-101 of SEQ ID NO. 42, and the amino acid sequences are shown as SEQ ID NO. 4-6 respectively.

The nucleotide sequence of a heavy chain variable region of RSFP D9 antibody is shown as SEQ ID NO. 49, the amino acid sequence is shown as SEQ ID NO. 43, the amino acid sequences of CDR1, CDR2 and CDR3 of the heavy chain variable region are shown as amino acids 26-33, 51-58 and 97-110 of SEQ ID NO. 43, and the amino acid sequences are shown as SEQ ID NO. 7-9 respectively; the nucleotide sequence of the light chain variable region is shown as SEQ ID NO. 50, the amino acid sequence is shown as SEQ ID NO. 44, the amino acid sequences of CDR1, CDR2 and CDR3 of the light chain variable region are shown as amino acids 27-32, 50-52 and 89-97 of SEQ ID NO. 44, respectively shown as SEQ ID NO. 10-12.

The nucleotide sequence of the heavy chain variable region of RSFP G7 antibody is shown as SEQ ID NO. 51, the amino acid sequence is shown as SEQ ID NO. 45, the amino acid sequences of CDR1, CDR2 and CDR3 of the heavy chain variable region are shown as amino acids 26-33, 51-58 and 97-108 of SEQ ID NO. 45, respectively shown as SEQ ID NO. 13-15; the nucleotide sequence of the light chain variable region is shown as SEQ ID NO. 52, the amino acid sequence is shown as SEQ ID NO. 46, the amino acid sequences of CDR1, CDR2 and CDR3 of the light chain variable region are shown as amino acids 26-33, 51-53 and 90-100 of SEQ ID NO. 46, and the amino acid sequences are shown as SEQ ID NO. 16-18 respectively.

EXAMPLE 2 determination of antibody binding Activity to different conformations F protein of RSV A/B

2.1 Different conformation F protein ELISA plate coating

2.1.1 Dilution with coating buffer respectively the pre-fusion F glycoprotein (Baizier RSF-V52H 7), the post-fusion protein (Baizier RSF-V52H 6), the pre-fusion protein (Baizier 18537), and the post-fusion protein (Baizier 18537) were added to 96-well ELISA plates to give 50ng of each well of protein, and incubated overnight at 4 ℃.

2.1.2 The following day the supernatant was discarded, 300. Mu.L of 5% BSA blocking solution was added to each well, incubated in an incubator at 37℃for 2h, the blocking solution was discarded, and the wells were washed once with PBST solution.

2.2 Antibody binding assays

2.2.1 Gradient diluting the antibody to be tested to 10. Mu.g/mL with PBS containing 0.5% BSA, sequentially diluting 15 gradients with PBS 3 times, adding to the blocked ELISA plate, incubating in an incubator at 37℃for 1h, discarding the solution, washing 3 times with PBST solution, and drying on absorbent paper.

2.2.2 Adding Sigma-Aldrich ^TM HRP conjugated anti-human IgG-Fc antibody (1:10000, PBS solution containing 0.5% BSA dilution), every hole 100u L, placing in 37 ℃ incubator incubation for 1h, discarding the solution, using PBST solution washing 3 times, on absorbent paper to dry.

2.2.3 Adding 100. Mu.L TMB color developing solution to each well, standing at room temperature for reaction for 10min, and adding 50. Mu.L stop solution to each well. Absorbance was read in a microplate reader at a wavelength of 450 nm. (see FIG. 3 and Table 1). From the results, the RSFP D9 antibody has good broad-spectrum binding capacity to the RSV A/B strain fusion protein, the binding capacity (EC ₅₀) is less than 30ng/mL, the RSFP G7 antibody tends to bind to the post-fusion conformation of the RSV A/B strain fusion protein, the binding capacity (EC ₅₀) is less than 70ng/mL, the RSFP B6 antibody has pre-fusion and post-fusion conformations of the RSV A/B strain fusion protein, and the binding capacity (EC ₅₀) is 292.2-602.7ng/mL.

