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

The identification of enterobacterial mutants that contain alterations in the lipopolysaccharide (LPS) oligosaccharide core structure facilitated the development of the model of the physicochemical and immunochemical structures of enteric LPS. Results of recent immunochemical studies have suggested that the structural model of the lipooligosaccharides (LOSs) of Neisseria gonorrhoeae may differ from the enteric LPS model. The difficulties in the analysis of the wild-type gonococcal LOS have precluded understanding of the precise nature of the LOS structure. This study was undertaken to isolate a series of mutants of N. gonorrhoeae 1291 that had sequential saccharide deletions in the LOS. Results of preliminary studies suggested that the pyocin, designated pyocin C, allowed selection of gonococci with such mutant LOS structures. Results also indicated that the receptor for pyocin C binding was an LOS component. Pyocin C selection led to the isolation of five strains with LOS patterns on sodium dodecyl sulfate-polyacrylamide gels which differed from the LOS of parent strain 1291. In this system, the Mr of the parent LOS was 4,715, while the LOSs from the mutant strains demonstrated progressive saccharide deletions, with Mrs of 4,230, 4,089, 3,627, 3,262, and 3,197. Protein patterns of these mutants on sodium dodecyl sulfate-polyacrylamide gels were qualitatively similar to those of the parent strains. Results of studies with five monoclonal antibodies specific for neisserial LOS indicated that shared as well as unique epitopes were present on the mutant LOSs. Results of ketodeoxyoctonate analysis of the mutant LOSs indicated that the majority of the ketodeoxyoctonate residues may be substituted on C-4 or C-5. Chemical and immunological analysis of such LOS mutants should expedite the development of the model for the structure of gonococcal LOS.
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PMID:Selection and immunochemical analysis of lipooligosaccharide mutants of Neisseria gonorrhoeae. 312 95

The gonococcal chromosome contains a sequence of closely linked genes (for example, sac-1, sac-3, nmp) known or presumed to affect cell envelope structure and which appear to influence susceptibility of gonococci to killing by normal human sera (NHS). Previous work has shown that the serum-resistant isolate FA19, and FA899, a serum-sensitive transformant of FA19, differ in outer membrane protein I (PI) and at the sac-3 genetic locus. However, the sac-3 locus is separable from changes determined by nmp-3, the gene determining PI species. We found that FA19 and FA899 differ in lipopolysaccharide (LPS) molecular size and in reactivity with a monoclonal antibody which recognizes an LPS (L8) epitope. To address the question of whether the changes in LPS were due to the sac-3 locus, we constructed new transformants of FA19 using donor DNA prepared from FA899. The new transformants could be divided into three groups: (1) those identical to FA19 in serum resistance (greater than 90% survival at 120 min), in LPS molecular size and in expression of the L8 epitope; (2) those identical to FA899 in serum sensitivity (100% killed at 30 min), in LPS molecular size and in lack of expression of the L8 epitope; (3) those significantly killed by 50% NHS at 120 min, whose LPS molecular size was greater than that of FA19 but less than that of FA899 and which did not express the L8 epitope. Except for PI there were no differences in other outer-membrane proteins (e.g. PII, PIII, H.8) among these transformants.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Evidence that the serum resistance genetic locus sac-3 of Neisseria gonorrhoeae is involved in lipopolysaccharide structure. 312 37

A small M, heat and acid labile, host inducer(s) of gonococcal resistance to complement mediated killing by fresh human serum (-FHS), being purified from red blood cell (RBC) extracts, produced changed in lipopolysaccharide (LPS) structure, surface antigens and proteins; and acquirement of resistance related to loss of a target antigen for bactericidal IgM, possibly LPS components. A 20 kDalt. lipoprotein with a high content of glutamic acid isolated from outer membranes of a gonococcal strain selected in vivo is a determinant of gonococcal resistance to killing by human phagocytes. Sonic extracts of gonococci may contain a cytotoxin for human phagocytes. At the 4th International Pathogenic Neisseriae Conference, we reported (Parsons et al. 1985) that conditions in vivo induced phenotypic change leading to gonococcal resistance to complement-mediated killing by human serum; and, also, selected gonococcal types which showed a greater resistance to intracellular killing by human phagocytes than laboratory strains. Furthermore, evidence was presented that not only was resistance to complement mediated killing important in gonococcal pathogenesis, but also resistance to phagocytic defences. This paper describes the continuance of our studies on the determinants of induced serum resistance and of resistance to killing by phagocytes including toxicity to these cells. Each section begins by summarising previous work that was referenced in Parsons et al. (1985).
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PMID:Gonococci in vivo and in vitro. Further studies on the host and bacterial determinants of gonococcal resistance to killing by human serum, and by phagocytes. 313 Jul 91

