title: Synergistic stimulatory effects of tumour necrosis factor alpha and interferon gamma on replication of human immunodeficiency virus type 1 and on apoptosis of HIV-1-infected host cells.
abstract: Differential and sometimes contradictory effects have been described for tumour necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma) on replication of human immunodeficiency virus type 1 (HIV-1). The authors examined individual and coordinate action of these cytokines on HIV-1 expression, and on apoptosis of HIV-1-infected host cells by determination of reverse transcriptase activity in cell culture supernatant, expression of HIV-1-RNA and production of p24 antigen in the promonocytic cell line U937 and its persistently HIV-1-infected clone U1. Apoptosis was demonstrated by typical cleavage of cellular DNA at internucleosomal regions in promonocytic and T-lymphocytic cell lines. TNF-alpha alone markedly stimulated HIV-1 replication in U1 cells at the transcriptional and on the translational level. Exclusive application of IFN-gamma only slightly enhanced HIV-1 expression, whereas it synergistically potentiated stimulatory effects of TNF-alpha. Both cytokines also synergistically induced apoptosis in HIV-1-infected host cells. Co-ordinate action of TNF-alpha and IFN-gamma is suggested to represent an important mechanism for disease progression in HIV infection. These findings demonstrate that cytokine effects on viral expression may vary depending on their single or combined application.
authors.affiliation: Institute of Virology and Immunobiology, University of Würzburg, Germany.
authors.forename: X
authors.initials: X
authors.lastname: Han
authors.forename: K
authors.initials: K
authors.lastname: Becker
authors.forename: H J
authors.initials: HJ
authors.lastname: Degen
authors.forename: H
authors.initials: H
authors.lastname: Jablonowski
authors.forename: G
authors.initials: G
authors.lastname: Strohmeyer
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002460:Cell Line; D016655:HIV Core Protein p24 / Q000096:biosynthesis; D054303:HIV Reverse Transcriptase; D015497:HIV-1 / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D012367:RNA, Viral / Q000096:biosynthesis; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D016655:HIV Core Protein p24; D012367:RNA, Viral; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D054303:HIV Reverse Transcriptase; D012194:RNA-Directed DNA Polymerase