The potential of targeting Toll-like receptor 2 in autoimmune and inflammatory diseases

The last decade has revealed interesting insights into the initiation and pathophysiology of the innate immune system. Toll-like receptors are of key importance for this process and they are a family of receptors expressed mainly on leukocytes that recognize a variety of microbial products derived from bacteria, viruses, protozoa and fungi. As key players of innate immunity, TLRs and downstream signalling components are important target candidates for drug development. In this review, we focus on TLR2, which recognizes bacterial lipopeptide. TLR2 forms dimers with TLR1 or TLR6. The TLR2/TLR1 dimer recognizes triacylated lipopeptides, whilst the TLR2/TLR6 dimer recognizes diacylated lipopeptides. TLR2 has been implicated in several auto-immune and inflammatory conditions, and its role in disease pathogenesis has been supported by numerous reports of TLR2 polymorphisms in humans linked to disease. Here we discuss the potential of TLR2 as a drug target in autoimmune and inflammatory disease.