Lactosyl-sepharose 4B columns were used for purification by affinity chromatography of anti-lactose antibodies from rabbit antisera to the gonococcal strains 8551 and VII, and the serogroup B meningococcal strain M982. Anti-lactose antibodies were obtained from all three antisera. SDS-PAGE of lipopolysaccharide and of bacterial cells and immunoblotting with the anti-lactose antibodies showed that the lipopolysaccharide was the only bacterial component with binding sites for the antibodies.
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PMID:Purification of anti-lactose antibodies from antisera to Neisseria gonorrhoeae and Neisseria meningitidis. 392 63

antisera were prepared in rabbits against whole organisms of colony type 1 Neisseria gonorrhoeae strains F62 and B (fron gonococcal urethritis) and 7122 (a strain typical of those associated with disseminated gonococcal infection), and against purified outer membrane components from the same strains including pili and principal outer membrane protein. Antibody levels to pili, principal outer membrane protein and lipopolysaccharide were determined using a quantitative enzyme-linked immunosorbent assay. Each antiserum was heat-inactivated and tested for opsonic for its homologous strain, and this immune-enhanced phagocytosis was decreased by adsorption with homologous purified outer membrane components: pili greater than lipopolysaccharide greater than principal outer membrane protein. Opsonic activity was approximately equal for antiserum to purified pili and antiserum to the whole organisms for each of the three strains, and purified antibody to pili was highly opsonic. The F(ab')2 fragments of antibody to pili were not opsonic, indicating a role for the Fc receptor on the phagocyte membrane in immune-enhanced phagocytosis of gonococci.
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PMID:Immune-enhanced phagocytosis of Neisseria gonorrhoeae by macrophages: characterization of the major antigens to which opsonins are directed. 611 82

A gonococcal pilus vaccine or placebo was injected subcutaneously or intramuscularly into 71 human volunteers. The vaccine was found to be safe. The principal adverse reaction was a complaint of a sore arm, which was caused, at least in part, to the volume of material injected. 6 of 64 (9%) volunteers receiving the larger doses also complained of malaise. The vaccine was found to be antigenic. All of the volunteers developed an immunoglobulin class-specific antibody response as measured by a solid phase radioimmunoassay. The antibody was capable of blocking the attachment of gonococci to epithelial cells. A slight antibody response was also demonstrated to gonococcal lipopolysaccharide but the antibody responsible for blocking attachment of gonococci was directed entirely at the pilus protein. The stimulated antibodies were shown to crossreact with isolated pili of heterologous gonococcal strains and to block the attachment of heterologous gonococci. Absorption of immune sera by a heterologous pilus reduced the inhibition of attachment antibodies to pre-immune level, suggesting that the immune response was directed at a common pilus determinant.
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PMID:Gonococcal pilus vaccine. Studies of antigenicity and inhibition of attachment. 611 23

Oligosaccharide was isolated from the lipopolysaccharide of Neisseria gonorrhoeae P9 following partial acid hydrolysis. The exposed terminal keto-deoxyoctonic acid group of the oligosaccharide was convert into the reactive phenylisothiocyanato derivative by reaction with 2-(4-aminophenyl)-ethylamine followed by reduction with sodium cyanoborohydride and treatment with thiophosgene. This intermediate was used to prepare an oligosaccharide-protein conjugate with either bovine serum albumin or purified gonococcal pili. Immunisation of rabbits with protein conjugates produced antibodies reactive with both pure protein and intact lipopolysaccharide.
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PMID:Synthesis of immunogenic oligosaccharide-protein conjugates from the lipopolysaccharide of Neisseria gonorrhoeae P9. 612 Jan 97

