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PubMed1996

Expression of listeriolysin O by intracellular Listeria monocytogenes following infection of lipopolysaccharide-treated or untreated J774.1 macrophage-like cells.

Listeria monocytogenes replicates in a phagocytic cell following escape into the host cytoplasm. Listeriolysin O, secreted by L. monocytogenes, which belongs to the thiol-activated hemolysin family, is known to play an important role in the escape of the bacterium into the host cytoplasm. In this study, we demonstrated that expression of listeriolysin O by infecting L. monocytogenes was lightly induced in J774.1 macrophage-like cells pretreated with lipopolysaccharide, although the growth of the bacteria was suppressed. The number of viable L. monocytogenes decreased until 4 h post-infection and then increased between 4 and 8 h post-infection in untreated J774.1 host cells, but it decreased until 8 h post-infection in lipopolysaccharide-treated host cells. However, expression of listeriolysin O by L. monocytogenes was not induced in the untreated host cells, while it increased 0 and 4 h post-infection in the lipopolysaccharide-treated host cells. Expression of listeriolysin O mRNA in the lipopolysaccharide-like cells. These results suggest that macrophage activation induced with lipopolysaccharide could lead to the expression of the listeriolysin O gene and the synthesis of listeriolysin O protein under suppression of the intracellular growth of L. monocytogenes.

Bacterial Proteins↗

PubMed1992

Use of o-phthalaldehyde to detect O-phosphorylethanolamine in bacterial lipopolysaccharide.

We have developed a method to measure O-phosphorylethanolamine groups in bacterial lipopolysaccharide using a fluorescent reagent, o-phthalaldehyde. The optimal excitation and emission wavelengths were 335 nm and 450 nm, respectively. The reaction was pH-dependent with an optimum at pH 10.5. The maximum fluorescence intensity occurred two min after mixing lipopolysaccharide with the reagent at pH 10.5. The assay was linear over a range of 1 microgram to 100 micrograms of lipopolysaccharide. When we compared the amount of primary amine (as O-phosphorylethanolamine) in native and p-hydroxyphenylacetic acid-derivatized lipopolysaccharide, we found that 97% of amine groups in native lipopolysaccharide were derivatized by p-hydroxyphenylacetic acid in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide.

Ethanolamines↗

PubMed2006

Mechanisms underlying lipopolysaccharide-induced kinin B1 receptor up-regulation in the pig iris sphincter in vitro.

Kinin B1 receptors are known to be highly induced after inflammatory stimuli in several biological systems. We report that incubation of pig iris sphincter with lipopolysaccharide from Escherichia coli caused a marked and time-related up-regulation of B1, accompanied by a reduction of B2 receptor-mediated contractile responses. The up-regulation of B1 receptors by lipopolysaccharide stimulation was decreased by the inhibitors of protein synthesis, cycloheximide and actinomycin D, and by dexamethasone and the nuclear factor-kappaB (NF-kappaB) inhibitor pyrrolidinedithiocarbamate (PDTC). In addition, lipopolysaccharide-induced up-regulation of B1 receptors in the pig iris sphincter was significantly reduced by the p38 inhibitor 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB203580) and to a lesser extent by the extracellular signal-regulated kinases 1 and 2 (ERK1/2) blocker 2'-amino-3'-methoxyflavone (PD98059). Molecular biology experiments demonstrated that in vitro incubation with lipopolysaccharide resulted in a time-dependent and remarkable activation of NF-kappaB and of p38 and ERK1/2 mitogen-activated protein (MAP) kinases, in pig iris sphincter preparations. While attempting to verify how MAP kinases are part of the B1 receptor-activated signaling transduction pathways, we observed that PD98059 was able to markedly reduce the contraction induced by B1 receptor activation in lipopolysaccharide-pretreated pig iris sphincter muscle but that this response was only partially decreased by SB203580. Our results extend the previous evidence on the mechanisms underlying the B1 receptor upregulation processes and demonstrate for the first time how this takes place in an ocular tissue, the pig iris sphincter. It is therefore possible to define B1 receptors as therapeutic targets for the treatment of infectious and inflammatory alterations of the eye.

