2 DISTINCT SERUM MANNOSE-BINDING LECTINS FUNCTION AS BETA-INHIBITORS OF INFLUENZA-VIRUS - IDENTIFICATION OF BOVINE SERUM BETA-INHIBITOR AS CONGLUTININ
2 DISTINCT SERUM MANNOSE-BINDING LECTINS FUNCTION AS BETA-INHIBITORS OF INFLUENZA-VIRUS - IDENTIFICATION OF BOVINE SERUM BETA-INHIBITOR AS CONGLUTININ
复制标题
DOI：
10.1128/jvi.66.7.4358-4363.1992
复制
发表时间：
1992-07-01
影响因子：
5.4
通讯作者：
ANDERS, EM
中科院分区：
文献类型：
--
作者：
HARTLEY, CA;JACKSON, DC;ANDERS, EM
正常牛和小鼠血清含有一种称为β-抑制剂的组分，其抑制H1和H3亚型甲型流感病毒的感染性和血凝活性。我们先前已经证明这些β-抑制剂是甘露糖结合凝集素，其显然通过与病毒血凝素上的碳水化合物结合而起作用，阻断受体结合位点与宿主细胞上的受体的接触（E. M.安德斯角A. Hartley和D. C.杰克逊，Proc. Natl. Acad. Sci. USA 87：4485-4489，1990）。对于H3亚型病毒A/孟菲斯/1/71 x A/Bel/42（H3 N1），对β-抑制剂的敏感性由血凝素残基165处的寡糖决定，该糖基化位点在通过在牛血清存在下生长而选择的抗性突变体中丢失。在本研究中，我们对来自流感病毒A/Philippines/2/82（H3 N2）和A/Brazil/11/78（H1N1）的其他牛血清抗性突变体的血凝素基因进行了测序。结果证实了残基165处的碳水化合物对H3病毒抑制剂敏感性的重要性，并暗示残基87处的碳水化合物（H3编号系统中的94 a）是H1亚型病毒对牛抑制剂敏感性的重要决定因素。不像两个H3突变体，这也获得了抗小鼠血清血凝抑制，H1牛血清抗性突变体仍然敏感的小鼠β-抑制剂，这表明抑制由两种类型的血清介导的不同的甘露糖结合凝集素。为了支持这一假设，牛和小鼠血清中的β-抑制剂显示出单糖的抑制模式和对2-巯基乙醇的敏感性不同。在这些和其他属性，牛抑制剂非常相似的connectin，钙依赖性N-乙酰葡糖胺和甘露糖结合凝集素存在于牛血清中，但不存在从其他物种的血清。此外，多克隆和单克隆anticonglutinin抗体废除了牛血清的血凝抑制活性。通过放射免疫测定法证实了连接蛋白与亲本病毒的直接结合和与其各自突变体的结合减少。
Normal bovine and mouse sera contain a component, termed beta-inhibitor, that inhibits the infectivity and hemagglutinating activity of influenza A viruses of the H1 and H3 subtypes. We have previously shown these beta-inhibitors to be mannose-binding lectins that apparently act by binding to carbohydrate on the viral hemagglutinin, blocking access of the receptor-binding site to receptors on host cells (E. M. Anders, C. A. Hartley, and D. C. Jackson, Proc. Natl. Acad. Sci. USA 87:4485-4489, 1990). For the H3-subtype virus A/Memphis/1/71 x A/Bel/42 (H3N1), sensitivity to beta-inhibitors is determined by the oligosaccharide at residue 165 of the hemagglutinin, this glycosylation site being lost in a resistant mutant selected by growth in the presence of bovine serum. In the present study, we sequenced the hemagglutinin genes of additional bovine serum-resistant mutants derived from influenza viruses A/Philippines/2/82 (H3N2) and A/Brazil/11/78 (H1N1). The results confirm the importance of carbohydrate at residue 165 for inhibitor sensitivity of H3 viruses and implicate carbohydrate at residue 87 (94a in the H3 numbering system) as an important determinant in the sensitivity of H1-subtype viruses to the bovine inhibitor. Unlike the two H3 mutants, which had also gained resistance to hemagglutination inhibition by mouse serum, the H1 bovine serum-resistant mutant remained sensitive to the mouse beta-inhibitor, suggesting that inhibition by the two types of sera is mediated by distinct mannose-binding lectins. In support of this hypothesis, the beta-inhibitors in bovine and mouse sera were shown to differ in their pattern of inhibition by monosaccharides and in their sensitivity to 2-mercaptoethanol. In these and other properties, the bovine inhibitor closely resembled conglutinin, a Ca2+-dependent N-acetylglucosamine- and mannose-binding lectin present in bovine serum but absent from the serum of other species. Furthermore, polyclonal and monoclonal anticonglutinin antibodies abrogated the hemagglutination-inhibiting activity of bovine serum. Direct binding of conglutinin to the parent viruses and reduced binding to their respective mutants were confirmed by radioimmunoassay.