Ma Xiaohua, Gao Min, Zhang Xiangmin, Ma Weiwei, Xue Fei, Wang Xue-Feng, Wang Xiaojun
State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China.
Institute of Western Agriculture, The Chinese Academy of Agricultural Sciences, Changji, China.
Front Microbiol. 2024 Aug 1;15:1452063. doi: 10.3389/fmicb.2024.1452063. eCollection 2024.
Maedi-visna virus (MVV) and caprine arthritis encephalitis virus (CAEV) are members of a group of genetically highly homologous lentiviruses collectively referred to as small ruminant lentiviruses (SRLVs). SRLVs can infect sheep, goats and other small ruminants, causing multisystemic disease with progressive and persistent inflammatory changes, severely reducing animal productivity and impeding animal trade. The capsid protein of SRLVs, p28, is highly conserved among strains and is a commonly used marker for the detection of SRLVs. In this study, two monoclonal antibodies (mAbs), designated G8F7 and A10C12, against p28 were generated using a recombinant p28 protein expressed in as an immunogen. Functional analysis showed that these two monoclonal antibodies could be used in iELISA, immunofluorescence assays (IFA) and western blot assays to detect p28 or Gag precursor proteins of SRLVs. Two linear epitopes, GNRAQKELIQGKLNEEA (E61-77) and CQKQMDRVLGTRVQQATVEEKMQACR (E187-212), which are recognized by G8F7 and A10C12, respectively, were identified through truncation of the GST-fused p28. Amino acid sequence alignment showed that the epitope E61-77 is conserved among SRLVs, with a dominant mutation site (K72R) that does not disrupt recognition by G8F7. E187-212 was found to exhibit variability among SRLVs, but the majority of mutant epitopes are recognized by A10C12, with the exception of a mutant epitope from an isolate with undefined subtypes from , which was not recognized. These findings may facilitate future study of SRLVs and promote the development of methods for the detection of these viruses.
梅迪-维斯纳病毒（MVV）和山羊关节炎脑炎病毒（CAEV）是一组基因高度同源的慢病毒成员，统称为小反刍兽慢病毒（SRLV）。SRLV可感染绵羊、山羊和其他小反刍兽，引起多系统疾病，伴有进行性和持续性炎症变化，严重降低动物生产力并阻碍动物贸易。SRLV的衣壳蛋白p28在各毒株间高度保守，是检测SRLV常用的标志物。在本研究中，以在大肠杆菌中表达的重组p28蛋白作为免疫原，制备了两种抗p28的单克隆抗体（mAb），命名为G8F7和A10C12。功能分析表明，这两种单克隆抗体可用于间接酶联免疫吸附测定（iELISA）、免疫荧光测定（IFA）和蛋白质印迹分析，以检测SRLV的p28或Gag前体蛋白。通过截短谷胱甘肽-S-转移酶（GST）融合的p28，鉴定出分别被G8F7和A10C12识别的两个线性表位，即GNRAQKELIQGKLNEEA（E61 - 77）和CQKQMDRVLGTRVQQATVEEKMQACR（E187 - 212）。氨基酸序列比对显示，表位E61 - 77在SRLV中保守，有一个优势突变位点（K72R），但不影响G8F7的识别。发现E187 - 212在SRLV中存在变异性，但大多数突变表位可被A10C12识别，来自中国一株未确定亚型分离株的突变表位除外，该表位不被识别。这些发现可能有助于未来对SRLV的研究，并促进这些病毒检测方法的开发。
