Structure of an α‐2,6‐sialylated lipooligosaccharide from <i>Neisseria meningitidis</i> immunotype L1

Wakarchuk, Warren W.; Gilbert, Michel; Martin, Andrew; Wu, Yuyang; Brisson, Jean‐Robert; Thibault, Pierre; Richards, James C.

doi:10.1046/j.1432-1327.1998.2540626.x

Cited by 62 publications

(50 citation statements)

References 6 publications

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“…In contrast, the three proton resonances assigned to H-5, H-6a, and H-6b showed downfield chemical shift values, indicating acetylation at O-6. These results are in agreement with previous reports of 1 H NMR assignment studies that showed meningococcal LOS to be acetylated at O-6 of GlcNAc (41,42).…”

Section: Analysis Of Petn Substitution By Maldi-tof Mass Spectrometrysupporting

confidence: 94%

Genetic and Structural Characterization of L11 Lipooligosaccharide from Neisseria meningitidis Serogroup A Strains

Mistretta

Seguin

Thiébaud

et al. 2010

Journal of Biological Chemistry

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The lipooligosaccharide (LOS) of immunotype L11 is unique within serogroup A meningococci. In order to resolve its molecular structure, we conducted LOS genotyping by PCR analysis of genes responsible for ␣-chain sugar addition (lgtA, -B, -C, -E, -H, and -F) and inner core substituents (lgtG, lpt-3, and lpt-6). For this study, we selected seven strains belonging to subgroup III, a major clonal complex responsible for meningococcal meningitis epidemics in Africa. In addition, we sequenced the homopolymeric tract regions of three phase-variable genes (lgtA, lgtG, and lot-3) to predict gene functionality. The fine structure of the L11 LOS of each strain was determined using composition and glycosyl linkage analyses, NMR, and mass spectrometry. The masses of the dephosphorylated oligosaccharides were consistent with an oligosaccharide composed of two hexoses, one N-acetyl-hexosamine, two heptoses, and one KDO, as proposed previously. The molar composition of LOS showed two glucose residues to be present, in agreement with lgtH sequence prediction. Despite phosphoethanolaminetransferase genes lpt-3 and lpt-6 being present in all seven Neisseria meningitidis strains, phosphoethanolamine (PEtn) was found at both O-3 and O-6 of HepII among the three ST-5 strains, whereas among the four ST-7 strains, only one PEtn was found and located at O-3 of the HepII. The L11 LOS was found to be O-acetylated, as was indicated by the presence of the lot-3 gene being in-frame in all of the seven N. meningitidis strains. To our knowledge, these studies represent the first full genetic and structural characterization of the L11 LOS of N. meningitidis. These investigations also suggest the presence of further regulatory mechanisms affecting LOS structure microheterogeneity in N. meningitidis related to PEtn decoration of the inner core.

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Section: Analysis Of Petn Substitution By Maldi-tof Mass Spectrometrysupporting

confidence: 94%

Genetic and Structural Characterization of L11 Lipooligosaccharide from Neisseria meningitidis Serogroup A Strains

Mistretta

Seguin

Thiébaud

et al. 2010

Journal of Biological Chemistry

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“…Genomic and Allelic Differences in LOS Biosynthetic GenesTo lend support for our conclusions of correlations between LOS structure and disease outcome, we analyzed the sequence diversity of LOS biosynthetic genes in a very large database of meningococcal genomes (32,202 genomes) found at the Pub-MLST website. The average number of unique alleles for the seven genes used for multilocus sequence typing was 529 alleles/gene (data not shown).…”

Section: Differences In Os Structures Of Los Between Invasive Andmentioning

confidence: 94%

“…OS Compositions-A number of groups, including our own, have studied the structure of the OS from N. meningitidis (1, 23, 24,26,32,33). Compositions for the OS were assigned based on peaks we detected, the previously reported structures, and using the following potential components: 2 Kdo, 2 Hep, 1 or more Hex, and 1 or more HexNAc, 0 -1 Neu5Ac, 0 -1 O-Ac, 0 -1 O-Gly, and 0 -2 PEA.…”

Section: Relative Abundance Of Lipid a Phosphoforms Correlates With Tmentioning

confidence: 99%

Lipooligosaccharide Structures of Invasive and Carrier Isolates of Neisseria meningitidis Are Correlated with Pathogenicity and Carriage

