Regulated expression of the v-rel oncogene in vitro and in vivo

The avian reticuloendothelial virus strain T (REV-T) is among the most overtly transforming of all known retroviruses, and has been shown to transform a wide range of lymphocytes. The transforming ability of REV-T is attributed the v-rel oncogene, a member of the Rel/NFkappaB family of transcription factors. Although it is believed that v- rel mediated transformation involves the disregulation of normal NF-kappaB function, the intracellular requirements for transformation are still unknown.We have used the RCAS vectors (R&barbelow;eplication C&barbelow;ompetent A&barbelow;vian Leukosis LTR with S&barbelow;plice Acceptor) for infection and dissemination of viral particles in chicken cells, permitting somatic transgenesis of the v-rel oncogene in vivo. In addition, the RCAS system has been combined with a tetracycline regulated gene expression system, in order to allow for conditional expression of the v- rel oncogene in transgenic birds.Using this novel system, we have been able to study in situ transformation by the v-rel oncogene. By addressing the questions pertaining to the cells targeted for transformation by v-rel, we hoped to gain a better understanding of the mechanism for v-rel mediated transformation. Preliminary data suggests that B cells were targeted for transformation by v-rel in the transgenic birds. Phenotypic analysis revealed that transformed cells were not representative of all stages of B cell development, but rather had a mature B cell phenotype