Toll Like Receptor 3 (TLR3)

TLR 3 is a member of the Toll-like receptor family of pattern recognition receptors of the innate immune system. Discovered in 2001,TLR3 recognizes double-stranded RNA, a form of genetic information carried by some viruses such as reoviruses. Upon recognition, TLR 3 induces the activation of NF-kB to increase production of type I interferons which signal other cells to increase their antiviral defenses.

Double-stranded RNA is also recognised by the cytoplasmic receptors RIG-I and MDA-5.The structure of TLR3 was reported in June 2005 by researchers at The Scripps Research Institute. TLR3 forms a large horseshoe shape that contacts with a neighboring horseshoe, forming a "dimer" of two horseshoes.