TLR5

Toll-like receptor 5
Available structures
PDB Ortholog search: PDBe, RCSB
Identifiers
Symbols TLR5 ; MELIOS; SLE1; SLEB1; TIL3
External IDs OMIM: 603031 MGI: 1858171 HomoloGene: 20698 GeneCards: TLR5 Gene
RNA expression pattern
More reference expression data
Orthologs
Species Human Mouse
Entrez 7100 53791
Ensembl ENSG00000187554 ENSMUSG00000079164
UniProt O60602 Q9JLF7
RefSeq (mRNA) NM_003268 NM_016928
RefSeq (protein) NP_003259 NP_058624
Location (UCSC) Chr 1:
223.11 – 223.14 Mb		 Chr 1:
182.95 – 182.98 Mb
PubMed search

Toll-like receptor 5, also known as TLR5, is a protein which in humans is encoded by the TLR5 gene.[1] It is a member of the toll-like receptor (TLR) family.

Function

The TLR family plays a fundamental role in pathogen recognition and activation of innate immunity. TLRs are highly conserved from Drosophila to humans and share structural and functional similarities. They recognize pathogen-associated molecular patterns (PAMPs) that are expressed on infectious agents, and mediate the production of cytokines necessary for the development of effective immunity. The various TLRs exhibit different patterns of expression. TLR5 is expressed on both immune and non-immune cells.[2] TLR5 recognizes bacterial flagellin, a principal component of bacterial flagella and a virulence factor. The activation of this receptor mobilizes the nuclear factor NF-κB and stimulates tumor necrosis factor-alpha production.[3]

TLR5 recognizes flagellin,[4] which is the protein monomer that makes up the filament of bacterial flagella, found on nearly all motile bacteria. There are highly conserved regions in the flagellin protein among all bacteria, facilitating the recognition of flagellin by a germ-line encoded receptor such as TLR5.[5] However, some Proteobacteria flagella have acquired mutations preventing their recognition by TLR5.[6]

Clinical significance

TLR5 may play a role in Inflammatory Bowel Disease (IBD). Statistically significant lower levels of TLR5 expression have been found in patients exhibiting moderate to severe ulcerative colitis (UC). In these patients, lower TLR5 mRNA levels were found along with decreased immunoreactivity of TLR5 in the inflamed mucosa of UC patients.[7]

References

  1. ↑ Rock FL, Hardiman G, Timans JC, Kastelein RA, Bazan JF (Jan 1998). "A family of human receptors structurally related to Drosophila Toll". Proceedings of the National Academy of Sciences of the United States of America 95 (2): 588–93. doi:10.1073/pnas.95.2.588. PMC 18464. PMID 9435236.
  2. ↑ Sharma N, Akhade AS, Qadri A (Apr 2013). "Sphingosine-1-phosphate suppresses TLR-induced CXCL8 secretion from human T cells". Journal of Leukocyte Biology 93 (4): 521–8. doi:10.1189/jlb.0712328. PMID 23345392.
  3. ↑ "Entrez Gene: TLR5 toll-like receptor 5".
  4. ↑ Hayashi F, Smith KD, Ozinsky A, Hawn TR, Yi EC, Goodlett DR, Eng JK, Akira S, Underhill DM, Aderem A (Apr 2001). "The innate immune response to bacterial flagellin is mediated by Toll-like receptor 5". Nature 410 (6832): 1099–103. doi:10.1038/35074106. PMID 11323673.
  5. ↑ Smith KD, Andersen-Nissen E, Hayashi F, Strobe K, Bergman MA, Barrett SL, Cookson BT, Aderem A (Dec 2003). "Toll-like receptor 5 recognizes a conserved site on flagellin required for protofilament formation and bacterial motility". Nature Immunology 4 (12): 1247–53. doi:10.1038/ni1011. PMID 14625549.
  6. ↑ Andersen-Nissen E, Smith KD, Strobe KL, Barrett SL, Cookson BT, Logan SM, Aderem A (Jun 2005). "Evasion of Toll-like receptor 5 by flagellated bacteria". Proceedings of the National Academy of Sciences of the United States of America 102 (26): 9247–52. doi:10.1073/pnas.0502040102. PMC 1166605. PMID 15956202.
  7. ↑ Stanislawowski M, Wierzbicki PM, Golab A, Adrych K, Kartanowicz D, Wypych J, Godlewski J, Smoczynski M, Kmiec Z (Oct 2009). "Decreased Toll-like receptor-5 (TLR-5) expression in the mucosa of ulcerative colitis patients". Journal of Physiology and Pharmacology. 60 Suppl 4: 71–5. PMID 20083854.

Further reading

  • Hayashi F, Smith KD, Ozinsky A, Hawn TR, Yi EC, Goodlett DR, Eng JK, Akira S, Underhill DM, Aderem A (Apr 2001). "The innate immune response to bacterial flagellin is mediated by Toll-like receptor 5". Nature 410 (6832): 1099–103. doi:10.1038/35074106. PMID 11323673. 
  • Lien E, Ingalls RR (Jan 2002). "Toll-like receptors". Critical Care Medicine 30 (1 Suppl): S1–11. doi:10.1097/00003246-200201001-00001. PMID 11782555. 

External links


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