激动型CD40单克隆抗体体外抑制结肠癌细胞增殖的实验研究

目的 探讨激动型CD40单克隆抗体在体外对结肠癌细胞增殖的抑制作用.方法 树突状细胞(DCs)经结肠癌冻融抗原致敏后予以不同条件激活,分为激动型CD40单克隆抗体组、阴性对照组及肿瘤坏死因子-α(TNF-α)阳性对照组,诱导培养至第7天,用流式细胞仪检测各组DCs表面分化相关抗原CD80、CD83、CD86和HLA-DR的表达,酶联免疫吸附测定法检测DCs培养液上清中白细胞介素-12(IL-12)的质量浓度,噻唑蓝比色法检测DCs体外刺激T淋巴细胞增殖的能力,进而检测DCs所诱导的肿瘤特异性细胞毒性T淋巴细胞(CTL)对人结肠癌细胞HCT116的杀伤作用.结果 与阴性对照组相比,激动型CD40单克隆抗体组活化的DCs表面抗原CD80、CD83、CD86和HLA-DR的表达率均显著升高(均P＜0.05),DCs上清中IL-12的质量浓度亦显著升高((716.80±53.43) pg/ml比(405.51±12.17) pg/ml,P＜0.05),活化的DCs具有更强的刺激T淋巴细胞增殖的能力(刺激指数2.006 2±0.438 3比1.365 0±0.209 8,P＜0.05),活化的DCs所诱导的CTL对HCT116细胞具有更强的杀伤作用(抑制率(66.08±0.41)％比(46.60±1.10)％,P＜0.05);而与TNF-α阳性对照组相比,其差异均无统计学意义(均P＞0.05).结论 激动型CD40单克隆抗体在体外可促进DCs的活化与成熟,进而诱导肿瘤特异性CTL的产生,从而抑制人结肠癌细胞HCT116的增殖.

The proliferation inhibition of colon cancer cells by agonistic CD40 monoclonal antibody in vitro

Objective To investigate the inhibitory effect of agonistic CD40 monoclonal antibody on the colon cancer cells (HCT116) proliferation in vitro.Methods The DCs (dendritic cells) loaded with tumor cells (HCT116) antigens were activated by different methods.According to the activation method,the cells were divided into three groups:agonistic CD40 monoclonal antibody group,blank control group and TNF-α positive control group.The cells were cultured for 7 days,and the expression rates of CD80,CD83,CD86 and HLA-DR on DC surface in each group were detected by flow cytometry.The concentration of cytokine IL-12(p70) in DCs culture supernatant was determined by ELISA kit.The proliferation activity of the T lymphocytes was evaluated by MTT (methyl thiazolyl tetrazolium).Then the inhibition rate of colon cancer HCT116 cells proliferation,which induced by the tumor-specific effector T lymphocytes,was assayed.Results Compared with the blank control group,the agonistic CD40 monoclonal antibody group had a significantly higher expression rates of CD80,CD83,CD86 and HLA-DR on DC surface (P＜0.05).The concentration of IL-12 in the supernatant of DC was also much higher in the agonistic CD40 monoclonal antibody group (P＜0.05,(716.80±53.43) pg/ml vs.(405.51 ±12.17) pg/ml).The DCs activated by CD40 monoclonal antibody had stronger ability to stimulate proliferation of T lymphocytes (P＜0.05,the stimulation index was (2.006 2±0.438 3) to (1.365 0±0.209 8)).The tumor-specific CTLs induced by DCs in the agonistic CD40 monoclonal antibody group had stronger ability to inhibit colon cancer HCT116 cells (P＜0.05,the inhibition rate was (66.08±0.41)％ vs.(46.60± 1.10)％).However,there was no statistical significance between the agonistic CD40 monoclonal antibody group and the TNF-α positive control group (P＞0.05).Conclusion Agonistic CD40 monoclonal antibody in vitro can promote activation and mature of DCs,then the activated DCs can induce the production of tumor-specific CTL,which can significantly inhibit the proliferation of colon cancer HCT116 cells.