ANALYSIS OF CD8+CD28- T-SUPPRESSOR CELLS IN GASTRIC CANCER PATIENTS

Host anti-tumor immune responses can be attenuated by suppressor T cells of the phenotype CD8(+) CD28(-) (T-s cells). In the present study, we investigated the presence of CD8(+) CD28(-) (T-s cells) in the peripheral blood compartment of gastric cancer (CC) patients. How cytometry was used to detect the population of CD8(+) CD28(-) T-s cells present in peripheral blood in therapy naive patients with gastric cancer (n = 26), postoperative chemotherapy naive gastric cancer patients (n = 23), and healthy controls (n = 27). Meanwhile, the clinical data of gastric cancer patients were analyzed. A significant difference in the percentage of T-s cells was observed when comparing peripheral blood samples from cancer patients to healthy volunteers (27.08 +/- 1.60% versus 10.86 +/- 0.75%). In the patient group, the percentage of CD8(+) CD28(-) cells among lymphocytes was higher in patients with LN metastasis than those without LN metastasis. The percentage of CD8(+) CD28(-) cells was also related to tumor infiltration and size, but not with the degree of differentiation of cancer cells. Moreover, the percentage of CD8(+) CD28(-) cells was higher in preoperative gastric cancer patients (26.24 +/- 1.78%) than in those of postoperation patients (15.79 +/- 1.11%). These findings may reflect the possibility of tumor-induced immunosuppression, and they should be complemented with further studies.