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Eckmair B, Gao C, Mehta AY, Dutkiewicz Z, Vanbeselaere J, Cummings RD, Paschinger K, Wilson IBH. Recognition of Highly Branched N-Glycans of the Porcine Whipworm by the Immune System. Mol Cell Proteomics 2024; 23:100711. [PMID: 38182041 PMCID: PMC10850124 DOI: 10.1016/j.mcpro.2024.100711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/14/2023] [Accepted: 01/02/2024] [Indexed: 01/07/2024] Open
Abstract
Glycans are key to host-pathogen interactions, whereby recognition by the host and immunomodulation by the pathogen can be mediated by carbohydrate binding proteins, such as lectins of the innate immune system, and their glycoconjugate ligands. Previous studies have shown that excretory-secretory products of the porcine nematode parasite Trichuris suis exert immunomodulatory effects in a glycan-dependent manner. To better understand the mechanisms of these interactions, we prepared N-glycans from T. suis and both analyzed their structures and used them to generate a natural glycan microarray. With this array, we explored the interactions of glycans with C-type lectins, C-reactive protein, and sera from T. suis-infected pigs. Glycans containing LacdiNAc and phosphorylcholine-modified glycans were associated with the highest binding by most of these proteins. In-depth analysis revealed not only fucosylated LacdiNAc motifs with and without phosphorylcholine moieties but phosphorylcholine-modified mannose and N-acetylhexosamine-substituted fucose residues, in the context of maximally tetraantennary N-glycan scaffolds. Furthermore, O-glycans also contained fucosylated motifs. In summary, the glycans of T. suis are recognized by both the innate and adaptive immune systems and also exhibit species-specific features distinguishing its glycome from those of other nematodes.
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Affiliation(s)
- Barbara Eckmair
- Department für Chemie, Institut für Biochemie, Universität für Bodenkultur, Wien, Austria
| | - Chao Gao
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Akul Y Mehta
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Zuzanna Dutkiewicz
- Department für Chemie, Institut für Biochemie, Universität für Bodenkultur, Wien, Austria
| | - Jorick Vanbeselaere
- Department für Chemie, Institut für Biochemie, Universität für Bodenkultur, Wien, Austria
| | - Richard D Cummings
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Katharina Paschinger
- Department für Chemie, Institut für Biochemie, Universität für Bodenkultur, Wien, Austria
| | - Iain B H Wilson
- Department für Chemie, Institut für Biochemie, Universität für Bodenkultur, Wien, Austria.
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2
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Eckmair B, Gao C, Mehta AY, Dutkiewicz Z, Vanbeselaere J, Cummings RD, Paschinger K, Wilson IBH. Recognition of highly branched N-glycans of the porcine whipworm by the immune system. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.21.557549. [PMID: 37790353 PMCID: PMC10542551 DOI: 10.1101/2023.09.21.557549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Glycans are key to host-pathogen interactions, whereby recognition by the host and immunomodulation by the pathogen can be mediated by carbohydrate binding proteins, such as lectins of the innate immune system, and their glycoconjugate ligands. Previous studies have shown that excretory-secretory products of the porcine nematode parasite Trichuris suis exert immunomodulatory effects in a glycan-dependent manner. To better understand the mechanisms of these interactions, we prepared N-glycans from T. suis and both analyzed their structures and used them to generate a natural glycan microarray. With this array we explored the interactions of glycans with C-type lectins, C-reactive protein and sera from T. suis infected pigs. Glycans containing LacdiNAc and phosphorylcholine-modified glycans were associated with the highest binding by most of these proteins. In-depth analysis revealed not only fucosylated LacdiNAc motifs with and without phosphorylcholine moieties, but phosphorylcholine-modified mannose and N-acetylhexosamine-substituted fucose residues, in the context of maximally tetraantennary N-glycan scaffolds. Furthermore, O-glycans also contained fucosylated motifs. In summary, the glycans of T. suis are recognized by both the innate and adaptive immune systems, and also exhibit species-specific features distinguishing its glycome from those of other nematodes.
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Affiliation(s)
- Barbara Eckmair
- Institut für Biochemie, Department für Chemie, Universität für Bodenkultur, Muthgasse 18, 1190 Wien, Austria
| | - Chao Gao
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, 3 Blackfan Circle, Boston, MA 02115, USA
| | - Akul Y Mehta
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, 3 Blackfan Circle, Boston, MA 02115, USA
| | - Zuzanna Dutkiewicz
- Institut für Biochemie, Department für Chemie, Universität für Bodenkultur, Muthgasse 18, 1190 Wien, Austria
| | - Jorick Vanbeselaere
- Institut für Biochemie, Department für Chemie, Universität für Bodenkultur, Muthgasse 18, 1190 Wien, Austria
| | - Richard D Cummings
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, 3 Blackfan Circle, Boston, MA 02115, USA
| | - Katharina Paschinger
- Institut für Biochemie, Department für Chemie, Universität für Bodenkultur, Muthgasse 18, 1190 Wien, Austria
| | - Iain B H Wilson
- Institut für Biochemie, Department für Chemie, Universität für Bodenkultur, Muthgasse 18, 1190 Wien, Austria
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3
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Mersha FB, McClung CM, Chen M, Ruse CI, Foster JM. Defining the filarial N-glycoproteome by glycosite mapping in the human parasitic nematode Brugia malayi. Sci Rep 2023; 13:7951. [PMID: 37193733 DOI: 10.1038/s41598-023-34936-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 05/10/2023] [Indexed: 05/18/2023] Open
Abstract
N-linked glycosylation is a critical post translational modification of eukaryotic proteins. N-linked glycans are present on surface and secreted filarial proteins that play a role in host parasite interactions. Examples of glycosylated Brugia malayi proteins have been previously identified but there has not been a systematic study of the N-linked glycoproteome of this or any other filarial parasite. In this study, we applied an enhanced N-glyco FASP protocol using an engineered carbohydrate-binding protein, Fbs1, to enrich N-glycosylated peptides for analysis by LC-MS/MS. We then mapped the N-glycosites on proteins from three host stages of the parasite: adult female, adult male and microfilariae. Fbs1 enrichment of N-glycosylated peptides enhanced the identification of N-glycosites. Our data identified 582 N-linked glycoproteins with 1273 N-glycosites. Gene ontology and cell localization prediction of the identified N-glycoproteins indicated that they were mostly membrane and extracellular proteins. Comparing results from adult female worms, adult male worms, and microfilariae, we find variability in N-glycosylation at the protein level as well as at the individual N-glycosite level. These variations are highlighted in cuticle N-glycoproteins and adult worm restricted N-glycoproteins as examples of proteins at the host parasite interface that are well positioned as potential therapeutic targets or biomarkers.
