Isolation via transfection of feline leukemia viruses from DNA of naturally occurring feline lymphomas

Feline leukemia viruses isolated via transfection from the DNAs of naturally occurring feline lymphoma tissue were compared with viruses representing the three subgroups of FeLV by host range, subgroup, and RNA fingerprinting analyses. A novel host range was observed for two subgroup A viruses obtained from independent tumors. Two distinct viruses with different host ranges, subgroup specificities, and fingerprint patterns were isolated from a third tumor. Although the tumor tissues used in this study were from unrelated cats, the RNA fingerprints of the four transfected viruses demonstrated striking similarities to one another. Approximately 88% of the RNase T1 resistant oligonucleotides present in any one isolate are also present in the other three viruses. The transfected viruses share approximately 67% of the RNase T1 resistant oligonucleotides found in FeLV subgroups B or C. However, approximately 80% of the RNase T1 resistant oligonucleotides of the new virus isolates are found in common with FeLV A/Glasgow 1.