101. Retroviral interference on STAT activation in individuals coinfected with human T cell leukemia virus type 2 and HIV-1.
- Author
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Bovolenta C, Pilotti E, Mauri M, Panzeri B, Sassi M, Dall'Aglio P, Bertazzoni U, Poli G, and Casoli C
- Subjects
- CD4-Positive T-Lymphocytes immunology, CD4-Positive T-Lymphocytes metabolism, CD4-Positive T-Lymphocytes virology, CD8-Positive T-Lymphocytes immunology, CD8-Positive T-Lymphocytes metabolism, CD8-Positive T-Lymphocytes virology, Cells, Cultured, DNA-Binding Proteins metabolism, HIV Infections complications, HTLV-II Infections complications, Humans, Interferon-gamma biosynthesis, Leukocytes, Mononuclear immunology, Leukocytes, Mononuclear metabolism, Leukocytes, Mononuclear virology, STAT1 Transcription Factor, STAT5 Transcription Factor, Trans-Activators metabolism, HIV Infections immunology, HIV Infections virology, HIV-1 immunology, HTLV-II Infections immunology, HTLV-II Infections virology, Human T-lymphotropic virus 2 immunology, Milk Proteins, Signal Transduction immunology, Viral Interference immunology
- Abstract
Human T cell leukemia virus (HTLV) type-2 is a human retrovirus whose infection has not been tightly linked to human diseases. However, the fairly high prevalence of this infection among HIV-1-positive individuals indicates the importance of better understanding the potential interference of HTLV-2 infection on HIV-1 infection and AIDS. We previously demonstrated that one signature of PBMC freshly derived from HIV-1-infected individuals is the constitutive activation of a C-terminal truncated STAT5 (STAT5Delta). Therefore, we analyzed the potential activation of STATs in HTLV-2 monoinfected and HTLV-2/HIV-1 dually infected individuals. We observed that PBMC of HTLV-2-infected individuals do not show STAT activation unless they are cultivated ex vivo, in the absence of any mitogenic stimuli, for at least 8 h. The emergence of STAT activation, namely of STAT1, in culture was mostly related to the secretion of IFN-gamma. Of note, this phenomenon is not only a characteristic feature of HTLV-2-infected individuals but also occurred with PBMC of HIV-1(+) individuals. Surprisingly, HTLV-2/HIV-1 coinfection resulted in low/absent STAT activation in vivo that paralleled a diminished secretion of IFN-gamma after ex vivo cultivation. Our findings indicate that both HTLV-2 and HIV-1 infection prime T lymphocytes for STAT1 activation, but they also highlight an interference exerted by HTLV-2 on HIV-1-induced STAT1 activation. Although the nature of such a phenomenon is unclear at the present, these findings support the hypothesis that HTLV-2 may interfere with HIV-1 infection at multiple levels.
- Published
- 2002
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