State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, China.
PLoS One. 2019 Jun 26;14(6):e0219091. doi: 10.1371/journal.pone.0219091. eCollection 2019.
Detection of human adenoviruses (HAdVs) in nasopharyngeal swab samples by immunofluorescence assay (IFA) will be valuable for diagnosing HAdV infection, which is a leading cause of severe respiratory tract disease, and will help in curbing the spread of HAdV. Monoclonal antibodies employed in IFA for HAdV detection should ideally target highly conserved epitope types. Here, we describe the development of two antigen-binding fragments (Fabs) with specific reactivity to HAdV using phage antibody library technology. When tested with IFA, both Fabs recognized cells infected with several types of HAdV, some of which have been identified in epidemics globally, or associated with outbreaks of severe or fatal acute respiratory diseases. The specificity and cross-reactivity of both Fabs to HAdVs indicated that the generated Fabs could be applied in the development of IFAs to detect HAdVs. Both Fabs bound to the knob proteins, as shown by chemiluminescence enzyme immunoassay and western blot. In addition, epitope mapping showed that both Fabs recognized a conserved linear epitope among several types of HAdV. Two different Fabs recognized the same epitope, suggesting that the epitope triggered the production of at least two kinds of antibodies in the body. The generated Fabs exerted no neutralization against HAdVs. The results demonstrate that both Fabs bind to an epitope that plays no role in neutralization of HAdV.
应用免疫荧光检测法（IFA）检测鼻咽拭子样本中的人类腺病毒（HAdV）对于诊断 HAdV 感染十分有价值，因为 HAdV 是引起严重呼吸道疾病的主要原因之一，有助于遏制 HAdV 的传播。IFA 中用于 HAdV 检测的单克隆抗体理想情况下应靶向高度保守的表位类型。在这里，我们使用噬菌体抗体库技术描述了两种针对 HAdV 具有特异性反应的抗原结合片段（Fab）的开发。当用 IFA 进行测试时，两种 Fab 都能识别感染了几种 HAdV 的细胞，其中一些 HAdV 已在全球流行中被鉴定出来，或者与严重或致命的急性呼吸道疾病的爆发有关。两种 Fab 对 HAdV 的特异性和交叉反应性表明，所产生的 Fab 可应用于开发 IFAs 来检测 HAdV。两种 Fab 都与 knob 蛋白结合，如化学发光酶免疫测定和 Western blot 所示。此外，表位作图显示，两种 Fab 都识别了几种 HAdV 之间的保守线性表位。两种不同的 Fab 识别相同的表位，表明该表位引发了体内至少两种类型的抗体产生。所产生的 Fab 对 HAdV 没有中和作用。结果表明，两种 Fab 都结合到一个在 HAdV 中和作用中不起作用的表位上。
