Clinical relevance of the number of interleukin-17-producing CD 8+ T cells in patients with gastric cancer.

PURPOSE

There is accumulating evidence that inflammation is linked to cancer development and progression. Interleukin-17 (IL-17), an inflammatory cytokine, is produced by CD 8+ T cells (Tc17 cells); however, the specific role of Tc17 cells in tumor immunity against gastric cancer remains unclear.

METHODS

The prevalence of Tc17 cells in both peripheral blood mononuclear cells and gastric tissue was evaluated by multicolor flow cytometry and the concentration of IL-17 in sera was quantitated by an enzyme-linked immunosorbent assay.

RESULTS

Circulating Tc17 cells were significantly more numerous in gastric cancer patients than in controls, and significantly more numerous before surgery than after surgery. IL-17 concentrations in gastric cancer patients and healthy controls were 0.51 ± 0.54 and 0.084 ± 0.084 pg/mL, respectively, with this difference being significant. The percentage of Tc17 cells was significantly related to serum IL-17 concentration. Tc17 cells were significantly more numerous than peripheral blood mononuclear cells in gastric cancer tissue. Furthermore, Tc17 cells were more numerous in cancerous gastric tissue than in normal gastric tissue.

CONCLUSIONS

Tc17 cells may be the main source of IL-17 in gastric cancer patients and thus involved in the progression of gastric cancer.