Killer dendritic cells and their potential role in immunotherapy

Tumor immunosurveillance is mediated by innate and adaptive components of cellular immunity. A complex network of cellular interactions is needed to elicit protective antitumoral CD4+ and CD8+T cell responses. Thereby dendritic cells (DCs) play a central role as professional antigen presenting cells (APCs) that take up antigens, process, and present them to prime naïve T cells. Recognition and lysis of tumor cells has been attributed to innate effectors such as natural killer (NK), NKT and γδT cells. Recently, novel subsets of cytotoxic DCs, called "killer DCs" (KDCs), have been reported in rodents and humans. Killer dendritic cells could directly link innate and adaptive immunity. This review aims at comparing the different KDC populations, their phenotypes, killer function, and their potential application for anticancer immunotherapy.