MHC-Ⅰ类链相关基因A修饰的口腔鳞癌细胞疫苗诱导抗肿瘤免疫应答的实验研究

Antitumor immune response of MHC classⅠchain-related gene A modified oral squamous cell carcinoma vaccine:An experimental study in mice

目的:研究MHC-Ⅰ类链相关基因A(MHC classⅠchain-related gene A,MICA)修饰的口腔鳞癌疫苗诱导机体抗肿瘤免疫应答的有效性并探讨其作用机制。方法:灭活稳定转染MICA基因的口腔鳞癌细胞,制备成肿瘤疫苗,通过腹腔注射严重联合免疫缺陷(severe combined immunodeficiency,SCID)鼠,观察其对皮下移植瘤生长的抑制作用;应用流式细胞术和乳酸脱氢酶(lactate dehydrogenase,LDH)释放法检测免疫重建荷瘤SCID鼠外周血单个核细胞(peripheral blood mononuclear cell,PBMC)和脾细胞表面NKG2D的表达及对肿瘤靶细胞的杀伤活性。采用SPSS16.0软件包对数据进行统计学处理。结果:转染MICA基因的口腔鳞癌疫苗能显著抑制免疫重建荷瘤SCID鼠皮下移植瘤的生长,上调PBMC和脾细胞表面NKG2D的表达,并增强对肿瘤靶细胞的杀伤活性,与未转染组及转染空白载体组比,差异有统计学意义(P<0.05)。结论:过表达MICA蛋白的口腔鳞癌疫苗能显著增强机体的抗肿瘤免疫应答能力,MICA有望作为口腔鳞癌免疫基因治疗的潜在靶标。

PURPOSE： To investigate the vaccine potency of MHC classⅠchain-related gene A（MICA） modified oral squamous cell carcinoma cells.METHODS： Oral squamous cell carcinoma Tb cells transfected with eukaryotic expression vector pEGFP-N1-MICA and overexpressing MICA protein were inactivated by 120Gy irradiation and vaccinated human peripheral blood leucocytes reconstituted SCID（Hu-PBL/SCID）mice via intra-peritoneal injection,and the non-transfected or blank vector transfected Tb cells were used as the controls.The inhibition effect on tumorigenicity of subcutaneously challenged Tb cells in vaccinated Hu-PBL/SCID mice was detected.The expression of NKG2D and the cytotoxicity in vitro to Tb cells of peripheral blood mononuclear cells（PBMCs） and spleen cells were measured by flow cytometry and lactate dehydrogenase（LDH） release assay.SPSS16.0 software package was used for statistical analysis.RESULTS： MICA gene modified Tb tumor vaccine resulted in remarkable loss of tumor size and tumor weight in vaccinated Hu-PBL/SCID mice.Flow cytometry and lactate dehydrogenase（LDH） release assay showed MICA gene modified Tb tumor vaccine up-regulated the expression of NKG2D on PBMC and spleen cells and enhanced the cytotoxicity to tumor cells.Significant difference was found between MICA-transfected vaccine and non-transfected and blank vector-transfected vaccine（P0.05）.CONCLUSIONS： MICA gene modified oral squamous cell carcinoma vaccine can enhance the ability of antitumor immune response,and MICA may be considered as a promising immunotherapy target of oral squamous cell carcinoma.