中文摘要：

目的探讨表达主要组织相容性复合体（MHC）Ⅱ类分子的甲状腺细胞如何发挥抗原递呈功能。方法分离表达MHCⅡ类分子的转基因鼠和对照小鼠的甲状腺细胞,免疫磁珠方法分离其自身T细胞,在体外共同培养,并加入抗CD28抗体。免疫荧光染色,流式细胞分析检测T细胞的增殖和活化。ELISA方法检测培养上清的细胞因子浓度。结果单纯表达MHCⅡ类分子的转基因小鼠甲状腺细胞不能刺激自身T细胞的增殖和活化,然而当加入抗CD28抗体后,表达MHCⅡ类分子的甲状腺细胞能刺激自身T细胞的增殖、活化及细胞因子γ干扰素（IFN-γ）的分泌,而T细胞对野生型小鼠的甲状腺细胞无反应。结论加入协同刺激信号后,表达MHCⅡ类分子的甲状腺细胞也可刺激T细胞增殖活化及分泌细胞因子,具有递呈抗原的能力。

英文摘要：

Objective To investigate how the major histo compatibility complex（MHC ） class Ⅱ expressing thyrocytes from transgenic mice conducting antigen presenting function in vitro. Methods Thyroeyles specifically expressing MHC class Ⅱ molecules were separated from transgenic mice made previously. The thyrocytes were co-cultured with native spleen T lymphocytes separated by MACS column and CD28 antibodies were also added. T cells activation and proliferation were observed with immunofluorescence staining and analyzed on flow cytometry. Cytokine production by T cells was also measured by EIJSA. Results MHC class Ⅱ-expressing thyrocytes from transgenic mice couldn＇t stimulate the proliferation of autologous T cells after a three-day co-culture. However, after CD28 antibodies were added to the culture medium,T cells were significantly activated and proliferated than T cells co-eultured with nan-MHC class Ⅱ expression thyrocytes. Elevated IFN-γ secretion was ＇also detected in the supernatant from T cell and MHC class Ⅱ expressing thyrocytes co-eulture system after the presence of CD28 antibodies. Conclusion With the costimulatory signal,MHC class Ⅱ--expressing thyrocytes from our transgenic mice could act as antigen presenting cell.