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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Escherichia coli K100 produces an antigenic determinant similar to, or identical with, the capsular antigen of Haemophilus influenzae type b. Studies of the effects of heat on the immunogenicity, erythrocyte-modifying capacity, and antigenicity of this cross-reacting antigen (CRA) revealed the following findings. Immunization of rabbits with viable or formaldehyde-killed suspensions of E. coli K100, producing CRA, engendered CRA antibodies in significant titers, as demonstrated by hemagglutination of erythrocytes modified by H. influenzae type b antigen. Heating of the suspensions for 1 h at 56 or 100 degrees C destroyed the immunogenicity of CRA, and the heated suspensions did not prime for a secondary antibody response. Supernatants of heated suspensions also were non-immunogenic. Repeated freezing and thawing of heated suspensions of E. coli K100 or their supernatants did not restore immunogenicity. Heat also abolished the immunogenicity of H. influenzae type b. The loss of immunogenicity of CRA of E. coli K100 by heat was not due to alteration of the antigenic determinant, since heated suspensions and supernatants thereof modified erythrocytes for agglutination by H. influenzae type b antiserum. The latter supernatants also inhibited hemagglutination by H. influenzae type b antibodies and absorbed the latter. We conclude that striking differences exist in the effects of heat on CRA on the one hand and of enterobacterial common antigen and lipopolysaccharide O antigen of enteric bacteria on the other. Heating of the latter two antigens does not abolish their priming effect, and repeated freezing and thawing restores the immunogenicity of heated antigens.
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PMID:Effect of heat on antigenicity and immunogenicity of the antigenic determinant shared by Haemophilus influenzae type b and Escherichia coli K100. 7 Dec 69

Four murine hybridoma clones secreting monoclonal antibodies (mAb) directed against lipopolysaccharide (LPS) antigen of S. newington, serogroup E1, were obtained after a fusion of spleen cells of mice immunized with formaldehyde-killed bacteria and mouse myeloma cells of the X63-Ag8.653 line. Antigen binding properties and specificity of the mAb were studied in bacterial agglutination tests, passive hemolysis and its inhibition, passive hemagglutination tests, passive hemolysis and its inhibition, passive hemagglutination and immunoenzyme tests (ELISA and immunoblotting). Three of the mAb (24E6, 29E1 and 45F6) were agglutinating and were active in all tests used, while mAb 31H12 did not agglutinate bacteria but revealed a high reactivity in the immunoenzyme reactions. It was found that the mAb reacted with LPS and Salmonella strains from serogroup E (E1, E2, E3 and E4) as well as from serogroups C (C1 and C4), F and S thus showing that the O3 antigen possesses more than one epitope, one of which is represented on the LPS antigens of the serovars from the cross-reacting groups mentioned. According to the known chemical the most probable recognized epitope consists of mannose with beta-linkage to the next monosaccharide residue in the LPS chain.
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PMID:Monoclonal antibodies directed to the O antigen of Salmonella serogroup E cross-react with lipopolysaccharides of Salmonella serogroups C, F and S. 128 92

Haemophilus ducreyi (H. ducreyi) strains, representing both reference strains and low-passage isolates, were investigated in terms of surface structures and enzymatic equipment. The interaction of these factors with host tissue was analysed using new in vitro- and in vivo-models. By electron microscopy studies there was no evidence of an extracellular capsule or surface appendages such as pili or flagella. Interaction of all isolates tested with the lectin Phaseolus vulgaris suggests N-acetyl-D-glucosamine units as common structural features of H. ducreyi cell envelope polysaccharide. In attachment to epithelial cells more than one hemagglutinin might be implicated as different haemagglutination patterns could be observed whereby the activity was not heat-labile, but was abolished by formaldehyde. Hydrophobic interactions might be of importance as well as strains showed a wide range of reactions from hydrophobic to hydrophilic, low hydrophobicity being more marked with the older strains. No elaboration of degradative enzymes based on the measurement of enzymatic activity using insoluble dye-protein complexes could be detected in case of H. ducreyi, using Azocoll and Remazol Brilliantblue hide powder for detection of proteolytic activity and elastinorcein for detection of elastase activity. In vitro studies using human keratinocytes and Vero cells did not show any morphological changes when incubated with H. ducreyi culture filtrates. In vivo studies with a new mouse model for H. ducreyi infection could confirm the results of the in vitro studies. Mere contact to undamaged skin both of whole cell organisms, live or heat-killed, and of culture filtrates did not lead to any reaction or even damage of mouse skin. However, when the outer epidermal layer was overcome by intradermal injection of shaved mice ulcers developed. Tissue necrosis production was not bound to live organisms as dead ones showed the same effect. There is great evidence that this tissue necrosis is associated with H. ducreyi lipopolysaccharide (LPS) because intradermal injection of purified H. ducreyi LPS lead to the same reaction pattern. For the first time a cell mediated immune response could be demonstrated in case of H. ducreyi infection as different antigen preparations of H. ducreyi isolates induced proliferation of lymphocytes isolated from healthy unexposed individuals and from a chancroid-sensitized male. In the latter case measured cell responses were much stronger. The dose-dependent phenomenon was associated with interleukin-2 production. In summary, H. ducreyi isolates do not exhibit cytotoxic effects on the epithelial cells of the skin.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Mechanisms of skin adherence, penetration and tissue necrosis production by Haemophilus ducreyi, the causative agent of chancroid. 163 61

