The human immune system can recognize and destroy cancer cells but cancer cells are capable of escaping from immune system by different ways, including the PD-1/PDL-1 axis and the VEGF signaling pathway. The PD-1/PD-L1 axis represents an adaptive immune resistance mechanism exerted by tumor cells. Previous study also revealed VEGF-A could induce tumor-associated macrophages, Treg cells, and myeloid-derived suppressor cells, creating an immunosuppressive microenvironment that prevent the maturation of dendritic cells (DCs) and inhibit the activation of NK cells and T cells. Our research group already completed some early phase clinical trials of DCs-based therapy, which illustrated tumor lysate or carcinoembryonic antigen (CEA) derived DCs-based therapy is feasible and safe in patients with advanced colorectal cancer and lung cancer, respectively. However, although DCs-based therapy elicited remarkable T-cell responses but mostly did not really transfer into significant clinical benefit in previous study. One possible reason is the lack of effective antigen and the immunosuppressive microenvironment. Now we are exploring another new strategy, prediction of neoantigen for priming DCs as cell-based therapy with or without booster of anti-VEGF/anti-PD-1.
Tumor lysate or carcinoembryonic antigen (CEA) derived DCs-based therapy is safe and can elicites remarkable T-cell responses but mostly did not really transfer into significant clinical benefit. One possible reason is the lack of effective antigen and the immunosuppressive microenvironment. Now we are exploring another new strategy, prediction of neoantigen for priming DCs as cell-based therapy with or without booster of anti-VEGF/anti-PD-1.