From: Toll-like receptors in cerebral ischemic inflammatory injury
TLRs | Major cell types | Exogenous ligands | Endogenous ligands |
---|---|---|---|
TLR1 | Myeloid cells T, B and NK cells, microglia, astrocytes | Bacterial triacyl-lipopeptide | Â |
TLR2 | Myeloid cells, T cells, microglia, astrocytes, oligodendrocytes, neurons | Lipoproteins/lipopeptides, lipoteichoic acid, lipoarabinomannan, peptidoglycan, glycoinositolphospholipids, glycolipids, porins, zymosan, atypical lipopolysaccharide | Heat-shock proteins 60 and 70, Gp96, Saturated fatty acids |
TLR3 | Epithelial cells, dendritic cells, microglia, astrocytes, oligodendrocytes, neurons | Double-stranded RNA | mRNA |
TLR4 | Myeloid cells, microglia, astrocytes, neurons | Lipopolysaccharide, paclitaxel, respiratory syncytial virus fusion protein, mouse mammary tumor virus envelope proteins | Heat-shock proteins 60 and 70, Gp96, Type III repeat extra domain A of fibronectin, oligosaccharides of hyaluronic acid, polysaccharide fragments of heparin sulfate, fibrinogen, high mobility group box 1, surfactant protein-A, β-defensin 2 |
TLR5 | Myeloid cells, epithelial cells, microglia, astrocytes | Flagellin | Â |
TLR6 | Myeloid cells, dendritic cells, microglia, astrocytes | Phenol-soluble modulin, diacyl lipopeptides, lipoteichoic acid, zymosan | Â |
TLR7 | B cells, dendritic cells, microglia, astrocytes | Imidazoquinoline, loxoribine, bropirimine, Single-stranded RNA | Â |
TLR8 | Myeloid cells, microglia, astrocytes, neurons | Single-stranded RNA | Â |
TLR9 | Epithelial and B cells, dendritic cells, microglia, astrocyte, neuron | Unmethylated CpG DNA | Chromatin-IgG complexes |
TLR10 | B cells, dendritic cells | Unknown, may interact with TLR2 | Â |
TLR11 | Myeloid cells, uroepithelial cells | Uropathogenic E. coli | Â |