title: Interleukin-7 mediates the homeostasis of naïve and memory CD8 T cells in vivo.
abstract: The naïve and memory T lymphocyte pools are maintained through poorly understood homeostatic mechanisms that may include signaling via cytokine receptors. We show that interleukin-7 (IL-7) plays multiple roles in regulating homeostasis of CD8+ T cells. We found that IL-7 was required for homeostatic expansion of naïve CD8+ and CD4+ T cells in lymphopenic hosts and for CD8+ T cell survival in normal hosts. In contrast, IL-7 was not necessary for growth of CD8+ T cells in response to a virus infection but was critical for generating T cell memory. Up-regulation of Bcl-2 in the absence of IL-7 signaling was impaired after activation in vivo. Homeostatic proliferation of memory cells was also partially dependent on IL-7. These results point to IL-7 as a pivotal cytokine in T cell homeostasis.
authors.affiliation: Department of Medicine, University of Connecticut Health Center, Farmington, CT 06030, USA.
authors.forename: K S
authors.initials: KS
authors.lastname: Schluns
authors.forename: W C
authors.initials: WC
authors.lastname: Kieper
authors.forename: S C
authors.initials: SC
authors.lastname: Jameson
authors.forename: L
authors.initials: L
authors.lastname: Lefrançois
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002455:Cell Division; D002460:Cell Line; D006706:Homeostasis; D007156:Immunologic Memory; D015851:Interleukin-7 / Q000235:genetics / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011836:Radiation Tolerance / Q000276:immunology; D020395:Receptors, Interleukin-7 / Q000235:genetics / Q000378:metabolism
chemical_list: D015851:Interleukin-7; D019253:Proto-Oncogene Proteins c-bcl-2; D020395:Receptors, Interleukin-7