IL-6 is an intermediate in IL-1-induced thymocyte proliferation.
Both IL-1 and IL-6 have been shown to be comitogenic for lectin-stimulated thymocytes. Thymocytes cultured in the presence of IL-1 produce IL-6 themselves. This IL-6 production is caused by a cell population with low buoyant density. After removal of these cells, IL-6 or IL-2 are still co-mitogenic for thymocytes whereas IL-1 is not. Addition of IL-1 to such thymocytes renders them about 100-fold more sensitive to IL-6. At all conditions proliferation is inhibitable with antibodies to IL-2 and to the IL-2R. Our experiments show that IL-1-driven proliferation of thymocytes is dependent on endogenous IL-6 production and that in the classical thymocyte assay IL-1 has a dual role: it induces IL-6 production and it greatly increases the sensitivity for IL-6.
Helle
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Central Laboratory, Netherlands Red Cross Blood Transfusion Service, Amsterdam.
Boeije
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Aarden
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D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000818:Animals; D002469:Cell Separation; D002499:Centrifugation, Density Gradient; D004357:Drug Synergism; D007375:Interleukin-1 / Q000494:pharmacology*; D007376:Interleukin-2 / Q000502:physiology; D015850:Interleukin-6; D007378:Interleukins / Q000096:biosynthesis / Q000494:pharmacology / Q000502:physiology*; D007958:Leukocyte Count; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008809:Mice, Inbred C3H; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
D000276:Adjuvants, Immunologic; D007375:Interleukin-1; D007376:Interleukin-2; D015850:Interleukin-6; D007378:Interleukins