sh.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Schweda, Elke K. H.
Alternative names
Publications (10 of 36) Show all publications
Hood, D. W., Deadman, M. E., Engskog, M. K. R., Vitiazeva, V., Makepeace, K., Schweda, E. K. & Moxon, R. (2010). Genes required for the synthesis of heptose-containing oligosaccharide outer core extensions in Haemophilus influenzae lipopolysaccharide. Microbiology, 156, 3421-3431
Open this publication in new window or tab >>Genes required for the synthesis of heptose-containing oligosaccharide outer core extensions in Haemophilus influenzae lipopolysaccharide
Show others...
2010 (English)In: Microbiology, ISSN 1350-0872, E-ISSN 1465-2080, Vol. 156, p. 3421-3431Article in journal (Refereed) Published
Abstract [en]

Heptose-containing oligosaccharides (OSs) are found in the outer core of the lipopolysaccharide (LPS) of a subset of non-typable Haemophilus influenzae (NTHi) strains. Candidate genes for the addition of either L-glycero-D-manno-heptose (LD-Hep) or D-glycero-D-manno-heptose (DD-Hep) and subsequent hexose sugars to these OSs have been identified from the recently completed genome sequences available for NTHi strains. losA1/losB1 and losA2/losB2 are two sets of related genes in which losA has homology to genes encoding glycosyltransferases and losB to genes encoding heptosyltransferases. Each set of genes is variably present across NTHi strains and is located in a region of the genome with an alternative gene organization between strains that contributes to LPS heterogeneity. Dependent upon the strain background, the LPS phenotype, structure and serum resistance of strains mutated in these genes were altered when compared with the relevant parent strain. Our studies confirm that losB1 and losB2 usually encode DD-heptosyl- and LD-heptosyl transferases, respectively, and that losA1 and losA2 encode glycosyltransferases that play a role in OS extensions of NTHi LPS.

National Category
Biological Sciences
Identifiers
urn:nbn:se:sh:diva-13962 (URN)10.1099/mic.0.041780-0 (DOI)000284660400023 ()2-s2.0-78049505102 (Scopus ID)
Available from: 2011-12-16 Created: 2011-12-15 Last updated: 2017-12-08Bibliographically approved
Schweda, E. K. & Richards, J. C. (2010). Profiling LPS Glycoforms of Non-typeable Haemophilus influenzae by Multiple-Stage Tandem Mass Spectrometry. In: Jianjun Li (Ed.), Jianjun Li (Ed.), Functional glycomics: methods and protocols (pp. 79-92). New York: Humana Press
Open this publication in new window or tab >>Profiling LPS Glycoforms of Non-typeable Haemophilus influenzae by Multiple-Stage Tandem Mass Spectrometry
2010 (English)In: Functional glycomics: methods and protocols / [ed] Jianjun Li, New York: Humana Press, 2010, p. 79-92Chapter in book (Refereed)
Abstract [en]

Non-typeable (acapsular) Haemophilus influenzae (NTHi) is a major cause of otitis media accounting for 25-30% of all cases of the disease. Lipopolysaccharide (LPS) is an essential and exposed component of the H. influenzae cell wall. A characteristic feature of H. influenzae LPS is the extensive inter-strain and intra-strain heterogeneity of glycoform structure which is key to the role of the molecule in both commensal and disease-causing behavior of the bacterium. However, to characterize LPS structure unambiguously is a major challenge due to the extreme heterogeneity of glycoforms that certain strains express. A powerful tool for obtaining sequence and branching information is multiple-stage tandem ESI-MS (ESI-MS(n)) performed on dephosphorylated and permethylated oligosaccharide material using an ESI-quadrupole ion trap mass spectrometer. In general, permethylation increases the MS response by several orders of magnitude and sequence information is readily obtained since methyl tagging allows the distinction between fragment ions generated by cleavage of a single glycosidic bond and inner fragments resulting from the rupture of two glycosidic linkages. Using this approach we are now able to identify all isomeric glycoforms in very heterogeneous LPS preparations.

