Characterization of the interaction between the herpes simplex virus type I Fc receptor and immunoglobulin G
Characterization of the interaction between the herpes simplex virus type I Fc receptor and immunoglobulin G
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DOI：
10.1074/jbc.274.11.6911
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发表时间：
1999-03-12
影响因子：
4.8
通讯作者：
Raghavan, M
中科院分区：
文献类型：
--
作者：
Chapman, TL;You, I;Raghavan, M
单纯疱疹病毒I型(HSV-1)病毒粒子和HSV-1感染细胞通过其Fc区与人免疫球蛋白G(HIgG)结合。HSV-1编码的两个表面糖蛋白Ge和Gi的复合体负责Fc的结合。我们在中国仓鼠卵巢细胞中共表达了可溶性截短型Ge和Gf。利用基于Ge-Gi Fc受体功能的纯化方案，可以从转基因细胞上清液中提纯可溶的Ge-Gi复合体。通过凝胶过滤和分析超速离心法，我们确定了可溶性Ge-GI是由一个Ge分子和一个Gi分子组成的杂二聚体，Ge-GI杂二聚体以1：1的化学计量比与HIGG结合。基于生物传感器的野生型或突变型免疫球蛋白与可溶性Ge-GI结合的研究表明，Ig G C(H)2-C(H)3结构域界面上的组氨酸435是Ig G与Ge-GI结合的关键残基。我们观察到Ge-Gi与类风湿因子和细菌Fc受体如金黄色葡萄球菌蛋白A结合的特征有许多相似之处。这些观察结果支持一些类风湿因子的起源模型，其中它们代表针对细菌和病毒Fc受体抗体的抗独特型抗体。
Herpes simplex virus type I (HSV-1) virions and HSV-1-infected cells bind to human immunoglobulin G (hIgG) via its Fc region. A complex of two surface glycoproteins encoded by HSV-1, gE and gI, is responsible for Fc binding. We have co-expressed soluble truncated forms of gE and gf in Chinese hamster ovary cells. Soluble gE-gI complexes can be purified from transfected cell supernatants using a purification scheme that is based upon the Fc receptor function of gE-gI. Using gel filtration and analytical ultracentrifugation, we determined that soluble gE-gI is a heterodimer composed of one molecule of gE and one molecule of gI and that gE-gI heterodimers bind hIgG with a 1:1 stoichiometry. Biosensor-based studies of the binding of wild type or mutant IgG proteins to soluble gE-gI indicate that histidine 435 at the C(H)2-C(H)3 domain interface of IgG is a critical residue for IgG binding to gE-gI, We observe many similarities between the characteristics of IgG binding by gE-gI and by rheumatoid factors and bacterial Fc receptors such as Staphylococcus aureus protein A. These observations support a model for the origin of some rheumatoid factors, in which they represent anti-idiotypic antibodies directed against antibodies to bacterial and viral Fc receptors.