Effect of exogenous sialylation of the lipooligosaccharide of Neisseria gonorrhoeae on opsonophagocytosis

Kim, J J; Zhou, Daoguo; Mandrell, Robert E.; Griffiss, J. McLeod

doi:10.1128/iai.60.10.4439-4442.1992

Cited by 73 publications

(29 citation statements)

References 18 publications

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“…For inhibition studies, invasion assays were performed as described but, before the addition of gonococci, the PHUECs were preincubated for 30 min at 378C in PrEGM containing 0-500 mg ml 21 purified LOS or 2 mg ml 21 ASF (Sigma), or for 1 h in PrEGM containing 250 mM MDC (Sigma) or 0.3 M sucrose (Fisher Scientific). Gonococcal LOS was sialylated using methods similar to those described previously (Kim et al, 1992). N. gonorrhoeae was preincubated for 3 h at 378C and 200 r.p.m.…”

Section: Gonococcal Challenge Of Phuecsmentioning

confidence: 99%

Receptor‐mediated endocytosis of Neisseria gonorrhoeae into primary human urethral epithelial cells: the role of the asialoglycoprotein receptor

Harvey

Jennings

Campbell

et al. 2001

Molecular Microbiology

109

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SummaryUrethral epithelial cells are invaded by Neisseria gonorrhoeae during gonococcal infection in men. To understand further the mechanisms of gonococcal entry into host cells, we used the primary human urethral epithelial cells (PHUECs) tissue culture system recently developed by our laboratory. These studies showed that human asialoglycoprotein receptor (ASGP-R) and the terminal lactosamine of lacto-N-neotetraose-expressing gonococcal lipooligosaccharide (LOS) play an important role in invasion of PHUECs. Microscopy studies showed that ASGP-R traffics to the cell surface after gonococcal challenge. Co-localization of ASGP-R with gonococci was observed. As ASGP-R-mediated endocytosis is clathrin dependent, clathrin localization in PHUECs was examined after infection. Infected PHUECs showed increased clathrin recruitment and co-localization of clathrin and gonococci. Preincubating PHUECs in 0.3 M sucrose or monodansylcadaverine (MDC), which both inhibit clathrin-coated pit formation, resulted in decreased invasion. N. gonorrhoeae strain 1291 produces a single LOS glycoform that terminates with Gal(b1 -4)GlcNac(b1 -3)Gal(b1 -4)Glc (lacto-N-neotetraose). Invasion assays showed that strain 1291 invades significantly more than four isogenic mutants expressing truncated LOS. Sialylation of strain 1291 LOS inhibited invasion significantly. Preincubation of PHUECs in asialofetuin (ASF), an ASGP-R ligand, significantly reduced invasion. A dose -response reduction in invasion was observed in PHUECs preincubated with increasing concentrations of NaOH-deacylated 1291 LOS. These studies indicated that an interaction between lacto-N-neotetraose-terminal LOS and ASGP-R allows gonococcal entry into PHUECs.

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Section: Gonococcal Challenge Of Phuecsmentioning

confidence: 99%

Receptor‐mediated endocytosis of Neisseria gonorrhoeae into primary human urethral epithelial cells: the role of the asialoglycoprotein receptor

Harvey

Jennings

Campbell

et al. 2001

Molecular Microbiology

109

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“…In contrast to meningococci, the closely related bacterium Neisseria gononttoeae, which is the causative agent of gonorrhoea in humans, does not express capsular polysaccharides on its cell surface. However, NeuNAc was recently found to be a carbohydrate moiety in gonococcal lipooligosaccharide (LOS), also conferring resistance to complement-mediated bacteriolysis (Parsons etai, 1988; and phagocytosis (Kim et al. 1992).…”

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confidence: 99%

Contribution of genes from the capsule gene complex (cps) to lipooligosaccharide biosynthesis and serum resistance in Neisseria meningitidis