Place, publisher, year, edition, pages
New York: Humana Press, 2010
Series
Methods in Molecular Biology, ISSN 1064-3745 ; 600
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:sh:diva-16213 (URN)10.1007/978-1-60761-454-8_6 (DOI)000272399800006 ()978-1-60761-453-1 (ISBN)
Available from: 2012-05-29 Created: 2012-05-16 Last updated: 2013-12-18Bibliographically approved
Engskog, M. K. R., Yildirim, H. H., Li, J., Richards, J. C., Deadman, M., Hood, D. W. & Schweda, E. K. H. (2009). A dual role for the lex2 locus: identification of galactosyltransferase activity in non-typeable Haemophilus influenzae strains 1124 and 2019. Carbohydrate Research, 344(5), 632-641
Open this publication in new window or tab >>A dual role for the lex2 locus: identification of galactosyltransferase activity in non-typeable Haemophilus influenzae strains 1124 and 2019
Show others...
2009 (English)In: Carbohydrate Research, ISSN 0008-6215, E-ISSN 1873-426X, Vol. 344, no 5, p. 632-641Article in journal (Refereed) Published
Abstract [en]

Lipopolysaccharide (LPS) of Haemophilus influenzae comprises a conserved tri-L-glycero-D-manno-heptosyl inner-core moiety (L-alpha-D-Hepp-(1 -> 2)-[PEtn -> 6]-L-alpha-D-Hepp-(1 -> 3)-[beta-D-Glclp-(1 -> 4)]-L-alpha-D-Hepp-(1 -> 5)-alpha-Kdop) to which addition of beta-D-Glcp to O-4 of Glcl in serotype b strains is controlled by the gene lex2B. In non-typeable H. influenzae strains 1124 and 2019, however, a beta-D-Galp is linked to O-4 of Glcl. In order to test the hypothesis that the 1ex2 locus is involved in the expression Of beta-D-Galp-(1 -> 4-beta-D-Glcp-(1 -> - from Hepl, 1ex2B was inactivated in strains 1124 and 2019, and LPS glycoform populations from the resulting mutant strains were investigated. Detailed structural analyses using NMR techniques and electrospray-ionisation mass spectrometry (ESIMS) on O-cleacylated LPS and core oligosaccharide material (OS), as well as ESIMS" on permethylated dephosphorylated OS, indicated both lex2B mutant strains to express only beta-D-Glcp extensions from Hepl. This provides strong evidence that Lex2B functions as a galactosyltransferase adding a beta-D-Galp to O-4 of Glcl in these strains, indicating that allelic polymorphisms in the lex2B sequence direct alternative functions of the gene product.

National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:sh:diva-13910 (URN)10.1016/j.carres.2009.01.005 (DOI)000265321500010 ()19211098 (PubMedID)2-s2.0-62749180259 (Scopus ID)
Available from: 2011-12-14 Created: 2011-12-14 Last updated: 2017-12-08Bibliographically approved
Lundström, S. L., Li, J., Månsson, M., Figueira, M., Leroy, M., Goldstein, R., . . . Schweda, E. K. H. (2008). Application of capillary electrophoresis mass spectrometry and liquid chromatography multiple-step tandem electrospray mass spectrometry to profile glycoform expression during Haemophilus influenzae pathogenesis in the chinchilla model of experimental otitis media. Infection and Immunity, 76(7), 3255-3267
Open this publication in new window or tab >>Application of capillary electrophoresis mass spectrometry and liquid chromatography multiple-step tandem electrospray mass spectrometry to profile glycoform expression during Haemophilus influenzae pathogenesis in the chinchilla model of experimental otitis media
Show others...
2008 (English)In: Infection and Immunity, ISSN 0019-9567, E-ISSN 1098-5522, Vol. 76, no 7, p. 3255-3267Article in journal (Refereed) Published
Abstract [en]

