Effects of BK Virus Infection on Primary Cultures of Rodent and Primate Cells (40220)

The effect of BK virus at high multiplicity was studied on cultures of hamster, rat, monkey, and human cells. BK virus induced multiple transforming events in cells of both rodent species. Rhesus monkey choroid plexus cells were insusceptible to the virus. Epithelial and fibroblastic human cell strains developed lytic infection. Fifteen to 20% of the fibroblastic cells (skin and muscle) contained T antigen at later passage levels when no evidence of productive infection could be detected; these cells did not, however, meet other criteria for transformation. Transformed rodent cells exhibited T antigen in 90-100% of cells. BK viral particles could be rescued from only one line of transformed rat cells. BK virus-transformed rat cells could not be transplanted, and the transformed hamster cells were poorly oncogenic for newborn and adult hamsters unless cheek pouch inoculation or immunosuppression was used, suggesting that the poor oncogenicity reported for BK virus in vivo may reflect immune recognition and rejection of transformed cells by the host.