高免疫原性胶质瘤细胞疫苗体外诱导Th-1漂移研究

目的 观察高免疫原性即膜型热休克蛋白70(HSP70)及主要组织相容性抗原复合体Ⅰ类分子(MHC-Ⅰ)双高表达人多形性胶质母细胞瘤U251(GBM U251)细胞疫苗在体外诱导Th-1漂移现象.方法 GBM U251分别以500 U/mL IFN-γ诱导48 h、43℃热休克2 h、500 U/mLIFN-γ诱导48 h+43℃热休克2 h诱导其MHC-Ⅰ类分子、膜型HSP70高表达,随后经丝裂霉素(MMC)灭活制成细胞疫苗.体外刺激健康捐献者外周血单个核细胞(PBMCs)作为效应细胞,进行肿瘤特异性杀伤试验;FCM检测疫苗刺激前后PBMCs CD4<'+>、CD8<'+>T淋巴细胞比例变化;ELISA法检测效应细胞攻击靶细胞后的IFN-γ、IL-2的分泌情况.结果 体外刺激后,HSP70和MHC-Ⅰ类分子双高表达的U251细胞疫苗CD4<'+>、CD8<'+>比例相对于MHC-Ⅰ类分子单高表达或HSP70分子单高表达细胞疫苗组明显增加,体外IFN-γ和IL-2分泌量亦增加,差异均有统计学意义(p<0.05).结论高免疫原性即HSP70和MHC-Ⅰ类分子双高表达U251细胞疫苗体外诱导产生Th-1漂移现象,推测是其体外抗瘤作用的重要机制之一.

Th-1 drift induced by glioma cell vaccine with high immunogenicity in vitro

Objective To observe Th-1 drift induced in vitro by high immunogenic glioblastoma multiforme (GBM) U251 cell vaccine with high expression of membrane-enriched heat shock protein 70 (Hsp70) and major histocompatibility complex class Ⅰ (MHC-Ⅰ) molecules. Methods The high expression of MHC-Ⅰ and Hsp70 in U251 cells were induced by 500 U/ml IFN-γ for 48 h, heat shock at 43 ℃ for 2 h, or their combination. The cells were then inactivated by the mitomycin C (MMC) to prepare the cell vaccine. Peripheral blood mononuclear cells (PBMCs) from healthy donators were incubated with GBM U251 cell vaccines as the effector cells. Flow cytometry was applied to analyze the changes of CD4<'+> and CD8<'+>T lymphocytes in the PBMCs. The secretion of IFN-γ and IL-2 of the effector cells, after assaulting the target cells, was evaluated by ELISA. Results The percentages of CD4<'+> and CD8<'+> T lymphocytes of the PBMCs incubated with the U251 cell vaccine increased significantly as compared to that stimulated by the membrane-enriched MHC class Ⅰ or Hsp 70 molecule U251 cell vaccines (P<0.05), and so was the secretion of IFN-γ and IL-2 (P<0.05). Conclusions Th-1 drift stimulated by GBM U251 cell vaccine with high immunogenicity, high expression of Hsp 70 and membrane-enriched MHC class Ⅰ molecules plays an important role in antitumor mechanism in vitro.