title: Cutting edge: IL-7-independent regulation of IL-7 receptor alpha expression and memory CD8 T cell development.
abstract: Expression of IL-7Ralpha on a subset of Ag-specific effector CD8 T cells is believed to identify memory cell precursors. However, whether IL-7 regulates IL-7Ralpha expression in vivo and is responsible for selective survival of IL-7Ralpha(+) effector cells is unknown. Our results show that in the absence of IL-7, IL-7Ralpha expression was extinguished on the majority of CD8 T cells responding to virus infection, sustained on a subset of effector cells transitioning to memory, and expressed at high levels by memory cells. Additionally, an IL-7-deficient environment was capable of supporting bcl-2 up-regulation and memory cell development in response to virus infection. Thus, IL-7Ralpha regulation occurs independently of IL-7 in responding CD8 T cells, indicating that CD8 memory T cell precursors are not selected by IL-7/IL-7Ralpha interactions.
authors.affiliation: Department of Immunology, Center for Integrative Immunology and Vaccine Research, University of Connecticut Health Center, 2634 Farmington Avenue, Farmington, CT 06030, USA.
authors.forename: Kimberly D
authors.initials: KD
authors.lastname: Klonowski
authors.forename: Kristina J
authors.initials: KJ
authors.lastname: Williams
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Marzo
authors.forename: Leo
authors.initials: L
authors.lastname: Lefrançois
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology; D005434:Flow Cytometry; D007156:Immunologic Memory; D015851:Interleukin-7 / Q000172:deficiency / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008817:Mice, Mutant Strains; D020395:Receptors, Interleukin-7 / Q000096:biosynthesis / Q000276:immunology*; D013234:Stem Cells / Q000166:cytology / Q000276:immunology; D014777:Virus Diseases / Q000276:immunology
chemical_list: D015851:Interleukin-7; D020395:Receptors, Interleukin-7