Toll-like receptor 2

Toll-like receptor 2 (TLR2) is a protein that in humans is encoded by the TLR2 gene. TLR2 has also been designated as CD282 (cluster of differentiation 282). It is a member of the Toll-like receptor (TLR) family, which plays a fundamental role in pathogen recognition and activation of innate immunity.

Structure

TLR2 is one of the most versatile receptors of the TLR family, recognizing a wide array of pathogen-associated molecular patterns (PAMPs). It forms heterodimers with either TLR1 or TLR6 to recognize bacterial lipoproteins. The TLR2/TLR1 heterodimer recognizes triacylated lipopeptides, while the TLR2/TLR6 heterodimer recognizes diacylated lipopeptides.

Function

TLR2 recognizes a variety of microbial products, including lipoproteins, peptidoglycan, and lipoteichoic acid from Gram-positive bacteria, as well as lipopolysaccharide (LPS) from Gram-negative bacteria. Upon activation, TLR2 initiates a signaling pathway that leads to the activation of the nuclear factor kappa B (NF-κB) and subsequent induction of inflammatory cytokines, which play a role in the innate immune response.

Clinical significance

Alterations in the function of TLR2 have been associated with increased susceptibility to infections and chronic inflammatory diseases. For example, TLR2 polymorphisms have been linked to an increased risk of tuberculosis, sepsis, and atherosclerosis. Furthermore, TLR2 has been implicated in the pathogenesis of several autoimmune diseases, including rheumatoid arthritis and systemic lupus erythematosus.

See also

• Toll-like receptor
• Innate immunity
• Inflammatory cytokines
• Nuclear factor kappa B