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

An experimental model of human fallopian tubes in organ culture was used to examine the ability of lipopolysaccharide (LPS) of Neisseria gonorrhoeae to damage the fallopian tube mucosa. Gonococcal LPS was purified by hot phenol-water extraction and sequential ultracentrifugation. This LPS was highly lethal for lead-sensitized mice and at a concentration as low as 6 pg/ml reproducibly gelled limulus amoebocyte lysate. Gonococcal LPS damaged fallopian tube mucosa in concentrations as low as 0.015 microgram/ml, a values less than the LPS concentration in organ culture medium surrounding fallopian tube mucosa that was damaged by gonococcal infection. The toxic effect of LPS was neutralized by polymyxin B. Gonococci were shown to elaborate blebs of outer membrane material that is likely to contain LPS. These studies suggest that gonococci elaborate LPS-containing material into their surrounding medium, that the LPS is capable of mediating damage to human fallopian tube mucosa, and that the production of mucosal damage requires the lipid A portion of the LPS molecule.
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PMID:Toxic activity of purified lipopolysaccharide of Neisseria gonorrhoeae for human fallopian tube mucosa. 678 65

Incubation of gonococci under conditions optimal for autolysis resulted in increased sensitivity and enhancement of the coagglutination reaction of the Phadebact gonococcus test. These conditions included an alkaline pH (pH 8.3) and the presence of divalent cation chelators such as ethylenediaminetetraacetic acid or ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid. Heating cell suspensions at 90 degrees C for 15 min before assay by coagglutination produced a further increase in sensitivity and enhancement of the reaction. Gonococcal lipopolysaccharide was found to be an important antigen in these coagglutination reactions. The detection of lipopolysaccharide was markedly enhanced by the addition of chelating agents.
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PMID:Enhancement of coagglutination reactions of the Phadebact gonococcus test by ethylenediaminetetraacetate and ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetate. 679 19

Strains of Neisseria gonorrhoeae were treated with pyocin 611 131 (pyocin 103) from Pseudomonas aeruginosa PA103, and isogenic resistant variants were isolated. The interaction of pyocin-sensitive and isogenic pyocin-resistant strains with wheat germ agglutinin (WGA) agglutinated all pyocin-sensitive, but not pyocin-resistant, strains. Binding of WGA to three pyocin-sensitive strains and their isogenic pyocin-resistant variants was examined quantitatively by using fluorescein-conjugated lectin. Pyocin-resistant strains maximally bound one-third to one-eighth the quantity of WGA bound by isogenic-sensitive strains. Linear Scatchard plots revealed homogeneous WGA-binding sites on three pyocin-sensitive and one pyocin-resistant strains. Biphasic Scatchard plots, obtained with two pyocin-resistant strains, show that WGA-binding sites in these strains are heterogeneous. The number of WGA-binding sites for pyocin-sensitive organisms ranged from 8 x 10(5) to 1 x 10(6) sites per coccus and from 1 x 10(5) to 3 x 10(5) sites per coccus for pyocin-resistant strains. The apparent association constant for WGA binding to pyocin-sensitive strains ranged from 3 x 10(6) to 6 x 10(6) liters/mol and from 6 x 10(6) to 1 x 10(7) liters/mol for pyocin-resistant strains. Gonococcal lipopolysaccharide was shown to serve as the pyocin 103 receptor by inhibition of pyocin activity. Lipopolysaccharide from a pyocin 103-resistant strain was not able to inhibit pyocin 103 activity. Pyocin 103 resistance was correlated with a structural alteration involving N-acetylglucosamine residues in gonococcal lipopolysaccharide. Based on interactions with wheat germ, soybean, and ricin lectins, a model of lipopolysaccharide structure in N. gonorrhoeae is presented.
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PMID:Interaction with lectins and differential wheat germ agglutinin binding of pyocin 103-sensitive and -resistant Neisseria gonorrhoeae. 679 62

The selective toxicity of gonococcal lipopolysaccharide for the mucosa of human fallopian tubes, which is demonstrated in these studies, may be responsible in part for the specificity of naturally occurring gonococcal infections for humans.
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PMID:Host species-specific damage to oviduct mucosa by Neisseria gonorrhoeae lipopolysaccharide. 680 Sep 51

Neisseria gonorrhoeae isolated from patients with disseminated infection (DGI) often resist complement (C')-dependent killing by normal human serum (NHS) and less commonly by convalescent DGI serum. 7 of 10 NHS specimens completely inhibited killing of serum-resistant (ser(r)) gonococci by convalescent or immune DGI serum. Immunoglobulin G (IgG) purified from NHS was shown to be the blocking agent. In addition, IgM (plus C') purified from NHS was shown to be fivefold more effective (wt/wt) in killing serum-sensitive (ser(s)) gonococci than equivalent amounts of IgM tested in the presence of IgG (whole serum). Although inhibition of NHS killing of ser(s) gonococci required a 640% excess of IgG, only a 40% excess was required to block immune serum killing of ser(r) gonococci. F(ab')(2) prepared from IgG also blocked killing of ser(r) gonococci by immune serum indicating antigenic specificity of blocking IgG.IgG immunoconcentrated against outer membrane protein (OMP) derived from ser(r) gonococci showed 40-fold increased blocking activity over normal IgG (wt/wt) and lacked antibody activity directed against gonococcal lipopolysaccharide by ELISA. Using direct immunoabsorption of IgG with purified gonococcal OMP; ser(r)-OMP was found sixfold more effective than ser(s)-OMP in neutralizing the blocking of immune serum killing of ser(r) gonococci, and 10-fold more effective in systems that used excess blocking IgG, NHS, and ser(s) gonococci. Blocking IgG preabsorbed with whole ser(r) gonococci lost 75% of its ability to block immune serum killing compared with no loss in this system using a similar absorption with ser(s) gonococci. IgG purified from NHS contained fivefold higher titers of antibody against ser(r)-OMP than ser(s)-OMP by ELISA.
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PMID:Characterization of serum resistance of Neisseria gonorrhoeae that disseminate. Roles of blocking antibody and gonococcal outer membrane proteins. 680 19

