Interleukins (IL)-1 and IL-2 control IL-2 receptor alpha and beta expression in immature thymocytes.
Functional high-affinity interleukin-2 receptors (IL-2R) contain three transmembrane proteins, IL-2R alpha, beta and gamma. We have investigated the expression of IL-2R alpha and beta genes in immature mouse thymocytes. Previous work has shown that during differentiation these cells transiently express IL-2R alpha on their surface. Stimulation of IL-2R alpha+ and IL-2R alpha- immature thymocytes with phorbol 12-myristate 13-acetate and calcium ionophore induces synthesis of IL-2R alpha and IL-2R beta mRNA. Most of this response depends on autocrine stimulation by IL-2. IL-1 synergizes with IL-2 to induce a 120-fold increase in IL-2R alpha mRNA and a 14-fold increase in IL-2R beta mRNA levels. A large proportion of the stimulated cells contains both transcripts. These interleukins do not induce any differentiation to more mature phenotypes. Collectively, these results show that IL-2 plays a major role in the regulation of IL-2R expression in normal immature thymocyte. We suggest that this response to interleukins may be part of a homeostatic mechanism to increase the production of immature thymocytes during stress.
Wilson
A
A
Ludwig Institute for Cancer Research, Epalinges, Switzerland.
Corthésy
P
P
Reichenbach
P
P
MacDonald
H R
HR
Nabholz
M
M
D000818:Animals; D002478:Cells, Cultured; D005260:Female; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D017403:In Situ Hybridization; D007375:Interleukin-1 / Q000502:physiology*; D007376:Interleukin-2 / Q000502:physiology*; D015759:Ionomycin / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000032:analysis; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis*; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology*
D007375:Interleukin-1; D007376:Interleukin-2; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2; D015759:Ionomycin; D013755:Tetradecanoylphorbol Acetate