Regulation of human interleukin-2 and interferon-gamma gene expression by suppressor T lymphocytes.
Concomitant with induction of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) gene expression in human tonsil cells, mitogenic stimulation induces a transient activation of cells able to effectively suppress expression of these genes. Induction of IL-2 and IFN-gamma genes largely precedes appearance of suppressor cell activity, allowing expression of both genes to occur before strong down-regulation is exerted by activated suppressor cells. Suppressive activity induced in one cell population can inhibit IL-2 and IFN-gamma gene expression in another population from the same donor. The distinct nature of suppressor cells is supported by the absence of down-regulation of IL-2 gene expression in a helper cell line, MLA-144; yet, in these cells, negative control can be expressed when active suppressor cells are introduced. Our findings support the concept that actual levels of IL-2 and IFN-gamma gene activity are regulated to a large extent by the differential kinetics of activation of suppressor cells on one hand and of cells expressing the IL-2 and IFN-gamma genes on the other.
Ketzinel
M
M
Department of Molecular Virology, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Efrat
S
S
Sayar
D
D
Gerez
L
L
Tal
C
C
Deutsch
E
E
Arad
G
G
Kaempfer
R
R
D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology; D016827:CD8 Antigens; D002460:Cell Line; D005720:Gamma Rays; D005786:Gene Expression Regulation / Q000528:radiation effects; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics*; D007376:Interleukin-2 / Q000235:genetics*; D010835:Phytohemagglutinins / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D050378:T-Lymphocytes, Regulatory / Q000502:physiology*
D000945:Antigens, Differentiation, T-Lymphocyte; D016827:CD8 Antigens; D007376:Interleukin-2; D010835:Phytohemagglutinins; D012333:RNA, Messenger; D007371:Interferon-gamma