FcεRI-α siRNA Inhibits the Antigen-Induced Activation of Mast Cells

Fcεri, the high affinity receptor for ige plays a critical role in triggering the allergicreactions. it is responsible for inducing mast cell degranulation and deliberation of allergymediators when it is aggregated by allergen and ige complexes. fcεri on the mast cellsconsists of three subunits; α chain directly binds ige, β chain and dimmer of γ chainstogether mediate intracellular signaling. cross-linking of ige-bound fcεri on the surface ofmast cells and basophils by the multivalent antigen induces release of chemical mediators.the present in vitro study was designed to investigate the effect of synthetic fcεri-α sirnaon the antigen-induced activation of mc/9 cells.mc/9 cells which are murine mast cells were transfected by fcεri-α sirna and negativecontrol sirna. after 6 h, anti-dnp (dinitrophenyl) ige was used for the cells sensitization.then the cells were challenged with dinitrophenyl-human serum albumin (dnp-hsa) formast cell degranulation induction before collection of supernatants. the amount of mrnaand protein expression was measured by real time pcr and western blot analysis,respectively. determination of the expression rate of fcεri-α on cell surface was achieved byflow cytometry. elisa and spectrophotometry methods were used subsequently formeasuring the effects of fcεri-α sirna on antigen-induced histamine and β-hexosaminidase release. fcεri-α sirna treated cells showed significant decrease in fcεri-αmrna and protein expression in comparison to control cells. fcεri-mediated mast cellrelease of β-hexosaminidase and histamine were also inhibited.in this study it was shown that fcεri-α sirna could suppress fcεri-α expression andinhibited degranulation and histamine release in antigen-stimulated mc/9 cells. inconclusion, knock-down of fcεri-α by sirna could be a promising method for inhibitionof the mast cell-mediated allergic reactions.