IL-7 enhances Ag-specific human T cell response by increasing expression of IL-2R alpha and gamma chains.
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.
Chou
Y K
YK
Veterans Affairs Medical Center, Department of Neurology, Oregon Health Sciences University, Portland 97201, USA. barnesd@ohsu.edu
Bourdette
D N
DN
Barnes
D
D
Finn
T P
TP
Murray
S
S
Unsicker
L
L
Robey
I
I
Whitham
R H
RH
Buenafe
A C
AC
Allegretta
M
M
Offner
H
H
Vandenbark
A A
AA
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
D018941:Antigens, CD19; D018845:CD11 Antigens; D019002:CD56 Antigen; D007376:Interleukin-2; D015851:Interleukin-7; D015375:Receptors, Interleukin-2; D007371:Interferon-gamma