[ODP-117] Staphylococcal Superantigen-like 12 activates murine mast cells and basophils
S. aureus is associated with immune allergic disorders such as atopic dermatitis and food allergy. Staphylococcal products including exotoxins are likely involved in the pathogenesis of the allergic disorders. Staphylococcal superantigen-like (SSL) is a family of exotoxins that consists of 14 SSLs and several SSLs interfere with the function of host immune proteins and play a role in immune evasion. However, it remains to clear that the involvement of SSLs in the development of allergic inflammations and Th2 type immune responses. In this study, we examined the effects of recombinant SSL proteins on the immune reactions of murine bone marrow-derived mast cells (BMMCs) and basophils (BMBa), important effector cells in allergic inflammations. Among 14SSLs, SSL12 but other SSLs induced the release of a granule enzyme β-hexosaminidase in BMMCs. SSL12 induced IL-6 and IL-13 in both mRNA and protein levels. SSL12 induced the production of IL-4 in BMBa. SSL12 induced IL-4 production in freshly isolated murine bone marrow basophils. The intradermal injection of SSL12 enhanced local extravasation. Two staphylococcal toxins, α-toxin and δ-toxin are previously reported to activate mast cells. S. aureus would contribute to the development of allergic inflammations via multiple toxins including SSL12.