CTLA4Ig修饰树突状细胞对实验动物淋巴细胞增殖及胞毒效应的影响

目的：探讨CTLA4Ig修饰的DC对实验动物免疫功能的影响。方法：将经CTLA4Ig基因修饰或未修饰Dc腹腔注射C57BL／6致敏小鼠，以致敏或未致敏C57BL／6单个核细胞作为反应细胞，以未修饰DC细胞及修饰DC为刺激细胞，共培养6天，采用MTT比色法检测细胞增殖，乳酸脱氢酶法测定细胞毒活性。结果：CTLA4Ig融合蛋白对未修饰DC致敏或未致敏小鼠的同种细胞刺激的增殖反应有明显的抑制作用。CTLA4Ig修饰DC诱导不同组小鼠淋巴细胞增殖反应均明显降低，CTLA4Ig融合蛋白对CTL细胞毒活性有显著抑制作用。CTLA4Ig修饰DC对不同组小鼠CTL细胞毒活性均具有抵抗作用，未修饰DC细胞对未致敏小鼠以及未修饰DC对致敏小鼠CTL细胞毒活性敏感。结论：稳定表达CTLA4Ig融合蛋白的DC诱导显著降低同种小鼠淋巴细胞的增殖反应和对CTL细胞毒活性的抵抗。

The influence of CTLA4Ig-modified dendritic cells on proliferation and cytotoxicity of lymphocytes in experimental animals

Objective:To study the influence of dendritic cells modified by CTLA4Ig on immunological f unction of experimental animals.Methods:The unmodified or modified dendritic cells were injected intraperitoneally into C57BL/6 mice to sensitize them.Peripheral blood mononuclear cells(PBMC) of sensi tized or unsensitized C57BL/6 mice as reaction cells,dendritic cells modified or unmodified by CTLA4Ig as stimulation cells.These two type cells were co-cultur ed for 6 days.MTT assay was used to detect lymphocyte proliferation.Lactate dehy drogenase release method was used to examine the cytotoxic activity.Results:The result showed that CTLA4Ig fusion protein could obviously inhibite lymphocyt e proliferation response of unsensitized or sensitized C57BL/6 mice.Lymphocyte p roliferation responses of different group mice induced by CTLA4Ig-modified de ndritic cells were significant decreased.CTLA4Ig fusion protein could obviously inhibit the cytotoxic activity of cytotoxic T lymphocyte.Modified dendritic cell s could resist the cytotoxic activity of cytotoxic T lymphocytes of different gr oup mice.Unmodified dendritic cells were susceptible to cytotoxic T lymphocytes of mice unsensitized or sensitized by unmodified dendritic cells.Conclusion:Dendritic cells stably expressing CTLA4Ig fusion protein can obviously decrease lymphocyte proliferation response of allogenic mice and reduce the cytotoxic act ivity.