Animals↗

PubMed1977

Lipid A antiserum-mediated protection against lipopolysaccharide- and lipid A-induced fever and skin necrosis.

The antiendotoxic activity of lipid A antiserum was studied in rabbits, using lipid A (lipopolysaccharide)-induced fever and skin necrosis as test systems. It was found that lipid A antiserum had no significant antipyretic effect when it was incubated with lipid A or injected intravenously before lipid A challenge. However, in animals that were pretreated (day 0) with a single dose of lipid A (lipopolysaccharide), a significant protective effect of passively transferred antiserum (day 1) to lipid A (lipopolysaccharide fever) (day 2) was observed. Also, the lipid A (lipopolysaccharide)-induced local shwartzman reaction could be prevented by lipid A antiserum. In the fever system, the degree of protection depended on the preparative and the challenge doses as well as on the amount of antiserum transferred. The fever protection mediated by lipid A antiserum seemed to be lipid A (lipopolysaccharide) specific with regard to both the preparative and the challenge injections. Lipid A specificity of the protective factor present in the antiserum was indicated by the fauggest that the factor might be identical with lipid A-specific immunoglobulin. The significance of the preparative injection is not understood at the present time. Iti is concluded, however, that in the fever protection system described, besides specific humoral factors, other factors, perhaps cellular, are involved.

Animals↗

PubMed1978

Effect of zinc chloride on hamster lymphoid cells: mitogenicity and differential enhancement of lipopolysaccharide stimulation of lymphocytes.

ZnCl2 over a very narrow concentration range was found to be mitogenic for hamster lymph node cells but not for thymocytes or splenocytes. Maximal leucine, [3H]uridine, and [3H]thymidine incorporation. Addition of 10 micron ZnCl2 was found to greatly enhance the stimulation observed with the B-lymphocyte mitogen lipopolysaccharide but not with dextran sulfate or the T-lymphocyte mitogen lipopolysaccharide but not with dextran sulfate or the T-lymphocyte mitogen concanavalin A. Although not mitogenic for splenocytes, 10 to 25 micron ZnCl2 slightly enhanced lipopolysaccharide stimulation but not concanavalin A or dextran sulfate stimulation. The effect of ZnCl2 on lipopolysaccharide stimulation was also confirmed with outbred Hartley guinea pig splenocytes and lymph node cells. Zinc chloride (50 micron) was mitogenic for both of these tissues; the response to lipopolysaccharide was enhanced by addition of 50 micron ZnCl2, but the concanavalin A response was unaffected. The possibility that the zinc effect is mediated by proteolytic mechanisms is discussed.

Animals↗

PubMed1979

Comparison of enzyme-linked immunosorbent assay and passive hemagglutination method for quantification of antibodies to lipopolysaccharide and tetanus toxoid in rats.

In a comparative study, the enzyme-linked immunosorbent assay, using peroxidase labeled anti-rat immunoglobulin M and immunoglobulin G, and the passive hemagglutination test were applied to determine the primary and secondary antibody response to lipopolysaccharide and tetanus toxoid in rats. In the enzyme-linked immunosorbent assay, the antigens were bound to the wells of polystyrene microplates, tetanus toxoid directly, and lipopolysaccharide after complexing it with methylated bovine serum albumin. After incubation with dilutions of the rat sera, the amount of antibody bound to the solid phase was quantified by means of peroxidase-labeled anti-immunoglobulin. The specificity of the enzyme immunoassay was tested by absorption of the sera with their respective antigens. The enzyme-linked immunosorbent assay proved to be more sensitive than the hemagglutination reaction, except when titers were determined during the secondary response to tetanus toxoid. Besides its specificity and sensitivity, the enzyme-linked immunosorbent assay is a convenient method for measuring both immunoglobulin M and immunoglobulin G antibodies. At low serum dilutions of lipopolysaccharide antisera, inhibition of the reaction in the enzyme-linked immunosorbent assay occurred. This phenomenon could be prevented by heating the sera at 56 degrees C for 30 min. Lipopolysaccharide was immunogenic in rats over an extremely wide dose range (from 10 pg to 1 mg); the optimal immunogenic dose of lipopolysaccharide for young adult rats was 0.1 to 1,000 mug when administered intravenously, and that of tetanus toxoid was 5 to 10 lines of flocculation, as determined by the Ramon flocculation test.

