Li Xiaofei, Zhu Haibo, Wang Qi, Sun Jiashan, Gao Yanni, Qi Xiaole, Wang Yongqiang, Gao Honglei, Gao Yulong, Wang Xiaomei
Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Nan Gang District, Harbin, 150001, Heilongjiang, People's Republic of China,
Arch Virol. 2015 Apr;160(4):995-1004. doi: 10.1007/s00705-014-2318-6. Epub 2015 Feb 6.
Avian leukosis virus subgroup J (ALV-J) is an avian oncogenic retrovirus that has caused severe economic losses in China. Gp85 protein is the main envelope protein and the most variable structural protein of ALV-J. It is also involved in virus neutralization. In this study, a specific monoclonal antibody, 4A3, was produced against the ALV-J gp85 protein. Immunofluorescence assays showed that 4A3 could react with different strains of ALV-J, including the British prototype isolate HPRS103, the American strains, an early Chinese broiler isolate, and layer isolates. A linear epitope on the gp85 protein was identified using a series of partially overlapping fragments spanning the gp85-encoding gene and subjecting them to western blot analysis. The results indicated that (134)AEAELRDFI(142) was the minimal linear epitope that could be recognized by mAb 4A3. Enzyme-linked immunosorbent assay (ELISA) revealed that chicken anti-ALV-J sera and mouse anti-ALV-J gp85 sera could also recognize the minimal linear epitope. Alignment analysis of amino acid sequences indicated that the epitope was highly conserved among 34 ALV-J strains. Furthermore, the epitope was not conserved among subgroup A and B of avian leukosis virus (ALV). Taken together, the mAb and the identified epitope may provide valuable tools for the development of new diagnostic methods for ALV-J.
禽白血病病毒J亚群（ALV-J）是一种禽致癌逆转录病毒，在中国已造成严重的经济损失。Gp85蛋白是ALV-J的主要包膜蛋白和变异最大的结构蛋白，也参与病毒中和反应。在本研究中，制备了一种针对ALV-J gp85蛋白的特异性单克隆抗体4A3。免疫荧光试验表明，4A3能与不同株的ALV-J发生反应，包括英国原型毒株HPRS103、美国毒株、中国早期肉鸡分离株和蛋鸡分离株。利用一系列跨越gp85编码基因的部分重叠片段并对其进行蛋白质印迹分析，鉴定出gp85蛋白上的一个线性表位。结果表明，(134)AEAELRDFI(142)是单克隆抗体4A3能识别的最小线性表位。酶联免疫吸附测定（ELISA）显示，鸡抗ALV-J血清和小鼠抗ALV-J gp85血清也能识别该最小线性表位。氨基酸序列比对分析表明，该表位在34株ALV-J毒株中高度保守。此外，该表位在禽白血病病毒（ALV）的A亚群和B亚群中不保守。综上所述，该单克隆抗体和鉴定出的表位可能为开发ALV-J新的诊断方法提供有价值的工具。
