Regulation of interleukin 3 receptor alpha chain (IL-3R alpha) on human monocytes by interleukin (IL)-4, IL-10, IL-13, and transforming growth factor beta (TGF-beta).
Human interleukin 3 receptor (IL-3R) is constitutively expressed on committed haematopoietic stem cells, where it mediates proliferation and differentiation. This receptor is also expressed by monocytes and may induce functional activation. Interleukin (IL)-4, IL-10, IL-13, and transforming growth factor beta (TGF-beta) have different effects on human monocytes. As IL-3R may be regulated by different cytokines, whether the above-mentioned cytokines were able to modulate the alpha chain of IL-3R (IL-3R alpha) on monocytes was examined. Effects on IL-3R alpha antigen (Ag) expression were analysed by direct immunofluorescence and flow cytometry. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect variations in IL-3R alpha mRNA expression. IL-10 and TGF-beta were found to downregulate IL-3R alpha Ag. In contrast, IL-4 and IL-13 both caused a dose- and time-dependent increase. A maximum effect was observed at 1 ng/ml of IL-4 for 18 h. Furthermore, in RT-PCR, IL-4 was found to slightly up-regulate IL-3R alpha mRNA expression. These observations suggest that IL-4 and IL-13 play a role in the regulation of IL-3R alpha expression and the effects of cytokines on human monocytes may be mediated, in part, through the regulation of IL-3R.
Laboratoire DIFEMA, Faculté de Médecine et de Pharmacie de Rouen, Saint-Etienne du Rouvray, France.
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D000941:Antigens / Q000096:biosynthesis; D002478:Cells, Cultured; D004306:Dose-Response Relationship, Immunologic; D006801:Humans; D016753:Interleukin-10 / Q000502:physiology; D018793:Interleukin-13 / Q000502:physiology; D015847:Interleukin-4 / Q000502:physiology; D007378:Interleukins / Q000502:physiology*; D009000:Monocytes / Q000276:immunology / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D016185:Receptors, Interleukin-3 / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000502:physiology*
D000941:Antigens; D018793:Interleukin-13; D007378:Interleukins; D012333:RNA, Messenger; D016185:Receptors, Interleukin-3; D016212:Transforming Growth Factor beta; D016753:Interleukin-10; D015847:Interleukin-4