Version July 2025
| PRRs | Localization | Ligand | Microbial origin of ligand |
| TLR1 | Plasma membrane | Triacyl lipoprotein | Bacteria |
| TLR2 | Plasma membrane | Lipoprotein | Bacteria, viruses, parasites |
| TLR3 | Endolysosome* | dsRNA | Viruses |
| TLR4 | Plasma membrane | LPS | Bacteria, viruses |
| TLR5 | Plasma membrane | Flagellin | Bacteria |
| TLR6 | Plasma membrane | Diacyl lipoprotein | Bacteria, viruses |
| TLR7/8 | Endolysosome | ssRNA | Viruses, bacteria |
| TLR9 | Endolysosome | CpG-DNA | Viruses, bacteria, protozoa |
| TLR10 | Endolysosome | Unknown | Influenza virus, Listeria monocytogenes |
PRRs: pattern recognition receptors; TLR: Toll-like receptor; dsRNA: double-stranded ribonucleic acid; LPS: lipopolysaccharide; ssRNA: single-stranded ribonucleic acid; CpG: cytosine guanine dinucleotides.
* An endosome is an intracellular membrane-bound compartment of the endocytic transport pathway from the plasma membrane to the lysosome. In the context of host defense, endolysosomal refers to localization in a vesicle containing internalized microbial debris or virus that has fused with lysosomes that contain degradative enzymes.