Interleukin 7 and sCD23 synergize in the induction of human T cell activation in HIV-1-infected subjects.
The role played by CD23 in retroviral infections is still unclear. The synergistic effects of interleukin 7 (IL-7) and sCD23 on T cell proliferation and the generation of HIV-1-specific cytotoxic T lymphocytes (CTL) in mitogen- and antigen-stimulated systems were examined. Addition of IL-7 and sCD23 at the onset of culture resulted in a marked augmentation of T cell proliferation and cytotoxic activity. Studies of CTL development in purified mitogen CD8+ T cells demonstrated that IL-7 and sCD23 could act directly on the CD8+ lymphocyte subset to augment cytotoxicity. The data demonstrate that IL-7 and sCD23 synergistically augmented CTL activity independently of IL-2 and IL-12. We analyzed the effects on IFN-gamma production by CD8+ T cells and found that IL-7 alone did not induce detectable levels of IFN-gamma production, but together with sCD23, it synergistically enhanced the production of IFN-gamma. We also found that IFN-gamma appeared not to be required for the enhanced CD8+ CTL activity because rabbit anti-IFN-gamma antibody did not block the synergistic effects of IL-7 and sCD23. These results indicate that IL-7 and sCD23 can exert major upregulatory effects on human CTL development and suggest that these effects are both proliferative and differentiative.
Fratazzi
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C
Department of Medicine, Harvard Medical School, Boston, Mass., USA.
Guerriero
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M
Carini
C
C
D000328:Adult; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D004357:Drug Synergism; D015686:Gene Products, env / Q000276:immunology; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D009980:Influenza A virus / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology; D018664:Interleukin-12 / Q000276:immunology; D007376:Interleukin-2 / Q000276:immunology; D015851:Interleukin-7 / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D017455:Receptors, IgE / Q000276:immunology*; D012995:Solubility; D013601:T-Lymphocytes / Q000276:immunology*
D015686:Gene Products, env; D007376:Interleukin-2; D015851:Interleukin-7; D017455:Receptors, IgE; D018664:Interleukin-12; D007371:Interferon-gamma