Study on Human Rotavirus Antigen by Use of Genetic Reassortants

用血清2型或血清1型特异性抗血清作为选择压力，从MA104细胞与人轮状病毒株Wa（血清1亚群II）和HN126（血清2亚群I）混合感染获得的病毒克隆中筛选出两种重组病毒。血清型特异性抗血清中和试验和亚群特异性单克隆抗体酶联免疫吸附试验显示，它们是临床标本中尚未遇到的具有独特抗原组成的重组菌株，即血清型1亚群I （C116株）和血清型2亚群II （C15株）。对病毒RNA进行聚丙烯酰胺凝胶电泳分析发现，C116中编码主要亚群蛋白VP6的RNA片段6来源于HN126亲本，而编码次要和主要血清型特异性中和蛋白VP3和VP7的RNA片段4和9分别来源于Wa亲本。相比之下，重组物C15含有来自Wa亲本的第6片段（编码亚群蛋白VP6）。对于编码中和蛋白的rna， C15在接收来自Wa亲本的编码VP3的第4片段的同时，含有来自HN126亲本的编码VP7的基因组片段（片段8或片段9）。尽管该血清型花叶病毒在与血清2型抗血清中和反应时表现出优先反应性（可能是因为主要的中和蛋白VP7来自HN126），但令人惊讶的是，C15的抗血清同时中和了血清1型和血清2型病毒。这一结果表明，基因重组株作为轮状病毒疫苗生产的有希望的候选株具有很大的效用。

Two reassortant viruses were selected from viral clones obtained by a mixed infection of MA104 cells with human rotavirus strains Wa (serotype 1-subgroup II) and HN126 (serotype 2-subgroup I),using either serotype 2 or serotype 1-specific antisera as selective pressure. Neutralization test with serotype-specific antisera and enzyme-linked immunosorbent assay with subgroup-specific monoclonal antibodies revealed that they were reassortant strains having unique antigenic compositions not yet encountered in clinical specimens, i.e. serotype 1-subgroup I (C116 strain) and serotype 2-subgroup II (C15 strain).Analysis by polyacrylamide gel electrophoresis of viral RNA concluded that while RNA segment 6 of C116 coding for the major subgrouping protein VP6 was derived from HN126 parent, its segments 4 and 9 coding for the minor and major serotype-specific neutralizing proteins VP3 and VP7, respectively were derived from Wa parent. In contrast, the reassortant C15 was found to contain segment 6 (encoding subgrouping protein VP6) originated from Wa parent. Regarding RNAs encoding neutralizing proteins, C15, while receiving segment 4 coding for VP3 from Wa parent, contained the genome segment coding for VP7 (either segment 8 or 9) from HN126 parent. Although this serotypic mosaic strain in terms of its genomic constitution was shown to be a serotype 2 virus on the basis of its preferential reactivity in neutralization reaction with serotype 2 antiserum (possibly because of the major neutralizing protein VP7 of HN126 origin), surprisingly the antiserum against C15 equally neutralized both serotype 1 and serotype 2 strains. This result indicates the great utility of genetically reassorted strains as promissing candidates for rotavirus vaccine production.