Pivotal Functions of Plasmacytoid Dendritic Cells in Systemic Autoimmune Pathogenesis

Plasmacytoid dendritic cells (pDCs) were initially identified as the prominent natural type I interferon-producing cells during viral infection. Over the past decade, the aberrant production of interferon α/β by pDCs in response to self-derived molecular entities has been critically implicated in the pathogenesis of systemic lupus erythematosus and recognized as a general feature underlying other autoimmune diseases. On top of imperative studies on human pDCs, the functional involvement and mechanism by which the pDC-interferon α/β pathway facilitates the progression of autoimmunity have been unraveled recently from investigations with several experimental lupus models. This article reviews correlating information obtained from human in vitro characterization and murine in vivo studies and highlights the fundamental and multifaceted contribution of pDCs to the pathogenesis of systemic autoimmune manifestation.