摘要目的 探讨转化生长因子(TGF) -β1基因转染后树突状细胞(DC)细胞表型和免疫生物学功能的变化.方法 利用大鼠骨髓细胞诱导、培养不成熟树突状细胞(imDC),以脂质体介导的pIRES2-EGFP-hTGF-β1转染imDC细胞,通过酶联免疫吸附试验(ELISA)和Western blot法检测转染后各组imDC培养上清TGF-β1蛋白表达；通过流式细胞法、免疫细胞化学法及混合淋巴细胞反应检测各组imDC表面分子的分子表型和免疫功能变化.结果 TGF-β1基因转染的imDC上清中均检测相应蛋白的高表达,TGF-β1基因转染组TGF-β1蛋白表达(252.75±11.31) μg/L均高于mDC组(11.19±2.29) μg/L、imDC组(35.18±6.17) μg/L、空载体组(33.67±4.61)μg／L；基因转染组的表面分子CD86、CD80及MHCⅡ表达明显低于空载体组和无任何转染的imDC组；基因转染组的imDC对T的增殖研究结果显示有显著抑制作用,低于空载体和无任何转染的imDC组.结论 TGF-β1基因成功导人imDC,基因改造的imDC不但能维持不成熟状态同时分泌免疫耐受抑制蛋白,致免疫耐受作用显著增强.

abstractsObjective To assess the biological functions of transforming growth factor-β1 (TGF-β1 ) in rat bone marrow-derived dendritic cells (DCs).Methods In the in vitro study,rat bone marrowderived imature dendritic cells (imDCs) and mature DCS (mDCs) were obtained after primary culture of bone marrow cells in RPMI 1640 medium with different cytokines.We used imDCs transfected with plasmid vectors encoding TGF-β1,imDCs transfected with plasmid vectors encoding enhanced GFP ( eGFP),untransfected imDCs,and un-transfected mDCs.The latter three kinds of imDCS were used as controls.CD86,CD80,and MHC class Ⅱ were compared by using flow cytometry and immuocytochemistry,and T lymphocyte proliferation was observed under mixed lymphocyte reaction.The biological functions of TGF-β1were assessed in rat bone marrow-derived DCs between two groups.Results The expression of TGF-β1 in imDCs transfected with TGF-β1 genes was (252.75 ± 11.31 ) μg/L,which was higher than in imDC group (35.18 ±6.17) μg/L,vector only imDC group (33.67 ±4.61 ) μg/L and mDC group ( 11.19 ±2.29)μg/L.The expression of MHC class Ⅱ,CD80 and CD86 in imDCs transfected with TGF-β1 genes was lower than the other three groups.These results suggest that the expression of MHC class Ⅱ,CD80 and CD86 can be significantly down-regulated,especially in imDCs transfected with TGF-β1.Strong allergenic T lymphocytes proliferation was induced in mDCs,and imDCs transfected with TGF-β1gene showed lower capability in stimulating T lymphocyte proliferation than the other groups.Conclusion The present study demonstrated that TGF-β1 gene can be successfully transferred to imDCs through plasmid vectors.The use of plasmid vectors encoding TGF-β1 gene can inhibit multiple immunological functions of imDCs and enhance their tolerogenicity.