Animals↗

PubMed1980

Chemical structure and inhalation toxicity of lipopolysaccharides from bacteria on cotton.

Lipopolysaccharides from different bacteria isolated from cotton were purified and chemically analyzed. Their pulmonary toxicity to animals was tested in inhalation tests. Lipopolysaccharides from Agrobacterium and Xanthomonas were shown to differ from the others in that they contained no heptose and no non-hydroxylated fatty acids with a chain length of 12, 14, or 16 carbon atoms. Lipopolysaccharides from Pseudomonas putida, Enterobacter agglomerans, and Klebsiella oxytoca were found to cause an influx of polymorphonuclear leukocytes into the airways. Lipopolysaccharides from Agrobacterium sp. and Xanthomonas sinensis caused no significant invasion. The data point to substances in both the lipid A part and the core part of the lipopolysaccharides being responsible for the capacity to induce leukocyte invasion into the airways.

Animals↗

PubMed1981

Induction of C3b-mediated phagocytosis in macrophages by distinct populations of lipopolysaccharide-stimulated lymphocytes.

Unelicited resident peritoneal macrophages do not significantly ingest erythrocytes coated with C3b. However, these resident macrophages can be induced to ingest via the C3b receptor when cocultured with peritoneal or splenic nonadherent cells obtained from mice previously injected with lipopolysaccharide. In this study, the extent of ingestion induced in resident macrophages was dependent on the number of stimulated nonadherent cells cocultured with the macrophages as well as on the amount of lipopolysaccharide injected in the mice from which the nonadherent cells were obtained. The ability of the stimulated nonadherent cells to convert resident macrophages to a state of C3b receptor-mediated ingestion was not abrogated by the inclusion of polymyxin B in the cocultivation medium. To further characterize these nonadherent cells, different lipopolysaccharide-stimulated cells were obtained by either nylon-wool filtration, depletion of C3b receptor-bearing cells, or depletion of Thy 1.2-positive cells. None of these populations by themselves were capable of inducing resident macrophages to ingest via the C3b receptor, whereas unfractionated cells were. However, coculture of resident macrophages with recombinations of splenic nylon-wool effluent (T cell-enriched) or bound (B cell-enriched) nonadherent cells from lipopolysaccharide-injected mice reconstituted the ability to induce ingestion via the C3b receptor. Taken together, these results suggest that one means by which lipopolysaccharide can induce C3b receptor-mediated ingestion by macrophages is through the cooperative effects of stimulated T and B lymphocytes.

Animals↗

PubMed1983

Monoclonal antibodies against Neisseria meningitidis lipopolysaccharide.

A cell line producing monoclonal antibodies directed against a lipopolysaccharide component of Neisseria meningitidis group A has been established. These antibodies reacted with only one of three lipopolysaccharide serotyping strains of group A meningococci by coagglutination, enzyme-linked immunosorbent assay, and Western blotting techniques. A Western blot analysis showed that a NaOH digest of lipopolysaccharide was detectable by the serotype-specific antibody. The monoclonal antibodies cross-reacted with a group B meningococcal strain in an enzyme-linked immunosorbent assay. The immunoblotting analysis also showed that these antibodies reacted with the lipopolysaccharides of a group B meningococcus as well as Haemophilus influenzae type B, but not with the lipopolysaccharides of several strains of Salmonella typhi, Escherichia coli, Streptococcus pneumoniae, and Neisseria gonorrhoeae.

Animals↗

PubMed1990

Antigenic relationships of the lipopolysaccharides of Escherichia hermannii strains with those of Escherichia coli O157:H7, Brucella melitensis, and Brucella abortus.

