IL-15 enhances the function and inhibits CD95/Fas-induced apoptosis of human CD4+ and CD8+ effector-memory T cells.
Although the effect of IL-15 has been described on murine cells in vitro and in vivo, its effect on human memory CD8(+) T cells is not well characterized. We show here that IL-15 preferentially enhances the activation and effector function of human effector-memory CD45RA(-)CD62L(-) and CD45RA(+)CD62L(-) CD4(+) and CD8(+) T cells in both healthy and HIV-infected individuals. We find that IL-15 increases 2- to 5-fold both the activation and secretion of the effector cytokines IFN-gamma and tumor necrosis factor (TNF)-alpha by anti-CD3-stimulated purified CD4(+) and CD8(+) T cells and peripheral blood mononuclear cells from healthy and HIV-infected individuals. Furthermore, IL-15 potently inhibits CD95/Fas-induced apoptosis of the effector-memory CD4(+) and CD8(+) T cells from HIV-infected individuals. These findings suggest that in addition to being a growth and survival factor for memory CD8(+) T cells, IL-15 is also a potent activator of human effector-memory CD8(+) T cells both in healthy and in HIV-infected individuals.
Mueller
Yvonne M
YM
Department of Microbiology and Immunology, Drexel University College of Medicine, Drexel University, 2900 Queen Lane, Philadelphia, PA 19129, USA.
Makar
Vera
V
Bojczuk
Paul M
PM
Witek
James
J
Katsikis
Peter D
PD
D000293:Adolescent; D017209:Apoptosis / Q000187:drug effects; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D015658:HIV Infections / Q000276:immunology*; D006801:Humans; D019409:Interleukin-15 / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000473:pathology*; D019014:fas Receptor / Q000502:physiology
D019409:Interleukin-15; D019014:fas Receptor