John

Phillips²,

Din

et al. 2016

Journal of Biological Chemistry

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The degree of phosphorylation and phosphoethanolaminylation of lipid A on neisserial lipooligosaccharide (LOS), a major cell-surface antigen, can be correlated with inflammatory potential and the ability to induce immune tolerance in vitro. On the oligosaccharide of the LOS, the presence of phosphoethanolamine and sialic acid substituents can be correlated with in vitro serum resistance. In this study, we analyzed the structure of the LOS from 40 invasive isolates and 25 isolates from carriers of Neisseria meningitidis without disease. Invasive strains were classified as groups 1-3 that caused meningitis, septicemia without meningitis, and septicemia with meningitis, respectively. Intact LOS was analyzed by high resolution matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Prominent peaks for lipid A fragment ions with three phosphates and one phosphoethanolamine were detected in all LOS analyzed. LOS from groups 2 and 3 had less abundant ions for highly phosphorylated lipid A forms and induced less TNF-␣ in THP-1 monocytic cells compared with LOS from group 1. Lipid A from all invasive strains was hexaacylated, whereas lipid A of 6/25 carrier strains was pentaacylated. There were fewer O-acetyl groups and more phosphoethanolamine and sialic acid substitutions on the oligosaccharide from invasive compared with carrier isolates. Bioinformatic and genomic analysis of LOS biosynthetic genes indicated significant skewing to specific alleles, dependent on the disease outcome. Our results suggest that variable LOS structures have multifaceted effects on homeostatic innate immune responses that have critical impact on the pathophysiology of meningococcal infections.Our previous studies of neisserial lipooligosaccharide (LOS) 2 and the human innate immune system have shown that the degree of phosphorylation of the lipid A component is correlated with the potential of the LOS to induce inflammation stimulated by innate immunity as revealed by cytokine induction in human monocytes in vitro and, in general, with the severity of infections (1-3). In the LOS of Neisseria meningitidis, the modification of lipid A with phosphoethanolamine (PEA) also has been shown to inhibit the bactericidal activity of cathepsin G within neutrophil extracellular traps (4) and to increase adhesion of the bacteria to human cells (5). Expression of PEA on the oligosaccharide (OS) of meningococcal LOS (Fig. 1), particularly in the O-3 position on heptose (Hep) II, or expression of sialic acid (Neu5Ac) have been shown to inhibit activation of complement via the classical and alternative pathways (6 -9). In this study, we postulated that analysis of the structures of the LOS and the genomic diversity of genes for LOS biosynthesis would reveal differences associated with the severity of meningococcal infection and with carrier versus invasive strains of N. meningitidis.To ascertain whether such differences exist, we characterized the structures of LOS from isolates from infected patients or from carriers of N. meningitidi...

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“…4). PCR amplification was performed to determine if the genes lpt6 and lpt3 were present in the N. meningitidis LPS immunotyping reference L1 to L10 strains, for each of which the LPS structure has been characterized (11,13,22,29,35,36,49). The lpt6 gene was found in the L2, L4, L6, and L10 strains, and lpt3 was present in the L1, L3, L7, L8, and L9 strains.…”

Section: Vol 186 2004 the Lpt6 Gene In N Meningitidis And H Influmentioning

confidence: 99%

lpt6 , a Gene Required for Addition of Phosphoethanolamine to Inner-Core Lipopolysaccharide of Neisseria meningitidis and Haemophilus influenzae

et al. 2004

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We previously described a gene, lpt3, required for the addition of phosphoethanolamine (PEtn) at the 3 position on the ␤-chain heptose (HepII) of the inner-core Neisseria meningitidis lipopolysaccharide (LPS), but it has long been recognized that the inner-core LPS of some strains possesses PEtn at the 6 position (PEtn-6) on HepII. We have now identified a gene, lpt6 (NMA0408), that is required for the addition of PEtn-6 on HepII. The lpt6 gene is located in a region previously identified as Lgt-3 and is associated with other LPS biosynthetic genes. We screened 113 strains, representing all serogroups and including disease and carriage strains, for the lpt3 and lpt6 genes and showed that 36% contained both genes, while 50% possessed lpt3 only and 12% possessed lpt6 only. The translated amino acid sequence of lpt6 has a homologue (72.5% similarity) in a product of the Haemophilus influenzae Rd genome sequence. Previous structural studies have shown that all H. influenzae strains investigated have PEtn-6 on HepII. Consistent with this, we found that, among 70 strains representing all capsular serotypes and nonencapsulated H. influenzae strains, the lpt6 homologue was invariably present. Structural analysis of LPS from H. influenzae and N. meningitidis strains where lpt6 had been insertionally inactivated revealed that PEtn-6 on HepII could not be detected. The translated amino acid sequences from the N. meningitidis and H. influenzae lpt6 genes have conserved residues across their lengths and are part of a family of proven or putative PEtn transferases present in a wide range of gram-negative bacteria.The lipopolysaccharides (LPS) of the gram-negative bacteria Neisseria meningitidis and Haemophilus influenzae lack the repeating O antigens that are characteristic of the LPS of enteric bacteria. The core LPS molecule of these bacteria is heterogeneous both within and among strains and plays a role in the commensal and pathogenic behavior of each species. N. meningitidis and H. influenzae are host-restricted bacteria found exclusively in humans. They normally reside in the nasopharynx of humans but can spread contiguously within the respiratory tract or disseminate systemically into the blood to cause serious diseases such as pneumonia, septicemia, and meningitis.N. meningitidis LPS has been classified into 12 distinct immunotypes (L1 to L12), on the basis of monoclonal antibody (MAb) reactivity (42), the basis of which has been further defined by structural analysis as detailed in the following references: L1 and L6, references 11 and 49; L2, reference 13; L3, reference 36; L4 and L7, reference 29; L5, reference 35; L9, reference 22. N. meningitidis LPS is based on a diheptose backbone, which is attached via one of two 3-deoxy-D-manno-2-octulosonic acid (Kdo) residues to the lipid A portion. Additions occur to the first heptose (HepI), and extension past the proximal glucose (Glc) residue is classed as the outer-core structure (Fig. 1). The second heptose (HepII) is invariably substituted by an N-acetylglucosamine (...

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Structure of an α‐2,6‐sialylated lipooligosaccharide from Neisseria meningitidis immunotype L1

Cited by 62 publications

References 6 publications

Genetic and Structural Characterization of L11 Lipooligosaccharide from Neisseria meningitidis Serogroup A Strains

Genetic and Structural Characterization of L11 Lipooligosaccharide from Neisseria meningitidis Serogroup A Strains

Lipooligosaccharide Structures of Invasive and Carrier Isolates of Neisseria meningitidis Are Correlated with Pathogenicity and Carriage

lpt6 , a Gene Required for Addition of Phosphoethanolamine to Inner-Core Lipopolysaccharide of Neisseria meningitidis and Haemophilus influenzae

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