Human T-cell growth factor (interleukin 2) and gamma-interferon genes: expression in human T-lymphotropic virus type III- and type I-infected cells.
Acquired immune deficiency syndrome (AIDS) is characterized by severe depletion of OKT4+ T lymphocytes and leukemia is associated with abnormal proliferation of maturation-arrested lymphocytes. Human T-lymphotropic virus type III (HTLV-III) or lymphoadenopathy virus (LAV) and type I (HTLV-I) are etiologically linked to AIDS and adult T-cell leukemia/lymphoma, respectively. T-cell growth factor (TCGF, also known as interleukin 2) is required for the growth of activated T-cells, which play an important role in immune regulation. gamma-Interferon (IFN-gamma) is also implicated in immune modulation. It was possible that T-cell depletion in acquired immune deficiency syndrome could be due to an impairment of TCGF synthesis and that adult T-cell leukemia could be due to unregulated production of TCGF. The results reported here show that the transcription of the TCGF gene was not impaired in cultured HTLV-III-infected cells. Paradoxically, the TCGF gene in HTLV-I-infected cells was transcriptionally inactive. The reverse was the case for the gamma-interferon gene--it was actively transcribed in HTLV-I-infected cells but not in the HTLV-III-infected and virus-producing H9 and H4 cell line. No evidence was obtained suggesting abnormal regulation of the TCGF or of the IFN-gamma gene consequent to HTLV-III infection. It thus appears that in both HTLV-III and HTLV-I infection, growth control and immune regulatory mechanisms may bypass a modulatory role of TCGF or of IFN-gamma.
D000163:Acquired Immunodeficiency Syndrome / Q000503:physiopathology*; D002467:Cell Nucleus / Q000378:metabolism; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D017977:Deltaretrovirus; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics*; D007376:Interleukin-2 / Q000235:genetics*; D010835:Phytohemagglutinins / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics; D013601:T-Lymphocytes / Q000382:microbiology / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects
D007376:Interleukin-2; D010835:Phytohemagglutinins; D012333:RNA, Messenger; D007371:Interferon-gamma; D013755:Tetradecanoylphorbol Acetate