CD281/TLR1
CD281 is Toll-like receptor 1 (TLR1), an innate immune pattern-recognition receptor of the TLR2 subfamily. TLR1 does not act alone: it pairs with TLR2 to form the heterodimer that recognizes triacylated lipopeptides from bacteria, including mycobacterial and Gram-positive lipoproteins, initiating MyD88-dependent NF-κB and MAPK signaling. Expression is prominent on monocytes, macrophages and dendritic cells, placing TLR1 at the front line of antibacterial sensing. Human genetic variation in TLR1 has been linked to altered susceptibility to tuberculosis, leprosy and sepsis, and the receptor is studied as an adjuvant target for vaccine development.
