Flavie Moreau, Geanncarlo Lugo-Villarino, Aurélien Boyance, Arnaud Métais, Peter J. Peters, Karin Santoni, Céline Cougoule, Stephen Adonai Leon-Icaza, Hans Clevers, Lise Lefèvre, Etienne Meunier, Yoann Rombouts, Agnès Coste, Pierre-Jean Bordignon, Miriam Pinilla, Emmanuelle Naser, Audrey Hessel, David Péricat, Ina Attrée, Rémi Planès, Nino Iakobachvili, Dara W. Frank, Elif Eren, Salimata Bagayoko, Céline Berrone, Institut de pharmacologie et de biologie structurale (IPBS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Geroscience and rejuvenation research center (RESTORE), Université de Toulouse (UT)-Université de Toulouse (UT)-EFS-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Maastricht University [Maastricht], Groupe Pathogenèse Bactérienne et Réponses Cellulaires / Bacterial Pathogenesis and Cellular Responses Group (IBS-PBRC), Institut de biologie structurale (IBS - UMR 5075), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Medical College of Wisconsin [Milwaukee] (MCW), Hubrecht Institute [Utrecht, Netherlands], University Medical Center [Utrecht]-Royal Netherlands Academy of Arts and Sciences (KNAW), ANR-18-CE14-0007,ENDIABAC,LE SYSTEME NERVEUX ENTERIQUE COMME CIBLE POUR TRAITER LE DIABETE DE TYPE 2 : ROLES DES LIPIDES BIOACTIFS BACTERIENS(2018), ANR-17-CE11-0006,MacGlycoTB,Rôle de ST8SIA4 et de la polysialylation des protéines des macrophages dans la réponse immunitaire contre une infection par Mycobacterium tuberculosis(2017), European Project: 804249,INFLAME, Hubrecht Institute for Developmental Biology and Stem Cell Research, ATTREE, Ina, APPEL À PROJETS GÉNÉRIQUE 2018 - LE SYSTEME NERVEUX ENTERIQUE COMME CIBLE POUR TRAITER LE DIABETE DE TYPE 2 : ROLES DES LIPIDES BIOACTIFS BACTERIENS - - ENDIABAC2018 - ANR-18-CE14-0007 - AAPG2018 - VALID, Rôle de ST8SIA4 et de la polysialylation des protéines des macrophages dans la réponse immunitaire contre une infection par Mycobacterium tuberculosis - - MacGlycoTB2017 - ANR-17-CE11-0006 - AAPG2017 - VALID, Deciphering the host and microbial grounds that license inflammasome-mediated execution - INFLAME - 804249 - INCOMING, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-EFS-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, RS: M4I - Nanoscopy, and Institute of Nanoscopy (IoN)
Regulated cell necrosis supports immune and anti-infectious strategies of the body; however, dysregulation of these processes drives pathological organ damage. Pseudomonas aeruginosa expresses a phospholipase, ExoU that triggers pathological host cell necrosis through a poorly characterized pathway. Here, we investigated the molecular and cellular mechanisms of ExoU-mediated necrosis. We show that cellular peroxidised phospholipids enhance ExoU phospholipase activity, which drives necrosis of immune and non-immune cells. Conversely, both the endogenous lipid peroxidation regulator GPX4 and the pharmacological inhibition of lipid peroxidation delay ExoU-dependent cell necrosis and improve bacterial elimination in vitro and in vivo. Our findings also pertain to the ExoU-related phospholipase from the bacterial pathogen Burkholderia thailandensis, suggesting that exploitation of peroxidised phospholipids might be a conserved virulence mechanism among various microbial phospholipases. Overall, our results identify an original lipid peroxidation-based virulence mechanism as a strong contributor of microbial phospholipase-driven pathology., Author summary Although a proper activation of various regulated cell necrosis confer a significant advantage against various infectious agents, their dysregulation drives host tissue damages that can end up with fatal sepsis. Specifically, 30% of the bacterial strains of Pseudomonas aeruginosa (P. aeruginosa) express the phospholipase A2-like toxin ExoU that is injected into host target cells through the Type-3 Secretion System. This toxin induces, through a yet unknown mechanism, a strong and fast necrotic cell death that supports fatal respiratory infections. Therefore, in this study, we sought to determine the cellular mechanisms by which ExoU triggers host cell necrosis. In this context, we found that ExoU exploits basal cellular phospholipid peroxidation to promote cell necrosis. Mechanistically, host cell lipid peroxidation stimulates ExoU phospholipase activity, which then triggers a pathological cell necrosis both in vitro and in vivo. Altogether, our results unveil that targeting host cell lipid peroxidation constitutes a virulence mechanism developed by microbial phospholipases, a process that contributes to P. aeruginosa-mediated pathology.