树突状细胞功能异常对结直肠癌肝转移的影响

Peripheral dendritic cell dysfunction and liver metastasis in colorectal cancer patients

目的探讨树突状细胞（DC）功能异常对结直肠癌肝转移的影响及其意义。方法收集2008年1月至2010年6月健康成年人30例、结直肠癌术前、术后无肝转移者30例和术后肝转移30例患者外周血，分离单核细胞后分别加入GM—CSF（1000U／ml）、IL-4（1000U／m1）和TNF-α（1000U／ml）诱导分化成熟DC，通过加入HT29大肠癌细胞抗原处理（100μg／ml）或不处理，DC：T细胞为1：10，培养7d，用ELISA方法测定培养液中IFN-γ和IL-10水平，酶标仪测定CCK8和LDH光密度（OO）值，间接测定T细胞增殖和杀伤能力。结果结直肠癌术后肝转移患者外周血DC在无肿瘤抗原刺激时与健康人T细胞混合培养液IL-10水平显著低于结直肠癌术前患者和健康人[（11．9±1．3）pg／ml比（29．6±9．7）pg／ml、（23．4±8．0）pg／ml，F=4．475，P〈0．05]。结直肠癌术后肝转移患者外周血DC经肿瘤抗原刺激与健康人T细胞混合培养液IFN-γ水平均显著高于结直肠癌术后和健康人[（34±9）pg／ml比（26±12）pg／ml、（24±6）pg／ml，F=5．206，P〈0．05]。结直肠癌术后肝转移患者DC经HT29肠癌细胞抗原刺激后诱导健康人T淋巴细胞杀伤能力显著高于结直肠癌术前患者和健康成年人[（30．6±8．6）pg／ml比（12．1±2．4）pg／ml、（14．9±1．7）pg／ml，F=4．147，P〈0．05]。结论结直肠癌患者外周血DC在肿瘤抗原刺激下诱导T淋巴细胞产生IL-10，导致肿瘤免疫逃逸，发生肝转移；外源肿瘤抗原刺激能够提高T淋巴细胞杀伤能力。

Objective To observe the clinical significance and effect of dysfunction of dendritic cell（DC） in colorectal cancer with liver metastasis. Methods Peripheral blood were respectively collected from healthy adult donors （30 cases）, preoperative and postoperative coloreatal cancer patients without liver metastasis （30 cases）, and 30 postoperative coloreatal cancer patients with liver metastasis from Jan 2008 to Jun 2010. Peripheral blood mononuclear cells were separated, GM-CSF （ 1000 U/ml）, IL-4 （ 1000 U/ml） and TNF-α（ 1000 U/ml） were added into cell culture fluid to induce the mononuclear cells for mature dendritic cells. There were two subgroups, and in antigen processing subgroup the lysate of HT29 colonic carcinoma ceils （ 100μg/ml） were added into the cell culture fluid. The T lymphocytes from healthy adults were added into two subgroups by ratio of 1 ： 10 （ DCs： T cells）, cocuhured for 7 days. The level of INF-γ/ and IL-10 in cell culture fluid was assayed with ELISA method. The optical density （OD） of CCK8 ans LDH was assayed with ELIASA to indirectly measure the reproductive activity and the killing efficacy of T lymphocytes. Results The IL-10 level in cocultured fluid of peripheral blood DCs in postoperative colorectal carcinoma patients with liver metastasis and T lymphocytes of healthy adults was significantly higher than that of preoperative patients of colorectal carcinoma and health adults without tumor antigenic stimulation（ 11.9± 1.3 ） pg/ml vs. （29. 6± 9.7 ） pg/ml, （23.4 ± 8.0） pg/ml, F = 4. 475, P 〈 0.05 ）. The IFN-γ/level in cocultured fluid of peripheral blood DCs in postoperative colorectal carcinoma patients with liver metastasis and T lymphocytes of healthy adults was significantly higher than that of postoperative patients of colorectal carcinoma and healthy adults with or without tumor antigenic stimulation （34±9） pg/ml vs. （26 ±12） pg/ml, （24 ±6 ） pg/ml, F = 5. 206, P 〈 0. 05 ）. The killing activity of healthy adults T lymphocytes induced by HT29 colonic carcinoma cells in postoperative colorectal carcinoma patients with liver metastasis was significantly higher than that of preoperative patients of coloreetal carcinoma and healthy adults （30.6±8.6） pg/ml vs. （12.1 ±2.4） pg/ml, （14.9±1.7） pg,/ml, F=4.147, P〈 0.05 ）. Conclusions T lymphocytes produce IL-10 when indued by DCs from patients with colorectal carcinoma under stimulation of tumor antigen leading to tumor immune escape and liver metastasis. The killing activity of T lymphocytes can be enhanced when stimulated by exogenous tmuor antigen.