TLR2

TLR2 is a plasma-membrane Toll-like receptor that supports innate immune surveillance by sensing microbial patterns and initiating inflammatory cytokine signaling^[1]. Mechanistically, TLR2 functions through heterodimerization with TLR1 or TLR6, and ligand-triggered TLR2/1 or TLR2/6 complexes initiate downstream immune signaling^[2]. In dendritic cells, TLR2-mediated uptake promotes clathrin-mediated endocytosis, Rab7 upregulation, and TAP-independent antigen cross-presentation, linking innate recognition to CTL priming^[3]. In disease models, TLR2 activation participates in inflammatory bowel disease, traumatic deep venous thrombosis, hypoxic-ischemic brain damage, and splenic marginal zone lymphoma signaling^[4][5][6][7]. Compared with nucleic-acid-sensing endosomal TLR3, TLR7, TLR8, and TLR9, TLR2 belongs to the non-endosomal receptor group and emphasizes cell-surface recognition with TLR1/TLR6 pairing^[1][2]. For experimental applications, Pam3CSK4 is used as a TLR2 agonist, while C29, M2000, and phloretin have been reported to suppress TLR2-related inflammatory signaling in defined cell or animal models^[4][5][8][9].