ABC de los «Toll-like receptors»: relación con el desarrollo y progresión de enfermedades autoinmunes

The Toll-like receptor family is an important group of pattern-recognition receptors whose ligands include a wide range of molecules with strong adjuvant activity (such as lipopolysaccharide, lipopeptides and bacterial DNA). These ligands can activate dendritic cells, macrophages and other antigen presenting cells that allow the effective presentation of microbial antigens to cells of the adaptive immune system. Nowadays, the identification and characterization of endogenous ligands for these receptors has provided a novel perspective for examining the etiology of some autoimmune diseases. Instead of being considered as an aberrant response to host antigens by the adaptive immune system, autoimmunity can be viewed as arising from a response to exogenous or endogenous ligands by the innate immune system, at least in some cases. This review summarizes recently published data that indicate an important connection between DNA-and RNA-containing immune complexes, activation of Toll-like receptors, production of type I interferons (INF-α, INF-β) and the development of some systemic autoimmune diseases.