Changes in Treg cells and their cytokine production in the peripheral blood of gastric cancer patients following immunotherapy with DC-CIK cells

Objective: To assess changes in the proportion of CD4 ⁺ CD25 ⁺ FoxP3 ⁺ regulatory T (Treg) cells and their cytokine production in the peripheral blood of gastric cancer patients after immunotherapy with DC-CIK cells. Methods: This study enrolled 158 patients with gastric cancer who were admitted to the Biotherapy Center, Qingdao Center Hospital between April, 2009 and December, 2013. They received immunotherapy with DC-CIK cells for one to four cycles. At the end of the treatment, peripheral blood was collected. The proportion of Treg cells and levels of Treg cell-derived cytokines IL-10 and TGF-β1 were assessed by flow cytometry and ELISA respectively. Results: In patients (n=75) who received more than 3 cycles of immunotherapy, the proportion of Treg cells and levels of IL-10 and TGF-β1 were decreased significantly after DC-CIK therapy (Z＝−2.65, −3.21, −3.95, P<0.05). In patients who received less than 2 cycles of immunotherapy, the proportion of Treg cells and levels of IL-10 and TGF-β1 did not change significantly after treatment (P>0.05). In patients receiving the same number of cycle of treatment, the proportion of Treg cells and levels of IL-10 and TGF-β1 were not significantly different between recurrent and non-recurrence cases (P>0.05). Conclusion: Immunotherapy with DC-CIK cells for ≥3 cycles may significantly decrease the proportion of Treg cells and their cytokine levels in the peripheral blood. In the patients receiving treatment for the same number of cycles, recurrence has not effect on the proportion of Treg cells.