TLR5 Ligands
Toll-like receptor 5 (TLR5) recognizes flagellin from both Gram-positive and Gram-negative bacteria. Activation of the receptor stimulates the production of proinflammatory cytokines, such as TNF-α, through signaling via the adaptor protein MyD88 [1, 2]. TLR5 can generate a proinflammatory signal as a homodimer suggesting that it might be the only TLR participating in flagellin recognition [2]. However, TLR5 may require the presence of a co-receptor or adaptor molecule for efficient ligand recognition and/or signaling [3].
InvivoGen provides flagellin purified from B.subtilis (Gram+) and S.typhimurium (Gram-) bacteria and a new recombinant form. Flagellin FliC VacciGrade™ (preclinical grade: sterile and endotoxin level <0.004 EU/µg) for use as a vaccine adjuvant is also available. HEK-Blue™ TLR5 Cells are used to validate the functionality of the TLR5 ligands.
1. Gewirtz AT. et al., 2001. Cutting edge: bacterial flagellin activates basolaterally expressed TLR5 to induce epithelial proinflammatory gene expression. J Immunol, 167(4):1882-5.
2. Hayashi F. et al., 2001. The innate immune response to bacterial flagellin is mediated by Toll-like receptor 5. Nature, 410(6832):1099-103.
3. Tallant T. et al., 2004. Flagellin acting via TLR5 is the major activator of key signaling pathways leading to NF-kappa B and proinflammatory gene program activation in intestinal epithelial cells. BMC Microbiol. 4(1):33.