Toll-like receptors: Applications to dermatologic disease

Toll-like receptors are a recently identified group of receptors that are an important component of the immune system. Thus far, ten different receptors have been identified and have unique tissue distribution, ligand binding properties, cellular signaling pathways, and cytokine production profiles. Importantly, ligand binding has been shown to regulate both the adaptive and host immune response; thus, defects in this pathway have the potential to lead to increased susceptibility to infection and inflammatory dysregulation. In this article, the burgeoning literature pertinent to the discovery and signaling mechanisms are reviewed in addition to the discussion of the important role Toll-like receptors may play in the pathogenesis of numerous skin diseases.Learning objectiveAt the completion of this learning activity, participants should be familiar with the role of Toll-like receptors in host defenses and their relevance to dermatologic diseases.