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CN-121991212-A - Humanized neutralizing antibody against severe acute respiratory syndrome type II coronavirus and application thereof

CN121991212ACN 121991212 ACN121991212 ACN 121991212ACN-121991212-A

Abstract

The invention discloses a humanized neutralizing antibody for resisting severe acute respiratory syndrome type II coronavirus and application thereof. Antibody nCoV P156P 6C was obtained by screening using phage surface display technology. The antibody specifically recognizes the severe acute respiratory syndrome type II coronavirus spike protein antigen, has obvious enzyme-linked immune reaction with the severe acute respiratory syndrome type II coronavirus spike protein, and has the neutralization activity function of resisting severe acute respiratory syndrome type II coronavirus infection. Is expected to be prepared into specific antibody medicines for preventing and treating novel coronavirus infection clinically.

Inventors

  • WU WEI
  • LIANG MIFANG
  • WANG MENGXUAN
  • HUANG FANG
  • LI BOYANG
  • JIANG YONG

Assignees

  • 武汉江源新抗生物科技有限公司

Dates

Publication Date
20260508
Application Date
20260228

Claims (10)

  1. 1. A neutralizing antibody or an active fragment thereof against severe acute respiratory syndrome type II coronavirus of human origin, characterized in that the amino acid sequences of complementarity determining regions CDR1, CDR2, CDR3 of the light chain variable region of the antibody or the active fragment thereof are QSIPSTY, GAS, QHYGTSPFT, respectively, and the amino acid sequences of complementarity determining regions CDR1, CDR2, CDR3 of the heavy chain variable region are EIIVNRNY, IYPGGST, ARSYGDF, respectively.
  2. 2. The antibody or active fragment thereof according to claim 1, wherein the amino acid sequence of the light chain variable region of the antibody or active fragment thereof is shown in SEQ ID No.1 and the amino acid sequence of the heavy chain variable region is shown in SEQ ID No. 2.
  3. 3. The antibody or active fragment thereof according to claim 1 or 2, wherein said active fragment is selected from the group consisting of Fab ', fab, F (ab') 2, fv and scFv fragments.
  4. 4. A nucleic acid molecule encoding the antibody or active fragment thereof of any one of claims 1-3.
  5. 5. A biological material comprising the nucleic acid molecule of claim 4, wherein the biological material is an expression cassette, a transposon, a plasmid vector, a viral vector or an engineering bacterium.
  6. 6. Use of an antibody or active fragment thereof according to any one of claims 1-3 for the preparation of a medicament or diagnostic reagent for the prevention or treatment of severe acute respiratory syndrome type II coronavirus infection.
  7. 7. Use of an antibody or active fragment thereof according to any one of claims 1-3 for the preparation of a medicament or composition for the prevention or treatment of a novel coronavirus infection caused by severe acute respiratory syndrome type II coronavirus.
  8. 8. A medicament for preventing or treating severe acute respiratory syndrome type II coronavirus infection, characterized in that the active ingredient is the antibody or the active fragment thereof according to any one of claims 1 to 3.
  9. 9. A medicament for preventing or treating novel coronavirus infection caused by severe acute respiratory syndrome type II coronavirus, characterized in that the antibody or an active fragment thereof according to any one of claims 1 to 3 is an active ingredient.
  10. 10. The medicament according to claim 8 or 9, further comprising pharmaceutical excipients.

