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Intracellular pattern recognition receptors in the host response

Abstract

The innate immune system relies on its capacity to rapidly detect invading pathogenic microbes as foreign and eliminate them. Indeed, Toll-like receptors are a class of membrane receptors that sense extracellular microbes and trigger anti-pathogen signalling cascades. Recently, intracellular microbial sensors have also been identified, including NOD-like receptors and the helicase-domain-containing antiviral proteins RIG-I and MDA5. Some of these cytoplasmic molecules sense microbial, as well as non-microbial, danger signals, but the mechanisms of recognition used by these sensors remain poorly understood. Nonetheless, it is apparent that these proteins are likely to have critical roles in health and disease.

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Figure 1: Intracellular sensors of bacteria, viruses and danger signals.
Figure 2: Activation of NLRs by bacterial and host-derived components.
Figure 3: Sensing of viral dsRNA by TLR3 and RLH.

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Acknowledgements

We thank H. Everett, D. Muruve and F. Martinon for critical reading of the manuscript. This work was supported by grants from the Swiss National Science Foundation (J.T.), the Commission of Technology and Innovation (J.T.), and the National Institutes of Health (M.K.). M.K. is an American Cancer Society Research Professor.

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Meylan, E., Tschopp, J. & Karin, M. Intracellular pattern recognition receptors in the host response. Nature 442, 39–44 (2006). https://doi.org/10.1038/nature04946

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