The peripheral blood samples from 20 GC patients and 20 healthy volunteers were obtained. The peripheral blood mononuclear cells were isolated and incubated in a solution containing phorbol-myristate-acetate and ionomycin (2 μL/mL) in the presence or absence of morphine (50 ng/mL) or different-concentration ketamine (25, 50, and 100 μM). The CD4+ T cells, CD8+ T cells, and Tregs were determined using the flow cytometric assay.
The percentages of CD8+ T cells were significantly decreased, but the ratio of CD4+/CD8+ T cells and Tregs populations was significantly increased in the GC control group compared with the normal control group (P < 0.05). The ratio of CD4+/CD8+ T cells was significantly increased in the groups M and K3 compared with the control group (P < 0.05) but was significantly decreased in the group K1 compared with the group K3. The percentage of Tregs was significantly increased in the groups M, K1, K2, and K3 compared with the control group. With the increased concentrations, ketamine increased the number of Tregs.
GC shifts the balance of CD4+/CD8+ T cells toward CD4+ T cells and increases the Tregs populations by inducing immune responses. Morphine increases the ratio of CD4+/CD8+ T cells and Tregs populations. Ketamine affects the ratio of CD4+/CD8+ T cells and Tregs populations in a dose-dependent model.