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Paschinger K, Wöls F, Yan S, Jin C, Vanbeselaere J, Dutkiewicz Z, Arcalis E, Malzl D, Wilson IBH. N-glycan antennal modifications are altered in Caenorhabditis elegans lacking the HEX-4 N-acetylgalactosamine-specific hexosaminidase. J Biol Chem 2023; 299:103053. [PMID: 36813232 PMCID: PMC10060765 DOI: 10.1016/j.jbc.2023.103053] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 02/16/2023] [Accepted: 02/17/2023] [Indexed: 02/24/2023] Open
Abstract
Simple organisms are often considered to have simple glycomes, but plentiful paucimannosidic and oligomannosidic glycans overshadow the less abundant N-glycans with highly variable core and antennal modifications; Caenorhabditis elegans is no exception. By use of optimized fractionation and assessing wildtype in comparison to mutant strains lacking either the HEX-4 or HEX-5 β-N-acetylgalactosaminidases, we conclude that the model nematode has a total N-glycomic potential of 300 verified isomers. Three pools of glycans were analyzed for each strain: either PNGase F released and eluted from a reversed-phase C18 resin with either water or 15% methanol or PNGase Ar released. While the water-eluted fractions were dominated by typical paucimannosidic and oligomannosidic glycans and the PNGase Ar-released pools by glycans with various core modifications, the methanol-eluted fractions contained a huge range of phosphorylcholine-modified structures with up to three antennae, sometimes with four N-acetylhexosamine residues in series. There were no major differences between the C. elegans wildtype and hex-5 mutant strains, but the hex-4 mutant strains displayed altered sets of methanol-eluted and PNGase Ar-released pools. In keeping with the specificity of HEX-4, there were more glycans capped with N-acetylgalactosamine in the hex-4 mutants, as compared with isomeric chito-oligomer motifs in the wildtype. Considering that fluorescence microscopy showed that a HEX-4::enhanced GFP fusion protein colocalizes with a Golgi tracker, we conclude that HEX-4 plays a significant role in late-stage Golgi processing of N-glycans in C. elegans. Furthermore, finding more "parasite-like" structures in the model worm may facilitate discovery of glycan-processing enzymes occurring in other nematodes.
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Affiliation(s)
| | - Florian Wöls
- Department für Chemie, Universität für Bodenkultur, Wien, Austria
| | - Shi Yan
- Department für Chemie, Universität für Bodenkultur, Wien, Austria; Institut für Parasitologie, Veterinärmedizinische Universität, Wien, Austria
| | - Chunsheng Jin
- Institutionen för Biomedicin, Göteborgs universitet, Göteborg, Sweden
| | | | | | - Elsa Arcalis
- Department für angewandte Genetik und Zellbiologie, Universität für Bodenkultur, Wien, Austria
| | - Daniel Malzl
- Department für Chemie, Universität für Bodenkultur, Wien, Austria
| | - Iain B H Wilson
- Department für Chemie, Universität für Bodenkultur, Wien, Austria.
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5
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Wilson IBH, Yan S, Jin C, Dutkiewicz Z, Rendić D, Palmberger D, Schnabel R, Paschinger K. Increasing Complexity of the N-Glycome During Caenorhabditis Development. Mol Cell Proteomics 2023; 22:100505. [PMID: 36717059 PMCID: PMC7614267 DOI: 10.1016/j.mcpro.2023.100505] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 01/06/2023] [Accepted: 01/24/2023] [Indexed: 01/30/2023] Open
Abstract
Caenorhabditis elegans is a frequently employed genetic model organism and has been the object of a wide range of developmental, genetic, proteomic, and glycomic studies. Here, using an off-line MALDI-TOF-MS approach, we have analyzed the N-glycans of mixed embryos and liquid- or plate-grown L4 larvae. Of the over 200 different annotatable N-glycan structures, variations between the stages as well as the mode of cultivation were observed. While the embryonal N-glycome appears less complicated overall, the liquid- and plate-grown larvae differ especially in terms of methylation of bisecting fucose, α-galactosylation of mannose, and di-β-galactosylation of core α1,6-fucose. Furthermore, we analyzed the O-glycans by LC-electrospray ionization-MS following β-elimination; especially the embryonal O-glycomes included a set of phosphorylcholine-modified structures, previously not shown to exist in nematodes. However, the set of glycan structures cannot be clearly correlated with levels of glycosyltransferase transcripts in developmental RNA-Seq datasets, but there is an indication for coordinated expression of clusters of potential glycosylation-relevant genes. Thus, there are still questions to be answered in terms of how and why a simple nematode synthesizes such a diverse glycome.
