IL-10 enhances IgE-mediated mast cell responses and is essential for the development of experimental food allergy in IL-10-deficient mice

摘要

IL-10 is a key pleiotropic cytokine that can both promote and curb Th2-dependent allergic responses. Herein we demonstrate a novel role for IL-10 in promoting mast cell expansion and the development of IgE-mediated food allergy. Oral ovalbumin challenge in sensitized BALB/c mice resulted in a robust intestinal mast cell response accompanied by allergic diarrhea, mast cell activation, and a predominance of Th2 cytokines, including enhanced IL-10 expression. In contrast, the development of intestinal anaphylaxis including diarrhea, mast cell activation, and Th2 cytokine production was significantly attenuated in IL-10^−/− mice compared to WT controls. IL-10 also directly promoted the expansion, survival, and activation of mast cells, increased FcɛRI expression on mast cells, and enhanced the production of mast cell cytokines. IL-10^−/− mast cells had reduced functional capacity, which could be restored by exogenous IL-10. Similarly, attenuated passive anaphylaxis in IL-10^−/− mice could be restored by IL-10 administration. The adoptive transfer of WT mast cells restored allergic symptoms in IL-10^−/− mice, suggesting that the attenuated phenotype observed in these animals is due to a deficiency in IL-10-responding mast cells. Lastly, transfer of WT CD4 T cells also restored allergic diarrhea and intestinal mast cell numbers in IL-10^−/− mice, suggesting that the regulation of IL-10-mediated intestinal mast cell expansion is T cell-dependent. Our observations demonstrate a critical role for IL-10 in driving mucosal mast cell expansion and activation, suggesting that in its absence, mast cell function is impaired, leading to attenuated food allergy symptoms.