Effect of Interleukin-9 on Cell Proliferation and Histamine Release of Cord Blood-derived Human Mast Cells / 소아알레르기및호흡기학회지

ABSTRACT

PURPOSE: Interleukin-9(IL-9), one of Th2-type cytokines, might be important in the pathophysiology of allergic diseases. We investigated the effect of IL-9 on human mast cells by assessing cell proliferation and histamine release. METHODS: Human umbilical cord blood cells were cultured in the presence of stem cell factor(SCF, 100 ng/mL) and IL-6(50 ng/mL) in liquid medium for 8 weeks. Then these cells were divided into 3 aliquots. Each aliquot was cultured for 4 more weeks in different conditions SCF alone(100 ng/mL), IL-9 alone(50 ng/mL) and SCF+IL-9. Cell numbers were counted using hemocytometer. For evaluation of apoptosis, DNA fragmentation was determined by propidium iodide(PI) staining and flow cytometric analysis. Histamine concentration was measured by ELISA after stimulation with human IgE and anti-human IgE. RESULTS: Cell numbers increased significantly when they were cultured in the presence of SCF and IL-9 compared with SCF alone(P<0.05). Proliferation of mast cells was mediated by decreased apoptosis. Histamine release in activated mast cells was not different regardless of incubation with IL-9. CONCLUSION: IL-9 might be involved in allergic inflammation via proliferation of mast cells in target tissue.