Figure 2.

The life history of dendritic cells (DC). DC precursors derived from the bone marrow (BM) migrate via peripheral blood to lymphoid tissue or non-lymphoid tissue where they briefly reside as “immature” cells capable of efficient antigen uptake but expressing low levels of costimulatory molecules. In response to cytokines and microbial products, these DC migrate to draining lymph nodes and mature into highly immunostimulatory cells. Some DC constitutively migrate as non-activated or partially activated cells and these DC may play a role in tolerance.