Understanding Dendritic Cells and Their Role in Cutaneous Carcinoma and Cancer Immunotherapy
Different DC subsets have unique roles in shaping the immune response. (a) LCs are key mediators of cellular immunity and will preferentially activate CD8+ T cells and NK cells through the secretion of IL-15. LCs are also capable of cross-presenting foreign antigen, which results in a robust proliferation of naive CD8+ T cells and the generation of a highly specific cytotoxic T cell (CTL) response. This may contribute to the formation of immunologic memory. (b) PDCs respond to foreign antigen with the release of large amounts in IFN-α. This serves to activate a predominantly CD8+ and NK cell response. (c) Dermal CD14+ DCs are critical in the regulation of humoral immunity. When activated, they secrete IL-6 and IL-12, which promotes IgM secretion from naive B cells and the generation of mature antibody-secreting plasma cells. IL-12 will also trigger the differentiation of T follicular helper cells (Tfh) from CD4+ T cells, which may contribute to the formation of memory B cells.