title: IL-15 induces antigen-independent expansion and differentiation of human naive CD8+ T cells in vitro.
abstract: Recent studies in mice have shown that although interleukin 15 (IL-15) plays an important role in regulating homeostasis of memory CD8+ T cells, it has no apparent function in controlling homeostatic proliferation of naive T cells. We here assessed the influence of IL-15 on antigen-independent expansion and differentiation of human CD8+ T cells. Both naive and primed human T cells divided in response to IL-15. In this process, naive CD8+ T cells successively down-regulated CD45RA and CD28 but maintained CD27 expression. Concomitant with these phenotypic changes, naive cells acquired the ability to produce interferon gamma (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha), expressed perforin and granzyme B, and acquired cytotoxic properties. Primed CD8+ T cells, from both noncytotoxic (CD45RA-CD27+) and cytotoxic (CD45RA+CD27-) subsets, responded to IL-15 and yielded ample numbers of cytokine-secreting and cytotoxic effector cells. In summary, all human CD8+ T-cell subsets had the ability to respond to IL-15, which suggests a generic influence of this cytokine on CD8+ T-cell homeostasis in man.
authors.affiliation: Laboratory for Experimental Immunology, G1-133, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands. n.m.lagesalves@amc.uva.nl
authors.forename: Nuno L
authors.initials: NL
authors.lastname: Alves
authors.forename: Berend
authors.initials: B
authors.lastname: Hooibrink
authors.forename: Fernando A
authors.initials: FA
authors.lastname: Arosa
authors.forename: René A W
authors.initials: RA
authors.lastname: van Lier
mesh_terms: D018414:CD8-Positive T-Lymphocytes / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D002455:Cell Division / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D006801:Humans; D016130:Immunophenotyping; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000096:biosynthesis; D019409:Interleukin-15 / Q000494:pharmacology*; D017493:Leukocyte Common Antigens / Q000378:metabolism; D053647:Receptors, Interleukin-15; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: C508024:IL15RA protein, human; D019409:Interleukin-15; D053647:Receptors, Interleukin-15; D015375:Receptors, Interleukin-2; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D017493:Leukocyte Common Antigens