title: Porin Loss Impacts the Host Inflammatory Response to Outer Membrane Vesicles of Klebsiella pneumoniae.
abstract: Antibiotic-resistant strains of Klebsiella pneumoniae often exhibit porin loss. In this study, we investigated how porin loss impacted the composition of secreted outer membrane vesicles as well as their ability to trigger proinflammatory cytokine secretion by macrophages. We hypothesize that porin loss associated with antibiotic resistance will directly impact both the composition of outer membrane vesicles and their interactions with phagocytic cells. Using clonally related clinical isolates of extended-spectrum beta-lactamase (ESBL)-positive Klebsiella pneumoniae with different patterns of porin expression, we demonstrated that altered expression of OmpK35 and OmpK36 results in broad alterations to the protein profile of secreted vesicles. Additionally, the level of OmpA incorporation was elevated in strains lacking a single porin. Porin loss significantly impacted macrophage inflammatory responses to purified vesicles. Outer membrane vesicles lacking both OmpK35 and OmpK36 elicited significantly lower levels of proinflammatory cytokine secretion than vesicles from strains expressing one or both porins. These data demonstrate that antibiotic resistance-associated porin loss has a broad and significant effect on both the composition of outer membrane vesicles and their interactions with phagocytic cells, which may impact bacterial survival and inflammatory reactions in the host.
authors.affiliation: Department of Biology, University of North Florida, Jacksonville, Florida, USA.
authors.forename: Kelli L
authors.initials: KL
authors.lastname: Turner
authors.affiliation: Department of Biology, University of North Florida, Jacksonville, Florida, USA.
authors.forename: Bethaney K
authors.initials: BK
authors.lastname: Cahill
authors.affiliation: Department of Biology, University of North Florida, Jacksonville, Florida, USA.
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Dilello
authors.affiliation: Department of Biology, University of North Florida, Jacksonville, Florida, USA.
authors.forename: Dedra
authors.initials: D
authors.lastname: Gutel
authors.affiliation: Department of Biology, University of North Florida, Jacksonville, Florida, USA.
authors.forename: Debra N
authors.initials: DN
authors.lastname: Brunson
authors.affiliation: IUNICS, University of the Balearic Islands, Palma de Mallorca, Spain.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Albertí
authors.affiliation: Department of Biology, University of North Florida, Jacksonville, Florida, USA terri.ellis@unf.edu.
authors.forename: Terri N
authors.initials: TN
authors.lastname: Ellis
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D015964:Gene Expression Regulation, Bacterial; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism; D054884:Host-Pathogen Interactions / Q000502:physiology*; D007249:Inflammation / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000254:growth & development / Q000472:pathogenicity*; D008264:Macrophages / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D051379:Mice; D018272:Porins / Q000235:genetics / Q000378:metabolism*; D022142:Secretory Vesicles / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; C119261:OmpK35 porin, Klebsiella pneumoniae; C092233:OmpK36 protein, Klebsiella pneumoniae; D018272:Porins; D014409:Tumor Necrosis Factor-alpha; D016178:Granulocyte-Macrophage Colony-Stimulating Factor