【摘要】 目的:探讨胃肠肿瘤(GIC)患者外周血单个核细胞(PBMCs)来源树突状细胞(DCs)和CD4+CD25+T细胞(Tregs)的免疫功能状态,以及其与肿瘤临床病理分期和手术的关系。方法:收集早期胃肠癌(Ⅰ/Ⅱ期)患者术前、术后第7天以及晚期癌(Ⅲ/Ⅳ期)患者外周血,以健康成人外周血为对照。提取单个核细胞(PBMCs),流式细胞术(FACS)分别检测Tregs占CD4+T细胞的比例。PBMCs经贴壁法分离提取DCs,经rhGM-CSF、rhIL-4体外扩增培养至第5天,获得未成熟DCs(imDCs),FACS检测表型;imDCs经rhTNF-α诱导培养至第7天,获得成熟DCs(mDCs),MTT法和ELISA法分别检测mDCs与自体T细胞混合培养时mDCs刺激T细胞增殖能力以及上清液中IFN-γ的含量。结果:晚期胃肠癌患者imDCs表型HLA-DR、CD80及CD86均显著低于健康成人和早期癌患者(P<0·01);早期胃肠癌术后第7天患者imDCs表型HLA-DR及CD86表达显著低于健康成人(P<0·05)。晚期胃肠癌患者mDCs刺激自体T细胞增殖及分泌IFN-γ的能力与健康成人相比均有所减弱(P=0·073,P=0·182)CD4+T细胞中Tregs的比例显著低于健康成人和早期癌患者(P<0·001);早期胃肠癌患者术后Tregs比例略低于术前(P=0·148)及健康成人(P=0·068)。HLA-DR、CD86表达与Tregs比例呈负相关性。结论:胃肠肿瘤患者尤其晚期和术后患者外周血DCs功能失调以及Tregs失衡可能和机体抗肿瘤细胞免疫耐受密切相关。更多还原

【Abstract】 Objective:To investigate the immune functions of peripheral blood monocyte-derived dendritic cells (DCs) and the proportion of CD4+CD25+T cells(Tregs) in CD4+T lymphocytes of the patients with gastrointestinal carcinoma (GIC),and their correlation with clinicopathological staging and the operation.Methods:PBMCs were obtained from normal healthy donors,patients with early GIC (stageⅠ/Ⅱ),including pre-or postoperative patients,and with advanced GIC (stage Ⅲ/Ⅳ),respectively.The proportion of Tregs in CD4+T lymphocytes was calculated by flow cytometry.DCs were isolated from PBMCs of healthy donors and the patients and cultured to d5 in the presence of rhGM-CSF and rhIL-4 to generate immature DCs (imDCs).The expression of HLA-DR,CD80 and CD86 on surface of the imDCs was analyzed by flow cytometry.The imDCs were further matured (mDCs) with an extra incubation to d7 by adding rhTNF-α,and the capacity of mDCs for stimulating the proliferation of T lymphocytes and IFN-γ production in co-culturing mDCs with autologous T lymphocytes were measured by MTT assay and ELISA,respectively.Results:The expression levels of HLA-DR,CD80 and CD86 on imDCs from the patients with advanced GIC were significantly lower in comparison with those with preoperative early cancer and the healthy donors (P<0.01,respectively).The expression of HLA-DR and CD86 in postoperative patients with early GIC cancer was significantly down regulated in comparison with the healthy donors (P<0.05).In advanced GIC,T lymphocyte proliferation and IFN-γ production induced by mDCs tend to be decreased in comparison with healthy donors(P=0.073,P=0.182,respectively).The proportion of Tregs in advanced GIC was significantly increased when compared to the early cancers or healthy donors (P<0.001,respectively),and similar tendency was also observed in postoperative patients with early cancer when compared to those preoperative patients (P=0.148) and healthy donors (P=0.068).A negative correlation was observed between the expression of HLA-DR and CD86 molecules on imDCs and the proportion of Tregs in CD4+T lymphocytes.Conclusion:The dysfunction of peripheral blood dendritic cells and imbalance of Tregs in patients with GIC,especially in the patients with advanced cancers and postoperative patients,may play an important role in immunotolerance of the patients with GIC.更多还原