02139nas a2200397   4500000000100000008004100001260000900042653001800051653002900069653002400098653001500122653002400137653002300161653002400184653001600208653001100224653001800235653001200253653001600265653001400281653002400295653000900319653001800328653001300346653002400359100001500383700001400398700001300412700001100425700001300436245009900449300000900548490000700557520116300564022001401727       2010                            d  c201010aAcne Vulgaris10aAntigen-Presenting Cells10aAutoimmune Diseases10aBiomarkers10aBorrelia Infections10aDermatitis, Atopic10aDermatologic Agents10aFibroblasts10aHumans10aKeratinocytes10aleprosy10aMelanocytes10aPsoriasis10aSignal Transduction10aSkin10aSkin Diseases10aSyphilis10aToll-Like Receptors1 aTerhorst D1 aKalali BN1 aOllert M1 aRing J1 aMempel M00aThe role of toll-like receptors in host defenses and their relevance to dermatologic diseases.  a1-100 v113 a<p>The family of toll-like receptors (TLRs) plays a central role in the cutaneous immune defense system. To date, different TLRs have been found on several major cell populations of the skin, such as keratinocytes, fibroblasts, antigen-presenting cells, and melanocytes. Activation of TLRs leads, via different intracellular signaling pathways, to the production of pro-inflammatory stimuli, and is considered a danger signal that should transform the skin in to the functional state of defense. However, TLRs have also been implicated in tissue homeostasis and renewal. Within the group of TLRs, two types have been identified: surface-expressed TLRs, which are predominantly active against bacterial cell wall compounds; and intracellular receptors, which preferentially recognize virus-associated pattern molecules. In addition, surface-expressed receptors trigger phagocytotic and maturation signals, while the intracellular TLRs lead to the induction of antiviral genes. Our review aims to outline the importance of TLRs in the pathogenesis of numerous skin diseases and the potential of TLR agonists as a treatment option for various skin diseases.</p>  a1175-0561