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Affiliation(s)
- Iain B H Wilson
- Department für Chemie, Universität für Bodenkultur, Wien, Austria.
| | - Shi Yan
- Department für Chemie, Universität für Bodenkultur, Wien, Austria; Institut für Parasitologie, Veterinärmedizinische Universität Wien, Wien, Austria
| | - Chunsheng Jin
- Institutionen för Biomedicin, Göteborgs universitet, Göteborg, Sweden
| | | | - Dubravko Rendić
- Department für Chemie, Universität für Bodenkultur, Wien, Austria
| | | | - Ralf Schnabel
- Institut für Genetik, Technische Universität Braunschweig, Braunschweig, Germany
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Petralia LM, van Diepen A, Lokker LA, Nguyen DL, Sartono E, Khatri V, Kalyanasundaram R, Taron CH, Foster JM, Hokke CH. Mass spectrometric and glycan microarray-based characterization of the filarial nematode Brugia malayi glycome reveals anionic and zwitterionic glycan antigens. Mol Cell Proteomics 2022; 21:100201. [PMID: 35065273 PMCID: PMC9046957 DOI: 10.1016/j.mcpro.2022.100201] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 01/03/2022] [Accepted: 01/16/2022] [Indexed: 11/30/2022] Open
Abstract
Millions of people worldwide are infected with filarial nematodes, responsible for lymphatic filariasis (LF) and other diseases causing chronic disablement. Elimination programs have resulted in a substantial reduction of the rate of infection in certain areas creating a need for improved diagnostic tools to establish robust population surveillance and avoid LF resurgence. Glycans from parasitic helminths are emerging as potential antigens for use in diagnostic assays. However, despite its crucial role in host–parasite interactions, filarial glycosylation is still largely, structurally, and functionally uncharacterized. Therefore, we investigated the glycan repertoire of the filarial nematode Brugia malayi. Glycosphingolipid and N-linked glycans were extracted from several life-stages using enzymatic release and characterized using a combination of MALDI-TOF-MS and glycan sequencing techniques. Next, glycans were purified by HPLC and printed onto microarrays to assess the host anti-glycan antibody response. Comprehensive glycomic analysis of B. malayi revealed the presence of several putative antigenic motifs such as phosphorylcholine and terminal glucuronic acid. Glycan microarray screening showed a recognition of most B. malayi glycans by immunoglobulins from rhesus macaques at different time points after infection, which permitted the characterization of the dynamics of anti-glycan immunoglobulin G and M during the establishment of brugian filariasis. A significant level of IgG binding to the parasite glycans was also detected in infected human plasma, while IgG binding to glycans decreased after anthelmintic treatment. Altogether, our work identifies B. malayi glycan antigens and reveals antibody responses from the host that could be exploited as potential markers for LF. Antigenic B. malayi N-linked and GSL glycans were structurally defined. IgG/IgM is induced to a subset of B. malayi glycans upon infection of rhesus macaques. Preferential IgG response to B. malayi glycans observed in chronically infected humans. Marked drop of anti-glycan IgG following treatment of individuals with anthelminthic.
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7
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Buitrago G, Duncombe-Moore J, Harnett MM, Harnett W. Mini Review: Structure and Function of Nematode Phosphorylcholine-Containing Glycoconjugates. FRONTIERS IN TROPICAL DISEASES 2021. [DOI: 10.3389/fitd.2021.769000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
An unusual aspect of the biology of nematodes is the covalent attachment of phosphorylcholine (PC) to carbohydrate in glycoconjugates. Investigation of the structure of these molecules by ever-increasingly sophisticated analytical procedures has revealed that PC is generally in phosphodiester linkage with C6 of N-acetylglucosamine (GlcNAc) in both N-type glycans and glycosphingolipids. Up to five PC groups have been detected in the former, being located on both antenna and core GlcNAc. The PC donor for transfer to carbohydrate appears to be phosphatidylcholine but the enzyme responsible for transfer remains to be identified. Work primarily involving the PC-containing Acanthocheilonema viteae secreted product ES-62, has shown that the PC attached to nematode N-glycans possesses a range of immunomodulatory properties, subverting for example, pro-inflammatory signalling in various immune system cell-types including lymphocytes, mast cells, dendritic cells and macrophages. This has led to the generation of PC-based ES-62 small molecule analogues (SMAs), which mirror the parent molecule in preventing the initiation or progression of disease in mouse models of a number of human conditions associated with aberrant inflammatory responses. These include rheumatoid arthritis, systemic lupus erythematosus and lung and skin allergy such that the SMAs are considered to have widespread therapeutic potential.
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8
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Risch F, Ritter M, Hoerauf A, Hübner MP. Human filariasis-contributions of the Litomosoides sigmodontis and Acanthocheilonema viteae animal model. Parasitol Res 2021; 120:4125-4143. [PMID: 33547508 PMCID: PMC8599372 DOI: 10.1007/s00436-020-07026-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/20/2020] [Indexed: 12/16/2022]
Abstract
Filariae are vector-borne parasitic nematodes that are endemic worldwide, in tropical and subtropical regions. Important human filariae spp. include Onchocerca volvulus, Wuchereria bancrofti and Brugia spp., and Loa loa and Mansonella spp. causing onchocerciasis (river blindness), lymphatic filariasis (lymphedema and hydrocele), loiasis (eye worm), and mansonelliasis, respectively. It is estimated that over 1 billion individuals live in endemic regions where filarial diseases are a public health concern contributing to significant disability adjusted life years (DALYs). Thus, efforts to control and eliminate filarial diseases were already launched by the WHO in the 1970s, especially against lymphatic filariasis and onchocerciasis, and are mainly based on mass drug administration (MDA) of microfilaricidal drugs (ivermectin, diethylcarbamazine, albendazole) to filarial endemic areas accompanied with vector control strategies with the goal to reduce the transmission. With the United Nations Sustainable Development Goals (SDGs), it was decided to eliminate transmission of onchocerciasis and stop lymphatic filariasis as a public health problem by 2030. It was also requested that novel drugs and treatment strategies be developed. Mouse models provide an important platform for anti-filarial drug research in a preclinical setting. This review presents an overview about the Litomosoides sigmodontis and Acanthocheilonema viteae filarial mouse models and their role in immunological research as well as preclinical studies about novel anti-filarial drugs and treatment strategies.
