Differences in the capacity of reovirus strains to induce apoptosis are determined by the viral attachment protein sigma 1
Journal of Virology
Reoviruses are important models for studies of viral pathogenesis; however, the mechanisms by which these viruses produce cytopathic effects in infected cells have not been defined. In this report, we show that murine L929 (L) cells infected with prototype reovirus strains type 1 Lang (T1L) and type 3 Dearing (T3D) undergo apoptosis and that T3D induces apoptosis to a substantially greater extent than T1L. Using T1L ؋ T3D reassortant viruses, we found that differences in the capacity of T1L and
... capacity of T1L and T3D to induce apoptosis are determined by the viral S1 gene segment, which encodes the viral attachment protein 1 and the non-virionassociated protein 1s. Apoptosis was induced by UV-inactivated, replication-incompetent reovirus virions, which do not contain 1s and do not mediate its synthesis in infected cells. Additionally, T3D-induced apoptosis was inhibited by anti-reovirus monoclonal antibodies that inhibit T3D cell attachment and disassembly. These results indicate that 1, rather than 1s, is required for induction of apoptosis by the reovirus and suggest that interaction of virions with cell surface receptors is an essential step in this mechanism of cell killing.