Equine connective tissue tumors contain unintegrated bovine papilloma virus DNA

Studies on connective tissue tumors in the hamster produced by bovine papilloma virus.

Bovine papilloma virus was injected s.c. and intracerebrally in newborn and weanling hamsters. Connective tissue tumors (fibromas, chondromas, and meningiomas) were produced in the subcutaneous regions of the back, pinna of the ear, and the meninges. The tumors did not contain evidence of viral infection when examined by histologie, immunofluorescent, and electron microscopic means. The tumors ...

Unintegrated viral DNA sequences in a hamster tumor induced by bovine papilloma virus.

A fibrosarcoma was induced in a hamster by bovine papilloma virus type 2 (BPV2). The content of BPV2 DNA sequences was measured by DNA-DNA and cRNA-DNA hybridizations. The tumor contained approximately 300 BPV2 genome equivalents per cell. Southern blot hybridization indicated that the viral DNA was in free form, the entire genome most likely being present. In situ hybridization with BPV2 cRNA ...

Bovine papilloma virus-transformed cells contain multiple E2 proteins.

Genetic evidence suggests that the bovine papilloma virus type 1 (BPV) E2 open reading frame may encode at least two gene products involved in the regulation of viral gene expression. One, which is probably the full-length product, trans-activates transcription via an enhancer in the viral regulatory region. A second, containing sequences from the 3' end of the open reading frame, inhibits the ...

Papilloma-like virus from bovine urinary bladder tumors.

Bovine Leukemia Virus DNA in Human Breast Tissue

Bovine leukemia virus (BLV), a deltaretrovirus, causes B-cell leukemia/lymphoma in cattle and is prevalent in herds globally. A previous finding of antibodies against BLV in humans led us to examine the possibility of human infection with BLV. We focused on breast tissue because, in cattle, BLV DNA and protein have been found to be more abundant in mammary epithelium than in lymphocytes. In hum...