Human TLR5 Antibody

Toll-like receptors (TLRs) play a critical role in early innate immunity to invading pathogens by sensing microorganisms. These evolutionarily conserved receptors recognize highly conserved structural motifs only expressed by microbial pathogens, called pathogen-associated microbial patterns (PAMPs). Stimulation of TLRs by PAMPs initiates a signaling cascade leading to the secretion of proinflammatory cytokines following NF-κB activation. To date ten human and twelve murine TLRs have been characterized, TLR1 to TLR10 in humans, and TLR1 to TLR9, TLR11, TLR12, and TLR13 in mice, the homolog of TLR10 being a pseudogene.

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 and the serine kinase IRAK [1-3]. TLR5 can generate a pro-inflammatory signal as a homodimer suggesting that it might be the only TLR participating in flagellin recognition [3]. However, TLR5 may require the presence of a co-receptor or adaptor molecule for efficient ligand recognition and/or signaling [4].

1. Yang J. & Yan H. 2017. TLR5: beyond the recognition of flagellin.Cell Mol Immunol. 14(12):1017-1019.
2. Gewirtz A.T. et al., 2001. Cutting edge: bacterial flagellin activates basolaterally expressed TLR5 to induce epithelial proinflammatory gene expression. J Immunol, 167(4):1882-5.
3. Hayashi F. et al., 2001. The innate immune response to bacterial flagellin is mediated by Toll-like receptor 5. Nature, 410(6832):1099-103.
4. 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.