Clinical isolates of Escherichia hermannii which showed serological cross-reaction with polyclonal antisera to the O-polysaccharide portion of the lipopolysaccharide of E. coli O157 strains and with antisera to the O antigens of Brucella abortus and B. melitensis were found by chemical and nuclear magnetic resonance analyses to have lipopolysaccharide O chains composed of linear polymers containing 1,2- and 1,3-linked 4-acetamido-4,6-dideoxy-alpha-D-mannopyranosyl (alpha-D-Rhap4NAc) residues. Two O-antigen structures were identified; each had an unbranched pentasaccharide repeating unit, and one was composed of three 1,2- and two 1,3-linked alpha-D-Rhap4NAc residues and the other had two 1,2- and three 1,3-linked alpha-D-Rhap4NAc residues. The above-described cross-serological reactivities, which have led to false-positive identifications, are related to the common occurrence of epitopes involving the presence of N-acyl derivatives of 4-amino-4,6-dideoxy-D-mannopyranosyl residues in the O-polysaccharide portions of the respective lipopolysaccharides of the organisms. Strains of E. hermannii which did not show serological cross-reactions with E. coli O157 and Brucella antisera were found to have unique lipopolysaccharide O chains devoid of D-Rhap4NAc residues, demonstrating the existence of serotypes of E. hermannii that are distinct on the basis of their lipopolysaccharide components.

Antigens, Bacterial↗

PubMed1997

Marked reduction of mouse peritoneal CD5+ B cells by intraperitoneal administration of lipopolysaccharide.

Intraperitoneal administration of lipopolysaccharide to mice induced a marked reduction of CD5+ B cells in the peritoneal cavity. The reduction was not induced by intravenous, subcutaneous, or oral administration of lipopolysaccharide. The reduction continued for about 10 days after the injection, and the CD5+ B-cell count recovered to the normal state about 14 days after the injection. The reduction of peritoneal CD5+ B cells might be caused by apoptotic cell death. Injection of lipopolysaccharide did not result in production of antibody to lipopolysaccharide. On the other hand, intraperitoneal injection of heat-killed bacteria did not induce a reduction of peritoneal CD5+ B cells and elicited the definite production of antibody to lipopolysaccharide.

Animals↗

PubMed1973

Structure of cell wall lipopolysaccharide from Salmonella typhimurium. IV. Anomeric configuration of L-rhamnose residues and its taxonomic implications.

A major portion of cell wall lipopolysaccharide from group A, group B, or group D(1)Salmonella corresponds to a linear polysaccharide chain, which consists of alpha-d-galactosyl-(1 --> 2)-alpha-d-mannosyl-(1 --> 4)-l-rhamnosyl-(1 --> 3)-repeating units, and has short branches of single 3,6-dideoxyhexose residues. The groups differ in the configuration of the 3,6-dideoxyhexose present. Furthermore, it has been claimed that the anomeric configuration of the rhamnosyl residues is beta-l in group B, in contrast to the alpha-l configuration found in groups A and D(1). In this study, oligosaccharides containing more than one repeating unit were isolated from a lipopolysaccharide of a group B Salmonella, and the anomeric configuration of the rhamnosyl residues was determined by the comparison of optical rotatory powers of these oligosaccharides with that of the repeating unit trisaccharide. The results established the configuration of rhamnose as alpha-l, in contrast to the beta-l configuration suggested in the literature. Since rhamnosyl linkages in lipopolysaccharide of a group D(1)Salmonella are hydrolyzed in acid at exactly the same rate as are those in group B Salmonella, the configuration of rhamnose residues in groups D(1) lipopolysaccharide is also likely to be alpha-l. These results indicate that lipopolysaccharides of Salmonella groups A, B, and D(1) share an identical main chain polysaccharide and differ essentially only in the configuration of 3,6-dideoxyhexose branches; they thus suggest close evolutionary relationship between these three serogroups of Salmonella.

Carbon Isotopes↗

PubMed1975

Outer membrane of Salmonella typhimurium: chemical analysis and freeze-fracture studies with lipopolysaccharide mutants.

