Toll-like receptor 1 and Toll-like receptor 2 (TLR1 and TLR2)

Toll-like receptor 1 and Toll-like receptor 2 (TLR1 and TLR2) are cell-surface pattern recognition receptors that play a critical role in the innate immune system by detecting pathogen-associated molecular patterns (PAMPs) from bacteria, fungi, and other microbes[1][2][5][6][7]. Both are type I transmembrane proteins with extracellular leucine-rich repeat (LRR) domains for ligand recognition, a single transmembrane helix, and an intracellular Toll/interleukin-1 receptor (TIR) domain for signal transduction[5][6]. TLR1 and TLR2 commonly function as a heterodimer, recognizing bacterial lipoproteins and lipopeptides and initiating MyD88-dependent (and to a lesser extent, TRIF-dependent) intracellular signaling cascades[3][4][7]. Their activation results in the production of pro-inflammatory cytokines, linking the innate and adaptive immune response, but their dysregulation is implicated in infectious, inflammatory, and autoimmune diseases[6][7][1]. If you need further breakdown for each individual receptor (TLR1 or TLR2), specify which, as both frequently function together as a heterodimer for ligand recognition and downstream signaling[5][3].

Other names

TLR1TLR2toll/interleukin-1 receptor-like protein 1toll/interleukin-1 receptor-like protein 2CD281 (TLR1)CD282 (TLR2)

Agonists: Trigger TLR1/2 dimerization and downstream MyD88-dependent signaling, promoting immune response Antagonists: Block ligand binding, preventing receptor activation and reducing inflammation