Characterization of a retravirus isolated from squirrel monkeys

Abstract

A new retravirus (SMRV) isolated from a squirrel monkey, Saimiri sciureus, has an Mg2+-dependent reverse transcriptase and a buoyant density of 1.17 g/cm3 in sucrose and 1.21 g/cm3 in CsCl, similar to the mouse mammary tumor virus and the Mason-Pfizer monkey virus. The polypeptide pattern of SMRV as determined by sodium dodecyl sulfate-polyacrylamide gel elctrophoresis was distinct from the reported polypeptide patterns of known retraviruses. Four major polypeptides of MW 40,000, 20,000, 14,000 and 8000 were resolved in virus propagated in human, mink [fetal lung Mv1Lu] and canine [fetal thymus FCf2th] cells. In A204 human rhabdomyosarcoma cells, a protein of 73,000 daltons (gp 73) represented the major viral glycoprotein as determined by [3H]glucosamine labeling. Additional proteins were also observed, but their presence depended on the cell type in which the virus was propagated. In both species- and interspecies-specific assays, no antigenic relatedness was observed between SMRV and Mason-Pfizer monkey virus, mouse mammary tumor virus, baboon endogenous virus (BaLV), woolly monkey virus (SSV-1), murine leukemia virus, endogenous feline type C virus (RD-114), bovine leukemia virus and equine infectious anemia virus. These findings indicate that SMRV represents a new retravirus and the 1st isolate from a New World monkey.