title: Memory CD4 T cells induce selective expression of IL-27 in CD8+ dendritic cells and regulate homeostatic naive T cell proliferation.
abstract: Naive T cells undergo robust proliferation in lymphopenic conditions, whereas they remain quiescent in steady-state conditions. However, a mechanism by which naive T cells are kept from proliferating under steady-state conditions remains unclear. In this study, we report that memory CD4 T cells are able to limit naive T cell proliferation within lymphopenic hosts by modulating stimulatory functions of dendritic cells (DC). The inhibition was mediated by IL-27, which was primarily expressed in CD8(+) DC subsets as the result of memory CD4 T cell-DC interaction. IL-27 appeared to be the major mediator of inhibition, as naive T cells deficient in IL-27R were resistant to memory CD4 T cell-mediated inhibition. Finally, IL-27-mediated regulation of T cell proliferation was also observed in steady-state conditions as well as during Ag-mediated immune responses. We propose a new model for maintaining peripheral T cell homeostasis via memory CD4 T cells and CD8(+) DC-derived IL-27 in vivo.
authors: Department of Immunology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
authors: Jeong-Su
authors: JS
authors: Do
authors: Anabelle
authors: A
authors: Visperas
authors: Keunhee
authors: K
authors: Oh
authors: Stephen A
authors: SA
authors: Stohlman
authors: Booki
authors: B
authors: Min
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D016827:CD8 Antigens; D002450:Cell Communication / Q000235:genetics / Q000276:immunology; D049109:Cell Proliferation; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000235:genetics / Q000276:immunology*; D006706:Homeostasis / Q000235:genetics / Q000276:immunology; D007156:Immunologic Memory; D007378:Interleukins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout; D018448:Models, Immunological
chemical_list: D016827:CD8 Antigens; C486767:Il27 protein, mouse; D007378:Interleukins