Journal of Molecular Medicine

, Volume 84, Issue 9, pp 712–725

Toll-like receptors and innate immunity


DOI: 10.1007/s00109-006-0084-y

Cite this article as:
Uematsu, S. & Akira, S. J Mol Med (2006) 84: 712. doi:10.1007/s00109-006-0084-y


The innate immune system is an evolutionally conserved host defense mechanism against pathogens. Innate immune responses are initiated by pattern recognition receptors (PRRs), which recognize specific structures of microorganisms. Among them, Toll-like receptors (TLRs) are capable of sensing organisms ranging from bacteria to fungi, protozoa, and viruses, and play a major role in innate immunity. However, TLRs recognize pathogens either on the cell surface or in the lysosome/endosome compartment. Recently, cytoplasmic PRRs have been identified to detect pathogens that have invaded cytosols. In this review, we focus on the functions of PRRs in innate immunity and their downstream signaling cascades.



Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  1. 1.Department of Host Defense, Research Institute for Microbial DiseasesOsaka UniversitySuitaJapan
  2. 2.ERATOJapan Science and Technology CorporationSuitaJapan