Examples of PRRs, their ligands (PAMPs) and their origin
| PRR | PAMP | Origin |
|---|---|---|
| TLRs | ||
| TLR1 | Triacylated lipopeptides | Bacteria |
| TLR2 | Peptidoglycan | Bacteria, viruses |
| TLR3 | Double-stranded RNA | Virus |
| TLR4 | Lipopolysaccharides | Bacteria |
| TLR5 | Flagellin | Bacteria |
| TLR6 | Diacylated lipopeptides | Bacteria, viruses |
| TLR7 (human TLR8) | Single-stranded RNA | Virus, bacteria |
| TLR9 | CpG-DNA | Virus, bacteria |
| NLR | ||
| NOD1 | γ-d-Glutamyl-mesodiaminopimelic acid | Bacteria |
| NOD2 | Muramyl dipeptide | Bacteria |
| RIG-I-like receptors | ||
| DDX58 (alias: RIG-I) | Short double-stranded RNA | Viruses |
| IFIH1 (MDA5) | Long double-stranded RNA | Viruses |
| Cytosolic DNA receptors | ||
| AIM2 IFI16 ZBP1 MB21D1 (alias cGAS) | Double-stranded DNA | Virus, bacteria |
| C-type lectin receptors | ||
| Dectin-1 | β-Glucan | Fungi |
| Dectin-1 | β-Glucan | Fungi |
| MINCLE | SAP130 | Fungi |
AIM2, absent in melanoma 2; cGAS, cyclic GMP-AMP synthase; CpG-DNA, DNA containing the unmethylated phosphate-guanine (CpG) dideoxynucleotide motif; IFI16, interferon, gamma-inducible protein 16; MINCLE, macrophage inducible C-type lectin; NLR, NOD-like receptor; NOD, nucleotide-binding oligomerisation domain; PAMP, pathogen-associated molecular patterns; PRR, pattern recognition receptor; RIG-I, retinoic acid-inducible gene I; ZBP1, Z-DNA binding protein 1, MB21D1, Mab-21 domain containing 1; TLR, toll-like receptor.