Reverse Genetics System for a Human Group A Rotavirus.

Group A rotavirus (RV) is a major cause of acute gastroenteritis in infants and young children worldwide. Recently, we established an entirely plasmid-based reverse genetics system for simian RV strain SA11. Although that system was robust enough to generate reassortant RVs, including human RV gene segments, and enabled better understanding of the biological differences between animal and human RV strains, a complete reverse genetics system for human RV strains is desirable. Here, we established a plasmid-based reverse genetics system for G4P[8] human RV strain Odelia. This technology was used to generate a panel of monoreassortant viruses between human and simian RV strains for all of the 11 gene segments demonstrating full compatibility between human and simian RV strains. Furthermore, we generated recombinant viruses lacking the C-terminal region of the viral nonstructural protein NSP1 and used it to define the biological function of the interaction between NSP1 and its target protein β-transducin repeat-containing protein (β-TrCP) during viral replication. While the NSP1 truncation mutant lacking the C-terminal 13 amino acids displayed lower β-TrCP degradation activity, it replicated as efficiently as the wild-type virus. In contrast, the truncation mutant lacking the C-terminal 166 amino acids of NSP1 replicated poorly, suggesting that the C-terminal region of NSP1 plays critical roles in viral replication. The system reported here will allow generation of engineered recombinant virus harboring desired mutations, increase our understanding of the molecular biology of human RV, and facilitate development of novel therapeutics and vaccines.IMPORTANCE Reverse genetics, an approach used to generate viruses from cloned cDNA, has increased our understanding of virus biology. Worldwide research led to the development of an entirely plasmid-based reverse genetics system for the simian RV laboratory strain. Although the technique allows generation of gene-modified recombinant RVs, biological differences between animal and human RVs mean that reverse genetics systems for human RV strains are still needed. Here, we describe a reverse genetics system for the high-yield human RV strain Odelia, which replicates efficiently and is suitable for in vitro molecular studies. Monoreassortant viruses between simian and human RV strains and NSP1 mutant viruses generated by the rescue system enabled study of the biological functions of viral gene segments. This human RV reverse genetics system will facilitate study of RV biology and development of vaccines and vectors.