HIV-1 tat induced apoptosis of T-cells is not mediated by TGF-beta.
Recent reports have demonstrated that the HIV-1 transactivator protein, tat, induces apoptosis in T-lymphocyte cell lines, as well as in peripheral blood mononuclear cells, and stimulates a cascade of events resulting in up-regulation of the potent immunosuppressive cytokine, transforming growth factor-beta (TGF-beta). In this study we evaluated the ability of TGF-beta to mediate tat induced apoptosis in T-lymphocyte cell lines. T-cells treated exogenously with either TGF-beta1 or a combination of tat and pan-specific TGF-beta neutralizing antibodies showed little change in the amount of apoptosis. When treated with pan-specific TGF-beta neutralizing antibodies, Jurkat cells that stably express tat protein (Jurkat-tat ) showed only a modest decrease in apoptosis, while CEM-TART cells (CEM T-cells expressing both HIV-1 tat and rev ) demonstrated little change in the amount of apoptosis. In conclusion, we have demonstrated that TGF-beta does not play a significant role in mediating tat induced T-cell apoptosis.
Salzman
S A
SA
Marshfield Medical Research and Education Foundation, Marshfield, WI 54449, USA.
Burmester
J K
JK
D017209:Apoptosis; D015696:Gene Products, tat / Q000494:pharmacology*; D015497:HIV-1 / Q000737:chemistry; D006801:Humans; D015458:Leukemia, T-Cell / Q000473:pathology; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D016212:Transforming Growth Factor beta / Q000276:immunology / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D054322:tat Gene Products, Human Immunodeficiency Virus
D015696:Gene Products, tat; D016212:Transforming Growth Factor beta; D054322:tat Gene Products, Human Immunodeficiency Virus