Study on Induction of Th2 response and allergic inflammation by basophils

占循环粒细胞总数不到1%的嗜碱性粒细胞组成性地表达FcεR1，当FcεR1结合的IgE与多价抗原交联后，立即释放各种效应分子，如组胺和脂质介质，以及th2相关的细胞因子，如IL-4和IL-13，引起立即型超敏反应。此外，嗜碱性细胞表达IL-18R和IL-33R，并强烈产生IL-4和IL-13，以响应IL-18和/或IL-33。我们已经证明，嗜碱性细胞表达MHC II类和CD80/86，具有摄取和加工蛋白抗原（Ag）的潜力，特别是Ag- ige复合物，并与MHC II类呈递肽并产生IL-4，表明嗜碱性细胞是APC，可选择性诱导Th2细胞。

Basophils, accounting for less than 1% of total circulating granulocytes, constitutively express FcεR1, and upon crosslinking of FcεR1-bound IgE with multivalent antigens, immediately release various kinds of effector molecules such as histamine and lipid mediators, and Th2-associated cytokines such as IL-4 and IL-13, causing immediate type hypersensitivity. Furthemore, basophils express IL-18R and IL-33R and very strongly produce IL-4 and IL-13 in response to IL-18 and/or IL-33. We have demonstrated that basophils express MHC class II and CD80/86, have the potential to take-up and process protein antigen (Ag), particularly Ag-IgE complexes, and to present peptide with MHC class II and produce IL-4, revealing that basophils are APC, which selectively induce Th2 cells.