Twenty two hybridoma strains producing monoclonal antibodies against Francisella tularensis ATCC 6223, var. tularensis, were characterized. In an enzyme-linked-immunosorbent-assay (ELISA) using formaldehyde fixed bacteria as antigens, neither cross-reactions with six different Brucella spp., with Yersinia enterocolitica 0:9 nor with two biotypes of Yersinia pseudotuberculosis could be detected. The antibodies gave comparable titres with the three strains of F.tularensis tested. ELISA binding studies indicated that fifteen of the antibodies bound with high affinities to their epitopes of the three Francisella strains, while the others each seemed to bind with low affinity to at least one of the antigens. Immunoblot analysis showed that six of the antibodies were directed to epitopes on the core moiety of the lipopolysaccharide molecule, while the other 16 antibodies bound to O side chain components.
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PMID:Monoclonal antibodies reacting specifically with Francisella sp. 259

The opsonic capacity of antisera to Pseudomonas aeruginosa ribosomal vaccine fractions was determined by a chemiluminescent technique. Antiserum to a vaccine fraction ("peak A") containing lipopolysaccharide (antiserum A), and antiserum to a vaccine fraction ("peak B"), which did not contain detectable amounts of lipopolysaccharide (antiserum B), were used to opsonify live or formalin-treated bacteria. Polymorphonuclear leukocytes were then stimulated by the opsonified bacteria in the presence of the chemiluminigenic probe, luminol, resulting in the observed chemiluminescence. The data obtained indicated that the antisera had comparable opsonic activity with live (untreated) bacteria. However, antiserum B had far less opsonic activity than did antiserum A when formalinized bacteria were used. Owing to the effects of formaldehyde on protein, these results were interpreted as evidence to suggest that the opsonic activities of the two antisera are dependent on different antigens on the bacterial cell surface. Antiserum A activity is probably dependent on lipopolysaccharide to a great extent, whereas antiserum B activity is most likely dependent primarily on a protein(s).
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PMID:Opsonic activity of antisera to ribosomal vaccine fractions with live and formalinized Pseudomonas aeruginosa. 308 71

The plasmid-mediated formaldehyde resistance of Serratia marcescens and Escherichia coli was examined. For that purpose the outer membranes of isogenic strains (with and without resistance plasmid) were compared. No quantitative or immunological differences in lipopolysaccharide of resistant and sensitive strains were noted. By contrast analysis of outer membrane proteins revealed that the sensitive variants had a higher protein content than the resistant strains. When outer membrane proteins were separated by SDS-PAGE the number of bands seemed identical for sensitive and resistant strains but the intensity of some of the bands was greater for the sensitive isolates. In addition, the surface hydrophobicity was greater for the resistance than for the sensitive strains. These findings suggest that the formaldehyde resistance plasmid of Serratia marcescens confer changes in cell surface proteins and surface hydrophobicity.
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PMID:Plasmid-mediated formaldehyde resistance in Serratia marcescens and Escherichia coli: alterations in the cell surface. 332 66

Strain TA102 of S. typhimurium is a new histidine-requiring mutant, particularly suited to the detection of oxidative mutagens acting at A.T base pairs. 10 oxidizing chemicals, previously tested in strain TA102, were used to evaluate the mutagenic sensitivity of the L-arabinose forward mutation assay of S. typhimurium with respect to those types of mutagens. The mutagenicity of each compound was determined by liquid test, measuring both the frequency of mutants among the survivors and the absolute number of mutants growing in selective plates with traces of D-glucose. Strain BA13 with a wild-type lipopolysaccharide barrier was used as compared to the deep rough derivative strain BA9. The chemicals studied were: bleomycin, t-butyl hydroperoxide, chromium trioxide, cumene hydroperoxide, formaldehyde, glyoxal, glutaraldehyde, hydrogen peroxide, paraquat, and phenylhydrazine. Additionally, ultrasonic oscillation was used as a presumable non-mutagenic lethal control treatment. The L-arabinose forward mutation assay detected the mutagenic activity of all the chemicals under study with a high degree of sensitivity, including paraquat which is unable to revert strain TA102. Positive responses were obtained at doses equivalent to or 10 times lower than the doses detected by strain TA102. The results support the idea that the L-arabinose forward mutation assay could replace the set of specific tester strains used by the histidine reverse mutation assay in general screening for genetic toxins.
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PMID:Oxidative mutagens specific for A-T base pairs induce forward mutations to L-arabinose resistance in Salmonella typhimurium. 389 49

