Dendritic cells are the conductors of the immune orchestra, traveling throughout the bloodstream to identify foreign pathogens, digest them and present their antigen messages to T-cells and B-cells to mount an immune defense. In cancer, dendritic cells don’t readily recognize malignant cells since they are cloaked in markers of “self”, and therefore they don’t process their antigens to activate an anti-cancer immune responses.
In order to obtain large numbers of dendritic cells from a patient, it is necessary to nurture them from their monocyte cellular precursors. A patient’s monocytes are withdrawn and purified from plasma, and then mixed with a cocktail of chemical stimulants (cytokines) to mature them into dendritic cells. This process typically uses IL-4 and GM-CSF, two cytokines, to mature dendritic cells in a process that takes 5-6 days in culture.
By contrast, ExoCyte is collaborating with Prof. Zwi Berneman of the University of Antwerp, Belgium, who has developed a new cytokine process using IL-15 to mature monocytes. This not only makes dendritic cells that present cancer antigens, but by themselves have natural killer activity against tumors (see below). IL-15 generated enhanced dendritic cells (eDCs) take less time to mature, approximately 4 days, and target both innate and acquired immunity.