Jacques Banchereau

Dendritic Cells in SLE

Publisher Summary The innate and the adaptive immune systems act in concert to eradicate pathogens through cells such as macrophages, granulocytes, dendritic cells (DCs), and lymphocytes, and through effector proteins such as cytokines, antimicrobial peptides, complement, and antibodies. Alterations in DC biology are involved in autoimmune diseases, such as systemic lupus erythematosus (SLE) and in malignant diseases, such as myeloma and breast cancer. DCs are composed of multiple subsets with distinct functions. The two major subsets are myeloid DCs (mDCs) and plasmacytoid DCs (pDCs). This chapter describes phenotypical and functional differences among human DC subsets. In vivo, DCs exist in at least three compartments—peripheral tissue DCs, secondary lymphoid organ resident DCs, and circulating blood mDCs. The role of DCs in the establishment of peripheral tolerance represents a recent area of research in DC biology. It is generally accepted that immature DCs are tolerogenic while mature DCs are immunogenic. However, mature DCs also play a role in the induction of tolerance. This chapter reviews the mechanisms that DCs utilize to implement peripheral tolerance. Furthermore, it explains the role of DCs in human autoimmune diseases. Finally, it states that understanding human DCs and their complex interplays with other immune effectors will continue to provide insight into the pathogenesis of autoimmune diseases and help discover new, better targets for therapeutic intervention.