二種の血清型特異性,すなわち血清型4のVP3と血清型3のVP7を有する組換え体ヒトロタウイルスの作製

The reassortment of viral genome segments has been reported to occur during coinfection of cultured cells with two different rotaviruses. Further, epidemiologic findings suggesting that genetic reassortment of viral RNAs may account for an antigenic shift in rotavirus in nature have also been accumulated. In the present study a reassortant virus, C148, was selected from fifty-one progeny virus clones obtained under an antibody pressure from a mixed infection of MA104 cells with human rotavirus serotype 3 (YO) and serotype 4 (Hochi) strains. Antigenic characterization and genotype analysis by polyacrylamide gel electrophoresis concluded that C148 virus possessed a mosaic antigenicity defined by two serotype-specific viral proteins (VP), i. e. the serotype 4-specific VP3 and the serotype 3-specific VP7. While the reassortant C148 was judged to belong to serotype 3 on the basis of its preferential neutralizability by serotype 3 antiserum, the antiserum prepared against C148 equally neutralized both serotype 3 and 4 viruses. These results seem to further support the possible emergence of a genetic reassortant in nature between human rotaviruses beloneinu to different serotypes

Molecular and antigenic analyses of serotypes 8 and 10 of bovine rotaviruses in

Antigenic and genomic properties of non-serotype 6 bovine rotaviruses isolated in Thailand and Japan were studied by cross-neutralization tests, nucleotide sequence determination of the VP7 gene, and RNA-RNA hybridization. Two Thai strains (61A and A44) were serologically related to a Japanese isolate KK3 which has been assigned to serotype 10. In contrast, strain A5 was found to be antigenically similar to human strain 69M with serotype 8 specificity, although strain A5 showed a one-way cross-reaction with serotype 6 strain NCDV. VP7 sequence analysis confirmed these results. High degrees of similarity in nucleotide and amino acid sequences (92-5 to 98.2% and 96.3 to 97.9%, respectively) were found among the VP7 genes of the four serotype 10 bovine strains (61A, A44, KK3 and B223). The VP7 amino acid sequence of strain A5 was similar to those of serotype 8 human strains (91-7 % and 94-8 % for strains B37 and 69M, respectively). In RNA-RNA hybridization experiments, a high level of overall relatedness was found among the three serotype 10 bovine strains (61 A, A44 and KK3), and strains A5 and NCDV were also moderately related to the three serotype 10 viruses. All the bovine rotaviruses tested in this study, regardless of their serotype specificity, exhibited a moderate geneticrelatedness to strain 69M of serotype 8, and, to a lesser extent, to serotype 2 human rotavirus strains