Otitis media caused by nontypeable Haemophilus influenzae (NTHi) is a common and recurrent bacterial infection of childhood. The structural variability and diversity of H. influenzae lipopolysaccharide (LPS) glycoforms are known to play a significant role in the commensal and disease-causing behavior of this pathogen. In this study, we determined LPS glycoform populations from NTHi strain 1003 during the course of experimental otitis media in the chinchilla model of infection by mass spectrometric techniques. Building on an established structural model of the major LPS glycoforms expressed by this NTHi strain in vitro (M. Mansson, W. Hood, J. Li, J. C. Richards, E. R. Moxon, and E. K. Schweda, Eur. J. Biochem. 269:808-818, 2002), minor isomeric glycoform populations were determined by liquid chromatography multiple-step tandem electrospray mass spectrometry (LC-ESI-MSn). Using capillary electrophoresis ESI-MS (CE-ESI-MS), we determined glycoform profiles for bacteria from direct middle ear fluid (MEF) samples. The LPS glycan profiles were essentially the same when the MEF samples of 7 of 10 animals were passaged on solid medium (chocolate agar). LC-ESI-MSn provided a sensitive method for determining the isomeric distribution of LPS glycoforms in MEF and passaged specimens. To investigate changes in LPS glycoform distribution during the course of infection, MEF samples were analyzed at 2, 5, and 9 days postinfection by CE-ESI-MS following minimal passage on chocolate agar. As previously observed, sialic acid-containing glycoforms were detected during the early stages of infection, but a trend toward more-truncated and less-complex LPS glycoforms that lacked sialic acid was found as disease progressed.

National Category
Immunology
Identifiers
urn:nbn:se:sh:diva-14142 (URN)10.1128/IAI.01710-07 (DOI)000257172300048 ()
Available from: 2011-12-18 Created: 2011-12-16 Last updated: 2017-12-08Bibliographically approved
Dzieciatkowska, M., Schweda, E. K. H., Moxon, E. R., Richards, J. C. & Li, J. (2008). Characterization of intact lipopolysaccharides from the Haemophilus influenzae strain RM 118 using electrophoresis-assisted open-tubular liquid chromatography-mass spectrometry. Electrophoresis, 29(10), 2171-2181
Open this publication in new window or tab >>Characterization of intact lipopolysaccharides from the Haemophilus influenzae strain RM 118 using electrophoresis-assisted open-tubular liquid chromatography-mass spectrometry
Show others...
2008 (English)In: Electrophoresis, ISSN 0173-0835, E-ISSN 1522-2683, Vol. 29, no 10, p. 2171-2181Article in journal (Refereed) Published
Abstract [en]

We have applied an electrophoresis-assisted open-tubular LC-MS method for analyzing intact lipopolysaccharides (LPSs) from Haemophilus influenzae strain RM 118 (Rd). We were able to obtain structural information on both core oligosaccharides (OSs) and the lipid A moiety including the sialylation, glycylation, and the distribution of fatty acid residues on the disaccharide backbone of lipid A. The fragmentation patterns of sodiated and protonated LPS molecules were investigated for determining the location of sialic acid. It was found that the tandem mass spectra of sodiated ions provided unambiguous evidence of both sialylated lactose and sialylated lacto-N-neotetraose. In contrast, the fragment ions of protonated ions only offered the evidence for the existence of sialylated lacto-N-neotetraose. The lipid A of Gram-negative bacteria, as the principal endotoxic component of LP S, plays a major role in the pathogenesis of bacterial infections. We have previously characterized lipid. A species after mild acid hydrolysis of LPS during which lipid A precipitates. In this study, intact LPS was directly introduced to a tandem mass spectrometer. In-source dissociation strategy was employed, followed by multiple-stage MS/MS on the ions originating from the lipid part to obtain structural information. This is the first time that the structure of lipid A of H. influenzae was characterized by MS/MS on intact LPS molecules without any prior chemical modifications. In the same way information on the OS can be obtained by MS/MS by focusing on ions originating from core OS.

