The system of dendritic antigen-presenting cells derive from hematopoetic precursors and reside as sentinels of the immune system in all tissues, particularly in skin and mucous membranes. They are specifically equipped with pathogen recognition receptors which enable them to recognize harmful microbial infections and take up foreign antigens.
Activation of dendritic cells triggers (1) their migration to the regional lymph nodes, (2) antigen processing, and (3) functional maturation for optimal antigen presentation and stimulation of T-cell proliferation.
Dendritic cells are the key regulators of cellular immunity against both infected as well as malignant cells. They are, therefore, targets of many Cancer vaccine strategies both ex vivo (using cultured dendritic cells) as well as in vivo.