|
|||||
|
|
RIG‐I detects infection with live Listeria by sensing secreted bacterial nucleic acids |
|
| Authors: | Susanne Roth Mobarak Abu Mraheil Winfried Barchet Jan Böttcher Torsten Hain Sergej Geiger Yoshihiro Hayakawa Jörg H Fritz Filiz Civril Karl‐Peter Hopfner Christian Kurts Jürgen Ruland Gunther Hartmann Trinad Chakraborty Percy A Knolle |
| Affiliation: | 1. Institut für Klinische Chemie und Pathobiochemie, Klinikum rechts der Isar, Technische Universit?t München, , Munich, Germany;2. Institute for Medical Microbiology, Justus‐Liebig‐Universit?t Giessen, , Giessen, Germany;3. Institute for Clinical Chemistry and Clinical Pharmacology, Friedrich‐Wilhelms‐Universit?t Bonn, , Bonn, Germany;4. Institutes of Molecular Medicine and Experimental Immunology, Friedrich‐Wilhelms‐Universit?t Bonn, , Bonn, Germany;5. Department of Applied Chemistry, Aichi Institute of Technology, , Aichi, Japan;6. Department of Microbiology and Immunology, McGill University, , Montreal, Quebec, Canada;7. Department of Biochemistry, Gene Center, Ludwig‐Maximilian Universit?t Munich, , Munich, Germany;8. Laboratory of Signaling in the Immune System, Helmholtz Zentrum München, , Neuherberg, Germany |
| Abstract: | Immunity against infection with Listeria monocytogenes is not achieved from innate immune stimulation by contact with killed but requires viable Listeria gaining access to the cytosol of infected cells. It has remained ill‐defined how such immune sensing of live Listeria occurs. Here, we report that efficient cytosolic immune sensing requires access of nucleic acids derived from live Listeria to the cytoplasm of infected cells. We found that Listeria released nucleic acids and that such secreted bacterial RNA/DNA was recognized by the cytosolic sensors RIG‐I, MDA5 and STING thereby triggering interferon β production. Secreted Listeria nucleic acids also caused RIG‐I‐dependent IL‐1β‐production and inflammasome activation. The signalling molecule CARD9 contributed to IL‐1β production in response to secreted nucleic acids. In conclusion, cytosolic recognition of secreted bacterial nucleic acids by RIG‐I provides a mechanistic explanation for efficient induction of immunity by live bacteria. |
| Keywords: | inflammasome activation innate immunity Listeria infection nucleic‐acid secretion protective immunity |