Mapping regions of herpes simplex virus type 1 glycoprotein I required for formation of the viral Fc receptor for monomeric IgG.
Mapping regions of herpes simplex virus type 1 glycoprotein I required for formation of the viral Fc receptor for monomeric IgG.
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DOI：
10.4049/jimmunol.158.1.209
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发表时间：
1997-01
影响因子：
4.4
通讯作者：
Samik Basu;G. Dubin;Thandavarayan Nagashunmugam;M. Basu;L. Goldstein;Liyang Wang;Benjamin S. Weeks;Harvey M. Friedman
中科院分区：
文献类型：
--
作者：
Samik Basu;G. Dubin;Thandavarayan Nagashunmugam;M. Basu;L. Goldstein;Liyang Wang;Benjamin S. Weeks;Harvey M. Friedman
1 型单纯疱疹病毒 (HSV-1) 的糖蛋白 E (gE) 和糖蛋白 I (gI) 形成复合物，与单体 IgG 的 Fc 结构域结合。在本研究中，我们使用两种方法来绘制单体 IgG 的 HSV-1 Fc 受体形成所需的 gI-1 区域。首先，我们构建了六个编码 gD-1/gI-1 融合蛋白的质粒。每个融合蛋白都包含插入 gD-1 胞外域的大 gI-1 肽。使用转染-感染测定将gD-1/gI-1融合蛋白与gE-1共表达，其中细胞用单独的融合蛋白构建体转染，然后用gE+/gI-病毒感染。然后使用免疫荧光显微镜检测细胞的单体 IgG 结合。用六种融合蛋白中的两种进行转染，赋予细胞单体 IgG 结合活性，而单独用 gE+/gI- 病毒感染的细胞无法结合 IgG 单体。赋予单体 IgG 结合活性的最小 gI-1 肽包含氨基酸 43 至 192。为了更精确地绘制单体 IgG 结合所需的 gI-1 区域，我们构建了一组 10 个 gI-1 连接子插入突变体。转染-感染研究鉴定出两个在 gI-1 氨基酸 128 和 145 处含有接头插入的突变体，它们无法结合单体 IgG。其他八个突变体表现出野生型 IgG 结合活性。总之，这些结果表明gI-1氨基酸128和145之间的区域是形成单体IgG的HSV-1 Fc受体所必需的。
Glycoprotein E (gE) and glycoprotein I (gI) of herpes simplex virus type 1 (HSV-1) form a complex that binds the Fc domain of monomeric IgG. In this study, we used two approaches to map the regions of gI-1 required for formation of the HSV-1 Fc receptor for monomeric IgG. First, we constructed six plasmids encoding gD-1/gI-1 fusion proteins. Each fusion protein contains a large gI-1 peptide inserted into the ectodomain of gD-1. gD-1/gI-1 fusion proteins were coexpressed with gE-1 using a transfection-infection assay in which cells were transfected with individual fusion protein constructs and then infected with a gE+/gI- virus. Cells were then assayed for monomeric IgG binding using immunofluorescence microscopy. Transfection-infection with two of six fusion proteins conferred monomeric IgG binding activity to cells, whereas cells infected with gE+/gI- virus alone failed to bind IgG monomers. The smallest gI-1 peptide to confer monomeric IgG binding activity contained amino acids 43 to 192. To more precisely map the region of gI-1 required for monomeric IgG binding, we constructed a panel of 10 gI-1 linker insertion mutants. Transfection-infection studies identified two mutants containing linker insertions at gI-1 amino acids 128 and 145, which failed to bind monomeric IgG. The other eight mutants demonstrated wild-type IgG binding activity. Taken together, these results indicate that the region of gI-1 between amino acids 128 and 145 is required for formation of the HSV-1 Fc receptor for monomeric IgG.