Identification of a novel antigenic epitope in envelope protein of avian reticuloendotheliosis virus

Reticuloendotheliosis is a devastating poultry disease causing tumors and immunosuppression in infected birds. Caused by reticuloendotheliosis virus, it carries a surface glycoprotein (gp90) that mediates viral infection, assembly, release and induces protective antibodies, yet the specific gp90 regions triggering immune responses remain poorly understood. In this study, we expressed gp90 of a prevalent REV strain via a prokaryotic system and established a hybridoma cell line stably secreting gp90-specific monoclonal antibodies through cell fusion and flow cytometric screening. Most notably, we identified a novel linear B-cell epitope, 195REESVRERL203, on gp90 for the first time. Localized to the outer mid-domain of gp90 and conserved across REV strains, this epitope defines a key immunogenic structure, offering insights for targeted diagnostics and control strategies against this economically impactful disease.

网状内皮组织增生症（Reticuloendotheliosis）是一种极具破坏性的禽类传染病，可导致受感染禽类发生肿瘤病变并引发免疫抑制。该病由网状内皮组织增生症病毒（Reticuloendotheliosis Virus, REV）引发，其表面带有介导病毒感染、组装与释放的表面糖蛋白gp90，且该蛋白可诱导保护性抗体的产生，但目前学界对gp90中触发免疫应答的具体区域仍知之甚少。
本研究通过原核表达系统对一株流行的REV毒株的gp90蛋白进行了表达，并通过细胞融合与流式细胞术筛选，获得了可稳定分泌gp90特异性单克隆抗体的杂交瘤细胞株。尤为关键的是，本研究首次在gp90上鉴定出一种全新的线性B细胞表位195REESVRERL203。该表位定位于gp90的外侧中间结构域，且在所有REV毒株中均高度保守，作为关键的免疫原性结构，其可为针对这一具有重大经济影响的禽类疾病的靶向诊断与防控策略提供重要理论依据。