Synergistic induction of apoptosis in primary CD4(+) T cells by macrophage-tropic HIV-1 and TGF-beta1.
Depletion of CD4(+) T lymphocytes is a central immunological characteristic of HIV-1 infection. Although the mechanism of such CD4(+) cell loss following macrophage-tropic (R5) HIV-1 infection remains unclear, interactions between viral and host cell factors are thought to play an important role in the pathogenesis of HIV-1 disease. Based on the observation that TGF-beta1 enhanced expression of HIV chemokine coreceptors, the role of this host factor in virus effects was investigated using PBLs cultured in a nonmitogen-added system in the absence or presence of TGF-beta1. Most CD4 cells in such cultures had the phenotype CD25(-)CD69(-)DR(-)Ki67(-) and were CD45RO(bright)CD45RA(dim). Cultured cells had increased expression of CCR5 and CXCR4 and supported both HIV-1 entry and completion of viral reverse transcription. Virus production by cells cultured in the presence of IL-2 was inhibited by TGF-beta1, and this inhibition was accompanied by a loss of T cells from the culture and an increase in CD4(+) T cell apoptosis. Whereas R5X4 and X4 HIV-1 infection was sufficient to induce T cell apoptosis, R5 HIV-1 failed to induce apoptosis of PBLs in the absence of TGF-beta1 despite the fact that R5 HIV-1 depletes CD4(+) T cells in vivo. Increased apoptosis with HIV and TGF-beta1 was associated with reduced levels of Bcl-2 and increased expression of apoptosis-inducing factor, caspase-3, and cleavage of BID, c-IAP-1, and X-linked inhibitor of apoptosis. These results show that TGF-beta1 promotes depletion of CD4(+) T cells after R5 HIV-1 infection by inducing apoptosis and suggest that TGF-beta1 might contribute to the pathogenesis of HIV-1 infection in vivo.
Wang
J
J
Laboratory of Gene Regulation, Division of Therapeutic Proteins, Center for Biologics Evaluation and Research, Food and Drug Administration, National Institutes of Health, Bethesda, MD 20892, USA. wangj@cber.fda.gov
Guan
E
E
Roderiquez
G
G
Norcross
M A
MA
D000328:Adult; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D051033:Apoptosis Inducing Factor; D051023:BH3 Interacting Domain Death Agonist Protein; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology* / Q000187:drug effects / Q000821:virology; D002352:Carrier Proteins / Q000378:metabolism; D053148:Caspase 3; D020169:Caspases / Q000096:biosynthesis / Q000235:genetics; D002478:Cells, Cultured; D005420:Flavoproteins / Q000096:biosynthesis / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D054303:HIV Reverse Transcriptase / Q000378:metabolism; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D008264:Macrophages / Q000821:virology; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics; D008928:Mitochondria / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics; D019713:Receptors, CCR5 / Q000096:biosynthesis / Q000235:genetics; D019718:Receptors, CXCR4 / Q000096:biosynthesis / Q000235:genetics; D013268:Stimulation, Chemical; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1; D014779:Virus Replication / Q000187:drug effects; D051636:X-Linked Inhibitor of Apoptosis Protein
C494829:AIFM1 protein, human; D051033:Apoptosis Inducing Factor; D051023:BH3 Interacting Domain Death Agonist Protein; C494814:BID protein, human; D002352:Carrier Proteins; D005420:Flavoproteins; D008565:Membrane Proteins; D011506:Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D019713:Receptors, CCR5; D019718:Receptors, CXCR4; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D051636:X-Linked Inhibitor of Apoptosis Protein; C496866:XIAP protein, human; D054303:HIV Reverse Transcriptase; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases