ABSTRACT
Objective To investigate.the co-stimulatory pathway of gastric cancer patients by examining the expression of co-stimulatory molecules CD28,CTLA.4(CDl 52)and B7 molecules on peripheral blood lymphocytes(PBLC)in patients with gastric cancer,and to discuss the role of costimulatory pathway in the pathogenesis of gastric cancer.Methods The expression of CD28,CD152,CD3,CD4,CD8 and B7 molecules on peripheral blood lymphocytes and T cell subpopulation were measured by flow cytometry in 56 patients with gastric cancer,and the data was compared and analyzed with that in gastric benign tumor group and healthy control group.Results The expression levels of CD3+,CD4+,CD3+ CD28+,B7-1(CD80),B7-2(CD86)and CD41/CD8+on PBLC in patients with gastric cancer was significantly lower than that of benign stomach tumor group and healthy control group.The expression levels of CD3+ CDl52+ and CD8+ on PBLC in patients with gastric cancer were significantly higher than those of gastric benign tumor group and healthy control group.Conclusion Peripheral lymphocytcs in gastric cancer patients express low level of CD28 and B7 molecules and high level of CDI 52 molecules,which results in dysfunction of B7:CD28/CTLA-4 co-stimulation pathway and in turn affects the capacity of T cell to eliminate tumor cells,which makes tumor cells evading the immune surveillance and metastasizing.