Table 1 TLRs and their ligands, adaptor usage, and cytokine production
From: Negative regulatory approaches to the attenuation of Toll-like receptor signaling
Ligands | ||||
|---|---|---|---|---|
Receptor | PAMPs | DAMPs | Signal adaptor | Production |
TLR1/ TLR2 | Lipoproteins/ triacyl lipoproteins (Pam3CSK4) | Not determined | MAL/MyD88 | Proinflammatory cytokines |
TLR2/ TLR6 | Diacylated lipoproteins, lipoteichoic acid, zymosan | Heat-shock proteins such as HSP60, HSP70, and Gp96; HMGB1; ECM fragments such as versican and hyaluronic acid | MAL/MyD88 | Proinflammatory cytokines |
TLR3 | dsRNA (poly I:C) | mRNA | TRIF | Proinflammatory cytokines, type I IFNs |
TLR4 | Lipopolysaccharides, viral envelope proteins | Heat-shock proteins such as HSP22, HSP 60, HSP70, HSP72, and Gp96; HMGB1; ECM fragments such as versican, hyaluronic acid, heparin sulfate and fibronectin; tenascin-C; oxidized phospholipids; β-defensin 2 | MAL/MyD88 TRAM/TRIF | Proinflammatory cytokines Type I IFNs |
TLR5 | Flagellin | Not determined | MyD88 | Proinflammatory cytokines |
TLR6/ TLR4 | Not determined | Amyloid-β, oxidized low-density lipoprotein | MyD88 TRIF | Proinflammatory cytokines Type I IFNs |
TLR7 | ssRNA, imidazoquinolines (R848), guanosine analogs (loxoribine) | ssRNA (immune complex) | MyD88 | Proinflammatory cytokines, type I IFNs |
TLR8 | ssRNA, imidazoquinolines (R848) | ssRNA (immune complex) | MyD88 | Proinflammatory cytokines, type I IFNs |
TLR9 | Unmethylated CpG DNA, CpG oligodinucleotides, hemozoin | Chromatin IgG complex | MyD88 | Proinflammatory cytokines, type I IFNs |
TLR10 | Profilin-like molecule | Not determined | MyD88 | Proinflammatory cytokines |
TLR11 | Profilin-like molecule, uropathogenic bacteria | Not determined | MyD88 | Proinflammatory cytokines |
TLR13 | Bacterial 23S rRNA | Not determined | MyD88 | Proinflammatory cytokines |
