Study on Human Cytomegalovirus Proteins - specifically on 65 kDa protein -

65 kDa的巨细胞病毒蛋白被认为是位于衣壳和外膜之间的一个模糊的区域--病毒粒子被层。对65 kDa蛋白的抗原性分析进行了两年的研究，结果如下。用抗65 kDa蛋白的单特异性抗体和单抗进行免疫荧光试验，以监测该蛋白在感染细胞中的表达。结果：1.无论单抗的反应性有何差异，所有染色的胞浆内包涵体均定位于HCMV诱导的免疫球蛋白Fc部分受体的部位，提示与HCMV共定位的65 kDa抗体可诱导FCR，且具有多种不同的抗原决定簇。结果表明，130、65、50和36 kDa的FCR蛋白参与了Ig G的结合。阻断实验证实了65 kDa抗体与Ig G Fc结合的特异性。我们研究了HCMV诱导的IgGFCR与65 kDa蛋白上的B_2微球蛋白受体的关系。用SV-8水解酶对65 kDa蛋白进行酶切，得到6个多肽。用65 kDa的单抗和单特异性抗体定位消化后的多肽上的抗原决定簇。存在Ig G FCR的kDa为33、32和28的多肽也能与B_2m结合，提示B_2m与Ig G Fc具有相同的结合部位。

The 65 kDa HCMV protein has been considered a constitute of the virion tegument, a poorly defined area located between the capsid and the outer membrane.The study toward analysis of antigenicity of the 65 kDa protein during 2 years has revealed the results as follows.1. Immunofluorescence assay using monospecific and monoclonal antibodies to the 65 kDa protein was carried out to monitor the expression of this protein in infected cells. Regardless of differences in the reactivity of the monoclonal antibodies, all stained cytoplasmic inclusion bodies localized to the site of the HCMV induced receptor for the Fc portion of IgG, suggesting that of the 65 kDa colocalized with HCMV induced FcR and had several different antigenic determinants.2. FcR species of 130, 65, 50 and 36 kDa proteins were found to mediate the binding of IgG. The specificity of binding with of the 65 kDa with IgG Fc were confirmed by the blocking experiments.3. We investigated the relationship between IgG FcR induced by HCMV and B_2 microglobulin receptor on the 65 kDa protein. Digestion of the 65 kDa protein with SV-8 protease generated six peptides. Monoclonal and monospecific antibodies to the 65 kDa were used to map the antigenic determinants on the digested peptides. Peptides with kDa of 33, 32 and 28 on which IgG FcR existed could also be bound by B_2m suggesting that B_2m shares the same binding sites with IgG Fc.