Effects of adaptive immune cell therapy on the immune cell profile in patients with advanced gastric cancer

BACKGROUND: Immunotherapy for cancer patients has been the subject of attention in recent years. In this study, we investigated whether αβT‐cell therapy causes changes in the host's immune cell profile, and if so, the effect of these changes on prognosis. METHODS: Peripheral blood mononuclear cells (PBMCs) from 30 gastric cancer patients who had completed one course of αβT‐cell therapy were analyzed. The peripheral blood immune cell profile was established using PBMCs by counting the frequency of CD4+ helper T cells, CD8+ killer T cells, regulatory T cells (Tregs), and myeloid‐derived suppressor cells and measuring the expression of their surface markers. The changes after treatment and their association with response to treatment were investigated. RESULTS: Immune cell profiles changed greatly after treatment. The frequency of CD4+ helper T cells decreased, but that of CD8+ killer T cells increased. The frequency of programmed cell death 1 (PD‐1)+ effector Tregs increased significantly, but only in the non‐progressive disease (non‐PD) group, in which it was significantly higher compared with the PD group. Patients in whom the frequency of PD‐1+ effector Tregs increased had a significantly better prognosis than those in whom it decreased. CONCLUSION: Our results suggested that αβT‐cell therapy changes the host's immune cell profile, and an increase in PD‐1+ effector Tregs may help improve prognosis.