National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:sh:diva-14156 (URN)10.1002/elps.200700762 (DOI)000256773700024 ()
Available from: 2011-12-18 Created: 2011-12-16 Last updated: 2017-12-08Bibliographically approved
Fox, K. L., Li, J., Schweda, E. K. H., Vitiazeva, A., Makepeace, K., Jennings, M. P., . . . Hood, D. W. (2008). Duplicate copies of lic1 direct the addition of multiple phosphocholine residues in the lipopolysaccharide of Haemophilus influenzae. Infection and Immunity, 76(2), 588-600
Open this publication in new window or tab >>Duplicate copies of lic1 direct the addition of multiple phosphocholine residues in the lipopolysaccharide of Haemophilus influenzae
Show others...
2008 (English)In: Infection and Immunity, ISSN 0019-9567, E-ISSN 1098-5522, Vol. 76, no 2, p. 588-600Article in journal (Refereed) Published
Abstract [en]

The genes of the lic1 operon (lic1A to lic1D) are responsible for incorporation of phosphocholine (PCho) into the lipopolysaccharide (LPS) of Haemophilus influenzae. PCho plays a multifaceted role in the commensal and pathogenic lifestyles of a range of mucosal pathogens, including H. influenzae. Structural studies of the LPS of nontypeable H. influenzae (NTHI) have revealed that PCho can be linked to a hexose on any one of the oligosaccharide chain extensions from the conserved inner core triheptosyl backbone. In a collection of NTHI strains we found several strains in which there were two distinct but variant lic1D DNA sequences, genes predicted to encode the transferase responsible for directing the addition of PCho to LPS. The same isolates were also found to express concomitantly two PCho residues at distinct positions in their LPS. In one such NTHI isolate, isolate 1158, structural analysis of LPS from lic1 mutants confirmed that each of the two copies of lic1D directs the addition of PCho to a distinct location on the LPS. One position for PCho addition is a novel heptose, which is part of the oligosaccharide extension from the proximal heptose of the LPS inner core. Modification of the LPS by addition of two PCho residues resulted in increased binding of C-reactive protein and had consequential effects on the resistance of the organism to the killing effects of normal human serum compared to the effects of glycoforms containing one or no PCho. When bound, C-reactive protein leads to complement-mediated killing, indicating the potential biological significance of multiple PCho residues.

National Category
Immunology
Identifiers
urn:nbn:se:sh:diva-14169 (URN)10.1128/IAI.00748-07 (DOI)000252978600015 ()
Available from: 2011-12-18 Created: 2011-12-16 Last updated: 2017-12-08Bibliographically approved
Schweda, E. K. H., Twelkmeyer, B. & Li, J. (2008). Profiling structural elements of short-chain lipopolysaccharide of non-typeable Haemophilus influenzae. Innate Immunity, 14(4), 199-211
Open this publication in new window or tab >>Profiling structural elements of short-chain lipopolysaccharide of non-typeable Haemophilus influenzae
2008 (English)In: Innate Immunity, ISSN 1753-4259, E-ISSN 1753-4267, Vol. 14, no 4, p. 199-211Article in journal (Refereed) Published
Abstract [en]

Lipopolysaccharide (LPS) is a major Virulence determinant of the human bacterial pathogen Hoemophilus influenzae. A characteristic feature of H. influenzae LPS is the extensive intra- and inter-strain heterogeneity of glycoform structure which is key to the role of the molecule in both commensal and disease-causing behaviour of the bacterium. The chemical composition of non-typeable Haemophilus influenzae (NTHi) LPS is hi-lily diverse. It contains a number of different monosaccharides (Neu5Ac, L-glycero-D-manno heptose, D-glycero-D-manno heptose, Kdo, D-Glc, D-Gal, D-GlcNAc, D-GaINAc) and non-carbohydrate substituents. Prominent non-carbohydrate components are O-acetyl groups, glycine and phosphates. We now know that sialic acid (N-acetylneuraminic acid or Neu5Ac) and certain oligosaccharide extensions are important in the pathogenesis of NTHi: however, the biological implications for many of the various features are Still unknown. Electrospray ionization mass spectrometry ill combination with separation techniques like CE and HPLC is an indispensable tool in profiling glycoform populations ill heterogeneous LPS samples. Mass Spectrometry is characterized by its extreme sensitivity. Trace amounts of glycoforms expressing important Virulence determinants can be detected and characterized on minute amounts of material. The present review focuses oil LPS structures and mass spectrometric methods which enable us to profile these in complex mixtures.

