title: IL-12 directly enhances in vitro murine erythropoiesis in combination with IL-4 and stem cell factor.
abstract: It has been demonstrated recently that in vivo administration of murine IL-12 to mice enhances the activity of cytotoxic NK cells and lymphocyte-activated killer cells, and that it has antitumor and antimetastatic activity. However, one side effect observed in response to systemic IL-12 treatment is anemia. In the present study, we examined for the first time the ability of IL-12 to affect directly the growth of murine erythroid progenitor cells in vitro. Whereas IL-12 alone or in combination with Erythropoietin (Epo) showed no stimulatory effect on erythroid progenitors, IL-12 potently enhanced the number of erythroid burst-forming unit (BFU-E) colonies formed in response to Epo+IL-4 by 63% and Epo+stem cell factor by 80%. The stimulatory effect of IL-12 occurred in a concentration-dependent fashion, with maximum enhancing effect observed at 50 ng/ml. Furthermore, single cell experiments suggested that the stimulatory effect of IL-12 on erythroid colony formation was directly mediated. Thus, IL-12 can directly enhance murine erythropoiesis in vitro, suggesting that IL-12-induced anemia is mediated through an indirect mechanism.
authors.affiliation: Institute of Cancer Research, University of Trondheim, Norway.
authors.forename: I
authors.initials: I
authors.lastname: Dybedal
authors.forename: S
authors.initials: S
authors.lastname: Larsen
authors.forename: S E
authors.initials: SE
authors.lastname: Jacobsen
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D015672:Erythroid Precursor Cells / Q000187:drug effects*; D004920:Erythropoiesis / Q000187:drug effects*; D016298:Hematopoietic Cell Growth Factors / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D018664:Interleukin-12 / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D015847:Interleukin-4 / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins / Q000494:pharmacology; D019089:Stem Cell Factor; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D016298:Hematopoietic Cell Growth Factors; D011994:Recombinant Proteins; D019089:Stem Cell Factor; D014409:Tumor Necrosis Factor-alpha; D018664:Interleukin-12; D015847:Interleukin-4; D007371:Interferon-gamma