Increased cycles of DC/CIK immunotherapy decreases frequency of Tregs in patients with resected NSCLC

Abstract Regulatory T cells (Tregs) suppress antitumor immune responses. Cycles of Dendritic cells (DC) vaccination combined with cytokine-induced killer (CIK) cells (DC/CIK) treatment were significantly related with good prognosis. Therefore, we investigated whether increased cycles of immunotherapy could decrease frequency of Tregs in patients with resected non-small cell lung cancer (NSCLC). Previous study from our laboratory has determined that the optimal cutoff point of the cycle count was 3 cycles. We examined the levels of Tregs and the related cytokines by flow cytometric and cytokine analysis in these patients after more than (≥) 3 cycles or less than (