| TLR1a | Bacterial lipoproteins from Mycobacteria, Neisseria |
| TLR2a | Zymosan yeast particles, peptidoglycan, lipoproteins, glycolipids, lipopolysaccharide |
| TLR3 | Viral double-stranded RNA, poly:IC |
| TLR4 | Bacterial lipopolysaccharides, plant product taxol |
| TLR5 | Bacterial flagellins |
| TLR6a | Yeast zymosan particles, lipotechoic acid, lipopeptides from mycoplasma |
| TLR7 | Single-stranded RNA, R-837 and R848b, other synthetic compounds such as loxoribine and bropirimine |
| TLR8c | Single-stranded RNA, R848 |
| TLR9d | CpG oligonucleotides |
| TLR10 | Unknown |
| TLR11 | Bacterial components from uropathogenic bacteria |
| NOD1, NOD2e | Peptidoglycans |
| Scavenger receptorsf | Acetylated/malelylated proteins; modified low-density lipoproteins and other polyanionic ligands |
| Macrophage mannose receptors and other c-type lectin receptors | Sulfated sugars, mannose-, fucose- and galactose-modified polysaccharides and proteins |
| Type 3 complement receptors and dectin type receptors | Zymosan particles,  -glucan |
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aTLRs can form heterodimers, which further changes their specificity. For example, TLR2 and TLR6 form heterodimers that recognize a mycoplasmal lipoprotein44. TLR1 and TLR2 have similarly been shown to cooperatively recognize a mycobacterial lipoprotein45.
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bR-837 (imiquimod) and R-848 (resiquimod) are the first small-molecule synthetic TLR ligands to be identified30. R-837 is licensed for use as a topical cream (Aldara) against anogenital warts caused by human papilloma virus.
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cTLR8 is suggested to be nonfunctional in mice46.
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dTLR9 from human and mouse shows CpG ODN sequence specificity47.
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eNucleotide oligomerizing domain protein. Naturally occurring mutations in human have been shown to profoundly alter responsiveness to bacterial infections.
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fScavenger receptors are further subdivided into SR-A, SR-B, SR-D and SR-F depending on structure and ligand recognition10.
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