title: Highly pathogenic porcine reproductive and respiratory syndrome virus GP5 B antigenic region is not a neutralizing antigenic region.
abstract: In 2006, highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) caused great economic losses emerged in China and continues to be a threat for the pig industry. B antigenic region (AR) ((37)SHL/FQLIYNL(45)) of GP5 was considered to be a major linear neutralizing AR in PRRSV classical strains. However, peptide-purified antibodies against this AR did not neutralize PRRSV in a recent report. Compared with classical PRRSV, one amino acid mutation (L/F(39)→ I(39)) was found in B AR of HP-PRRSV. To study the ability of B AR of HP-PRRSV to induce neutralizing antibody (NA) in vitro and in vivo, rabbit antisera against B AR with and without the mutation and pig hyperimmune sera with high titer of NAs against HP-PRRSV were prepared. Immunofluorescence assays (IFA) showed that the two rabbit antisera both had reactivity to classical PRRSV CH-1a and HP-PRRSV HuN4 with no observable difference in IFA titer. However, antisera did not have neutralizing activity against classical PRRSV CH-1a and HP-PRRSV HuN4. No correlation was observed between the levels of anti-B AR peptide antibodies and NAs in pig hyperimmune sera that were detected by indirect ELISA and virus neutralization, respectively. B AR peptide-specific serum antibodies had no neutralizing activity and, GST-B fusion protein could not inhibit neutralization of NAs in pig hyperimmune sera. Based on these findings, we conclude that B AR of HP-PRRSV is not a neutralizing AR of HP-PRRSV GP5.
authors: Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, China.
authors: Chao-Liang
authors: CL
authors: Leng
authors: Tong-Qing
authors: TQ
authors: An
authors: Jia-Zeng
authors: JZ
authors: Chen
authors: Da-Qing
authors: DQ
authors: Gong
authors: Jin-Mei
authors: JM
authors: Peng
authors: Yong-Qian
authors: YQ
authors: Yang
authors: Jiang
authors: J
authors: Wu
authors: Juan-Juan
authors: JJ
authors: Guo
authors: Deng-Yun
authors: DY
authors: Li
authors: Yi
authors: Y
authors: Zhang
authors: Zhen-Xiang
authors: ZX
authors: Meng
authors: Yu-Quan
authors: YQ
authors: Wu
authors: Zhi-Jun
authors: ZJ
authors: Tian
authors: Guang-Zhi
authors: GZ
authors: Tong
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing; D002681:China; D004797:Enzyme-Linked Immunosorbent Assay; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D019318:Porcine Reproductive and Respiratory Syndrome / Q000276:immunology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000737:chemistry*; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000276:immunology; D013552:Swine; D014764:Viral Proteins / Q000737:chemistry / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D057134:Antibodies, Neutralizing; D010455:Peptides; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; D014765:Viral Vaccines