In recent years, hepatitis-hydropericardium syndrome (HHS) and inclusion body hepatitis (IBH) caused by fowl adenovirus (FAdV) infection have resulted in significant economic losses to the poultry industry worldwide. Epidemiological analysis revealed that serotype FAdV-8 is one of the major pathogenic FAdVs currently prevalent in domestic flocks. Although the fiber protein of FAdV plays vital roles in viral infection and pathogenesis, the B cell epitope in the fiber protein is less known. In this study, two monoclonal antibodies (mAbs) specific to fiber protein of FAdV-8, designated as 4D9 and 5F10, were prepared. Although the mAb 4D9 and 5F10 could not neutralize FAdV-8 infection, 4D9 and 5F10 showed good activities of indirect immunofluorescence, western blot and immunoprecipitation. Epitope analysis revealed that mAb 5F10 recognized 187–219aa in the fiber whereas mAb 4D9 recognized 113–149aa in the fiber. Sequence analysis showed that the epitope recognized by mAb 5F10 was conserve across serotypes FAdV-7, 8a and 8b whereas that for mAb 4D9 was only conserve in FAdV-8b. The generation of mAbs specific to fiber of FAdV-8 and the identification of the novel B cell epitopes here lay the foundation for further studying the antigenicity of the fiber and developing specific diagnosis for FAdV-8.

中文翻译：

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血清型8禽腺病毒纤维蛋白中新的B细胞表位的鉴定

近年来，由禽腺病毒（FAdV）感染引起的肝炎－水囊病综合症（HHS）和包涵体肝炎（IBH）已给全世界的家禽业造成了巨大的经济损失。流行病学分析表明，血清型FAdV-8是目前家禽中普遍存在的主要致病性FAdV之一。尽管FAdV的纤维蛋白在病毒感染和发病机理中起着至关重要的作用，但是纤维蛋白中的B细胞表位却鲜为人知。在这项研究中，制备了两种对FAdV-8纤维蛋白具有特异性的单克隆抗体（mAb），分别命名为4D9和5F10。尽管mAb 4D9和5F10无法中和FAdV-8感染，但4D9和5F10表现出良好的间接免疫荧光，蛋白质印迹和免疫沉淀活性。表位分析表明，mAb 5F10识别出光纤中的187–219aa，而mAb 4D9识别出光纤中的113–149aa。序列分析表明，mAb 5F10识别的抗原决定簇在血清型FAdV-7、8a和8b中是保守的，而mAb 4D9的抗原表位仅在FAdV-8b中是保守的。在此，FAdV-8纤维特异的mAb的产生和新型B细胞表位的鉴定为进一步研究纤维的抗原性和开发针对FAdV-8的特异性诊断奠定了基础。