Table 1RSV antibodies binding ability to RSV fusion proteins

EXAMPLE 3 determination of neutralizing Activity of antibodies against RSV pseudoviruses

3.1 Packaging of pseudoviruses

The F protein sequence (reference sequence: uniprot: P03420) after codon optimization of the human gene was ligated to the plasmid at EcoRI-XhoI double cleavage sites using the pCAGGS plasmid (purchased) as a backbone to obtain a pCAGGS-RSV-F expression vector.

5X 10 ⁶ 293T cells were seeded in 10cm cell culture dishes and incubated overnight in 5% CO ₂ at 37℃in a cell incubator and transfected with PEI: 1.2. Mu. gpCAGGS-RSVA2-F plasmid and 4.8. Mu. g psPAVX2 plasmid and 6. Mu. gpLenti-Luc/GFP plasmid were transfected into cell culture dishes and the medium was changed after 6 hours. After 48h of transfection, the culture supernatant is collected and filtered to obtain the RSV-A2F pseudovirus, and the RSV-A2F pseudovirus is frozen and stored in a refrigerator at the temperature of minus 80 ℃.

3.2 Pseudovirus neutralization assay:

(1) One day in advance, 100. Mu.L of 293T cell culture broth (at a concentration of 3X 10 ⁵/mL) was added to each well of a 96-well brown cell culture plate, and incubated in a CO ₂ cell incubator at 37℃for 16 hours.

(2) The next day, 50. Mu.L of the antibody to be tested was added to each well of a 96-well cell culture plate, followed by 50. Mu.L of RSV-A2F pseudovirus, thoroughly mixed by shaking, and incubated at 37℃for 1 hour.

(3) The cell supernatant was discarded, 60. Mu.L of the virus neutralization mixture was added, and the mixture was placed in a CO ₂ cell incubator at 37℃for 6 hours, and after the culture was replaced with a new medium, the culture was continued in a CO ₂ cell incubator at 37℃for 48 hours.

(4) After 48h of culture, 50. Mu.L of a luciferase detection substrate reagent (Novain, DD 1204-03) was added, and the mixture was thoroughly mixed by shaking. And reading the luminescence value in a multifunctional enzyme-labeled instrument. Neutralization inhibition was calculated and IC ₅₀ of the antibody to pseudovirus was calculated based on the neutralization inhibition results (results are shown in fig. 4 and table 2). As can be seen from the results, RSFP D9 had good neutralization activity (IC ₅₀) against the RSV-A2 pseudovirus, which was 0.5319 μg/mL, which was better than 3.89 μg/mL for the RSFP B2B 6 antibody and 1.704 μg/mL for the RSFP2G7 antibody.

Table 2 RSV F neutralizing IC of antibodies to RSV-A2 pseudoviruses ₅₀

Antibody name	RSFP2B6	RSFP2D9	RSFP2G7
				IC₅₀(μg/mL)	3.89	0.5319	1.704

EXAMPLE 4 neutralizing Activity of antibodies against RSV (strain A2) euvirus

4.1 Neutralization assay for live virus of RSV A2 strain

(1) One day in advance, 100. Mu.L of 293T cell culture broth (at a concentration of 2X 10 ⁵/mL) was added to each well of a 96-well cell culture plate, and the mixture was cultured in a CO ₂ cell incubator at 37℃for 16 hours.

(2) 50 Mu L of antibody to be tested is added into each well of a 96-well plate, 50 mu L RSV STRAIN A virus (200 FFU per well) is then added, and the mixture is fully and evenly mixed by shaking and placed in a cell culture incubator at 37 ℃ for incubation for 1h.

(3) The medium in the 96-well cell culture plate was aspirated, 100. Mu.L of the antibody-virus mixture was added to each well, and the mixture was placed in a cell culture box at 37℃for 6 hours. The supernatant was aspirated, and the cells were washed with PBS and incubated in a 5% CO ₂, 37℃incubator for 48h.

