Comparative Nucleotide Sequence Analyses of the Entire Genomes of B95a Cell-Isolated and Vero Cell-Isolated Measles Viruses from the same Patient
Comparative Nucleotide Sequence Analyses of the Entire Genomes of B95a Cell-Isolated and Vero Cell-Isolated Measles Viruses from the same Patient
复制标题
对来自同一患者的 B95a 细胞分离和 Vero 细胞分离的麻疹病毒的整个基因组进行比较核苷酸序列分析
作者：
K. Takeuchi;N. Miyajima;F. Kobune;M. Tashiro
麻疹病毒（MV）的IC-B株（从急性麻疹患者的狨猴B淋巴母细胞B95a细胞中分离出来）对猴子进行实验性感染，引起了麻疹典型的临床症状，而从同一患者的非洲绿猴肾Vero细胞中分离出的IC-V株的感染并没有在受感染的猴子中引起任何临床症状。 IC-B 菌株仅在 B95a 细胞中复制，而 IC-V 菌株在 B95a 和 Vero 细胞中复制 (3,6)。为了阐明哪些基因或突变导致这些表型的差异，确定了 IC-B 和 IC-V 菌株的整个基因组的核苷酸序列。比较核苷酸序列分析显示仅两个核苷酸差异，一个在P/V/C基因中，另一个在M基因中，预测IC-V菌株的P、V和M蛋白中的氨基酸差异以及C蛋白中的19个氨基酸缺失。通过使用C蛋白特异性抗血清的免疫沉淀，证实了IC-V株的C蛋白的截短。包膜H基因中未发现核苷酸差异。这些结果表明，P/V/C 或/和 M 基因（而不是 H 基因）中的核苷酸差异导致了本例中 MV 的不同细胞向性和致病性。
Experimental infection of monkeys with the IC-B strain of measles virus (MV), which was isolated in marmoset B lymphoblastoid B95a cells from an acute measles patient, caused clinical signs typical for measles, while infection by the IC-V strain isolated in African green monkey kidney Vero cells from the same patient did not cause any clinical signs in infected monkeys. The IC-B strain replicated only in B95a cells, whereas the IC-V strain replicated in both B95a and Vero cells (3,6). To clarify which gene or mutation(s) was responsible for the difference in these phenotypes, the nucleotide sequences of the entire genomes of the IC-B and IC-V strains were determined. Comparative nucleotide sequence analyses revealed only two nucleotide differences, one in the P/V/C gene and the other in the M gene, predicting amino acid differences in the P, V and M proteins and a 19 amino acid deletion in the C protein of the IC-V strain. The truncation in the C protein was confirmed for the IC-V strain by immunoprecipitation using the C protein specific antiserum. No nucleotide difference was found in the envelope H gene. These results indicated that nucleotide difference(s) in the P/V/C or/and M gene, and not H gene, was responsible for the different cell tropism and pathogenicity of MV in this case.