Diversity of sugar chain recognition by hemagglutinin and transmission mechanism of influenza viruses

本项目旨在阐明血凝素在流感病毒复制和病毒在宿主之间传播中的作用。本课题的研究成果如下：我们测试了1968 ~ 1979年分离的人H3型甲型流感病毒对含有不同末端唾液酸分子种的唾液糖脂的结合反应性。所有测试的人类H3病毒都结合Neu5Ac和Neu5Gc.2。我们检测了马气管上皮细胞中Neu5Ac和Neu5Gc的相对丰度。90%以上的唾液酸为Neu5Gc，其余部分为NeuAc。马气管上皮细胞中主要的唾液酸半乳糖片段是Neu5Gcα2.3Gal。我们研究了对血凝素的需求，以支持病毒复制在马，使用病毒具有不同的受体特异性。结果表明，neu5gc - α2,3 gal片段的识别对病毒在马体内的复制至关重要。具有neu5gc - α 2,3gal的糖缀合物片段的识别与鸭肠中的病毒复制有关。硫胺结合位点定位于HA的唾液酸结合袋或袋附近。

This project aims at explicating the role of hemagglutinin on the replication of influenza viruses and transmission of the viruses between the hosts.The results of the project are as follows.1. We tested the binding reactivity of human H3 influenza A viruses, which were isolated from 1968 to 1979, to sialylglycolipids containing different molecular species of terminal sialic acids. All human H3 viruses tested bound both Neu5Ac and Neu5Gc.2. We examined the relative abundance of Neu5Ac and Neu5Gc in the epithelial cells of horse trachea. More than 90 % of the sialic acid was Neu5Gc, while the remaining proportion was NeuAc. The major sialic acid-Galactose moiety present in horse tracheal epithelial cells is Neu5Gcα2.3Gal. We examined the requirement for the hemagglutinin for support of viral replication in horses, using viruses whose Has differ in receptor specificity. The results indicated that recognition of Neu5Gcα2,3Gal moiety is critical for viral replication in horses.3. The recognition of a glycoconjugate moiety possessing Neu5Gcα2,3Gal was associated with viral replication in duck intestine.4. Sulfatide binding site is localized in the sialic acid binding pocket of HA or the neighborhood of the pocket.