(4) After 48h, the cell supernatant was discarded, the cells were washed with PBS, 4% cell fixative (4% paraformaldehyde) was added, incubated at room temperature for 30 min, after the supernatant was aspirated, the cells were washed with PBS, after the supernatant was aspirated, the cells were read in a microplate fluorescent spot counter. Neutralization inhibition was calculated and IC ₅₀ of the antibody to the true virus was calculated based on the neutralization inhibition results (results are shown in fig. 5 and table 3). As a result, RSFP D9 had a good neutralizing activity (IC ₅₀) against RSV (strain A2) virus, and the neutralizing activity was 0.054. Mu.g/mL, which was superior to 1.003. Mu.g/mL of RSFP B6 antibody and 0.734. Mu.g/mL of RSFP G7 antibody.

Table 3 RSV F neutralizing IC of antibodies to RSV (strain A2) virus ₅₀

Antibody name	RSFP2B6	RSFP2D9	RSFP2G7
				IC₅₀(μg/mL)	1.003	0.054	0.734

Claims

1. An antibody against respiratory syncytial virus comprising a heavy chain variable region and a light chain variable region, wherein:

or alternatively

2. The antibody of claim 1, wherein:

the heavy chain variable region also comprises HFR1 with an amino acid sequence shown as SEQ ID NO. 19, HFR2 with an amino acid sequence shown as SEQ ID NO.20, HFR3 with an amino acid sequence shown as SEQ ID NO. 21 and HFR4 with an amino acid sequence shown as SEQ ID NO. 22; and

The light chain variable region also comprises LFR1 with an amino acid sequence shown as SEQ ID NO. 23, LFR2 with an amino acid sequence shown as SEQ ID NO. 24, LFR3 with an amino acid sequence shown as SEQ ID NO. 25 and LFR4 with an amino acid sequence shown as SEQ ID NO. 26; or alternatively

The light chain variable region also comprises LFR1 with an amino acid sequence shown as SEQ ID NO. 30, LFR2 with an amino acid sequence shown as SEQ ID NO. 31, LFR3 with an amino acid sequence shown as SEQ ID NO. 32 and LFR4 with an amino acid sequence shown as SEQ ID NO. 33; or alternatively

3. The antibody of claim 1 or 2, wherein:

The amino acid sequence of the heavy chain variable region is shown as SEQ ID NO. 41, and the amino acid sequence of the light chain variable region is shown as SEQ ID NO. 42; or alternatively

4. The antibody of any one of claims 1-3, wherein the antibody is a humanized monoclonal antibody.

5. A nucleic acid molecule comprising a nucleotide sequence encoding the antibody of any one of claims 1-4.

6. The nucleic acid molecule of claim 5, wherein the nucleotide sequence encoding the antibody comprises:

1) A nucleotide sequence encoding the heavy chain variable region as shown in SEQ ID NO. 47; and a nucleotide sequence encoding the light chain variable region as set forth in SEQ ID NO. 48; or alternatively

2) A nucleotide sequence encoding the heavy chain variable region as set forth in SEQ ID NO. 49; and a nucleotide sequence encoding the light chain variable region as set forth in SEQ ID NO. 50; or alternatively

7. A vector comprising the nucleic acid molecule of claim 5 or 6.

8. A cell comprising the nucleic acid molecule of claim 5 or 6 or the vector of claim 7.

9. A pharmaceutical composition comprising the antibody of any one of claims 1-4, the nucleic acid molecule of claim 5 or 6, the vector of claim 7 or the cell of claim 8, and a pharmaceutically acceptable carrier.

10. Use of an antibody according to any one of claims 1-4, a nucleic acid molecule according to claim 5 or 6, a vector according to claim 7, a cell according to claim 8 or a pharmaceutical composition according to claim 9 for the preparation of a medicament for the prophylaxis and/or treatment of respiratory syncytial virus or for the preparation of a respiratory syncytial virus detection reagent.