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Affiliation(s)
- Frederic Risch
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Manuel Ritter
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany
| | - Marc P Hübner
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany.
- German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany.
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Hertz MI, Rush A, Nutman TB, Weil GJ, Bennuru S, Budge PJ. Characterization of glycan determinants that mediate recognition of the major Wuchereria bancrofti circulating antigen by diagnostic antibodies. Mol Biochem Parasitol 2020; 240:111317. [PMID: 32961208 PMCID: PMC11006022 DOI: 10.1016/j.molbiopara.2020.111317] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 12/17/2022]
Abstract
The Global Program to Eliminate Lymphatic Filariasis (GPELF) relies heavily on a rapid diagnostic test (RDT) to a Wuchereria bancrofti circulating filarial antigen (Wb-CFA) to identify endemic areas and for determining when mass drug administration can stop. The antigen contains a carbohydrate epitope that is recognized by monoclonal antibody AD12. Og4C3, a monoclonal antibody that is used in a commercial ELISA for Wb-CFA recognizes the same moiety. Despite its diagnostic importance, little is known about the structure and function of this "AD12 epitope". It is also present on other W. bancrofti glycoproteins and on glycoproteins of other filarial worms, but such antigens are not detected in the sera of individuals with most other filarial infections. We report here functional and biochemical analyses that shed light on the interaction between filarial glycoproteins and AD12 and/or Og4C3. Binding of these monoclonal antibodies to a mammalian glycan array suggests the reactive moiety has structural similarity to terminal β-d-glucuronic acid in a 1-3 linkage to other hexoses. However, sera collected from individuals with patent W. bancrofti infection had very low or undetectable serum antibodies to the GlcA-containing array glycans. Unlike other filarial glycoproteins, the Wb-CFA is relatively resistant to protease digestion by pronase and trypsin and completely resistant to the mucinase O-sialoglycoprotein endopeptidase (OSGE). The protease resistance of the Wb-CFA may contribute to its consistent detection in Wb-infected sera.
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Affiliation(s)
- Marla I Hertz
- Infectious Diseases Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
| | - Amy Rush
- Infectious Diseases Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Thomas B Nutman
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Gary J Weil
- Infectious Diseases Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Sasisekhar Bennuru
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Philip J Budge
- Infectious Diseases Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
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10
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North SJ, Botchway K, Doonan J, Lumb FE, Dell A, Harnett W, Haslam SM. Site-specific glycoproteomic characterization of ES-62: The major secreted product of the parasitic worm Acanthocheilonema viteae. Glycobiology 2020; 29:562-571. [PMID: 31094418 PMCID: PMC6639541 DOI: 10.1093/glycob/cwz035] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 05/10/2019] [Accepted: 05/10/2019] [Indexed: 12/29/2022] Open
Abstract
ES-62 is the major secreted product of the parasitic filarial nematode Acanthocheilonema viteae and has potent anti-inflammatory activities as a consequence of posttranslational decoration by phosphorylcholine (PC). Previously, we showed that ES-62’s PC was attached to N-linked glycans, and using fast atom bombardment mass spectrometry, we characterized the structure of the glycans. However, it was unknown at this time which of ES-62’s four potential N-glycosylation sites carries the PC-modified glycans. In the present study, we now employ more advanced analytical tools—nano-flow liquid chromatography with high-definition electrospray mass spectrometry—to show that PC-modified glycans are found at all four potential N-glycosylation sites. Also, our earlier studies showed that up to two PC groups were detected per glycan, and we are now able to characterize N-glycans with up to five PC groups. The number per glycan varies in three of the four glycosylation sites, and in addition, for the first time, we have detected PC on the N-glycan chitobiose core in addition to terminal GlcNAc. Nevertheless, the majority of PC is detected on terminal GlcNAc, enabling it to interact with the cells and molecules of the immune system. Such expression may explain the potent immunomodulatory effects of a molecule that is considered to have significant therapeutic potential in the treatment of certain human allergic and autoimmune conditions.
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Affiliation(s)
- Simon J North
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Kwamina Botchway
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - James Doonan
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, United Kingdom
| | - Felicity E Lumb
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, United Kingdom
| | - Anne Dell
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, United Kingdom
| | - William Harnett
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, United Kingdom
| | - Stuart M Haslam
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
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11
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Paschinger K, Wilson IBH. Anionic and zwitterionic moieties as widespread glycan modifications in non-vertebrates. Glycoconj J 2019; 37:27-40. [PMID: 31278613 PMCID: PMC6994554 DOI: 10.1007/s10719-019-09874-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/20/2019] [Accepted: 05/24/2019] [Indexed: 02/07/2023]
Abstract
Glycan structures in non-vertebrates are highly variable; it can be assumed that this is a product of evolution and speciation, not that it is just a random event. However, in animals and protists, there is a relatively limited repertoire of around ten monosaccharide building blocks, most of which are neutral in terms of charge. While two monosaccharide types in eukaryotes (hexuronic and sialic acids) are anionic, there are a number of organic or inorganic modifications of glycans such as sulphate, pyruvate, phosphate, phosphorylcholine, phosphoethanolamine and aminoethylphosphonate that also confer a 'charged' nature (either anionic or zwitterionic) to glycoconjugate structures. These alter the physicochemical properties of the glycans to which they are attached, change their ionisation when analysing them by mass spectrometry and result in different interactions with protein receptors. Here, we focus on N-glycans carrying anionic and zwitterionic modifications in protists and invertebrates, but make some reference to O-glycans, glycolipids and glycosaminoglycans which also contain such moieties. The conclusion is that 'charged' glycoconjugates are a widespread, but easily overlooked, feature of 'lower' organisms.
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Affiliation(s)
| | - Iain B H Wilson
- Department für Chemie, Universität für Bodenkultur, 1190, Wien, Austria.