The outer membrane layer of the cell wall was isolated from wild-type Salmonella typhimurium LT2 as well as from its mutants producing lipopolysaccharides with shorter saccharide chains. Chemical analysis of these preparations indicated the following. (i) The number of lipopolysaccharide molecules per unit area was constant, regardless of the length of the saccharide side chain in lipopolysaccharide. (ii) In contrast, in "deep rough" (Rd or Re) mutants producing the lipopolysaccharides with very short saccharide chains, the amount of outer membrane protein per unit surface area decreased to about 60% of the value in the wild type. (iii) In the wild type, the amount of phospholipids is slightly less than what is needed to cover one side of the membrane as a monolayer. In comparison with the wild type, the outer membrane of Rd and Re mutants contains about 70% more phospholipids, which therefore must be distributed in both the outer and inner leaflets of the membrane. Freeze-fracture studies showed that the outer membrane of Re mutants were easily fractured, but fracture became increasingly difficult in strains producing lipopolysaccharides with longer side chains. The convex fracture face was always nearly smooth, but the concave fracture face or the outer half of the membrane was densely covered with particles 8 to 10 nm in diameter. The density of particles was decreased in Re mutants to the same extent as the reduction in proteins, suggesting the largely proteinaceous nature of particles. A model for the supramolecular structure of the outer membrane is presented on the basis of these and other results.

Bacterial Proteins↗

PubMed1979

Accelerated adsorption of bacteriophage T5 to Escherichia coli F, resulting from reversible tail fiber-lipopolysaccharide binding.

A dual specificity for phage T5 adsorption to Escherichia coli cells is shown. The tail fiber-containing phages T5(+) and mutant hd-3 adsorbed rapidly to E. coli F (1.2 x 10(-9) ml min(-1)), whereas the adsorption rate of the tail fiber-less mutants hd-1, hd-2, and hd-4 was low (7 x 10(-11) ml min(-1)). The differences in adsorption rates were due to the particular lipopolysaccharide structure of E. coli F. Phage T4-resistant mutants of E. coli F with an altered lipopolysaccharide structure exhibited similar low adsorption for all phage strains with and without tail fibers. The same held true for E. coli K-12 and B which also differ from E. coli F in their lipopolysaccharide structures. Only the tail fiber-containing phages reversibly bound to isolated lipopolysaccharides of E. coli F. Infection by all phage strains strictly depended on the tonA-coded protein in the outer membrane of E. coli. We assume that the reversible preadsorption by the tail fibers to lipopolysaccharide accelerates infection which occurs via the highly specific irreversible binding of the phage tail to the tonA-coded protein receptor. The difference between rapid and slow adsorption was also revealed by the competition between ferrichrome and T5 for binding to their common tonA-coded receptor in tonB strains of E. coli. Whereas binding of T5(+) to E. coli K-12 and of the tail-fiber-less mutant hd-2 to E. coli F and K-12 was inhibited 50% by about 0.01 muM ferrichrome, adsorption of T5 to E. coli F was inhibited only 40% by even 1,000-fold higher ferrichrome concentrations.

Adsorption↗

PubMed1980

Isolation of two protein-free and chemically different lipopolysaccharides from Bordetella pertussis phenol-extracted endotoxin.

Endotoxin prepared from several Bordetella pertussis strains in both immunological phases I and IV gave two lipopolysaccharide peaks (LPS-I and LPS-II) when analyzed on hydroxylapatite columns in a phosphate buffer containing 0.1% sodium dodecyl sulfate; these lipopolysaccharides, present in the ratio of 2:3, are true endotoxins by both chemical and biological criteria. Endotoxins isolated from Escherichia coli, Salmonella typhimurium, and Shigella flexneri gave single lipopolysaccharide peaks when analyzed by the same procedure. Upon hydrolysis with acetic acid (pH 3.4) at 100 degrees C for 1 h, LPS-I released a polysaccharide (PS-I); the linkage broken was that of the glycosidic bond of a non-phosphorylated 3-deoxy-oct-2-ulosonic acid. Treatment with 0.25 M mineral acid at 100 degrees C for 30 min was required to free the polysaccharide moiety (PS-II) of LPS-II, the linkage broken being the glycosidic bond of a phosphorylated 3-deoxy-oct-2-ulosonic acid. Chemical and physical differences of the polysaccharide moieties PS-I and PS-II present in LPS-I and LPS-II have been described previously (25). By using the technique of 125I labeling, it was shown that the totality of labeled proteins present in the endotoxin extracted from Bordetella pertussis by the phenol-water procedure could be separated from the lipopolysaccharide by column chromatography on hydroxylapatite; it follows that these proteins are not linked by covalent bonds to the lipopolysaccharide.

