Oleszak E L, Perlman S, Parr R, Collisson E W, Leibowitz J L
Department of Pathology and Laboratory Medicine, University of Texas Health Science Center Medical School at Houston.
Adv Exp Med Biol. 1993;342:183-8. doi: 10.1007/978-1-4615-2996-5_29.
In previous studies we have demonstrated molecular mimicry between the S peplomer protein of Mouse Hepatitis Virus (MHV) and Fc gamma Receptor (Fc gamma R) of IgG. Rabbit IgG, but not its F(ab')2 fragments, monoclonal rat and mouse IgG and the rat 2.4G2 anti-mouse Fc gamma R monoclonal antibody (mab) immunoprecipitated natural and recombinant MHV S protein. On the basis of a number of criteria, MHV S peplomer protein exhibits Fc IgG binding ability. We report here a molecular mimicry between the S peplomer protein of Bovine Coronavirus (BCV) and Fc gamma R. BCV S peplomer protein which belongs to the same antigenic subgroup as MHV also binds Fc portion of rabbit IgG and is immunoprecipitated by the 2.4G2 anti-Fc gamma R mab. In contrast, Transmissible Gastroenteritis Coronavirus (TGEV) and Infectious Bronchitis Virus (IBV) S peplomer proteins which represent two distinct antigenic subgroups of Coronaviridae do not bind rabbit IgG and do not react with anti-Fc gamma R mab. However, homologous swine IgG, but not its F(ab')2 fragments, immunoprecipitated from TGEV-infected cells a polypeptide chain with molecular mass of 195 kDa, identical to that immunoprecipitated by the T36 mab anti-TGEV S peplomer protein.
在先前的研究中，我们已经证明了小鼠肝炎病毒（MHV）的S纤突蛋白与IgG的Fcγ受体（FcγR）之间存在分子模拟。兔IgG可免疫沉淀天然和重组的MHV S蛋白，但其F(ab')2片段、大鼠和小鼠单克隆IgG以及大鼠2.4G2抗小鼠FcγR单克隆抗体（mab）则不能。基于多项标准，MHV S纤突蛋白表现出Fc IgG结合能力。我们在此报告牛冠状病毒（BCV）的S纤突蛋白与FcγR之间存在分子模拟。与MHV属于同一抗原亚组的BCV S纤突蛋白也能结合兔IgG的Fc部分，并被2.4G2抗FcγR mab免疫沉淀。相比之下，代表冠状病毒科两个不同抗原亚组的传染性胃肠炎病毒（TGEV）和传染性支气管炎病毒（IBV）的S纤突蛋白不结合兔IgG，也不与抗FcγR mab反应。然而，从感染TGEV的细胞中免疫沉淀出的同源猪IgG（而非其F(ab')2片段），沉淀出一条分子量为195 kDa的多肽链，与抗TGEV S纤突蛋白的T36 mab免疫沉淀出的多肽链相同。
