THE REOVIRUS M1 GENE DETERMINES THE RELATIVE CAPACITY OF GROWTH OF REOVIRUS IN CULTURED BOVINE AORTIC ENDOTHELIAL-CELLS

Since blood-borne viruses often interact with endothelial cells before tissue invasion, the interaction between viruses and endothelial cell s is likely to be important in viral pathogenicity. Two reovirus isola tes (type 1 Lang and type 3 Dearing) differ in their capacity to grow in cultured bovine aortic endothelial cells. The mammalian reoviruses have 10 double-stranded RNA gene segments in their genome. By using 24 reassortant viruses, observed differences in the capacity of differen t strains to grow in cultured endothelial cells were mapped to the Ml gene (P = 0.00019), which encodes the viral core protein mu2. No diffe rences were detected in binding or proteolytic processing of viral out er capsid proteins of parental virions between the two reovirus isolat es. Northern blot analysis showed a decreased production of viral mRNA in endothelial cells infected with type 3 Dearing reovirus, but not t ype 1 Lang. Thus, we have identified a viral gene (the M1 gene) respon sible for determining the difference in growth capacity of the two reo virus isolates in cultured endothelial cells. Reovirus is an attractiv e model in which to study the interaction of viruses with endothelial cells at a molecular genetic level.