PRRDB 2.0 : Pattern Recognition Receptor Database

TLR1 recognizes pathogen-associated molecular pattern with a specificity for gram-positive bacteria. TLR1 has also been designated as CD281 (cluster of differentiation 281).

Toll-like receptor 2 also known as TLR2 is a protein that in humans is encoded by the TLR2 gene.TLR2 has also been designated as CD282 (cluster of differentiation 282). TLR2 is one of the toll-like receptors and plays a role in the immune system. TLR2 is a membrane protein, a receptor, which is expressed on the surface of certain cells and recognizes foreign substances and passes on appropriate signals to the cells of the immune system.

Toll-like receptor 3 (TLR3) also known as CD283 (cluster of differentiation 283) is a protein that in humans is encoded by the TLR3 gene.This receptor is most abundantly expressed in placenta and pancreas, and is restricted to the dendritic subpopulation of the leukocytes. It recognizes dsRNA associated with viral infection, and induces the activation of IRF3 and NF-κB.

It is most well-known for recognizing lipopolysaccharide (LPS), a component present in many Gram-negative bacteria (e.g. Neisseria spp.) and select Gram-positive bacteria. Its ligands also include several viral proteins, polysaccharide, and a variety of endogenous proteins such as low-density lipoprotein, beta-defensins, and heat shock protein.TLR4 has also been designated as CD284 (cluster of differentiation 284).

TLR5 is known to recognize bacterial flagellin from invading mobile bacteria. Its has been shown to be involved in the onset of many diseases, which includes Inflammatory bowel disease

Toll-like receptor 6 is a protein that in humans is encoded by the TLR6 gene. TLR6 has also been designated as CD286 (cluster of differentiation 286).They recognize microbe-associated molecular patterns (MAMPs) that are expressed on infectious agents, and mediate the production of cytokines necessary for the development of effective immunity.

Toll-like receptor 7, also known as TLR7, is a protein that in humans is encoded by the TLR7 gene. Orthologs are found in mammals and birds. It is a member of the toll-like receptor (TLR) family and detects single stranded RNA.

TLR8 is an endosomal receptor that recognizes single stranded RNA (ssRNA), and can recognize ssRNA viruses such as Influenza, Sendai, and Coxsackie B viruses. TLR8 binding to the viral RNA recruits MyD88 and leads to activation of the transcription factor NF-κB and an antiviral response

Toll-like receptor 9 is a protein that in humans is encoded by the TLR9 gene. TLR9 has also been designated as CD289 (cluster of differentiation 289).TLR9 can recognize nucleotides other than unmethylated CpG present in bacterial or viral genomes. TLR9 has been shown to recognized DNA:RNA hybrids, but not ssDNA.

Toll-like receptor 10 is a protein that in humans is encoded by the TLR10 gene. TLR10 has also been designated as CD290 (cluster of differentiation 290).They recognize pathogen-associated molecular patterns (PAMPs) that are expressed on infectious agents, and mediate the production of cytokines necessary for the development of effective immunity.

Toll-like receptor 11 (TLR11) is a protein that in mice is encoded by the gene TLR11, whereas in humans it is represented by a pseudogene. TLR11 belongs to the toll-like receptor (TLR) family and the interleukin-1 receptor/toll-like receptor superfamily. In mice, TLR11 has been shown to recognise flagellin and/or profilin present on certain microbes,

They are single, membrane-spanning, non-catalytic receptors usually expressed on sentinel cells such as macrophages and dendritic cells, that recognize structurally conserved molecules derived from microbes.

Toll-like receptor 13 (TLR13) is an endosomal TLR expressed in mice, whose functions and ligands remain poorly understood. Recently, three separate groups have identified 23S ribosomal RNA (rRNA) as a ligand for TLR13. Interestingly, humans lack TLR13 and thus, rely on other pathogen receptors to detect pathogenic bacterial infection.

TLR14 expression was induced by viral hemorrhagic septicemia virus or bacterial (Strep- tococcus iniae and Edwardsiella tarda) challenge. Ref 27037219

Teleost-Specific TLR19 Localizes to Endosome, Recognizes dsRNA, Recruits TRIF, Triggers both IFN and NF-κB Pathways, and Protects Cells from Grass Carp Reovirus Infection. Ref 29229676

Involvement of TLR21 in baculovirus-induced interleukin-12 gene expression in avian macrophage-like cell line HD11.. Ref 20471186

TLR22 recognizes dsRNA viruses or PolyI:C. Ref 27721456