Effects Of Different IL-15 Gene Transfections Into NCI-H446 On The Immunobiological Characteristics

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:...