Sphingosine 1-phosphate-mediated trafficking of pathogenic Th2 and mast cells for the control of food allergy

Sphingosine I-phosphate (SIP) has been proposed as a regulator of lymphocyte trafficking, but its role in mucosa-associated diseases, such as in food allergies, remains to be elucidated. To examine the role of SIP in allergic diseases in the intestine, we used a Th2 cell-mediated Ag-specific allergic diarrhea model and demonstrated that type 1 SIP receptor (S1P(1)) expression was preferentially associated with pathogenic CD4(+) T cells for the development of allergic reactions. Consistent with this demonstration, treatment with FTY720, a modulator of the SIP,, prevented allergic diarrhea by inhibiting the migration of systemically primed pathogenic CD4(+) T cells induced by oral challenge with allergen into the large intestine. In addition, FTY720 hampered mast cell infiltration into the large intestine, whereas eosinophil infiltration into the large intestine and total and allergen-specific serum IgE production were comparable between mock- and FTY720-treated groups. These results suggest that modulation of the SIP-mediated pathway to inhibit the migration of pathogenic CD4(+) T cells and mast cells into the large intestine could be a novel strategy for preventing allergic diarrhea.