Studies of the interaction between Neisseria gonorrhoeae and human fallopian tube mucosa in organ culture suggest that attachment of gonococci is important, not only to secure th organism in the host, but also to initiate the disease process. The steps observed in gonococcal infection of fallopian tube organ cultures are: 1) attachment of gonococci to microvilli of nonciliated cells; 2) release from gonococci of lipopolysaccharide and possibly other toxic moities to cause mucosa damage; 3) engulfment or phagocytosis of gonococci by nonciliated cells; 4) transport of phagocytic vacuoles containing gonococci to the base of the nonciliated cells; and 5) exocytosis of gonococci within phagocytic vacuoles into the subepithelial tissues. In vivo, these steps might result in extensive local disease (e.g. salpingitis) or in the invasion of blood vessels to cause disseminated disease. Preliminary studies of human nasopharyngeal tissue in organ culture infected with Neisseria meningitidis indicate that meningococci attach to microvilli of nonciliated cells and are phagocytized by these cells. Meningococci subsequently appear in subepithelial tissues, though the route they take is not yet certain. These observations suggest at least some of the ways in which attachment may play a role in disease caused by N. gonorrhoeae and N. meningitidis. Mechanisms to block this attachment may provide new approaches to the prevention of infections caused by the pathogenic Neisseria.
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PMID:Attachment of pathogenic Neisseria to human mucosal surfaces: role in pathogenesis. 612 78

Antibodies in genital secretions of patients with gonorrhea have been shown to inhibit the attachment of gonococci to epithelial cells. The gonococcal antigens for which these antibodies are specific were studied by adsorption of the genital secretions from a patient infected with gonorrhea with purified lipopolysaccharide, outer membrane complex, or purified pili of homologous Neisseria gonorrhoeae and measurement of the reduction of inhibition of attachment of the gonococci to epithelial cells. The removal of antibodies was documented with the use of a solid-phase radioimmunoassay in which the amount of antibody in the adsorbed secretions that bound to a specific gonococcal antigen was shown to be reduced as compared with the amount of antibody in unadsorbed secretions. The antibody in the secretions that inhibited attachment was removed primarily by adsorption with the homologous pili, not with homologous lipopolysaccharide. A preparation of the homologous outer membrane complex that contained pili, cell-wall proteins, and lipopolysaccharide also blocked the inhibitory antibody.
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PMID:Antigenic specificity of antibodies in vaginal secretions during infection with Neisseria gonorrhoeae. 615 72

Principal outer membrane protein (protein I) of Neisseria gonorrhoeae was prepared nearly free of lipopolysaccharide (LPS) and substantially purified from other membrane proteins by chromatography of partially purified gonococcal outer membranes over Sepharose 6B in the presence of deoxycholate at pH 9.0. This protein I of nine separate antigenic types was coated to polystyrene tubes and used in the enzyme-linked immunosorbent assay (ELISA) to measure antibody to protein I or in inhibition tests to quantitate protein I antigen. No significant inhibition of the ELISA test was produced by purified LPS from the strain used to prepare each of the protein I types or by whole gonococci bearing the same LPS but different protein I antigens as the strain used to produce a given protein I antigen. Of 125 strains of gonococci used as whole organisms to inhibit the protein I ELISA, 124 (99%) typed with one or more of the nine protein I types, and 35% of these typed with a single protein I serotype. Sixty-one of 65 (94%) strains from Seattle and Atlanta patients with disseminated gonococcal infection contained protein I serotype 1, and 16 of 24 (64%) strains from Seattle patients with salpingitis bore one or both of protein I serotypes 1 and 2.
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PMID:Antigen-specific serotyping of Neisseria gonorrhoeae: characterization based upon principal outer membrane protein. 616 68


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