CELLULAR-TRANSFORMATION BY HUMAN T-CELL LEUKEMIA-VIRUS TYPE-I

Human T-cell leukemia virus type I (HTLV-I) is an oncogenic retrovirus that was isolated in 1980 from a patient with adult T-cell leukemia. From numerous experiments using infected patient T-cells, transgenic m ice and tissue culture transformation assays, the Tax protein has been determined to be the transforming component of HTLV-I. Tax-mediated t ransformation is linked to its ability to transcriptionally regulate t he expression of cellular genes involved in growth and proliferation. Ultimately, unregulated and continued activation of these important gr owth modulating genes by Tax leads to transformation.