OX40 enhances T cell immune response to PD-1 blockade therapy in non-small cell lung cancer

Immune-checkpoint blockade is widely studied for cancer therapy. Although the co-inhibitory receptor Programmed death-1(PD-1) blockade benefits some non-small cell lung cancer (NSCLC) patients, a large portion of NSCLC patients still fail to respond to this immunotherapy, and the underlying mechanism is unclear. Thus, a synergistic therapy to enhance the effect of PD-1 is urgently needed to improve the poor outcome of NSCLC patients. Here, we demonstrated that effector memory T cells were increased and T cell response became stronger in PD-1 immunotherapy responders (n = 20) but not in non-responders (n = 10). The expression of co-stimulatory receptor OX40 was upregulated on T cells following PD-1 immunotherapy and was positively associated with the percentage of PD-1