Hou Minbo, Zhou Defang, Li Gen, Guo Huijun, Liu Jianzhu, Wang Guihua, Zheng Qiankun, Cheng Ziqiang
College of Veterinary Medicine, Shandong Agricultural University, Tai'an 271018, China.
College of Veterinary Medicine, Shandong Agricultural University, Tai'an 271018, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Tai'an 271018, China.
Vaccine. 2016 Mar 8;34(11):1399-404. doi: 10.1016/j.vaccine.2016.01.039. Epub 2016 Feb 2.
Avian leukosis virus subgroup J (ALV-J) is a hypervariable oncogenic retrovirus that causes great economic loss in poultry. Antigenic variations in the variable regions make the development of an effective vaccine a challenging task. In the present study, we identified a variant antigenic neutralizing epitope using reverse vaccinology methods. First, we predicted the B-cell epitopes in gp85 gene of ALV-J strains by DNAman and bioinformatics. Fourteen candidate epitopes were selected and linked in tandem with glycines or serines as a multi-epitope gene. The expressed protein of multi-epitope gene can induce high-titer antibody that can recognize nature ALV-J and neutralize the infectivity of ALV-J strains. Next, we identified a high effective epitope using eight overlapping fragments of gp85 gene reacting with mAb 2D5 and anti-multi-epitope sera. The identified epitope contained one of the predicted epitopes and localized in hyervariable region 1 (hr1), indicating a variant epitope. To better understand if the variants of the epitope have a good antigenicity, we synthesized four variants to react with mAb 2D5 and anti-ALV-J sera. The result showed that all variants could react with the two kinds of antibodies though they showed different antigenicity, while could not react with ALV-J negative sera. Thus, the variant antigenic neutralizing epitope was determined as 137-LRDFIA/E/TKWKS/GDDL/HLIRPYVNQS-158. The result shows a potential use of this variant epitopes as a novel multi-epitope vaccine against ALV-J in poultry.
禽白血病病毒J亚群（ALV-J）是一种高度可变的致癌逆转录病毒，给家禽业造成了巨大的经济损失。可变区的抗原变异使得开发有效的疫苗成为一项具有挑战性的任务。在本研究中，我们使用反向疫苗学方法鉴定了一种变异抗原中和表位。首先，我们通过DNAman和生物信息学预测了ALV-J毒株gp85基因中的B细胞表位。选择了14个候选表位，并与甘氨酸或丝氨酸串联连接作为多表位基因。多表位基因表达的蛋白可诱导产生高滴度抗体，该抗体可识别天然ALV-J并中和ALV-J毒株的感染性。接下来，我们使用gp85基因的八个重叠片段与单克隆抗体2D5和抗多表位血清反应，鉴定出一个高效表位。鉴定出的表位包含一个预测表位，位于高变区1（hr1），表明是一个变异表位。为了更好地了解该表位的变异体是否具有良好的抗原性，我们合成了四个变异体与单克隆抗体2D5和抗ALV-J血清反应。结果表明，所有变异体均可与这两种抗体反应，尽管它们表现出不同的抗原性，但均不与ALV-J阴性血清反应。因此，变异抗原中和表位被确定为137-LRDFIA/E/TKWKS/GDDL/HLIRPYVNQS-158。结果表明，这种变异表位有潜力作为一种新型多表位疫苗用于家禽抗ALV-J。
