Potent and selective stimulation of memory-phenotype CD8+ T cells in vivo by IL-15.
Proliferation of memory-phenotype (CD44hi) CD8+ cells induced by infectious agents can be mimicked by injection of type I interferon (IFN I) and by IFN I-inducing agents such as lipopolysaccharide and Poly I:C; such proliferation does not affect naive T cells and appears to be TCR independent. Since IFN I inhibits proliferation in vitro, IFN I-induced proliferation of CD8+ cells in vivo presumably occurs indirectly through production of secondary cytokines, e.g., interleukin-2 (IL-2) or IL-15. We show here that, unlike IL-2, IL-15 closely mimics the effects of IFN I in causing strong and selective stimulation of memory-phenotype CD44hi CD8+ (but not CD4+) cells in vivo; similar specificity applies to purified T cells in vitro and correlates with much higher expression of IL-2Rbeta on CD8+ cells than on CD4+ cells.
Zhang
X
X
Department of Immunology, IMM4, The Scripps Research Institute, La Jolla, California 92037, USA.
Sun
S
S
Hwang
I
I
Tough
D F
DF
Sprent
J
J
D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D018960:Hyaluronan Receptors / Q000032:analysis*; D007156:Immunologic Memory; D007370:Interferon Type I / Q000494:pharmacology; D019409:Interleukin-15 / Q000096:biosynthesis / Q000494:pharmacology*; D007376:Interleukin-2 / Q000494:pharmacology; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D010641:Phenotype; D011070:Poly I-C / Q000494:pharmacology; D015375:Receptors, Interleukin-2 / Q000032:analysis
D018960:Hyaluronan Receptors; D007370:Interferon Type I; D019409:Interleukin-15; D007376:Interleukin-2; D008070:Lipopolysaccharides; D015375:Receptors, Interleukin-2; D011070:Poly I-C