Genomic expressions of human T-lymphotropic virus (HTLV-I).

Human T-lymphocyte cell line termed MT-2 is producing persistently HTLV-I virion and has a strong potential to transform human T-lymphocytes when cocultivated. The virion of HTLV-I (MT-2) was isolated and its RNA was extracted to analyze the gene and gene products of HTLV-I. HTLV (MT-2) virion RNA was translated in a rabbit reticulocyte lysate system in vitro in which a gag precursor polyprotein (p53) and a putative gag-prt fusion protein (p76) were synthesized from a full length 35S RNA. The full length provirus, HTLV-I (MT-2), was molecularly cloned and its genomic expression was examined transiently and permanently by transfecting in human lymphoid and non-lymphoid cells. The cloned provirus expressed the same virological activities as observed in naturally occurring infection of the virus. A new protease gene of HTLV-I was found and its function of the gene product was studied.