Bacterial Toxins↗

PubMed1984

Structural and immunochemical homogeneity of Aeromonas salmonicida lipopolysaccharide.

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to analyze the lipopolysaccharides of typical and atypical strains of the fish pathogen Aeromonas salmonicida. 32P intrinsically radiolabeled lipopolysaccharide in sarcosinate-extracted outer membrane preparations, lipopolysaccharide stained by silver in proteinase K-digested outer membrane preparations and whole cell lysates, as well as purified lipopolysaccharide, displayed O-polysaccharide chains which were unusually homogeneous with respect to chain length. Chemical analysis further revealed that the sugar composition of the smooth lipopolysaccharide purified from three typical strains was very similar. Immunoblotting and immunofluorescent staining with both polyclonal and monoclonal antibody showed that the O-polysaccharide chains were strongly immunogenic and were antigenically cross-reactive on typical and atypical strains from diverse origins. Immunofluorescence analysis and phage binding studies demonstrated that a number of these O-polysaccharide chains traversed the surface protein array of virulent strains of A. salmonicida and were exposed on the cell surface.

Aeromonas↗

PubMed1985

Electrophoretic and immunochemical analyses of the lipopolysaccharides from various strains of Aeromonas hydrophila.

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to analyze the lipopolysaccharides isolated from strains of Aeromonas hydrophila which exhibit virulence for fish and which autoaggregate during growth in static broth culture. The lipopolysaccharides contained O-polysaccharide chains of homogeneous chain length. Two of the strains produced a surface protein array, and immunofluorescence and phage-binding studies revealed that a number of these O-polysaccharide chains of homogeneous length traversed the protein array and were exposed on the cell surface. Immunochemical analyses by immunoblotting, enzyme-linked immunosorbent assay, immunofluorescence, and immunoprecipitation with both polyclonal and monoclonal antibodies revealed the presence of three epitopes on the polysaccharide moiety of this homogenous-chain-length lipopolysaccharide morphotype. One epitope was species serogroup specific and reactive by immunoblotting. This epitope was not present on the heterogeneous-chain-length O polysaccharides of nonautoaggregating strains of A. hydrophila examined. The second epitope was conformation dependent and cross-reactive with an epitope on the homogenous-chain-length O polysaccharides of Aeromonas salmonicida lipopolysaccharide. The third epitope was recognized by a monoclonal antibody and appeared to involve that region of the A. hydrophila and A. salmonicida lipopolysaccharide molecules which contained the O-polysaccharide-core oligosaccharide glycosidic linkage.

Adsorption↗

PubMed1989

Defects in motility and development of Myxococcus xanthus lipopolysaccharide mutants.

Five transposon Tn5 mutants of the procaryote Myxococcus xanthus had been shown previously to be defective in lipopolysaccharide biosynthesis (J. M. Fink,-M. Kalos, and J. F. Zissler, J. Bacteriol. 171:2033-2041, 1989). These mutants were studied for possible defects in gliding motility and multicellular development. Wild-type M. xanthus cells glide both as single cells and as groups of cells. We found that the Tn5 lipopolysaccharide O-antigen mutants were defective in single-cell motility but were unaltered in group motility. These mutant strains were slow to develop but eventually gave rise to normal, spore-filled fruiting bodies. We also had shown previously that 56 (ethyl methanesulfonate-induced and spontaneous) phage-resistant mutants were defective in lipopolysaccharide biosynthesis. We found that many of these lipopolysaccharide O-antigen mutants were defective in single-cell motility but were unaltered in group motility. These mutants also gave rise to normal, spore-filled fruiting bodies. We also studied several phage-resistant mutants which were lacking a side-chain carbohydrate on the lipopolysaccharide core. These mutants possessed both single-cell motility and group motility but were altered in the magnitude of gliding. These mutants were blocked early in development and could not form multicellular fruiting bodies. Several of the mutations in the developmentally aberrant strains were mapped to a single locus by using a collection of genetically linked transposons as genetic markers.

Bacteriophages↗