title: Interleukin-1 (22-K factor) induces release of granulocyte-macrophage colony-stimulating activity from human mononuclear phagocytes.
abstract: An electrophoretically pure preparation of natural human interleukin-1 (IL-1) was shown to stimulate in vitro colony formation in human bone marrow cultures. Day 4 myeloid cluster-forming cells (CFC), as well as early (day 7) and late (day 10) granulocyte-macrophage colony-forming units (CFU-GM) were stimulated in a dose-dependent fashion. At optimal concentrations of IL-1, the number of day 4 CFC reached 72%, the number of day 7 CFU-GM reached 32%, and the number of day 10 CFU-GM reached 80% of the respective numbers of colonies obtained by addition of crude leukocyte-conditioned medium (LCM). The IL-1-induced stimulatory effect on CFU-GM growth could be completely neutralized by a rabbit anti-IL-1 antiserum. Colony growth was abrogated by depleting the marrow cell suspensions of phagocytic cells prior to IL-1 addition. Conversely, the effect could be reintroduced by addition of marrow-derived adherent cells to bone marrow cell suspensions that had been depleted of both phagocytic and E rosetting T cells. Furthermore, media conditioned by bone marrow-derived adherent cells or by peripheral blood mononuclear phagocytes in the presence but not in the absence of IL-1, stimulated in vitro colony growth of phagocyte-depleted bone marrow cell suspensions. These results indicate that IL-1 induces release of granulocyte-macrophage colony-stimulating activity (GM-CSA) from human mononuclear phagocytes.
mesh_terms: D001853:Bone Marrow / Q000502:physiology*; D002478:Cells, Cultured; D003470:Culture Media; D006410:Hematopoiesis / Q000187:drug effects*; D006801:Humans; D007158:Immunologic Techniques; D066298:In Vitro Techniques; D007375:Interleukin-1 / Q000276:immunology / Q000494:pharmacology*; D007377:Interleukin-3 / Q000378:metabolism*; D008264:Macrophages / Q000502:physiology; D010586:Phagocytes / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism
chemical_list: D003470:Culture Media; D007375:Interleukin-1; D007377:Interleukin-3