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Toll-like receptor 8
Available structures
PDB Ortholog search: PDBe, RCSB
Symbols TLR8 ; CD288
External IDs OMIM300366 MGI2176887 HomoloGene44054 ChEMBL: 5805 GeneCards: TLR8 Gene
RNA expression pattern
PBB GE TLR8 220832 at tn.png
More reference expression data
Species Human Mouse
Entrez 51311 170744
Ensembl ENSG00000101916 ENSMUSG00000040522
UniProt Q9NR97 P58682
RefSeq (mRNA) NM_016610 NM_133212
RefSeq (protein) NP_057694 NP_573475
Location (UCSC) Chr X:
12.91 – 12.92 Mb
Chr X:
167.24 – 167.26 Mb
PubMed search [1] [2]

Toll-like receptor 8 is a protein that in humans is encoded by the TLR8 gene.[1] TLR8 has also been designated as CD288 (cluster of differentiation 288). It is a member of the toll-like receptor (TLR) family.


TLR8 seems to function differently in humans and mice. Until recently, TLR8 was believed to be nonfunctional in mice, but it seems to counteract TLR7 activity[2][3]

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. This gene is predominantly expressed in lung and peripheral blood leukocytes, and lies in close proximity to another family member, TLR7, on chromosome X.[4]

TLR8 recognizes G-rich oligonucleotides.[5]

TLR8 is an endosomal receptor that recognizes single stranded RNA (ssRNA), and can recognize ssRNA viruses such as Influenza, Sendai, and Coxsackie B viruses. TLR8 binding to the viral RNA recruits MyD88 and leads to activation of the transcription factor NF-kB and an antiviral response.[6]

Clinical significance[edit]

Genetic variants in TLR8 has recently been linked to susceptibility to pulmonary tuberculosis.[7]

TLR7 is functional both in human and mouse, but TLR8 is only functional in human.[3]


  1. ^ Du X, Poltorak A, Wei Y, Beutler B (Sep 2000). "Three novel mammalian toll-like receptors: gene structure, expression, and evolution". European Cytokine Network 11 (3): 362–71. PMID 11022119. 
  2. ^ Demaria O, Pagni PP, Traub S, de Gassart A, Branzk N, Murphy AJ, Valenzuela DM, Yancopoulos GD, Flavell RA, Alexopoulou L (2010). "TLR8 deficiency leads to autoimmunity in mice". J. Clin. Invest. 120 (10): 3651–62. doi:10.1172/JCI42081. PMC 2947223. PMID 20811154. 
  3. ^ a b Sarvestani ST, Williams BR, Gantier MP (Aug 2012). "Human Toll-like receptor 8 can be cool too: implications for foreign RNA sensing". Journal of Interferon & Cytokine Research: The Official Journal of the International Society for Interferon and Cytokine Research 32 (8): 350–61. doi:10.1089/jir.2012.0014. PMID 22817608. 
  4. ^ "Entrez Gene: TLR8 toll-like receptor 8". 
  5. ^ Peng G, Guo Z, Kiniwa Y, Voo KS, Peng W, Fu T, Wang DY, Li Y, Wang HY, Wang RF (Aug 2005). "Toll-like receptor 8-mediated reversal of CD4+ regulatory T cell function". Science 309 (5739): 1380–4. doi:10.1126/science.1113401. PMID 16123302. 
  6. ^ "TLR7 and TLR8: Key players in the antiviral response - Innate immunity". invivoGen. Fall 2006. 
  7. ^ Davila S, Hibberd ML, Hari Dass R, Wong HE, Sahiratmadja E, Bonnard C, Alisjahbana B, Szeszko JS, Balabanova Y, Drobniewski F, van Crevel R, van de Vosse E, Nejentsev S, Ottenhoff TH, Seielstad M (Oct 2008). "Genetic association and expression studies indicate a role of toll-like receptor 8 in pulmonary tuberculosis". PLoS Genetics 4 (10): e1000218. doi:10.1371/journal.pgen.1000218. PMC 2568981. PMID 18927625. 

Further reading[edit]

External links[edit]