Dendritic Cells and Cancer Immunotherapy: The Adjuvant Effect

Abstract

Dendritic cells (DCs) are immune specialized cells playing a critical role in promoting immune response against antigens, and may represent important targets for therapeutic interventions in cancer. DCs can be stimulated ex vivo with pro-inflammatory molecules and loaded with tumor-specific antigen(s). Protocols describing the specific details of DCs vaccination manufacturing vary widely, but regardless of the employed protocol, the DCs vaccination safety and its ability to induce antitumor responses is clearly established. Many years of studies have focused on the ability of DCs to provide overall survival benefits at least for a selection of cancer patients. Lessons learned from early trials lead to the hypothesis that, to improve the efficacy of DCs-based immunotherapy, this should be combined with other treatments. Thus, the vaccine's ultimate role may lie in the combinatorial approaches of DCs-based immunotherapy with chemotherapy and radiotherapy, more than in monotherapy. In this review, we address some key questions regarding the integration of DCs vaccination with multimodality therapy approaches for cancer treatment paradigms.

Keywords: adjuvant therapy; cancer; dendritic cells; immunotherapy.

Figure 1

Combined therapy. Tumor escape mechanisms often inhibit the effect of dendritic cell vaccination. Conventional therapies such as chemo/radiotherapy can collaborate with DCs vaccination, promoting the activation of immune cells effectors and hampering the functions of immunosuppressive cells. Other innovative strategies are under investigation as a support to contrast tumor immune escape, such as inhibitors of Tregs and MDSCs; ICI, adoptive cells therapies and preconditioning of the pre-vaccine injection site.