Major antigens in Neisseria gonorrhoeae were identified by surface labelling the organisms with 125I and electrophoresing extracts in polyacrylamide with sodium dodecyl sulphate. Horizontal slices of the gels were cut out and tested in individual wells against patients' sera using ELISA. Serum from local gonococcal infections reacted with Protein II and, probably, lipopolysaccharide, but not with Protein I in deoxycholate (DOC) extracts and gave no reaction with Triton X-100 extracts. Serum from disseminated gonococcal infections reacted with Protein I in the DOC extract and with pili and a number of undefined possibly cytoplasmic membrane antigens in the Triton X-100 extract. The significance of the results and the potential of the method are discussed.
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PMID:Analysis of antibodies in local and disseminated Neisseria gonorrhoeae infections by means of gel electrophoresis-derived ELISA. 681 21

Two methods are reported for the production of rabbit anti-gonococcal lipopolysaccharide sera. One is produced by a conjugate between the core oligosaccharide and bovine serum albumin. The other is obtained by immunizing rabbits with heat-killed, ethanol-acetone washed bacteria. The specificity of the latter serum is studied, and it is shown that most of the antibodies are against a lactose-like determinant situated in the core region of the lipopolysaccharide. Preliminary studies show that this serum is able to cause specific agglutination of gonococci.
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PMID:Production and characterization of high titre rabbit antigonococcal R-type lipopolysaccharide serum. 681 39

The gonococcal strain R-10 is shown to contain two antigenically different R-type lipopolysaccharides: one of these has the same properties described for the gonococcal lipopolysaccharide, while the other does not have any cross-reaction with it. The latter was purified from a mutated colony able to express only one type of lipopolysaccharide. By inhibition enzyme-linked immunosorbent assay it was shown that the difference between the two lipopolysaccharides is located in the core region which, when purified and analyzed by gel filtration and gas liquid chromatography, did not show any difference either in size or in chemical composition, leading to the conclusion that the two cores must differ just in the structure of the antigenic determinant.
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PMID:Purification of gonococcal R-type lipopolysaccharide not bearing the lactose-like antigen. 681 73

The detection of gonococcal antigens by an indirect sandwich ELISA system is described. The feasibility of using rabbit antiserum raised against whole cells of Neisseria gonorrhoeae strain 9 to detect gonococcal lipopolysaccharide, whole cells, and outer membrane (OM) protein was investigated. OM protein was found to be the main antigen detectable with the antiserum in a direct ELISA system. A positive result in the indirect assay could be obtained with a minimum of 46 to 92 ng of gonococcal OM protein or with 6.6 X 10(3) cfu of N. gonorrhoeae. The sensitivity of the assay was found to be approximately eightfold lower with OM complex from a strain of N. meningitidis serogroup B for which the minimum amount of OM protein detected was 375 ng. Negative results were obtained with OM complex from Streptococcus agalactiae, Bacteroides bivius and Escherichia coli. The assay seems to be highly specific for gonococcal antigens. The sensitivity of the assay and its specificity commend it for further evaluation in the detection of gonococcal antigens in clinical specimens.
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PMID:Detection of gonococcal antigens by an indirect sandwich enzyme-linked immunosorbent assay. 681 36

Growth of gonococci in the presence of CMP-N-acetylneuraminic acid (CMP-NANA) has previously been shown to induce resistance to the bactericidal effect of normal human serum and is accompanied by sialylation of the gonococcal lipopolysaccharide (LPS). We have used monoclonal antibodies (mAbs) to compare the effect of LPS sialylation on recognition of gonococci and complement-mediated killing by antibodies directed either against LPS or against defined epitopes on outer-membrane protein PI. Despite differences in binding to sialylated LPS on Western blots, all three mAbs directed against LPS showed considerably reduced binding to gonococci grown in the presence of CMP-NANA and a concomitant reduction in ability to promote complement-mediated killing. In contrast, mAbs directed against previously defined epitopes on a surface exposed loop of PI showed little difference in binding between sialylated and non-sialylated gonococci and promoted killing of the sialylated gonococci. Similarly a mAb directed against an epitope on a loop of the outer-membrane Rmp protein, which had previously been shown to block killing by antibodies directed against other surface antigens, also exerted a blocking effect with sialylated gonococci. Thus in the present study the continued biological effect of mAbs was correlated with the ability of the antibody to recognize surface-exposed epitopes on sialylated gonococci. Despite the presence of the sialylation which is likely to occur in vivo, it should be possible to induce complement-mediated killing by focusing the immune response to those surface-exposed epitopes which are least susceptible to the potential inhibitory effect of LPS sialylation.
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PMID:Effect of sialylation of lipopolysaccharide of Neisseria gonorrhoeae on recognition and complement-mediated killing by monoclonal antibodies directed against different outer-membrane antigens. 753 87


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