TLR6
Description
The TLR6 (toll like receptor 6) is a protein-coding gene located on chromosome 4.
Toll-like receptor 6 (TLR6) is a transmembrane protein that belongs to the toll-like receptor family and acts as a pattern recognition receptor (PRR). TLR6 forms a heterodimer with toll-like receptor 2 (TLR2) and recognizes diacyl lipopeptides from gram-positive bacteria and mycoplasma, as well as fungal cell wall saccharides. Upon dimerization with TLR2, TLR6 activates the NF-κB intracellular signaling pathway, leading to pro-inflammatory cytokine production and activation of the innate immune response. TLR6 is also known as CD286 (cluster of differentiation 286). TLRs play a crucial role in pathogen recognition and activation of innate immunity. They recognize pathogen-associated molecular patterns (PAMPs) expressed on infectious agents and mediate the production of cytokines necessary for effective immunity. Different TLRs exhibit diverse expression patterns.
TLR6 plays a crucial role in the innate immune response against Gram-positive bacteria and fungi. It specifically recognizes diacylated and, to a lesser extent, triacylated lipopeptides. When encountering diacylated lipopeptides, TLR6 forms an activation cluster with TLR2, CD14, and CD36, initiating signaling from the cell surface and subsequently being transported to the Golgi apparatus via a lipid-raft dependent pathway. TLR6 utilizes the MYD88 and TRAF6 signaling pathway, leading to NF-kappa-B activation, cytokine secretion, and the inflammatory response. TLR6, in cooperation with TLR2, recognizes various microbial molecules such as mycoplasmal macrophage-activating lipopeptide-2kD (MALP-2), soluble tuberculosis factor (STF), phenol-soluble modulin (PSM), and B.burgdorferi outer surface protein A lipoprotein (OspA-L). Notably, TLR6, in complex with TLR4, facilitates sterile inflammation in monocytes and macrophages upon encountering oxidized low-density lipoprotein (oxLDL) or amyloid-beta 42. This process begins with oxLDL or amyloid-beta 42 binding to CD36, triggering the formation of a TLR4:TLR6 heterodimer, which is quickly internalized and triggers the inflammatory response. This leads to NF-kappa-B-dependent production of CXCL1, CXCL2, and CCL9 cytokines through the MYD88 signaling pathway, CCL5 cytokine through the TICAM1 signaling pathway, and IL1B secretion.
TLR6 is also known as CD286.
