title: IL-7 enhances Ag-specific human T cell response by increasing expression of IL-2R alpha and gamma chains.
abstract: Interleukin-7 has demonstrated potent enhancing effects on the growth and differentiation of several immature cell types, including thymocytes, and on survival of resting and antigen activated T cells. In this study, we evaluated the effects of IL-7 on post-thymic antigen-specific T cells from human blood. IL-7 was found to enhance proliferation responses and IFN-gamma secretion of myelin or recall Ag-specific Th1 cells through the selective up-regulation of the IL-2Ralpha and gamma but not beta chains in both an Ag-dependent and Ag-independent manner, but did not affect monocytes, B cells, or NK cells. These functions of IL-7 enhanced the detection of Th1 but not Th2 cell frequency by >2.5 fold, and promoted selection of Ag-specific Th1 cells by the limiting dilution method. Moreover, IL-7 pretreatment conferred increased resistance of CD4+ T cells to CD8+ cell lysis. These studies demonstrate that IL-7 promotes the growth and survival of circulating Ag-specific human Th1 cells through a mechanism that probably involves the gammac common receptor for IL-2 family members that includes IL-7.
authors.affiliation: Veterans Affairs Medical Center, Department of Neurology, Oregon Health Sciences University, Portland 97201, USA. barnesd@ohsu.edu
authors.forename: Y K
authors.initials: YK
authors.lastname: Chou
authors.forename: D N
authors.initials: DN
authors.lastname: Bourdette
authors.forename: D
authors.initials: D
authors.lastname: Barnes
authors.forename: T P
authors.initials: TP
authors.lastname: Finn
authors.forename: S
authors.initials: S
authors.lastname: Murray
authors.forename: L
authors.initials: L
authors.lastname: Unsicker
authors.forename: I
authors.initials: I
authors.lastname: Robey
authors.forename: R H
authors.initials: RH
authors.lastname: Whitham
authors.forename: A C
authors.initials: AC
authors.lastname: Buenafe
authors.forename: M
authors.initials: M
authors.lastname: Allegretta
authors.forename: H
authors.initials: H
authors.lastname: Offner
authors.forename: A A
authors.initials: AA
authors.lastname: Vandenbark
mesh_terms: D018941:Antigens, CD19 / Q000276:immunology / Q000378:metabolism; D018845:CD11 Antigens / Q000276:immunology / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D019002:CD56 Antigen / Q000276:immunology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D002455:Cell Division / Q000276:immunology; D002470:Cell Survival / Q000276:immunology; D002999:Clone Cells; D006801:Humans; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000276:immunology / Q000378:metabolism; D007376:Interleukin-2 / Q000494:pharmacology; D015851:Interleukin-7 / Q000494:pharmacology*; D015375:Receptors, Interleukin-2 / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D013950:Thymus Gland / Q000166:cytology
chemical_list: D018941:Antigens, CD19; D018845:CD11 Antigens; D019002:CD56 Antigen; D007376:Interleukin-2; D015851:Interleukin-7; D015375:Receptors, Interleukin-2; D007371:Interferon-gamma