Dendritic cells in acute kidney injury: cues from the microenvironment.

Dendritic cells (DCs) and macrophages are critical early initiators of innate immunity in the kidney; they also orchestrate inflammation subsequent to ischemia-reperfusion injury. Hence, these cells hold great promise as targets for pharmacological interventions. Macrophages and DCs are the most abundant leukocytes present in the kidney, and they represent a heterogeneous population of cells that are capable of inducing sterile inflammation after reperfusion, directly through the production of proinflammatory cytokines, chemokines, and other soluble inflammatory mediators, or indirectly through activation of effector T lymphocytes and natural killer T cells. In addition, recent studies have indicated that macrophages participate in tissue repair and DCs possess tolerogenic functions in normal and disease states. Understanding the function of DCs and macrophages as well as the microenvironment that governs their phenotype will shed light on the pathogenesis of kidney disease and offer novel drug targets.