Identification Of A B-cell Epitope In The Nucleocapsid Protein Of Highly Pathogenic Porcine Reproductive And Respiratory Syndrome Virus HuN4Strain

Highly pathogenic porcine reproductive and respiratory syndrome (HP-PRRS) is a kind ofvirulent viral diseases, case fatality rate is high; HP-PRRSV can cause immune suppression andsecondary other diseases. The disease is widely spread across China, great harm to the develop-ment of pig industry in our country and the economic loss is very serious.For the preparation of highly pathogenic porcine reproductive and respiratory syndromevirus (HP-PRRSV) HuN4strains of monoclonal antibodies (MAb), SP2/0cells was fused withthe splenic cell from BALB/c mice immunized with HP-PRRSV HuN4strain. Three hybridomacell lines that stably secreted MAbs against HP-PRRSV N was scanned by indirectimmunofluorescence assay (IFA),named as2E9,3G2,4E3，respectively. the titer of McAb ascitesagainst HP-PRRSV HuN4by IFA is1:5120~1:10240. Antibodies and the identification ofheavy chain type IgG1, light chain are kappa chain predominate. Three MAbs were able to reactspecifically with PRRSV HuN4, HuN4-F112, JXA1-R, TJM-F92, CH-1R, RespPRRSV-MLVand pCAGGS-ORF7transfected cells, but not with DV, HBL strains detected by IFA. Westernblot analysis showed that the MAbs were capable of reaction with N expressed in E.coli. Therecognized antigenic region of the2E9MAb was localized at aa38-105and aa56-117inHP-PRRSV N. The results for the further research on the HP-PRRSV N protein structure andfunction, and to establish a diagnosis method laid a foundation.