Constitutive expression of c-jun and jun-B in cell lines infected with human T-lymphotropic virus types I and II

To better understand the transcriptional regulation of human T-lymphotropic viruses, expression of the nuclear proto-oncogenes, jun-B and c-jun were examined in cell lines infected with HTLV-I/II. Constitutive high levels of jun-B and c-jun expression were observed in HTLV-I (MT-2, Hut-102, IR, FS, SP) and HTLV-II infected cell lines (Mo-T, PAN). In contrast, the uninfected cell lines (Jurkat, Hut-78) expressed only basal levels of jun. This expression of jun was not dependent upon IL-2, as both IL-2 dependent (IR, FS, SP, and Pan) and IL-2 independent (MT-2, Hut-102, Mo-T) cell lines constitutively expressed transcripts for jun-B and c-jun. These data demonstrate that deregulated expression of nuclear protooncogenes such as jun may lead to cellular proliferation and the protein products of these nuclear oncogenes may potentially serve as transcriptional activators of HTLV-LTR by complexing with other nuclear proteins.