We show that formaldehyde fixation of Salmonella typhimurium lipopolysaccharide (LPS) to ribosomes purified from Brucella abortus induced a primary immunoglobulin M (IgM) response to LPS in C3H/HeJ mice and upon revaccination resulted in elevated titers of IgM and induction of IgG antibody to the O antigens of LPS, as measured by an enzyme-linked immunosorbent assay. A similar LPS-Aspergillus fumigatus ribosomal complex yielded IgM and IgG antibody to LPS only after secondary stimulation. These results demonstrate that the hyporesponsiveness of C3H/HeJ mice with respect to antibody formation to LPS can be overcome by complexing this molecule to ribosomal particles and provide a theoretical mechanism for the action of some "ribosomal" vaccines. The results are compatible with the hypothesis that LPS in complex with the ribosomes is converted to a T-dependent form of the antigen to which the C3H/HeJ mice can respond.
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PMID:Immunomodulation of the antibody response to lipopolysaccharide in C3H/HeJ mice by complexing with heterologous ribosomes. 398 87

Female B6C3F1 mice were given i.p. injections with 1.5, 3.0 and 5.0 mg/kg N-nitrosodimethylamine (DMN) daily for 14 days and evaluated on day 15. The day 4 immunoglobulin M (peak day) antibody response to sheep red blood cells (sRBC) was inhibited by 20, 53 and 81%, respectively. The day 5 immunoglobulin G (peak day) antibody response to sRBC was only inhibited significantly (60%) at the highest dose. Recovery studies indicated that the IgM antibody response was still significantly inhibited (48%) 30 days after the completion of the exposure to 5 mg/kg of DMN. The peak response (day 3) to 100 micrograms of the B-cell mitogen, lipopolysaccharide, was inhibited by 15, 26 and 32%, respectively, indicating that a portion of the suppression of the antibody response by DMN may be due to an effect on the ability of the lymphocytes to proliferate. Concentrations of DMN up to 100 mM added directly to untreated spleen cell suspensions had no effect on the in vitro antibody responses to lipopolysaccharide and sRBC. Preincubating DMN (100 mM) with either phenobarbital-induced or 3-methylcholanthrene-induced liver proteins (postmitochondrial supernatant from a 9000 X g liver homogenate) was still ineffective. The activation of DMN by either preparation was verified by measuring formaldehyde production, which reflects demethylation. In contrast to the results with DMN added directly to untreated spleen cell suspensions, the most sensitive indicator of suppression by DMN was the in vitro antibody responses to lipopolysaccharide and sRBC by spleen cell suspensions from DMN-treated mice.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of N-nitrosodimethylamine on humoral immunity. 671 71

Antisera against isolated outer membrane (OM) proteins I and II of Escherichia coli O26 K60 were elicited in rabbits. Antisera obtained after intramuscular administration with Freund's complete adjuvant showed high titres of specific antibodies. Intravenous administration of the same preparations yielded a considerable antibody response against bacterial lipopolysaccharide, a minor contaminant of the protein preparations. Antibody titres against OM proteins I and II, lipopolysaccharide and murein-lipoprotein were determined by the enzyme-linked immunosorbent assay (ELISA) in these sera, and in antisera elicited against whole formaldehyde-fixed bacteria or isolated OM. Comparison of ELISA with single radial immunodiffusion and interfacial immunoprecipitation tests revealed that ELISA was not only the most uniformly applicable, but also the most specific and the most convenient method. In double diffusion tests no cross-reactivity between proteins I and II was seen. Antibodies against proteins I and II, lipopolysaccharide and lipoprotein could be specifically absorbed from the sera with the appropriate antigen preparations. Absorption experiments with intact E. coli O26 K60, Tris/EDTA-sheared bacteria and isolated OM revealed that antibodies against protein I were hardly absorbed at all probably because the antibody, evoked against denatured protein I, did not react with the protein in its native configuration. Antibodies against protein II and lipoprotein were absorbed by intact as well as by sheared bacteria, but to a much greater extent by isolated OM, which indicates that these OM components are accessible from the outside, but that they are situated relatively deep in the OM structure.
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PMID:Preparation and quantitative determination of antibodies against major outer mambranes proteins of Escherichia coli O26 K60. 677 43


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