The Study Of Association Between Indoleamine2,3-dioxygenase With Memory T Cells And Their Subpopulations In Microenviroment Of Gastric Cancer

Objective:Tumor could escape attacking from immune systems through many ways, IDO and memory T cells were two important factors among tumor immunity in recent years. Both of them played important roles in progress of tumors, also Treg cells had obvious influences on both of them, but it was still on debates whether there was connection between them. The purpose of this research was to discuss the expression of IDO and Treg cells’ marker Foxp3in the tumor microenvironment of patients with gastric cancer, and analyze the distribution of subsets of memory T cells in gastric cancer tissue. The relationship between IDO and memory T cells in tumor microenvironment with patients of gastric cancer would be further explored.Mertrials and Methods:1.50cases of gastric cancer patients were collected who were treated in Cancer Institute and Hospital of Tianjin Medical University from January2011to June2011, and then taking the tissue of gastric cancer, analyzing the expression of IDO and Foxp3in the tumor microenvironment by immunohistochemical method, and detecting the distribution of subsets of memory T cells in gastric cancer tissue by flow cytometry.2. For expression of IDO and Foxp3in the microenvironment of patients with gastric cancer, we analysised the relationship between both of them and clinical pathological features, and explored the relevance between them. We also analyzed the correlation between Treg cells and subsets of memory T cells, the relationship between IDO and memory T cells, and discussed the correlation between IDO and memory T cells.Results:1. In the microenvironment of gastric cancer, the level of IDO is connected to tumor infiltrating(χ2=5.773, P=0.016). The level of Foxp3had to do with age (F=4.071, P=0.049) and tumor infiltrating(F=5.303, P=0.026).2. The comparison of mean of Foxp3through different level of IDO had a statistical significance. Among this,(-) group and (++) group,(-) group and (+++) group,(+) group and (++) group,(+) group and (+++) group had statistical significances (F=1.76,P=0.02;F=3.91,P=0.034; F=1.65,P=0.041; F=3.80,P=0.039).3. Expression of Foxp3in gastric cancer had a positive correlation with distribution of CD8+Tem in tumor microenvironment(r=0.583, P<0.05), the linear regression equation was as follow:y=1.831+0.079x.4. Among memory T cells and their subpopulations in tumor microenvironment, with rising levels of IDO expression, CD8+Tem had upward trending. But there was no regularity about CD8+Tm and CD8+Tcm.Conclusion:1. The expression of IDO had a strong collection with tumor infiltrating in gastric cancer, suggested that the level of IDO was rising with increasing of tumor invasion. The expression of Foxp3was associated with tumor infiltrating and age. In tumor microenvironment of patients with gastric cancer, high level of IDO can take apart by inducing Treg cells-mediated immune suppression.2. Expression of Foxp3in gastric cancer has a positive correlation with distribution of CD8+Tem in tumor microenvironment. With the rising level IDO expression, CD8+Tem also showed an upward trending. It was suggested that there must be certain relationship between them. Treg cells, which weremarked by Foxp3, may mediate the regulation.