与抗原结合的结缔组织肥大细胞促进特异性T细胞反应

Antigen-incorporated connective tissue mast cells promote specific T cell activation

目的:研究结缔组织肥大细胞(Connective tissue mast cells,CTMCs)通过抗原依赖方式对T细胞反应的影响。方法:从小鼠骨髓细胞用细胞因子诱导培养CTMCs,荧光染料标记的模式抗原鸡卵清蛋白OVA与IgG形成免疫复合物后,与CTMCs共培养,通过流式细胞术观察CTMCs通过抗原抗体复合物摄取抗原的能力,并用CD69和Ki67指标进一步检测其刺激抗原特异性CD4+T淋巴细胞激活和增殖的能力。结果:从小鼠骨髓细胞成功诱导CTMCs。CTMCs能通过其表面的Fcγ受体(FcγRs)结合环境中的抗原抗体复合物,通过IgG有效摄取抗原,其水平高于摄取未与抗体结合的抗原。结合抗原后能以抗原依赖的方式激活CD4+T淋巴细胞并促进其增殖。结论:结缔组织肥大细胞通过其FcγRs和IgG抗体增加摄取抗原的能力,进而直接或间接将抗原递呈给CD4+T淋巴细胞,促进其增殖和活化,在获得性免疫中发挥重要作用。

To study the effects of connective tissue mast cells （ CTMCs ） on T cell activation in an antigen-dependent manner.Methods： Connective tissue mast cells were differentiated from mouse bone marrow cells.Alexa Fluor 488-conjugated ovalbumin （OVA）/IgG immune complexes were generated and incubated with CTMCs ,and analyzed by flow cytometry to detect the antigen uptake by CTMCs via Fcγreceptors （ FcγRs ）.The relevant effects on antigen-specific T cell activation and proliferation were further determined by CD 69 and Ki67 expression.Results： A magnificent increase in OVA uptake was seen in CTMCs treated with OVA/IgG immunocomplex after 24-hour incubation ,compared with that treated with fluorescent OVA alone.OVA-incorporated mast cells induced OVA-specific CD4＋T-cell activation and proliferation.Conclusion：It was suggested that the binding of IgG receptor FcγRs could elicit CTMCs reaction and ,as a result,to mediate crosstalk between professional APCs and T cells.