Fig. 4

Cellular cancer immunotherapy by using Th17 cells and DC vaccine cocktail. Proinflammatory T helper 17 (Th17) cells, one of the CD4+ T cells, can produce IL-17 and protect cells against microbial infection, expressing RORγt (orphan nuclear receptor) [143], while excessive activation of Treg cells suppresses antipathogenic or anticancer immunity by inactivation of Th1, CTL and NK cells [220], leading to chronic infection and tumor progression [144]. Dendritic cells (DCs), the most efficient antigen-presenting cells (APCs) of the innate immune system, can be produced from peripheral blood mononuclear cells (PBMCs) or human pluripotent stem cells (hPSC) including embryonic stem cells and induced pluripotent stem cells [221]. Loading tumor specific antigens on immature DCs is the first step for DC vaccine production and DCs can be activated for maturation by defined cytokine formulation such as IL-1β⁺ IL-6⁺ PGE2⁺ TNF and TLR agonists (IL-2, IFNα/γ, GM-CSF, bacterial toxoids). Combination of TGFβ1 and IL-6 can be used for Th7 differentiation by reprogramming Treg cells into Th17 cells [146] and also a cocktail of TGFβ1, IL-6,IL-23, IL-1β and IL-21 is used for Th17 differentiation expansion from human PBMCs [218, 222]. Next generation cancer immunotherapy by a cocktail of DC vaccines and Th17 cells is suggested for cancer regression, which should be validated in vivo or clinically by intradermal injection or infusion after checking safety in the future