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12
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Abstract
The investigation of the glycan repertoire of several organisms has revealed a wide variation in terms of structures and abundance of glycan moieties. Among the parasites, it is possible to observe different sets of glycoconjugates across taxa and developmental stages within a species. The presence of distinct glycoconjugates throughout the life cycle of a parasite could relate to the ability of that organism to adapt and survive in different hosts and environments. Carbohydrates on the surface, and in excretory-secretory products of parasites, play essential roles in host-parasite interactions. Carbohydrate portions of complex molecules of parasites stimulate and modulate host immune responses, mainly through interactions with specific receptors on the surface of dendritic cells, leading to the generation of a pattern of response that may benefit parasite survival. Available data reviewed here also show the frequent aspect of parasite immunomodulation of mammalian responses through specific glycan interactions, which ultimately makes these molecules promising in the fields of diagnostics and vaccinology.
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Abstract
Many invertebrates are either parasites themselves or vectors involved in parasite transmission; thereby, the interactions of parasites with final or intermediate hosts are often mediated by glycans. Therefore, it is of interest to compare the glycan structures or motifs present across invertebrate species. While a typical vertebrate modification such as sialic acid is rare in lower animals, antennal and core modifications of N-glycans are highly varied and range from core fucose, galactosylated fucose, fucosylated galactose, methyl groups, glucuronic acid and sulphate through to addition of zwitterionic moieties (phosphorylcholine, phosphoethanolamine and aminoethylphosphonate). Only in some cases are the enzymatic bases and the biological function of these modifications known. We are indeed still in the phase of discovering invertebrate glycomes primarily using mass spectrometry, but molecular biology and microarraying techniques are complementary to the determination of novel glycan structures and their functions.
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14
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Paschinger K, Yan S, Wilson IBH. N-glycomic Complexity in Anatomical Simplicity: Caenorhabditis elegans as a Non-model Nematode? Front Mol Biosci 2019; 6:9. [PMID: 30915340 PMCID: PMC6422873 DOI: 10.3389/fmolb.2019.00009] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 02/12/2019] [Indexed: 12/28/2022] Open
Abstract
Caenorhabditis elegans is a genetically well-studied model nematode or "worm"; however, its N-glycomic complexity is actually baffling and still not completely unraveled. Some features of its N-glycans are, to date, unique and include bisecting galactose and up to five fucose residues associated with the asparagine-linked Man2-3GlcNAc2 core; the substitutions include galactosylation of fucose, fucosylation of galactose and methylation of mannose or fucose residues as well as phosphorylcholine on antennal (non-reducing) N-acetylglucosamine. Only some of these modifications are shared with various other nematodes, while others have yet to be detected in any other species. Thus, C. elegans can be used as a model for some aspects of N-glycan function, but its glycome is far from identical to those of other organisms and is actually far from simple. Possibly the challenges of its native environment, which differ from those of parasitic or necromenic species, led to an anatomically simple worm possessing a complex glycome.
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Affiliation(s)
| | - Shi Yan
- Institut für Parasitologie, Veterinärmedizinische Universität, Wien, Austria
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15
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Martini F, Eckmair B, Štefanić S, Jin C, Garg M, Yan S, Jiménez-Castells C, Hykollari A, Neupert C, Venco L, Varón Silva D, Wilson IBH, Paschinger K. Highly modified and immunoactive N-glycans of the canine heartworm. Nat Commun 2019; 10:75. [PMID: 30622255 PMCID: PMC6325117 DOI: 10.1038/s41467-018-07948-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 12/06/2018] [Indexed: 01/05/2023] Open
Abstract
The canine heartworm (Dirofilaria immitis) is a mosquito-borne parasitic nematode whose range is extending due to climate change. In a four-dimensional analysis involving HPLC, MALDI-TOF–MS and MS/MS in combination with chemical and enzymatic digestions, we here reveal an N-glycome of unprecedented complexity. We detect N-glycans of up to 7000 Da, which contain long fucosylated HexNAc-based repeats, as well as glucuronylated structures. While some modifications including LacdiNAc, chitobiose, α1,3-fucose and phosphorylcholine are familiar, anionic N-glycans have previously not been reported in nematodes. Glycan array data show that the neutral glycans are preferentially recognised by IgM in dog sera or by mannose binding lectin when antennal fucose and phosphorylcholine residues are removed; this pattern of reactivity is reversed for mammalian C-reactive protein, which can in turn be bound by the complement component C1q. Thereby, the N-glycans of D. immitis contain features which may either mediate immunomodulation of the host or confer the ability to avoid immune surveillance. The glycome of parasites can have immunomodulatory properties or help to avoid immune surveillance, but details are unknown. Here, Martini et al. characterize the N-glycome of the canine heartworm, reveal an unprecedented complexity, particularly in anionic N-glycans, and determine recognition by components of the immune system.
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Affiliation(s)
| | - Barbara Eckmair
- Department für Chemie, Universität für Bodenkultur, Muthgasse 18, 1190, Wien, Austria
| | - Saša Štefanić
- Institute of Parasitology, Universität Zürich, Winterthurerstraße 266a, 8057, Zürich, Switzerland
| | - Chunsheng Jin
- Institutionen för Biomedicin, Göteborgs Universitet, 405 30, Göteborg, Sweden
| | - Monika Garg
- Max-Planck-Institut für Kolloid- und Grenzflächenforschung, Biomolekulare Systeme, 14424, Potsdam, Germany
| | - Shi Yan
- Department für Chemie, Universität für Bodenkultur, Muthgasse 18, 1190, Wien, Austria.,Institut für Parasitologie, Veterinärmedizinische Universität, 1210, Wien, Austria
| | | | - Alba Hykollari
- Department für Chemie, Universität für Bodenkultur, Muthgasse 18, 1190, Wien, Austria
| | | | - Luigi Venco
- Clinica Veterinaria Lago Maggiore, Arona, 28040, Italy
| | - Daniel Varón Silva
- Max-Planck-Institut für Kolloid- und Grenzflächenforschung, Biomolekulare Systeme, 14424, Potsdam, Germany
| | - Iain B H Wilson
- Department für Chemie, Universität für Bodenkultur, Muthgasse 18, 1190, Wien, Austria.
