【作者】 丁军颖；

【导师】 王润田；

【作者基本信息】 河北医科大学 ， 免疫学， 2006， 博士

【摘要】 目的:肿瘤是严重威胁人类生命健康的重大疾病,免疫功能与肿瘤的发生发展密切相关。随着对肿瘤发生、发展和治疗的研究,尤其是细胞与分子水平的研究逐步深入,转染抗瘤相关细胞因子基因,已成为探索肿瘤免疫的新热点。肿瘤免疫主要是细胞免疫,CD8~+细胞毒T细胞(CD8~+CTL)和NK细胞是细胞免疫的主体抗瘤细胞。IL-15是1994年发现,与IL-2有许多重叠生物活性的细胞因子;是能显著提高CD8~+CTL细胞和NK细胞增殖和杀瘤活性,而备受关注的抗瘤细胞因子。虽然已有一些关于IL-15基因转染肿瘤细胞对其在动物体内成瘤影响的报道,但原型IL-15基因转染的研究未达到预期的抗瘤效果,曾怀疑是其长信号肽影响分泌所致;转染促其分泌信号肽的改型IL-15基因研究也未达到预期结果。由于已知:CD8~+CTL杀瘤识别的抗原,需要肿瘤细胞表面的HLA I类分子提呈;CD8~+CTL的杀瘤功能活化,需要肿瘤细胞表面HLA II类分子提呈抗原激活的CD4~+Th细胞辅助;NK细胞杀瘤,需要肿瘤细胞对其杀伤敏感;肿瘤细胞表达NK细胞活化性受体NKG2D的配体MICA,可活化NK细胞对肿瘤细胞的杀伤;IFN-γ能活化CD8~+CTL细胞和NK细胞,并能促进HLA I类和II类分子表达。为此,本研究在已成功构建三种不同IL-15基因转染NCI-H446细胞(TC)模型基础上,研究不同IL-15基因转染,对NCI-H446细胞的HLA I类和II类分子及MICA基因表达、NK杀伤敏感性、诱导T细胞杀瘤和IFN-γ分泌的影响,从基因转染对肿瘤细胞免疫生物学特性改变的角度,揭示其肿瘤免疫的意义,为IL-15基因转染的抗瘤研究提供新的实验和理论依据。方法:1以野生株NCI-H446细胞(WC)为对照,分别检测不同IL-15基因转染对NCI-H446细胞的HLA I类和II类分子表达(直接免疫荧光FCM法)及对NK杀伤敏感性(MTT法)的影响。2在有或无实验选定无独立诱导PBMC增殖作用剂量IL-2存在下,分别更多还原

【Abstract】 Objective: Tumor threatens seriously the life and health of human. The immunofunction has a close relation with the generation and development of tumor. The anti-tumor cytokine gene transfections have become the new focus on exploring tumor immunity. CD8~+CTL and NK cells are important anti-tumor effectors. IL-15 shares similar biological activities with IL-2, and promotes the proliferation and anti-tumor effects of CD8~+CTL and NK cells greatly. Although the effect of IL-15 gene transfections on tumor had been reported, it was not satisfied. It was doubted that the inhibitory effect of the long signal peptide on IL-15 secretion was involved, but the modified IL-15 gene transfections with signal peptide that can increase IL-15 secretion was not satisfied either. It was known that the tumor antigen recognized by CD8~+CTL was presented by HLA I molecules on surface of tumor cells, the activation killing tumor of CD8~+CTL needed help of CD4~+Th activated by tumor antigen which was presented by HLA II molecules on the surface of tumor cells, NK cells only killed sensitive tumor cells, MICA(the ligand of NK cell activatory receptor NKG2D) expressed on tumor cells could activate the tumor-killing function of NK cells, and IFN-γcould activate CD8~+CTL and NK cells and up-regulate the expression of HLA I and HLA II molecules. Therefore, based on the three models of IL-15 gene transfective NCI-H446 cells (TC), we studied the effects of different IL-15 gene transfections into NCI-H446 on the expression of HLA I, HLA II and the MICA mRNA, on the NK sensitivity, on the inducing T cells to kill tumor cells, and on the IFN-γsecretion. So it would reveal implication of tumor immunity, and provide experimental and theoretic evidence in point of immunobiological characteristics of tumor cells changed by IL-15 gene transfections.Methods:更多还原