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CN-121991208-A - Antibody or antigen binding fragment thereof for N protein 2-87 amino acid fragment of porcine reproductive and respiratory syndrome virus and application thereof

CN121991208ACN 121991208 ACN121991208 ACN 121991208ACN-121991208-A

Abstract

The application discloses an antibody or an antigen binding fragment thereof aiming at an N protein 2-87 amino acid fragment of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), which has broad-spectrum recognition capability on PRRSV of different genotypes, has strong specificity and high titer, can be used for preparing PRRSV detection reagents or kits, realizes quick and accurate preliminary screening of PRRSV infection, solves the problems of single target spot, insufficient specificity, import dependence of core reagents and the like in the prior detection technology, provides a key biological reagent for PRRS prevention and control, and has important practical application value.

Inventors

  • SHAO MIN
  • ZHOU HEFENG
  • YANG CHANGYAN

Assignees

  • 遵义医科大学珠海校区

Dates

Publication Date
20260508
Application Date
20260129

Claims (10)

  1. 1. An antibody aiming at N protein 2-87 amino acid fragments of porcine reproductive and respiratory syndrome virus is characterized in that the amino acid sequence of a heavy chain variable region of the antibody is shown as SEQ ID NO. 1, and the amino acid sequence of a light chain variable region of the antibody is shown as SEQ ID NO. 2.
  2. 2. The antibody of claim 1, wherein the antibody is an IgG2a type antibody and the light chain is a kappa light chain.
  3. 3. An antigen binding fragment that specifically binds to the antibody of claim 1 or 2.
  4. 4. A nucleic acid molecule encoding the antibody of claim 1 or 2, wherein said nucleic acid molecule comprises a nucleotide sequence encoding a heavy chain variable region as set forth in SEQ ID No. 3 and a nucleotide sequence encoding a light chain variable region as set forth in SEQ ID No. 4.
  5. 5. A recombinant expression vector comprising the nucleic acid molecule of claim 4.
  6. 6. The vector of claim 5, wherein the vector is a pET-32a (+) expression vector.
  7. 7. A host cell comprising the recombinant expression vector of claim 5.
  8. 8. A recombinant protein of an N protein 2-87 amino acid fragment of a porcine reproductive and respiratory syndrome virus, which is obtained by inducible expression of the recombinant expression vector of claim 5 in the host cell of claim 6.
  9. 9. The use of the recombinant protein according to claim 8 for immunization against porcine reproductive and respiratory syndrome virus N protein antibodies.
  10. 10. Use of an antibody or antigen binding fragment thereof according to any one of claims 1-3 in the preparation of a reagent or kit for detecting porcine reproductive and respiratory syndrome virus N protein.

Description

Antibody or antigen binding fragment thereof for N protein 2-87 amino acid fragment of porcine reproductive and respiratory syndrome virus and application thereof Technical Field The invention relates to the technical field of antibodies, in particular to an antibody aiming at N protein 2-87 amino acid fragments of porcine reproductive and respiratory syndrome virus or an antigen binding fragment thereof and application thereof. Background Porcine reproductive and respiratory syndrome (Porcine Reproductiveand Respiratory Syndrome, PRRS), commonly known as porcine reproductive and respiratory syndrome, is a highly contagious disease caused by Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), can infect pigs of all ages through various ways such as contact and air transmission, has obvious harm to pregnant sows and piglets, has clinical manifestations mainly including sow reproductive disorders (such as abortion, stillbirth, mummy embryo, weaning baby) and piglet respiratory symptoms, and can cause remarkable increase of piglet mortality. More significantly, the PRRSV has remarkable immunosuppressive property, can target to attack the alveolar macrophages of pigs and destroy the core defense cells of the immune system of the organism, so that the resistance of the pigs is greatly reduced, and the mixed infection of bacteria and other viruses is extremely easy to form malignant circulation of 'immunosuppression-multiple infection', thereby not only increasing the difficulty of epidemic disease prevention and control, but also further expanding the range of economic loss and severely restricting the sustainable development of the intensive pig industry. At present, prevention and control of PRRS mainly depend on comprehensive measures taking vaccine immunity and monitoring purification as cores, wherein an accurate and rapid diagnosis technology is a key for realizing effective monitoring and epidemic situation tracing. Although the existing PRRS diagnosis technology is various, the existing PRRS diagnosis technology has the limitation that is difficult to overcome, and cannot completely meet the actual requirements of pig industry, especially basic pig farms. The method has the advantages that the method is definite in result, but complicated in process, long in time consumption and difficult to meet the requirement of rapid screening of a basic layer, the technology such as RT-PCR, real-time fluorescence quantitative PCR, loop-mediated isothermal amplification (LAMP) and the like has high sensitivity and specificity in the aspect of molecular biological detection, but depends on precise instruments and professional operation, and is not suitable for field application of pig farms, and in serological detection, an indirect immunofluorescence test and a virus neutralization test have specificity, but are low in flux and strong in subjectivity, or early diagnosis cannot be realized due to lag of neutralizing antibodies (1-2 months after infection). In contrast, enzyme-linked immunosorbent assay (ELISA) becomes the mainstream technology of PRRSV serological detection by virtue of the advantages of high throughput, low cost, simple operation and the like, but the current ELISA kit still faces the problems of single target point, difficulty in distinguishing wild virus infection from vaccine immunity, dependence of part of core reagents on import and the like, and the accurate application of the ELISA kit in a basic layer is restricted. PRRSV belongs to the genus arterivirus of the family arterividae, is a single-stranded positive strand RNA virus, and has a genome of about 15kb in length. The virus is largely divided into two genotypes, PRRSV-1 (European type) and PRRSV-2 (American type). At present, PRRSV-2 is the dominant strain in our country, and the strain can be divided into a plurality of lineages, wherein NADC30-like strain of the lineages 1 is the dominant epidemic strain. N protein is taken as PRRSV nucleocapsid protein, is encoded by ORF7 gene, has the molecular weight of about 15kDa and consists of 123 amino acid residues, has the greatest advantages of extremely high sequence conservation, the amino acid homology of N protein among different genotype strains can reach more than 90 percent, the content in virus particles is up to 40 percent, the expression abundance is high, and the N protein is an ideal broad-spectrum detection target point, but antibodies induced by the whole section of the N protein cannot distinguish wild toxin from vaccine immunity, and partial regions possibly have homologous sequences with other virus proteins, so that the specificity is insufficient. The prior art fails to accurately screen fragments which are conserved and have unique antigen epitopes in N protein, so that the advantages of targets cannot be fully exerted. Therefore, research and development of the PRRSV antibody with high specificity, high titer and independent intellectual property based on the ac