The heat sensitivity of cytokine-inducing effect of lipopolysaccharide.
AuthorsGao B, Wang Y, Tsan MF,
JournalJ Leukoc Biol
PubMed ID16720829
Heat inactivation by boiling has been widely used as a criterion to determine whether the observed effects of a protein preparation are a result of lipopolysaccharide (LPS) contamination. However, the heat sensitivity of LPS cytokine-inducing activity has not been characterized. In the current study, we demonstrated that the endotoxin activity, ... More
Bacterial cell wall synthesis gene uppP is required for burkholderia colonization of the Stinkbug Gut.
AuthorsKim JK, Lee HJ, Kikuchi Y, Kitagawa W, Nikoh N, Fukatsu T, Lee BL,
Journal
PubMed ID23747704
'To establish a host-bacterium symbiotic association, a number of factors involved in symbiosis must operate in a coordinated manner. In insects, bacterial factors for symbiosis have been poorly characterized at the molecular and biochemical levels, since many symbionts have not yet been cultured or are as yet genetically intractable. Recently, ... More
A cyanobacterial lipopolysaccharide antagonist inhibits cytokine production induced by Neisseria meningitidis in a human whole-blood model of septicemia.
AuthorsJemmett K, Macagno A, Molteni M, Heckels JE, Rossetti C, Christodoulides M,
JournalInfect Immun
PubMed ID18443097
'Septicemia caused by Neisseria meningitidis is characterized by increasing levels of meningococcal lipopolysaccharide (Nm-LPS) and cytokine production in the blood. We have used an in vitro human whole-blood model of meningococcal septicemia to investigate the potential of CyP, a selective Toll-like receptor 4 (TLR4)-MD-2 antagonist derived from the cyanobacterium Oscillatoria ... More
Colonial morphology of Burkholderia cepacia complex genomovar III: implications in exopolysaccharide production, pilus expression, and persistence in the mouse.
AuthorsChung JW, Altman E, Beveridge TJ, Speert DP
JournalInfect Immun
PubMed ID12540572
'The purpose of this study was to determine the role of colonial morphology of Burkholderia cepacia complex (BCC) organisms in pathogenicity in a mouse model of pulmonary infection. BCC strain C1394 was rapidly cleared by leukopenic mice after intranasal challenge, whereas a spontaneous variant (C1394mp2) that was indistinguishable from the ... More
The PmrA/PmrB regulatory system controls the expression of the wzzfepE gene involved in the O-antigen synthesis of Salmonella enterica serovar Typhimurium.
'The degree of polymerization of O-antigen from Salmonella enterica serovar Typhimurium is controlled by the products of the wzz(s)(t) and wzz(fepE) genes. In the present study we investigated the role of the PmrA/PmrB regulatory system in wzz(fepE) transcription. We report that the direct binding of the PmrA regulator to a ... More
Coadministration of the cyanobacterial lipopolysaccharide antagonist CyP with antibiotic inhibits cytokine production by an in vitro meningitis model infected with Neisseria meningitidis.
AuthorsOliver R, Staples KJ, Heckels J, Rossetti C, Molteni M, Christodoulides M,
JournalJ Antimicrob Chemother
PubMed ID22334603
In this study, the objective was to determine the anti-inflammatory properties of CyP, a cyanobacterial lipopolysaccharide (LPS) antagonist, used in combination with antibiotic chemotherapy during infection of an in vitro meningitis model infected with Neisseria meningitidis (meningococcus). Monocultures of human meningioma cells and meningioma-primary human macrophage co-cultures were infected with ... More
Vaccination with outer membrane complexes elicits rapid protective immunity to multidrug-resistant Acinetobacter baumannii.
Acinetobacter baumannii causes pneumonias, bacteremias, and skin and soft tissue infections, primarily in the hospitalized setting. The incidence of infections caused by A. baumannii has increased dramatically over the last 30 years, while at the same time the treatment of these infections has been complicated by the emergence of antibiotic-resistant ... More
Role of glycan synthesis in colonization of the mammalian gut by the bacterial symbiont Bacteroides fragilis.
AuthorsCoyne MJ, Chatzidaki-Livanis M, Paoletti LC, Comstock LE,
JournalProc Natl Acad Sci U S A
PubMed ID18723678
Bacteroides species are the most abundant Gram-negative bacteria of the human colonic microbiota. These endogenous organisms are unique in that they synthesize an extensive number of phase-variable surface polysaccharides. Pathogenic bacteria phase vary expression of surface molecules for immune evasion, but the importance of the synthesis of multiple phase-variable polysaccharides ... More
Low potency of Chlamydophila LPS to activate human mononuclear cells due to its reduced affinities for CD14 and LPS-binding protein.
AuthorsTsutsumi-Ishii Y, Shimada K, Daida H, Toman R, Nagaoka I,
JournalInt Immunol
PubMed ID18056918
Chlamydiaceae are small obligate intracellular parasites and classified as Gram-negative bacteria. Among Chlamydiaceae-derived components, LPS is known as an immunomodulator and possesses a unique lipid A structure with longer but fewer acyl chains. In this study, to elucidate the Chlamydiaceae-induced immune responses, we evaluated the actions of Chlamydophila psittaci LPS ... More
Impairment of O-antigen production confers resistance to grazing in a model amoeba-cyanobacterium predator-prey system.
The grazing activity of predators on photosynthetic organisms is a major mechanism of mortality and population restructuring in natural environments. Grazing is also one of the primary difficulties in growing cyanobacteria and other microalgae in large, open ponds for the production of biofuels, as contaminants destroy valuable biomass and prevent ... More
Helical disposition of proteins and lipopolysaccharide in the outer membrane of Escherichia coli.
AuthorsGhosh AS, Young KD
JournalJ Bacteriol
PubMed ID15743937
In bacteria, several physiological processes once thought to be the products of uniformly dispersed reactions are now known to be highly asymmetric, with some exhibiting interesting geometric localizations. In particular, the cell envelope of Escherichia coli displays a form of subcellular differentiation in which peptidoglycan and outer membrane proteins at ... More
Characterization of recombinant soluble macrophage scavenger receptor MARCO.
AuthorsSankala M, Brännström A, Schulthess T, Bergmann U, Morgunova E, Engel J, Tryggvason K, Pikkarainen T
JournalJ Biol Chem
PubMed ID12097327
MARCO is a type II transmembrane protein of the class A scavenger receptor family. It has a short N-terminal cytoplasmic domain, a transmembrane domain, and a large extracellular part composed of a 75-residue long spacer domain, a 270-residue collagenous domain, and a 99-residue long scavenger receptor cysteine-rich (SRCR) domain. Previous ... More