| | - Katharina Paschinger
- Department für Chemie, Universität für Bodenkultur, Muthgasse 18, 1190, Wien, Austria
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16
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Ahmed R, Cadman ET, Snapper CM, Lawrence RA. Decreased nematode clearance and anti-phosphorylcholine-specific IgM responses in mannose-binding lectin-deficient mice. Immunol Cell Biol 2019; 97:305-316. [DOI: 10.1111/imcb.12219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 11/15/2018] [Accepted: 11/16/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Rubina Ahmed
- Department of Comparative Biomedical Sciences; The Royal Veterinary College; Royal College Street London NW1 0TU UK
| | - Emma T Cadman
- Department of Comparative Biomedical Sciences; The Royal Veterinary College; Royal College Street London NW1 0TU UK
| | - Clifford M Snapper
- Department of Pathology; Uniformed Services University of the Health Sciences; 4301 Jones Bridge Road Bethesda MD 20814 USA
| | - Rachel A Lawrence
- Department of Comparative Biomedical Sciences; The Royal Veterinary College; Royal College Street London NW1 0TU UK
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17
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The Eukaryotic Elongation Factor 1 Alpha (eEF1α) from the Parasite Leishmania infantum Is Modified with the Immunomodulatory Substituent Phosphorylcholine (PC). Molecules 2017; 22:molecules22122094. [PMID: 29186074 PMCID: PMC6149742 DOI: 10.3390/molecules22122094] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 11/24/2017] [Indexed: 01/11/2023] Open
Abstract
Proteins and glycolipids have been found to be decorated with phosphorylcholine (PC) both in protozoa and nematodes that parasitize humans and animals. PC epitopes can provoke various effects on immune cells leading to an immunomodulation of the host’s immune system that allows long-term persistence of the parasites. So far, only a limited number of PC-modified proteins, mainly from nematodes, have been identified. Infections caused by Leishmania spp. (e.g., L. infantum in southern Europe) affect about 12 million people worldwide and are characterized by a wide spectrum of clinical forms in humans, ranging from cutaneous to fatal visceral leishmaniasis. To establish and maintain the infection, these protozoa are dependent on the secretion of effector molecules into the host for modulating their immune system. In this project, we analyzed the PC modification of L. infantum promastigotes by 2D-gel based proteomics. Western blot analysis with the PC-specific antibody TEPC-15 revealed one PC-substituted protein in this organism, identified as eEF1α. We could demonstrate that the binding of eEF1α to one of its downstream effectors is dependent on its PC-modification. In this study we provide evidence that in this parasite the modification of eEF1α with PC may be essential for its function as an important virulence factor.
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18
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Bennuru S, Lustigman S, Abraham D, Nutman TB. Metabolite profiling of infection-associated metabolic markers of onchocerciasis. Mol Biochem Parasitol 2017; 215:58-69. [PMID: 28188804 PMCID: PMC5474354 DOI: 10.1016/j.molbiopara.2017.01.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 01/25/2017] [Accepted: 01/28/2017] [Indexed: 11/30/2022]
Abstract
The global efforts for onchocerciasis elimination may require additional tools (safe micro and macrofilaricidal drugs, vaccines and biomarkers) as elimination efforts move toward the "end game". Efforts toward the identification of suitable biomarkers have focused on specific protein(s) and/or nucleic acids, but metabolites present an alternative option as they have limited half-lives and are the result of combinatorial effects. In comparison to previously used methodology of LC-MS for metabolomic approaches, we used a non-targeted capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS) to analyze the serum metabolic profiles of Ov-infected and -uninfected individuals (n=20). We identified 286 known metabolites (167 in the cation mode and 119 in the anion mode). In addition, putative metabolites were identified based on KEGG (51), HMDB (37) and HMT (6) databases. One hundred ten of these putative metabolites were quantified based on peak areas of internal standards and their ability to be mapped to known pathways (primary-, carbon-, lipid-, amino acid-, nucleotide and coenzyme-metabolism). Multivariate analysis demonstrated clustering and segregation of some of these metabolites to either the infected or control groups. The levels of serotonin, hypoxanthine, pipecolic acid and inosine were significantly elevated in those with onchocerciasis, whereas the levels of glycerophosphocholine, choline and adenine were significantly lower. This non-targeted metabolomic approach provides a global view of the metabolic variations that occur during Ov infection and thus allow the discovery of key metabolites (and associated pathways) that may serve as useful biomarkers in human onchocerciasis.
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Affiliation(s)
| | | | | | - Thomas B Nutman
- Laboratory of Parasitic Diseases, NIAID, NIH, Bethesda, MD, USA
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19
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Hokke CH, van Diepen A. Helminth glycomics - glycan repertoires and host-parasite interactions. Mol Biochem Parasitol 2016; 215:47-57. [PMID: 27939587 DOI: 10.1016/j.molbiopara.2016.12.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 11/18/2016] [Accepted: 12/01/2016] [Indexed: 01/12/2023]
Abstract
Glycoproteins and glycolipids of parasitic helminths play important roles in biology and host-parasite interaction. This review discusses recent helminth glycomics studies that have been expanding our insights into the glycan repertoire of helminths. Structural data are integrated with biological and immunological observations to highlight how glycomics advances our understanding of the critical roles that glycans and glycan motifs play in helminth infection biology. Prospects and challenges in helminth glycomics and glycobiology are discussed.
