Figure 2.

DC maturation, a control point for regulating tolerance and immunity. Immature DCs capture antigens by several pathways, whereas mature DCs stimulate T cell immunity, i.e., helper and cytolytic effector lymphocytes as well as memory. Maturation stimuli act via TLRs (wherein distinct microbial products act although distinct TLR) and TNF family receptors (such as TNF itself and CD40L). Maturation leads to several changes, including: the redistribution of MHC class II molecules and MHC–peptide complexes from within the endocytic system to the cell surface as diagrammed here, the production of several cytokines and membrane associated T cell stimulatory molecules, and the remodeling of expressed chemokine receptors.