Dendritic Cell Subsets, Maturation and Function

Dendritic cells (DCs) are the most efficient and professional antigen-presenting cells of the immune system required for induction and dispersion of immune responses. DCs also have an important role in the induction and maintenance of tolerance. In response to infections, DCs drive the production of effector CD4+ T helper 1 (Th1) and CD8+ T cell-dominated immune responses. DCs can be designated to become tolerogenic and enhance regulatory T cells (Tregs) that regulate effector T cell responses, a process that is essential for the maintenance of immune homeostasis and control of autoimmune diseases and hypersensitivities. DCs can exist in three states: immature, semi-mature, and mature DCs. The difference between immature and mature DCs is distinctly based on variations occurring on a phenotypic level and functional level. Immature dendritic cells manifested characteristics of primitive cells, defined by expression of classical dendritic cell surface markers CD11c, CD11b and major histocompatibility complex class II (MHC-II). Phenotypic maturation is accomplished when DCs upregulate surface maturation markers such as CD80, CD83, and CD86.