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Affiliation(s)
- Cornelis H Hokke
- Parasite Glycobiology Group, Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands.
| | - Angela van Diepen
- Parasite Glycobiology Group, Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
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20
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Jiménez-Castells C, Vanbeselaere J, Kohlhuber S, Ruttkowski B, Joachim A, Paschinger K. Gender and developmental specific N-glycomes of the porcine parasite Oesophagostomum dentatum. Biochim Biophys Acta Gen Subj 2016; 1861:418-430. [PMID: 27751954 DOI: 10.1016/j.bbagen.2016.10.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 10/06/2016] [Accepted: 10/13/2016] [Indexed: 12/31/2022]
Abstract
BACKGROUND The porcine nodule worm Oesophagostomum dentatum is a strongylid class V nematode rather closely related to the model organism Caenorhabditis elegans. However, in contrast to the non-parasitic C. elegans, the parasitic O. dentatum is an obligate sexual organism, which makes both a gender and developmental glycomic comparison possible. METHODS Different enzymatic and chemical methods were used to release N-glycans from male and female O. dentatum as well as from L3 and L4 larvae. Glycans were analysed by MALDI-TOF MS after either 2D-HPLC (normal then reversed phase) or fused core RP-HPLC. RESULTS Whereas the L3 N-glycome was simpler and more dominated by phosphorylcholine-modified structures, the male and female worms express a wide range of core fucosylated N-glycans with up to three fucose residues. Seemingly, simple methylated paucimannosidic structures can be considered 'male', while methylation of fucosylated glycans was more pronounced in females. On the other hand, while many of the fucosylated paucimannosidic glycans are identical with examples from other nematode species, but simpler than the tetrafucosylated glycans of C. elegans, there is a wide range of phosphorylcholine-modified glycans with extended HexNAc2-4PC2-4 motifs not observed in our previous studies on other nematodes. CONCLUSION The interspecies tendency of class V nematodes to share most, but not all, N-glycans applies also to O. dentatum; furthermore, we establish, for the first time in a parasitic nematode, that glycomes vary upon development and sexual differentiation. GENERAL SIGNIFICANCE Unusual methylated, core fucosylated and phosphorylcholine-containing N-glycans vary between stages and genders in a parasitic nematode.
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Affiliation(s)
| | | | - Sonja Kohlhuber
- Department für Chemie, Universität für Bodenkultur, 1190 Wien, Austria
| | - Bärbel Ruttkowski
- Institut für Parasitologie, Department für Pathobiologie, Veterinärmedizinische Universität, A-1210 Wien, Austria
| | - Anja Joachim
- Institut für Parasitologie, Department für Pathobiologie, Veterinärmedizinische Universität, A-1210 Wien, Austria
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21
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Ahmed UK, Maller NC, Iqbal AJ, Al-Riyami L, Harnett W, Raynes JG. The Carbohydrate-linked Phosphorylcholine of the Parasitic Nematode Product ES-62 Modulates Complement Activation. J Biol Chem 2016; 291:11939-53. [PMID: 27044740 PMCID: PMC4882459 DOI: 10.1074/jbc.m115.702746] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Indexed: 12/04/2022] Open
Abstract
Parasitic nematodes manufacture various carbohydrate-linked phosphorylcholine (PCh)-containing molecules, including ES-62, a protein with an N-linked glycan terminally substituted with PCh. The PCh component is biologically important because it is required for immunomodulatory effects. We showed that most ES-62 was bound to a single protein, C-reactive protein (CRP), in normal human serum, displaying a calcium-dependent, high-avidity interaction and ability to form large complexes. Unexpectedly, CRP binding to ES-62 failed to efficiently activate complement as far as the C3 convertase stage in comparison with PCh-BSA and PCh-containing Streptococcus pneumoniae cell wall polysaccharide. C1q capture assays demonstrated an ES-62-CRP-C1q interaction in serum. The three ligands all activated C1 and generated C4b to similar extents. However, a C2a active site was not generated following ES-62 binding to CRP, demonstrating that C2 cleavage was far less efficient for ES-62-containing complexes. We proposed that failure of C2 cleavage was due to the flexible nature of carbohydrate-bound PCh and that reduced proximity of the C1 complex was the reason that C2 was poorly cleaved. This was confirmed using synthetic analogues that were similar to ES-62 only in respect of having a flexible PCh. Furthermore, ES-62 was shown to deplete early complement components, such as the rate-limiting C4, following CRP interaction and thereby inhibit classical pathway activation. Thus, flexible PCh-glycan represents a novel mechanism for subversion of complement activation. These data illustrate the importance of the rate-limiting C4/C2 stage of complement activation and reveal a new addition to the repertoire of ES-62 immunomodulatory mechanisms with possible therapeutic applications.
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Affiliation(s)
- Umul Kulthum Ahmed
- From the Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT and
| | - N Claire Maller
- From the Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT and
| | - Asif J Iqbal
- From the Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT and
| | - Lamyaa Al-Riyami
- the Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, United Kingdom
| | - William Harnett
- the Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, United Kingdom
| | - John G Raynes
- From the Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT and
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22
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Yan S, Wilson IBH, Paschinger K. Comparison of RP-HPLC modes to analyse the N-glycome of the free-living nematode Pristionchus pacificus. Electrophoresis 2016; 36:1314-29. [PMID: 25639343 DOI: 10.1002/elps.201400528] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 01/09/2015] [Accepted: 01/11/2015] [Indexed: 11/09/2022]
Abstract
Pristionchus pacificus is a free-living nematode increasingly used as an organism for comparison to the more familiar model Caenorhabditis elegans. In this study, we examined the N-glycans of this organism isolated after serial release with peptide:N-glycosidases F and A; after fluorescent labelling with 2-aminopyridine, chromatographic fractionation by three types of RP-HPLC (with either classical C18, fused core C18 or alkylamide-bonded phases) followed by mass spectrometric analyses revealed key features of its N-glycome. In addition to paucimannosidic and oligomannosidic glycans typical of invertebrates, N-glycans with two core fucose residues were detected. Furthermore, a range of glycans carrying up to three phosphorylcholine residues was observed whereas, unlike C. elegans, no tetrafucosylated N-glycans were detected. Structures with three fucose residues, unusual methylation of core α1,3-fucose or with galactosylated fucose motifs were found in low amounts; these features may correlate with a different ensemble or expression of glycosyltransferase genes as compared to C. elegans. From an analytical perspective, both the alkylamide RP-amide and fused core C18 columns, as compared to a classical C18 material, offer advantages in terms of resolution and of elution properties, as some minor pyridylamino-labelled glycans (e.g. those carrying phosphorylcholine) appear in earlier fractions and so potential losses of such structures due to insufficient gradient length can be avoided.
