Toll-like receptor 3

Toll-like receptor 3 (TLR3) is a protein that in humans is encoded by the TLR3 gene. TLR3 is a member of the Toll-like receptor family of proteins, which play a fundamental role in pathogen recognition and activation of innate immunity.

Function

TLR3 is a pattern recognition receptor that recognizes double-stranded RNA (dsRNA), a molecular pattern associated with viral infections. Upon recognition of dsRNA, TLR3 initiates a signaling cascade that results in the production of type I interferons and pro-inflammatory cytokines, which are crucial for effective immune responses against viral pathogens.

Structure

TLR3 is a type I transmembrane protein characterized by an extracellular domain containing multiple leucine-rich repeat (LRR) motifs and a cytoplasmic Toll/interleukin-1 receptor (TIR) domain. The LRR motifs are responsible for the recognition of dsRNA, while the TIR domain is involved in downstream signaling.

Clinical significance

Mutations in the TLR3 gene have been associated with increased susceptibility to viral infections, including herpes simplex virus encephalitis and West Nile virus infection. Furthermore, dysregulation of TLR3 signaling has been implicated in various inflammatory and autoimmune diseases, such as systemic lupus erythematosus and psoriasis.

See also

• Toll-like receptor
• Pattern recognition receptor
• Innate immunity