Rescue of iCIKs transfer from PD-1/PD-L1 immune inhibition in patients with resectable tongue squamous cell carcinoma (TSCC).

Objectives The purpose of this study is to evaluate the therapeutic efficacy and the role of PD-1/PD-L1 pathway in tongue squamous cell carcinoma (TSCC) patients treated with radical operation combined with chemotherapy and improving cytokine induced killer cells (iCIKs) transfer. Methods Thirteen patients who received radical resection and chemotherapy were enrolled in this study. PD-1/PD-L1 expression was evaluated in TSCC patients. ICIKs were cultured from patient-derived peripheral blood mononuclear cells (PBMCs) in vitro. The immunological differences underlying iCIKs transfer were investigated through phenotype, cytokine secretion and PD-1/PD-L1 inhibition analysis. Results The serum PD-L1 levels were elevated in the TSCC patients. PD-L1 was detected on both human TSCC cells and tumour tissue sections. PD-1 expression was much higher on the PBMCs of TSCC patients than on in vitro cultured iCIKs. Interruption of PD-1/PD-L1 interaction enhanced the cytotoxicity of iCIKs in vitro. CD3 + CD8+ T cell proportion and cytokine IL-6 secretion decreased after chemotherapy. The infusion of iCIKs effectively reversed the immunosuppression through the upregulation of the CD3 + CD8+ T cell proportion and Th cell cytokine secretion (IFN-γ, TNF-α, IL-4 and IL-6). Twelve responders are currently alive (95.7+ months), another patient 83 months. Conclusion Our findings indicated that the PD-1/PD-L1 interaction contributes to the immunosuppression in TSCC patients. ICIKs transfer is an effective therapy to reverse the immunosuppression caused by surgical procedures and chemotherapy and improve immune system function. [ABSTRACT FROM AUTHOR]