title: Quantitative proteomics analysis of macrophage-derived lipid rafts reveals induction of autophagy pathway at the early time of Francisella tularensis LVS infection.
abstract: Francisella tularensis is a highly infectious intracellular pathogen that has evolved an efficient strategy to subvert host defense response to survive inside the host. The molecular mechanisms regulating these host-pathogen interactions and especially those that are initiated at the time of the bacterial entry via its attachment to the host plasma membrane likely predetermine the intracellular fate of pathogen. Here, we provide the evidence that infection of macrophages with F. tularensis leads to changes in protein composition of macrophage-derived lipid rafts, isolated as detergent-resistant membranes (DRMs). Using SILAC-based quantitative proteomic approach, we observed the accumulation of autophagic adaptor protein p62 at the early stages of microbe-host cell interaction. We confirmed the colocalization of the p62 with ubiquitinated and LC3-decorated intracellular F. tularensis microbes with its maximum at 1 h postinfection. Furthermore, the infection of p62-knockdown host cells led to the transient increase in the intracellular number of microbes up to 4 h after in vitro infection. Together, these data suggest that the activation of the autophagy pathway in F. tularensis infected macrophages, which impacts the early phase of microbial proliferation, is subsequently circumvented by ongoing infection.
authors.affiliation: Centre of Advanced Studies , Faculty of Military Health Sciences, Trebesska 1575, Hradec Kralove 500 01, Czech Republic.
authors.forename: Anetta
authors.initials: A
authors.lastname: Härtlova
authors.forename: Marek
authors.initials: M
authors.lastname: Link
authors.forename: Jana
authors.initials: J
authors.lastname: Balounova
authors.forename: Martina
authors.initials: M
authors.lastname: Benesova
authors.forename: Ulrike
authors.initials: U
authors.lastname: Resch
authors.forename: Adela
authors.initials: A
authors.lastname: Straskova
authors.forename: Margarita
authors.initials: M
authors.lastname: Sobol
authors.forename: Anatoly
authors.initials: A
authors.lastname: Philimonenko
authors.forename: Pavel
authors.initials: P
authors.lastname: Hozak
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Krocova
authors.forename: Nelson
authors.initials: N
authors.lastname: Gekara
authors.forename: Dominik
authors.initials: D
authors.lastname: Filipp
authors.forename: Jiri
authors.initials: J
authors.lastname: Stulik
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001343:Autophagy; D015153:Blotting, Western; D002460:Cell Line; D021962:Membrane Microdomains / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D040901:Proteomics; D014406:Tularemia / Q000378:metabolism*