MHV-S PEPLOMER PROTEIN EXPRESSED BY A RECOMBINANT VACCINIA VIRUS VECTOR EXHIBITS IGG FC-RECEPTOR ACTIVITY
MHV-S PEPLOMER PROTEIN EXPRESSED BY A RECOMBINANT VACCINIA VIRUS VECTOR EXHIBITS IGG FC-RECEPTOR ACTIVITY
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DOI：
10.1016/0042-6822(92)90066-x
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发表时间：
1992-01-01
期刊：
影响因子：
3.7
通讯作者：
LEIBOWITZ, JL
中科院分区：
文献类型：
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作者：
OLESZAK, EL;PERLMAN, S;LEIBOWITZ, JL
我们以前已经表明，感染小鼠肝炎病毒（MHV）的细胞通过IgG分子的Fc部分与兔、小鼠和大鼠IgG结合。这种Fc结合活性似乎由MHV S蛋白介导。抗鼠Fc γ受体（FcγR）的单克隆抗体也能从MHV感染的细胞中沉淀出S蛋白。为了明确证明S蛋白介导Fc结合活性，我们利用重组牛痘病毒表达了MHV S蛋白。抗Fc γR单克隆抗体2.4G2可沉淀鼠、人和兔来源细胞中的重组S蛋白。由于抗Fc受体单克隆抗体不与人和兔Fc受体反应，因此这些结果表明该抗体识别的表位携带在MHV S蛋白上，并且不是鼠源性的。对各种MHV分离株和逃逸突变体的检查未能确定S中负责鼠FcγR分子模拟的精确序列。这些数据与先前确定的S蛋白和FcγR之间的相似区域介导该活性的假设一致。S的Fc结合活性在细胞表面上表达，因为MHV-JHM感染的细胞，而不是未感染的细胞，与抗绵羊红细胞（SRBC）抗体包被的SRBC形成结合。抗Fc γR单克隆抗体可中和MHV JHM，抑制MHV S蛋白诱导的合胞体形成。
We have previously shown that cells infected with mouse hepatitis virus (MHV) bind rabbit, mouse, and rat IgG by the Fc portion of the IgG molecule. This Fc-binding activity appeared to be mediated by the MHV S protein. S protein could also be precipitated from MHV-infected cells by a monoclonal antibody directed against the murine Fc γ receptor (FcγR). To prove definitively that the S protein mediates Fc-binding activity, we have expressed the MHV S protein utilizing recombinant vaccinia viruses. The anti-FcγR monoclonal antibody, 2.4G2, precipitated recombinant S protein in cells of murine, human, and rabbit origin. Since the anti-Fc receptor monoclonal antibody does not react with human and rabbit Fc receptors these results demonstrate that the epitope recognized by this antibody is carried on the MHV S protein and is not murine in origin. Examination of various MHV isolates and escape mutants failed to identify the precise sequences in S responsible for the molecular mimicry of the murine FcγR. These data are consistent with the hypothesis that a previously identified region of similarity between the S protein and the FcγR mediates this activity. The Fc binding activity of S was expressed on the cell surface, since MHV-JHM-infected cells, but not uninfected cells, formed rosettes with anti-sheep red blood cell (SRBC) antibody-coated SRBC. The anti-FcγR monoclonal antibody neutralized MHV-JHM and inhibited syncytium formation induced by the MHV S protein.