Description

Humanized neutralizing antibody against severe acute respiratory syndrome type II coronavirus and application thereof Technical Field The invention relates to the technical field of genetic engineering antibodies, in particular to a humanized neutralizing antibody for resisting severe acute respiratory syndrome type II coronavirus and application thereof. Background Severe acute respiratory syndrome type II coronavirus (Severe acute respiratory syndrome coronavirus, SARS-CoV-2) is rapidly mutated under immune pressure and thus causes immunoblotting phenomenon, so that the antibody neutralization reaction of the organism on virus variant strain is reduced, immune escape is caused, and the effectiveness of the existing vaccine and antibody therapy is seriously threatened. The Receptor Binding domain (Receptor Binding domain, RBD) is the key part of SARS-CoV-2 viral particle entry into the cell, wherein the Receptor Binding Motif (RBM) is the functional region that binds to human angiotensin converting enzyme 2 (Human Angiotensin-Converting Enzyme 2, hACE 2). Antibodies are an important means of preventing and treating SARS-CoV-2 infection. It has been found that the majority of highly neutralizing antibodies target the RBM region, and that neutralization is achieved by blocking RBD binding hACE. Previous studies demonstrated that IGHV3-53/IGHV3-66 germline gene family antibodies form specific interactions with RBD residue A475 via CDR-H1 and CDR-H3 as part of a public immune response, primarily targeting the RBM region, and efficiently neutralizing SARS-CoV-2 Wild-type (Wild-type, WT). However, neutralizing antibodies affect the immune pressure of RBM, induce RBM to mutate L455S and the like and break the key binding interface of such antibodies, resulting in a large number of neutralizing antibodies from Omicron immune escape such as jn.1. Thus, how to restore the broad-spectrum neutralizing activity of IGHV3-66 antibodies by in vitro affinity maturation, resolve its neutralizing targets and develop new vaccines and antibodies is a key challenge for current research. The phage display technology provides a powerful platform for in vitro antibody affinity maturation and efficient screening of target epitopes by virtue of the advantages of high-throughput screening and directed evolution. The F61 antibody (reference 31, PDB: 7XMX_E) is a bnAb designed for administration in the form of a nasal spray. F61 was derived from early convalescence and had in vitro neutralising activity against a number of variants including omacron, the key innovation was that administration through the nasal cavity aimed at establishing a protective barrier directly on the respiratory mucosa, and the results of clinical trials (IIT) (ChiCTR 2200066841, chiCTR 2200066391) provided important evidence for the effectiveness of mucosal immunization strategies, under a multi-dose regimen, F61 nasal sprays showed significant prophylactic effects, reducing the cumulative 7 day infection rate from 23.83% in placebo to 6.55% in F61, with efficacy as high as 72.19% and good safety, with little antibody absorption in the blood, confirming its primary local role. Subsequent large-scale real world studies (involving 60225 volunteers) conducted during the Chinese omacron (ba.5/bf.7) epidemic further validated the high protective efficacy of F61 nasal sprays in practical applications (overall effective rate exceeding 90%). F61 belongs to the IGHV3-66 germ line gene family. However, with the popularity of omacron (bf.7, xbb.1.5, eg.5.1, etc.), the neutralizing activity of antibodies with the same heavy chain and different light chains is reduced to different extents, suggesting that light chain optimization has the potential to break through the broad-spectrum bottleneck of existing antibodies. Disclosure of Invention The invention aims to provide a humanized neutralizing antibody for resisting severe acute respiratory syndrome type II coronavirus and application thereof. Based on a phage display platform, the invention adopts a strategy of fixing heavy chains/replacing light chains to carry out in vitro affinity maturation on F61, and screens out a novel antibody nCoV P156P 6C which keeps high-efficiency neutralization activity on the variant strain. The broad-spectrum antiviral potential of nCoV P156P 6C was confirmed by functional experiments and AlphaFold structural predictions, and the neutralizing epitope was primarily analyzed. In order to achieve the object of the present invention, in a first aspect, the present invention provides a humanized anti-severe acute respiratory syndrome type II coronavirus neutralizing antibody nCoV P6C or an active fragment thereof, the amino acid sequences of complementarity determining regions CDR1, CDR2, CDR3 of the light chain variable region of the antibody or the active fragment thereof are QSIPSTY, GAS, QHYGTSPFT, respectively, and the amino acid sequences of complementarity determining regions CDR1, CDR2,