Iwatsuki K, Miyashita N, Yoshida E, Gemma T, Shin Y S, Mori T, Hirayama N, Kai C, Mikami T
Department of Veterinary Microbiology, Faculty of Agriculture, The University of Tokyo, Bunkyo-ku, Japan.
J Gen Virol. 1997 Feb;78 ( Pt 2):373-80. doi: 10.1099/0022-1317-78-2-373.
We isolated three strains of canine distemper virus (CDV)--the Ueno, Hamamatsu, and Yanaka strains--from dogs in Japan and analysed the molecular properties of their haemagglutinin (H) proteins. Immunoprecipitation of all three strains with a monoclonal antibody revealed H proteins with molecular masses of 84 kDa, which differs from the molecular mass (78 kDa) of the H protein of the Onderstepoort vaccine strain. However, after tunicamycin treatment immunoprecipitation identified H proteins of identical molecular mass (68 kDa) for all three field isolates and the vaccine strain. Sequence analysis showed nine potential sites for asparagine-linked glycosylation in the H proteins of the new isolates, in contrast to four in the H protein of the Onderstepoort strain. Thus, variation in glycosylation of the H proteins of the isolates and the vaccine strain may cause differences in antigenicity of the viruses. Sequences of the H genes showed that the new Japanese isolates have 99% identity with each other, 95% with other European and American isolates (from seals, a German dog, a ferret and large felids) and 90% with the vaccine strain. Phylogenetically, the new Japanese isolates form one cluster which is separate from recent European or American isolates, all of which are distinct from vaccine strains.
我们从日本的犬只中分离出三株犬瘟热病毒（CDV）——上野株、滨松株和柳町株，并分析了它们血凝素（H）蛋白的分子特性。用单克隆抗体对所有三株病毒进行免疫沉淀，结果显示H蛋白的分子量为84 kDa，这与 Onderstepoort 疫苗株H蛋白的分子量（78 kDa）不同。然而，在衣霉素处理后，免疫沉淀鉴定出所有三株野外分离株和疫苗株的H蛋白分子量相同（68 kDa）。序列分析表明，新分离株的H蛋白中有9个潜在的天冬酰胺连接糖基化位点，相比之下，Onderstepoort 株的H蛋白中有4个。因此，分离株和疫苗株H蛋白糖基化的差异可能导致病毒抗原性的不同。H基因序列显示，新的日本分离株彼此之间有99%的同源性，与其他欧美分离株（来自海豹、一只德国犬、一只雪貂和大型猫科动物）有95%的同源性，与疫苗株有90%的同源性。在系统发育上，新的日本分离株形成一个簇，与最近的欧美分离株分开，所有这些分离株都与疫苗株不同。
