title: Variants of Porphyromonas gingivalis lipopolysaccharide alter lipidation of autophagic protein, microtubule-associated protein 1 light chain 3, LC3.
abstract: Porphyromonas gingivalis often subverts host cell autophagic processes for its own survival. Our previous studies document the association of the cargo sorting protein, melanoregulin (MREG), with its binding partner, the autophagic protein, microtubule-associated protein 1 light chain 3 (LC3) in macrophages incubated with P. gingivalis (strain 33277). Differences in the lipid A moiety of lipopolysaccharide (LPS) affect the virulence of P. gingivalis; penta-acylated LPS1690is a weak Toll-like receptor 4 agonist compared with Escherichia coli LPS, whereas tetra-acylated LPS1435/1449acts as an LPS1690antagonist. To determine how P. gingivalis LPS1690affects autophagy we assessed LC3-dependent and MREG-dependent processes in green fluorescent protein (GFP)-LC3-expressing Saos-2 cells. LPS1690stimulated the formation of very large LC3-positive vacuoles and MREG puncta. This LPS1690-mediated LC3 lipidation decreased in the presence of LPS1435/1449. When Saos-2 cells were incubated with P. gingivalis the bacteria internalized but did not traffic to GFP-LC3-positive structures. Nevertheless, increases in LC3 lipidation and MREG puncta were observed. Collectively, these results suggest that P. gingivalis internalization is not necessary for LC3 lipidation. Primary human gingival epithelial cells isolated from patients with periodontitis showed both LC3II and MREG puncta whereas cells from disease-free individuals exhibited little co-localization of these two proteins. These results suggest that the prevalence of a particular LPS moiety may modulate the degradative capacity of host cells, so influencing bacterial survival.
authors.affiliation: Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.|Department of Orthodontics, School of Dentistry, International University of Catalonia, Barcelona, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Blasi
authors.affiliation: Department of Periodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: J
authors.initials: J
authors.lastname: Korostoff
authors.affiliation: Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Dhingra
authors.affiliation: Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: J
authors.initials: J
authors.lastname: Reyes-Reveles
authors.affiliation: Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: B J
authors.initials: BJ
authors.lastname: Shenker
authors.affiliation: Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: N
authors.initials: N
authors.lastname: Shahabuddin
authors.affiliation: Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: D
authors.initials: D
authors.lastname: Alexander
authors.affiliation: Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: E T
authors.initials: ET
authors.lastname: Lally
authors.affiliation: Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Bragin
authors.affiliation: Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA. battagli@upenn.edu.
authors.forename: K
authors.initials: K
authors.lastname: Boesze-Battaglia
mesh_terms: D000215:Acylation; D033942:Adaptor Proteins, Vesicular Transport; D001343:Autophagy; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D005881:Gingiva / Q000382:microbiology; D049452:Green Fluorescent Proteins; D006801:Humans; D008050:Lipid A / Q000378:metabolism; D008055:Lipids / Q000502:physiology*; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000378:metabolism; D008264:Macrophages / Q000382:microbiology*; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000378:metabolism*; D016966:Porphyromonas gingivalis / Q000737:chemistry* / Q000378:metabolism*; D051197:Toll-Like Receptor 4
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; D002352:Carrier Proteins; D008050:Lipid A; D008055:Lipids; D008070:Lipopolysaccharides; C477012:MAP1LC3A protein, human; C000609551:MREG protein, human; D008869:Microtubule-Associated Proteins; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D049452:Green Fluorescent Proteins
keywords: GFP-LC3; Porphyromonas gingivalis LPS1690; Saos-2 cells; human gingival epithelia; periodontal pathogens; toll-like receptor agonist