title: Intracellular phase for an extracellular bacterial pathogen: MgtC shows the way.
abstract: Pseudomonas aeruginosais an extracellular pathogen known to impair host phagocytic functions. However, our recent results identify MgtC as a novel actor inP. aeruginosavirulence, which plays a role in an intramacrophage phase of this pathogen. In agreement with its intracellular function,P. aeruginosamgtCgene expression is strongly induced when the bacteria reside within macrophages. MgtC was previously known as a horizontally-acquired virulence factor important for multiplication inside macrophages in several intracellular bacterial pathogens. MgtC thus provides a singular example of a virulence determinant that subverts macrophages both in intracellular and extracellular pathogens. Moreover, we demonstrate thatP. aeruginosaMgtC is required for optimal growth in Mg2+deprived medium, a property shared by MgtC factors from intracellular pathogens and, under Mg2+limitation,P. aeruginosaMgtC prevents biofilm formation. We propose that MgtC has a similar function in intracellular and extracellular pathogens, which contributes to macrophage resistance and fine-tune adaptation to the host in relation to the different bacterial lifestyles. MgtC thus appears as an attractive target for antivirulence strategies and our work provides a natural peptide as MgtC antagonist, which paves the way for the development of MgtC inhibitors.
authors.affiliation: Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier (DIMNP CNRS-UMR5235), Place Eugène Bataillon, 34095 Montpellier Cedex 05, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Bernut
authors.affiliation: Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier (DIMNP CNRS-UMR5235), Place Eugène Bataillon, 34095 Montpellier Cedex 05, France.
authors.forename: Claudine
authors.initials: C
authors.lastname: Belon
authors.affiliation: CNRS & Aix-Marseille University, Laboratoire d'Ingénierie des Systèmes Macromoléculaires (UMR7255), IMM, 31 Chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
authors.forename: Chantal
authors.initials: C
authors.lastname: Soscia
authors.affiliation: CNRS & Aix-Marseille University, Laboratoire d'Ingénierie des Systèmes Macromoléculaires (UMR7255), IMM, 31 Chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Bleves
authors.affiliation: Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier (DIMNP CNRS-UMR5235), Place Eugène Bataillon, 34095 Montpellier Cedex 05, France.
authors.forename: Anne-Béatrice
authors.initials: AB
authors.lastname: Blanc-Potard
keywords: MgtC; Pseudomonas aeruginosa; biofilm; macrophage; magnesium; zebrafish