Dendritic Cells in Cancer Immunology and Immunotherapy

Simple Summary Although immune check point inhibitors have been established as a new paradigm in cancer treatment, they have shown no clinical benefit in immune excluded or dessert tumors. Dendritic cells promote and coordinate the immune system. Dendritic cell vaccination enriches tumor milieu and potentiates patient systemic antitumoral responses. In this work we review the strengths and weaknesses of dendritic cell vaccines in different solid tumors regarding their role to improve their clinical efficacy. To date, dendritic cell vaccines have induced immune responses in patients without a significant impact on outcome. Improvements in vaccine formulations, selection of patients and combinations with other antitumoral therapies are needed to increase patients' survival.Abstract Cancer immunotherapy modulates the immune system, overcomes immune escape and stimulates immune defenses against tumors. Dendritic cells (DCs) are professional promoters of immune responses against tumor antigens with the outstanding ability to coordinate the innate and adaptive immune systems. Evidence suggests that there is a decrease in both the number and function of DCs in cancer patients. Therefore, they represent a strong scaffold for therapeutic interventions. DC vaccination (DCV) is safe, and the antitumoral responses induced are well established in solid tumors. Although the addition of checkpoint inhibitors (CPIs) to chemotherapy has provided new options in the treatment of cancer, they have shown no clinical benefit in immune desert tumors or in those tumors with dysfunctional or exhausted T-cells. In this way, DC-based therapy has demonstrated the ability to modify the tumor microenvironment for immune enriched tumors and to potentiate systemic host immune responses as an active approach to treating cancer patients. Application of DCV in cancer seeks to obtain long-term antitumor responses through an improved T-cell priming by enhancing previous or generating de novo immune responses. To date, DCV has induced immune responses in the peripheral blood of patients without a significant clinical impact on outcome. Thus, improvements in vaccines formulations, selection of patients based on biomarkers and combinations with other antitumoral therapies are needed to enhance patient survival. In this work, we review the role of DCV in different solid tumors with their strengths and weaknesses, and we finally mention new trends to improve the efficacy of this immune strategy.