Document 0457 DOCN M9590457 TI Sensitization of T cells to CD95-mediated apoptosis by HIV-1 Tat and gp120. DT 9509 AU Westendorp MO; Frank R; Ochsenbauer C; Stricker K; Dhein J; Walczak H; Debatin KM; Krammer PH; Tumorimmunology Program, German Cancer Research Centre,; Heidelberg. SO Nature. 1995 Jun 8;375(6531):497-500. Unique Identifier : AIDSLINE MED/95295832 AB The depletion of CD4+ T cells in AIDS is correlated with high turnover of the human immunodeficiency virus HIV-1 and associated with apoptosis. The molecular mechanism of apoptosis in HIV infection, however, is largely unknown. T-cell apoptosis might be affected by viral proteins such as HIV-1 Tat and gp120 (refs 10, 11). T-cell-receptor (TCR)-induced apoptosis was recently shown to involve the CD95 (APO-1/Fas) receptor. We show here that HIV-1 Tat strongly sensitizes TCR- and CD4(gp120)-induced apoptosis by upregulation of CD95 ligand expression. Concentrations of Tat found to be effective in cultures of HIV-1-infected cells were also observed in sera from HIV-1-infected individuals. Taken together, our results indicate that HIV-1 Tat and gp120 accelerate CD95-mediated, activation-induced T-cell apoptosis, a mechanism that may contribute to CD4+ T-cell depletion in AIDS. DE Antigens, CD3/IMMUNOLOGY Antigens, Surface/*IMMUNOLOGY *Apoptosis Cell Line Cross-Linking Reagents CD4-Positive T-Lymphocytes/IMMUNOLOGY CD8-Positive T-Lymphocytes/IMMUNOLOGY Gene Products, tat/BLOOD/*IMMUNOLOGY Human HIV Envelope Protein gp120/*IMMUNOLOGY HIV Infections/IMMUNOLOGY/PATHOLOGY Lymphocyte Transformation Membrane Glycoproteins/GENETICS/METABOLISM Receptors, Antigen, T-Cell/IMMUNOLOGY Support, Non-U.S. Gov't T-Lymphocytes/*IMMUNOLOGY Tumor Cells, Cultured JOURNAL ARTICLE SOURCE: National Library of Medicine. NOTICE: This material may be protected by Copyright Law (Title 17, U.S.Code).