Sensors of the innate immune system: their mode of action

Nat Rev Rheumatol. 2009 Aug;5(8):448-56. doi: 10.1038/nrrheum.2009.136. Epub 2009 Jul 14.


The discovery of molecular sensors that enable eukaryotes to recognize microbial pathogens and their products has been a key advance in our understanding of innate immunity. A tripartite sensing apparatus has developed to detect danger signals from infectious agents and damaged tissues, resulting in an immediate but short-lived defense response. This apparatus includes Toll-like receptors, retinoid acid-inducible gene-I-like receptors and other cytosolic nucleic acid sensors, and nucleotide-binding and oligomerization domain-like receptors; adaptors, kinases and other signaling molecules are required to elicit effective responses. Although this sensing is beneficial to the host, excessive activation and/or engagement by self molecules might induce autoimmune and other inflammatory disorders.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Cytosol / metabolism
  • Endosomes / metabolism
  • Humans
  • Immunity, Innate*
  • Nod Signaling Adaptor Proteins / metabolism*
  • Nucleic Acids / metabolism
  • Signal Transduction
  • Toll-Like Receptors / metabolism*


  • Nod Signaling Adaptor Proteins
  • Nucleic Acids
  • Toll-Like Receptors