title: The role of lipopolysaccharide moieties in macrophage response to Escherichia coli.
abstract: Lipopolysaccharide (LPS) is the main component of Gram-negative bacteria that - upon infection - activates the host immune system and is crucial in fighting pathogens as well as in the induction of sepsis. In the present study we addressed the question whether the key structural components of LPS equally take part in the activation of different macrophage immune responses. By genomic modifications of Escherichia coli MG1655, we constructed a series of strains harboring complete and truncated forms of LPS in their cell wall. These strains were exposed to RAW 264.7 macrophages, after which phagocytosis, fast release of pre-synthesized TNF and activation of NF-kappaB signal transduction pathway were quantified. According to our results the core and lipid A moieties are involved in immune recognition. The most ancient part, lipid A is crucial in evoking immediate TNF release and activation of NF-kappaB. The O-antigen inhibits phagocytosis, leading to immune evasion.
authors.affiliation: Biological Research Center of Hungarian Academy of Sciences, Institute of Biochemistry, Temesvari krt. 62., Szeged H-6726, Hungary.
authors.forename: Katalin
authors.initials: K
authors.lastname: Eder
authors.forename: Csaba
authors.initials: C
authors.lastname: Vizler
authors.forename: Erzsebet
authors.initials: E
authors.lastname: Kusz
authors.forename: Ildiko
authors.initials: I
authors.lastname: Karcagi
authors.forename: Hristos
authors.initials: H
authors.lastname: Glavinas
authors.forename: Gabor E
authors.initials: GE
authors.lastname: Balogh
authors.forename: Laszlo
authors.initials: L
authors.lastname: Vigh
authors.forename: Erno
authors.initials: E
authors.lastname: Duda
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Gyorfy
mesh_terms: D000818:Animals; D002460:Cell Line; D004926:Escherichia coli / Q000235:genetics / Q000276:immunology*; D016680:Genome, Bacterial; D008050:Lipid A / Q000235:genetics / Q000276:immunology; D008070:Lipopolysaccharides / Q000235:genetics / Q000276:immunology*; D008264:Macrophages / Q000276:immunology* / Q000382:microbiology; D051379:Mice; D016328:NF-kappa B / Q000096:biosynthesis; D019081:O Antigens / Q000235:genetics / Q000276:immunology; D010587:Phagocytosis / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D008050:Lipid A; D008070:Lipopolysaccharides; D016328:NF-kappa B; D019081:O Antigens; D014409:Tumor Necrosis Factor-alpha