Inflammasomes in inflammatory disorders: the role of TLRs and their interactions with NLRs

The innate immune system relies on a variety of pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs) and NOD-like receptors (NLRs) to sense microbial structures that are present in pathogens. Various levels of crosstalk between the TLR and NLR pathways have been described, most notably the description of a molecular scaffold complex, termed the inflammasome, which requires input from both pathways and leads to the activation of the proinflammatory cytokines interleukin (IL)-1beta and IL-18. In certain cases, the inflammatory process becomes dysregulated and chronic inflammatory diseases may develop. Understanding the interactions of the TLR and NLR pathways will provide further clues to the pathogeneses of these diseases and to the development of efficient therapies to combat them.