Human retrovirus 5 (HRV-5) represented a fragment of a novel retrovirus sequence identified in human RNA and DNA preparations. In this study, the genome of HRV-5 was cloned and sequenced and integration sites were analyzed. Using PCR and Southern hybridization, we showed that HRV-5 is not integrated into human DNA. A survey of other species revealed that HRV-5 is present in the genomic DNA of t...

We previously delineated a highly conserved immunosuppressive (IS) domain within murine and primate retroviral envelope proteins (Envs). The envelope-mediated immunosuppression was manifested by the ability of the proteins, when expressed by allogeneic tumor cells normally rejected by engrafted mice, to allow these cells to escape, at least transiently, immune rejection. Using this approach, we...

Bromodeoxyuridine-grown B16 melanoma cells (C3471) immunize mice against not only the parent melanoma but also two other C57BL/6 tumors: a mammary adenocarcinoma and a methylcholanthrene-induced sarcoma. We have shown that the endogenous retrovirus induced in C3471 cells by bromodeoxyuridine can persistently infect feral mouse (SC1) cells and that they then become as efficient as C3471 cells in...

To test the gliomagenic potential of adult glial progenitors, we infected adult rat white matter with a retrovirus that expresses high levels of PDGF and green fluorescent protein (GFP). Tumors that closely resembled human glioblastomas formed in 100% of the animals by 14 d postinfection. Surprisingly, the tumors were composed of a heterogeneous population of cells, <20% of which expressed the ...

Recent research implicates viral infection as a factor that may contribute to the risk of prostate cancer. Allelic variation at the RNASEL locus is associated with the risk of infection by a newly discovered retrovirus called XMRV, and with hereditary risk of prostate cancer. This evidence suggests that the RNASEL locus has undergone antagonistic coevolution with the retrovirus over evolutionar...

Cancer is primarily a somatic genetic disease resulting from the accumulation of several precancerous mutations in a cell lineage. The evolution of highly oncogenic retroviruses has been used as a model for the evolution of a cancer cell. The properties of intermediates between one set of replication-competent retrovirus and protooncogene progenitors and the homologous highly oncogenic retrovir...

To test the gliomagenic potential of adult glial progenitors, we infected adult rat white matter with a retrovirus that expresses high levels of PDGF and green fluorescent protein (GFP). Tumors that closely resembled human glioblastomas formed in 100% of the animals by 14 d postinfection. Surprisingly, the tumors were composed of a heterogeneous population of cells, 20% of which expressed the r...