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Affiliation(s)
- Shi Yan
- Department für Chemie, Universität für Bodenkultur, Wien, Austria
| | - Iain B H Wilson
- Department für Chemie, Universität für Bodenkultur, Wien, Austria
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23
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Analysis of zwitterionic and anionic N-linked glycans from invertebrates and protists by mass spectrometry. Glycoconj J 2016; 33:273-83. [PMID: 26899268 PMCID: PMC4891362 DOI: 10.1007/s10719-016-9650-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 12/11/2015] [Accepted: 01/18/2016] [Indexed: 11/04/2022]
Abstract
Glycomic analyses over the years have revealed that non-vertebrate eukaryotes express oligosaccharides with inorganic and zwitterionic modifications which are either occurring in different contexts as compared to, or are absent from, mammals. Examples of anionic N-glycans (carrying sulphate or phosphate) are known from amoebae, fungi, molluscs and insects, while zwitterionic modifications by phosphorylcholine, phosphoethanolamine and aminoethylphosphonate occur on N-, O- and lipid-linked glycans from trichomonads, annelids, fungi, molluscs, insects, cestodes and nematodes. For detection of zwitterionic and anionic glycans, mass spectrometry has been a key method, but their ionic character affects the preparation and purification; therefore, as part of a glycomic strategy, the possibility of their presence must be considered in advance. On the other hand, their ionisation and fragmentation in positive and negative ion mode mass spectrometry as well as specific chemical or enzymatic treatments can prove diagnostic to their analysis. In our laboratory, we combine solid-phase extraction, reversed and normal phase HPLC, MALDI-TOF MS, exoglycosidase digests and hydrofluoric acid treatment to reveal N-glycans modified with anionic and zwitterionic moieties in a wide range of organisms. It is to be anticipated that, as more species are glycomically analysed, zwitterionic and anionic modifications of N-glycans will prove rather widespread. This knowledge is - in the longer term - then the basis for understanding the function of this cornucopia of glycan modifications.
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24
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Timm T, Grabitzki J, Severcan C, Muratoglu S, Ewald L, Yilmaz Y, Lochnit G. The PCome of Ascaris suum as a model system for intestinal nematodes: identification of phosphorylcholine-substituted proteins and first characterization of the PC-epitope structures. Parasitol Res 2016; 115:1263-74. [PMID: 26728072 DOI: 10.1007/s00436-015-4863-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 11/30/2015] [Indexed: 11/25/2022]
Abstract
In multicellular parasites (e.g., nematodes and protozoa), proteins and glycolipids have been found to be decorated with phosphorylcholine (PC). PC can provoke various effects on immune cells leading to an immunomodulation of the host's immune system. This immunomodulation allows long-term persistence but also prevents severe pathology due to downregulation of cellular immune responses. PC-containing antigens have been found to interfere with key proliferative signaling pathways in B and T cells, development of dendritic cells and macrophages, and mast cell degranulation. These effects contribute to the observed modulated cytokine levels and impairment of lymphocyte proliferation. In contrast to glycosphingolipids, little is known about the PC-epitopes of proteins. So far, only a limited number of PC-modified proteins from nematodes have been identified. In this project, PC-substituted proteins and glycolipids in Ascaris suum have been localized by immunohistochemistry in specific tissues of the body wall, intestine, and reproductive tract. Subsequently, we investigated the PCome of A. suum by 2D gel-based proteomics and detection by Western blotting using the PC-specific antibody TEPC-15. By peptide-mass-fingerprint matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), we could identify 59 PC-substituted proteins, which are in involved multiple cellular processes. In addition to membrane proteins like vitellogenin-6, we found proteins with structural (e.g., tubulins) and metabolic (e.g., pyruvate dehydrogenase) functions or which can act in the defense against the host's immune response (e.g., serpins). Initial characterization of the PC-epitopes revealed a predominant linkage of PC to the proteins via N-glycans. Our data form the basis for more detailed investigations of the PC-epitope structures as a prerequisite for comprehensive understanding of the molecular mechanisms of immunomodulation.
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Affiliation(s)
- Thomas Timm
- Protein Analytics, Institute of Biochemistry, Faculty of Medicine, Justus-Liebig University, Friedrichstrasse 24, 35392, Giessen, Germany
| | - Julia Grabitzki
- Protein Analytics, Institute of Biochemistry, Faculty of Medicine, Justus-Liebig University, Friedrichstrasse 24, 35392, Giessen, Germany
| | - Cinar Severcan
- Protein Analytics, Institute of Biochemistry, Faculty of Medicine, Justus-Liebig University, Friedrichstrasse 24, 35392, Giessen, Germany
| | - Suzan Muratoglu
- Protein Analytics, Institute of Biochemistry, Faculty of Medicine, Justus-Liebig University, Friedrichstrasse 24, 35392, Giessen, Germany
| | - Lisa Ewald
- Protein Analytics, Institute of Biochemistry, Faculty of Medicine, Justus-Liebig University, Friedrichstrasse 24, 35392, Giessen, Germany
| | - Yavuz Yilmaz
- Protein Analytics, Institute of Biochemistry, Faculty of Medicine, Justus-Liebig University, Friedrichstrasse 24, 35392, Giessen, Germany
| | - Guenter Lochnit
- Protein Analytics, Institute of Biochemistry, Faculty of Medicine, Justus-Liebig University, