Unique features of chicken Toll-like receptors

Abstract

Toll-like receptors (TLRs) are a major class of innate immune pattern recognition receptors that have a key role in immune homeostasis and the defense against infections. The research explosion that followed the discovery of TLRs more than a decade ago has boosted fundamental knowledge on the function of the immune system and the resistance against disease, providing a rational for clinical modulation of the immune response. In addition, the conserved nature of the ancient TLR system throughout the animal kingdom has enabled a comparative biology approach to understand the evolution, structural architecture, and function of TLRs. In the present review we focus on TLR biology in the avian species, and, especially, on the unique functional properties of the chicken TLR repertoire.

Keywords: CD14; Chicken; Evolution; IFN; IL; IRAK; IRF3; Infection; Innate immunity; LBP; LPS; LRR; Ligand specificity; MD-2; MPL; MyD88; NF-κB; PMSF; PRAT4A; SNP; TIR; TIR domain-containing adaptor inducing interferon; TIRAP; TLR; TRAF6; TRAM; TRIF; TRIF-related adaptor molecule; Toll-interleukin 1 receptor (TIR) domain containing adaptor protein; Toll-like receptor; Toll/interleukin-1 receptor resistance domain; cluster of differentiation 14; double stranded ribonucleic acid; dsRNA; interferon; interferon regulatory factor 3; interleukin; interleukin-1 receptor-associated kinase; leucine-rich repeats; lipopolysaccharide; lipopolysaccharide-binding protein; monophosphoryl lipid A; myeloid differentiation primary response gene/protein 88; myeloid differentiation protein-2; nuclear factor kappa B; phenylmethylsulfonyl fluoride; protein associated with Toll-like receptor 4; single stranded ribonucleic acid; single-nucleotide polymorphism; ssRNA; tumor necrosis factor receptor-associated factor 6.