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. TLR3 is a member of the toll-like receptor family of pattern recognition receptors of the innate immune system. TLR3 recognizes double-stranded RNA in endosomes, which is a common feature of viral genomes internalised by macrophages and dendritic cells. TLR3 is a member of the toll-like receptor (TLR) family which plays a fundamental role in pathogen recognition and activation of innate immunity. TLRs are highly conserved from Drosophila to humans and share structural and functional similarities. 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. The various TLRs exhibit different patterns of expression. 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.[6] Unlike other TLRs, TLR3 uses TRIF as the sole adaptor.[6] IRF3 ultimately induces the production of type I interferons. It may thus play a role in host defense against viruses. TLR3 recognizes double-stranded RNA, a form of genetic information carried by some viruses such as reoviruses. Additionally, an ephemeral form of double-stranded RNA exists as a replicative intermediate during virus replication. Upon recognition, TLR 3 induces the activation of IRF3 to increase production of type I interferons which signal other cells to increase their antiviral defenses. Here you can see a beautiful structure of the mouse tetrameric form of TLR3 bound to a synthetic 90 bp DNA, determined by cryoEM (PDB code: 7WM4)

#molecularart ... #immolecular ... #toll-like ... #receptor ... #tlr3 ... #pattern ... #recognition ... #dna ... #cryoem

Structure rendered with @proteinimaging and depicted with @corelphotopaint