Sempere Borau Milagros, Gisbert Victor G, von Kempis Josephine, Arroyo-Fernández Laura M, Schiefer Samira, Alsteens David, Stertz Silke
Institute of Medical Virology, University of Zurich, Zurich, Switzerland.
Louvain Institute of Biomolecular Science and Technology (LIBST), UCLouvain, Louvain, Belgium.
PLoS Pathog. 2025 Jul 7;21(7):e1013338. doi: 10.1371/journal.ppat.1013338. eCollection 2025 Jul.
Influenza A virus (IAV) is a respiratory pathogen of global concern. Entry of most IAVs is mediated by binding of viral hemagglutinin to cellular sialic acid, facilitating virus attachment. A subsequent interaction with a surface receptor(s) triggers viral uptake. Although multiple host factors involved in viral entry are known, the identity of these receptors remains unclear. Here, we utilized proximity labelling to acquire the interactome of epsin 1, an adaptor protein utilized by IAV for clathrin-mediated endocytosis, during virus internalization to identify them. We uncover neogenin (Neo1), a member of the immunoglobulin superfamily expressed in primary human airway cultures, as a potential epsin 1 interactor and virus receptor candidate. Knockdown of Neo1 led to a reduction in replication of H1N1, H2N2 and H5N1 IAVs in primary and immortalized lung cells. Moreover, human recombinant Neo1 was found to bind IAV with a KD of 21 ± 14 nM by atomic force microscopy and Neo1 could co-localize with incoming IAV at early times post-infection, as well as affect viral entry. As Neo1 can interact with IAV and its depletion impairs IAV entry, this study reveals its potential as an IAV internalization receptor.
甲型流感病毒（IAV）是一种全球关注的呼吸道病原体。大多数IAV的进入是通过病毒血凝素与细胞唾液酸结合介导的，从而促进病毒附着。随后与一种或多种表面受体的相互作用触发病毒摄取。虽然已知多种参与病毒进入的宿主因子，但这些受体的身份仍不清楚。在这里，我们利用邻近标记技术在病毒内化过程中获取epsin 1的相互作用组，epsin 1是IAV用于网格蛋白介导的内吞作用的衔接蛋白，以识别这些受体。我们发现新生成蛋白（Neo1）是在原代人气道培养物中表达的免疫球蛋白超家族成员，是一种潜在的epsin 1相互作用蛋白和病毒受体候选物。敲低Neo1导致H1N1、H2N2和H5N1 IAV在原代和永生化肺细胞中的复制减少。此外，通过原子力显微镜发现人重组Neo1以21±14 nM的解离常数（KD）与IAV结合，并且Neo1在感染后早期可与进入的IAV共定位，还能影响病毒进入。由于Neo1可与IAV相互作用且其缺失会损害IAV进入，本研究揭示了其作为IAV内化受体的潜力。
