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目的探讨CD8+T细胞在生理或病理性免疫应答中的免疫调节作用及其机制。方法将特异性CD8+T细胞与骨髓体外诱导的或脾脏来源的树突状细胞(dendritic cells,DCs)共培养,检测DCs表面MHC-Ⅱ类分子和共刺激分子的表达;检测共培养后DCs刺激CD4+T细胞增殖的能力。OVA致敏小鼠体内回输特异性CD8+T细胞,分析CD8+T细胞对脾脏DCs抗原递呈能力的影响;CD8+T细胞干预后的致敏小鼠吸入OVA后,分析小鼠肺泡-支气管灌洗液(broncho-alveolar lavage fluid,BALF)中的白细胞和细胞因子,小鼠肺组织切片经HE和PAS染色观察其病理改变。结果 DCs与CD8+T细胞共培养后,其MHC-Ⅱ类分子和共刺激分子的表达均下调,刺激CD4+T细胞增殖能力显著下降;CD8+T细胞体内回输后,小鼠脾脏DCs共刺激分子的表达及其刺激CD4+T细胞增殖的能力均下调;与未干预组相比,CD8+T细胞干预小鼠BALF中IL-4、IL-5质量浓度降低,肺部炎性细胞浸润和杯状细胞增生减少。结论特异性CD8+T细胞活化可以通过下调DCs共刺激分子的表达来抑制DCs的抗原递呈能力,从而调节致敏CD4+T细胞的增殖,缓解哮喘小鼠的症状。
Objective To investigate the immunomodulatory effects of CD8 + T cells in physiological or pathological immune response and its mechanism. Methods Specific CD8 + T cells were co-cultured with dendritic cells (DCs) derived from bone marrow or spleen in vitro to detect the expression of MHC class II molecules and co-stimulatory molecules on the surface of DCs. DCs Stimulation of CD4 + T cell proliferation ability. OVA-sensitized mice were transfused with specific CD8 + T cells to analyze the effect of CD8 + T cells on the antigen presenting ability of splenic DCs. After sensitized mice were challenged with OVA by CD8 + T cells, the alveolar- The leukocytes and cytokines in broncho-alveolar lavage fluid (BALF) and the lung tissue sections of mice were stained with HE and PAS to observe the pathological changes. Results After co-cultured with DCs and CD8 + T cells, the expression of MHC-Ⅱ molecules and costimulatory molecules were downregulated, and the proliferation ability of CD4 + T cells was significantly decreased. After CD8 + T cells were transfused in vivo, Compared with the non-intervention group, the levels of IL-4 and IL-5 in the BALF of CD8 + T cells were significantly decreased, while the inflammatory cell infiltration And goblet cell proliferation reduced. Conclusion Activation of specific CD8 + T cells can down-regulate the expression of costimulatory molecules of DCs to inhibit the antigen presenting ability of DCs, thereby regulating the proliferation of sensitized CD4 + T cells and alleviating the symptoms of asthmatic mice.