HUMAN T-LYMPHOCYTE TRANSFORMATION WITH HUMAN T-CELL LYMPHOTROPIC VIRUS TYPE-2

Human T-cell lymphotrophic virus type 2 (HTLV-2), a common infection o f intravenous drug users and subpopulations of Native Americans, is un common in the general population. In contrast,vith the closely related HTLV-1, which is associated with both leukemia and neurologic disorde rs, HTLV-2 lacks a strong etiologic association with disease. HTLV-2 d oes shares many properties with HTLV-1, including in vitro lymphocyte transformation capability. To better assess the ability of HTLV-2 to t ransform lymphocytes, a limiting dilution assay was used to generate c lonal, transformed lymphocyte lines. As with HTLV-1, the transformatio n efficiency of HTLV-2 producer cells was proportionately related to t he number of lethally irradiated input cells and was comparable to HTL V-1-mediated transformation efficiency. HTLV-2-infected cells were rep roducibly isolated and had markedly increased growth potential compare d to uninfected cells; HTLV-2 transformants required the continued pre sence of exogenous interleukin 2 for growth for several months and wer e maintained for over 2 years in culture. All HTLV-2-transformed popul ations were CD2 and/or CD3 positive and B1 negative and were either CD 4(+) or CD8(+) populations or a mixture of CD4(+) and CD8(+) lymphocyt es. Clonality of the HTLV-2 transformants was confirmed by Southern bl ot analysis of T-cell receptor beta chain rearrangement. Southern blot analysis revealed a range of integrated full-length genomes from one to multiple. In situ hybridization analysis of HTLV-2 integration reve aled no obvious chromosomal integration pattern.