| Background and Objective:In china, PLC is one of high incidence rate malignant tumor, and its mortality ranks 3th in the digestive system cancer. The present treatment of PLC mainly through the surgery, radiotherapy, chemotherapy, biotherapy and auxiliary assist and recently the immunotherapy have attracted special attention. Recently, the T cell immune and the negative stimulus molecuie B7-H4 immune response have attracted special attention in tumortherapy. T cell immune plays important role in tumor immune response. Two signals are required in T cell activation and proliferation. The first signal by antigen presenting cells (APC) on the major histo-compatibility complexes (MHC) molecules and the receptor of T cell (TCR) complexes interaction. The second signal by coordinated stimulus molecule on the surface of the A PC and the receptor of T cell (TCR) complexes interaction. The coordinated stimulus molecule can enhance and maintain the postive second signal of T cell. On the other hand, it can reduce the negetive second signal of T cell. When lack of coordinated stimulus signal, it leads to inhibition of T-lymphocytes and immune suppression and escape in tumor cells. B7-H4 belongs to B7 immunoglobulin superfamily, which is a T cell co-stimulatory molecule to down-regulate the T cell-mediated immune response and lead to tumor immune suppression. Early for the subject we have made some related research and achieve some results:(1). B7-H4 expression is detected by Immunofluorescence staining in 80 cases of PLC and adjacent PLC tissues and 20 cases of liver tissue. Results of the statistical analysis shows the B7-H4 of PLC expression is higher than adjacent PLC tissues and normal liver tissue. (2). The number of tumor-infiltrating CD4+T and CD8+T lymphocytes and their TGF-β1 and IFN-.-.secretion in 80 cases of PLC and adjacent PLC tissues is detected by Immunofluorescence staining. The result shows expression of B7-H4 in PLC is significant negatively correlated with CD4 positive and CD8 positive T-lymphocytes infiltration and their TGF-β1 and IFN-γ secretion. (3). The purified CD8+T are isolated by magnetic activated cell sorting from PLC and adjacent PLC tissues. Using Western blot technique to detect B7-H4, IFN-..and PI3K/AKT/mTOR related protein expression in purified CD8+T cell. Results indicate that B7-H4 is up-regulated and IFN-.-.is down-regulated Similarity and P-AKT/AKT↑↑P-mTOR/mTOR are markedly up-regulated in purified CD8+T cell, which indicated that the expression levels of B7-H4 induced autophagy in CD8 positive T-lymphocytes indeed. Now, combining with previous results, we detect AT G7↑↑ATG5-ATG12↑↑LC 3Ⅰ ↑↑LC3Ⅱ related protein expression and mRNA of ATG7↑↑LC3II expression in purified CD8+T cell which is isolated by magnetic activated cell sorting from PLC and adjacent PLC tissues. Aanlysis of the B7-H4 high expression effects on T cell immune suppression in PLC tissue.Method:The purified CD8+T were isolated by magnetic activated cell sorting from PLC and adjacent PLC tissues. One side, using Western Blot technique to detect ATG7↑↑ATG5-ATG12↑↑LC3Ⅰ and LC3Ⅱ related protein expression in purified CD8+T cell. On the other hand, using real-time quantitative PCR to detect the mRNA expression of ATG7 and LC3II. Using SPSS13.0 software to analyze experimental data. The statistical method is:two sample test, p<0.05, the difference is statistically significant. To investigate the B7-H4 high expression in PLC tissue effects on T cell i mmune suppression.Result:(1) The autophagy related proteins of LC3I proteins expression in PLC is significantly lower than adjacent PLC tissues. The result has statistical significance ( t=6.72 , P=0.001)(2) The autophagy iconic proteins of LC3Ⅱ proteins expression in PLC is significantly higher than adjacent PLC tissues. The result has statistical significance (t=6.68,P=0.001)(3) The autophagy related proteins of ATG7 proteins expression in PLC is significantly higher than adjacent PLC tissues. The result has statistical significance ( t=4.49,P=0.004)(4) The autophagy related proteins of ATG5-ATG12 proteins expression in PLC is significantly higher than adjacent PLC tissues. The result has statistical significance ( t=4.72,P=0.003)(5) The autophagy related proteins of ATG7 mRNA expression in PLC is significantly higher than adjacent PLC tissues. The result has statistical significance (t =4.14,P=0.025)(6) The autophagy iconic proteins of LC3Ⅱ mRNA expression in PLC is significantly higher than adjacent PLC tissues. The result has statistical significance (t=4.29,P=0.005) Conclusion:The autophagy related proteins of ATG7↑↑ATG5-ATG12 and LC3Ⅱ proteins expression in PLC is significantly higher than adjacent PLC tissues. The autophagy related proteins of LC3I proteins expression in PLC is significantly lower than adjacent PLC tissues. Meanwhile,the autophagy related proteins of ATG7↑↑LC3Ⅱ mRNA expression in PLC is significantly higher than adjacent PLC tissues which consistent with protein expression. The Conclusion is high expression of B7-H4 in PLC leads to CD8+T abnormal autophagy which suppress T cell immune function and reduce the antitumor effect of T cells. Eventually lead to tumor immune suppression and immune escape. |
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