Activation of T cells by interleukin 1 involves internalization of interleukin 1.
The cytokine interleukin-1 plays an important role in the induction of IL-2 secretion and IL-2 receptor expression. The events that follow binding of IL-1 to its receptor are not known. We found that in a purified T cell population (comprising the Lyt2- and L3T4- T cells) IL-1 in the absence of antigen or mitogen induced strong proliferation and de novo expression of IL-2R light chain mRNA. This was accompanied by high affinity IL-2 binding. Production of IL-2 or IL-2 mRNA was not detected under these conditions. As a model system for IL-1 action two EL4 subclones were isolated. EL4 5D3 responded to IL-1 by augmentation of PMA induced IL-2 secretion and IL-2R expression. EL4D6/76 bound IL-1 with the same affinity but did not respond. We found that this line was unable to internalize surface bound IL-1. The finding suggests that in T cells internalization of IL-1 is required for its activity.
Falk
W
W
Institute for Immunology and Genetics, German Cancer Research Center, Heidelberg.
Von Högen
I
I
Krammer
P H
PH
D000818:Animals; D001693:Biological Transport, Active; D002999:Clone Cells / Q000276:immunology / Q000378:metabolism; D007375:Interleukin-1 / Q000493:pharmacokinetics / Q000494:pharmacology*; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis / Q000235:genetics; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D007375:Interleukin-1; D007376:Interleukin-2; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2; D013755:Tetradecanoylphorbol Acetate