Hammerschmidt

Birkholz

Zähringer

et al. 1994

Molecular Microbiology

123

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Within the capsule gene complex (cps) of Neisseria meningitidis B a 5.5 kb DNA fragment encodes proteins with strong homologies to enzymes of the lipopolysaccharide biosynthetic pathway of Salmonella typhimurium and Escherichia coli, GalE, RfbB, RfbC and RfbD. A meningococcal galE mutant expressed a truncated lipooligosaccharide (LOS), which terminated at the glucose residue between inner and outer core, and a second galE gene present outside the cps cluster was found to be transcriptionally and functionally inactive and, thus, unable to complement this defect. Because of the defect in the outer core, the LOS of the galE-defective meningococcal mutant was not sialylated. In contrast, carbohydrate analysis of the LOS of an rfb-defective meningococcal mutant revealed no difference from the LOS of the wild-type strain, suggesting that the rfb genes are inactive. This was supported by Northern blot analysis, which showed that expression of the rfb gene products was transcriptionally regulated. The inability of the meningococcal galE mutant, which cannot sialylate the LOS, allowed us to investigate the significance of LOS sialylation in relation to the presence of the polysialic acid capsule. Sialylated LOS, but not the polysialic acid capsule, is necessary to confer complete serum resistance on the meningococcus by inhibition of the alternative complement pathway.

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“…Sialic acids have been reported to render pathogenic Neisseria spp. serum resistant and resistant against opsonophagocytosis (8,15,18,21,23,24,29,30,39,46,48,52,54). Meningococci of serogroups B and C are the predominant serogroups causing meningococcal disease in the Northern hemisphere (28) and express a capsule consisting of homopolymers of sialic acid (PSA) (14).…”

mentioning

confidence: 99%

Complement factor C3 deposition and serum resistance in isogenic capsule and lipooligosaccharide sialic acid mutants of serogroup B Neisseria meningitidis

Vogel¹,

Weinberger²,

Frank³

et al. 1997

Infect Immun

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Serogroup B meningococci express sialic acids on their surfaces as a modification of the lipooligosaccharide (LOS) and as capsular material consisting of ␣2,8-linked sialic acid homopolymers. The aim of this study was to elucidate the impact of each sialic acid component on the deposition of complement factor C3 and serum resistance. For this purpose, we used isogenic mutants deficient in capsule expression (a polysialyltransferase mutant) or sialylation of the LOS (a galE mutant) or both (a mutant with a deletion of the cps gene locus). Bactericidal assays using 40% normal human serum (NHS) demonstrated that both the capsule and LOS sialic acid are indispensable for serum resistance. By immunoblotting with monoclonal antibody MAb755 that is specific for the C3 ␣-chain, we were able to demonstrate that C3 from 40% NHS was covalently linked to the surface structures of meningococci as C3b and iC3b, irrespective of the surface sialic acid compounds. However, C3b linkage was more pronounced and occurred on a larger number of target molecules in galE mutants with nonsialylated LOS than in meningococci with wild-type LOS, irrespective of the capsule phenotype. C3b deposition was caused by both the classical pathway (CP) and the alternative pathway of complement activation. Use of 10% NHS revealed that at low serum concentrations, C3 deposition occurred via the CP and was detected primarily on nonsialylated-LOS galE mutants, irrespective of the capsular phenotype. Accordingly, immunoglobulin M (IgM) binding to meningococci from heat-inactivated NHS was demonstrated only in both encapsulated and unencapsulated galE mutants. In contrast, inhibition of IgA binding required both encapsulation and LOS sialylation. We conclude that serum resistance in wild-type serogroup B meningococci can only be partly explained by an alteration of the C3b linkage pattern, which seems to depend primarily on the presence of wild-type LOS, since a serum-resistant phenotype also requires capsule expression.

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Effect of exogenous sialylation of the lipooligosaccharide of Neisseria gonorrhoeae on opsonophagocytosis

Cited by 73 publications

References 18 publications

Receptor‐mediated endocytosis of Neisseria gonorrhoeae into primary human urethral epithelial cells: the role of the asialoglycoprotein receptor

Receptor‐mediated endocytosis of Neisseria gonorrhoeae into primary human urethral epithelial cells: the role of the asialoglycoprotein receptor

Contribution of genes from the capsule gene complex (cps) to lipooligosaccharide biosynthesis and serum resistance in Neisseria meningitidis

Complement factor C3 deposition and serum resistance in isogenic capsule and lipooligosaccharide sialic acid mutants of serogroup B Neisseria meningitidis

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