Differential host range of viruses of feline leukemia-sarcoma complex

Abstract

Selected strains of feline leukemia and sarcoma viruses of subgroups A, B, and C show a differential pattern in their ability to cross species barrier and productively infect cells of heterologous host species. A virus of subgroup B showed the widest host range; it caused productive infection of cells of diverse host species including cells from cat, human, monkey, dog, bovine, pig, and hamster species. Two virus strains of subgroup A showed the narrowest host range; of the cells of several mammalian species examined, they only caused productive infection of cat and dog cells. Preliminary studies indicated that certain other strains of subgroup A viruses cause productive infection of whole human embryo cells. One strain of subgroup C virus examined showed a host range that was intermediate between that of A and B subgroup viruses. This strain caused productive infection of cat, dog, and certain human cells. In addition, the subgroup C virus caused productive infection of guinea pig cells found to be resistant to subgroup A as well as subgroup B virus strains examined. Preliminary studies suggested that certain, but not all, virus mixtures of A and B viruses can be purified into B type by passage of virus in heterologous human cells. The factor(s) that may govern the differential susceptibilities of heterologous host cells to the described strains of feline viruses are discussed.