HTLV

:  any of several retroviruses that formerly included the original strain of the AIDS virus before it was grouped with other strains, renamed HIV-1, and made the type species (Human immunodeficiency virus 1) of the genus Lentivirus—often used with a number or Roman numeral to indicate the type and order of discovery HTLV-III; called also human T-cell leukemia virus, human T-cell lymphotropic virus, human T-lymphotropic virus