title: IL-7 and IL-15 differentially regulate CD8+ T-cell subsets during contraction of the immune response.
abstract: Although it is known that interleukin-7 (IL-7) and IL-15 influence the survival and turnover of CD8+ T cells, less is known about how these cytokines affect different subsets during the course of the immune response. We find that IL-7 and IL-15 differentially regulate CD8+ T-cell subsets defined by KLRG1 and CD127 expression during the contraction phase of the immune response. The provision of IL-15, or the related cytokine IL-2, during contraction led to the preferential accumulation of KLRG1(hi)CD127(lo) CD8+ T cells, whereas provision of IL-7 instead favored the accumulation of KLRG1(lo)CD127(hi) cells. While IL-7 and IL-15 both induced proliferation of KLRG1(lo) cells, KLRG1(hi) cells exhibited an extraordinarily high level of resistance to cytokine-driven proliferation in vivo despite their dramatic accumulation upon IL-15 administration. These results suggest that IL-15 and IL-2 greatly improve the survival of KLRG1(hi) CD8+ T cells, which are usually destined to perish during contraction, without inducing proliferation. As the availability of IL-15 and IL-2 is enhanced during periods of extended inflammation, our results suggest a mechanism in which a population of cytokine-dependent KLRG1(hi) CD8+ T cells is temporarily retained for improved immunity. Consideration of these findings may aid in the development of immunotherapeutic strategies against infectious disease and cancer.
authors.affiliation: Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0377, USA.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Rubinstein
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Lind
authors.forename: Jared F
authors.initials: JF
authors.lastname: Purton
authors.forename: Pauline
authors.initials: P
authors.lastname: Filippou
authors.forename: J Adam
authors.initials: JA
authors.lastname: Best
authors.forename: Patrick A
authors.initials: PA
authors.lastname: McGhee
authors.forename: Charles D
authors.initials: CD
authors.lastname: Surh
authors.forename: Ananda W
authors.initials: AW
authors.lastname: Goldrath
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology*; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D019409:Interleukin-15 / Q000378:metabolism / Q000494:pharmacology*; D015851:Interleukin-7 / Q000378:metabolism / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010047:Ovalbumin / Q000276:immunology; D053647:Receptors, Interleukin-15 / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000187:drug effects / Q000276:immunology
chemical_list: D019409:Interleukin-15; D015851:Interleukin-7; D053647:Receptors, Interleukin-15; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins; D010047:Ovalbumin