National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:sh:diva-14137 (URN)10.1177/1753425908095958 (DOI)000258854800001 ()
Available from: 2011-12-18 Created: 2011-12-16 Last updated: 2017-12-08Bibliographically approved
Dzieciatkowska, M., Liu, X., Heikema, A. P., Houliston, R. S., van Belkum, A., Schweda, E. K. H., . . . Li, J. (2008). Rapid method for sensitive screening of oligosaccharide epitopes in the lipooligosaccharide from Campylobacter jejuni strains isolated from Guillain-Barre syndrome and Miller Fisher syndrome patients. Journal of Clinical Microbiology, 46(10), 3429-3436
Open this publication in new window or tab >>Rapid method for sensitive screening of oligosaccharide epitopes in the lipooligosaccharide from Campylobacter jejuni strains isolated from Guillain-Barre syndrome and Miller Fisher syndrome patients
Show others...
2008 (English)In: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 46, no 10, p. 3429-3436Article in journal (Refereed) Published
Abstract [en]

Campylobacter jejuni lipooligosaccharide (LOS) can trigger Guillain-Barre syndrome (GBS) due to its similarity to human gangliosides. Rapid and accurate structural elucidation of the LOS glycan of a strain isolated from a GBS patient could help physicians determine the spectrum of anti-ganglioside antibodies likely to be found and therefore provide valuable assistance in establishing an appropriate course of treatment. The ability of implemented mass spectrometry-based approaches in a clinical setting has been limited by the laborious and time-consuming nature of the protocols, typically 3 to 4 days, used to prepare LOS. In order to improve the analytical throughput, microwave-assisted enzymatic digestion was investigated. In this study, the bacterial cells were suspended in 50 mu l of 20 mM ammonium acetate buffer containing DNase and RNase and treated by direct microwave irradiation for 3 min. Then, proteinase K was added and the samples were again microwaved. The intact LOS samples were analyzed using electrophoresis-assisted open-tubular liquid chromatography-mass spectrometry. The reliability of the rapid, high-throughput technique was demonstrated through analysis of LOS glycans from 73 C. jejuni strains. The structure was elucidated using material from a single colony. The total time for sample preparation and MS analysis is less than 60 min.

National Category
Microbiology
Identifiers
urn:nbn:se:sh:diva-14120 (URN)10.1128/JCM.00681-08 (DOI)000259758900037 ()
Available from: 2011-12-18 Created: 2011-12-16 Last updated: 2017-12-08Bibliographically approved
Lundström, S. L., Li, J., Deadman, M. E., Hood, D. W., Moxon, E. R. & Schweda, E. K. H. (2008). Structural analysis of the lipopolysaccharide from nontypeable Haemophilus influenzae strain R2846. Biochemistry, 47(22), 6025-6038
Open this publication in new window or tab >>Structural analysis of the lipopolysaccharide from nontypeable Haemophilus influenzae strain R2846
Show others...
2008 (English)In: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 47, no 22, p. 6025-6038Article in journal (Refereed) Published
Abstract [en]

We here report the lipopolysaccharide (LPS) structures expressed by nontypeable Haemophilus influenzae R2846, a strain whose complete genome sequence has recently been obtained. Results were obtained by using NMR techniques and ESI-MS on O-deacylated LPS and core oligosaccharide material (OS) as well as ESI-MSn on permethylated dephosphorylated OS. A beta-D-Glcp-(1 -> 4)-D-alpha-D-Hepp-(1 -> 6)-beta-D-Glcp-(1 -> 4) unit was found linked to the proximal heptose (HepI) of the conserved triheptosyl inner-core moiety, L-alpha-D-Hepp-(1 -> 2)-[PEtn -> 6]-L-alpha-D-Hepp-(1 -> 3)-L-alpha-D-Hepp-(1 -> 5)-[PPEtn -> 4]-alpha-Kdo-(2 -> 6)-lipid A. The beta-D-Glcp (GlcI) linked to HepI was also branched with oligosaccharide extensions from O-4 and O-6. O-4 of GlcI was substituted with sialyllacto-N-neotetraose [alpha-Neu5Ac-(2 -> 3)-beta-D-Galp-(1 -> 4)-beta-GlcpNAc-(1 -> 3)-beta-D-Galp-(1 -> 4)-beta-D-Glcp-(1 ->] and the related structure [(PEtn -> 6)-alpha-D-GalpNAc-(1 -> 6)-beta-D-Galp-(1 -> 4)-beta-D-GlcpNAc-(1 -> 3)-beta-D-Galp-(1 -> 4)-beta-Glcp-(1-]. The distal heptose (HepIII) was substituted at O-2 by beta-D-Gal. Phosphate, phosphoethanolamine, phosphocholine, acetate, and glycine were found to substitute the core oligosaccharide. Two heptosyltransferase genes, losB1 and losB2, have been identified from the R2846 genome sequence and are candidates to add the noncore heptose to the LPS. Mutant strain R2846losB1 did not show DD-heptose in the extension from HepI but still contained minor quantities of LD-heptose at the same position, indicating that the losB1 gene is required to add DD-heptose to Glcl. The LPS from strain R2846losB1/losB2 expressed no noncore heptose, consistent with losB2 directing the addition of LD-heptose.

National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:sh:diva-14148 (URN)10.1021/bi702510b (DOI)000256256200014 ()
Available from: 2011-12-18 Created: 2011-12-16 Last updated: 2017-12-08Bibliographically approved
Houliston, R. S., Koga, M., Li, J., Jarrell, H. C., Richards, J. C., Vitiazeva, V., . . . Gilbert, M. (2007). A Haemophilus influenzae strain associated with fisher syndrome expresses a novel disialylated ganglioside mimic. Biochemistry, 46(27), 8164-8171
Open this publication in new window or tab >>A Haemophilus influenzae strain associated with fisher syndrome expresses a novel disialylated ganglioside mimic
Show others...
2007 (English)In: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 46, no 27, p. 8164-8171Article in journal (Refereed) Published
Abstract [en]

The non-typeable Haemophilus influenzae strain DH1 was isolated from a 25 year old male patient with Fisher syndrome, a postinfectious autoimmune condition characterized by the presence of anti-GQ1b IgG antibodies that target and initiate damage to peripheral nerves. DH1 was found to display an alpha NeuAc(2-8)alpha NeuAc(2-3)beta Gal branch bound to the tetraheptosyl backbone core of its lipooligosaccharide (LOS). The novel sialylation pattern was found to be dependent on the activity of a bifunctional sialyltransferase, Lic3B, which catalyzes the addition of both the terminal and subterminal sialic acid residues. Patient serum IgGs bind to DH1 LOS, and the reactivity is significantly influenced by the presence of sialylated glycoforms. The display by DH1, of a surface glycan that mimics the terminal trisaccharide portion of disialosyl-containing gangliosides, provides strong evidence for its involvement in the development of Fisher syndrome.

National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:sh:diva-14218 (URN)10.1021/bi700685s (DOI)000247677700024 ()
Available from: 2011-12-20 Created: 2011-12-19 Last updated: 2017-12-08Bibliographically approved
Organisations

Search in DiVA

Show all publications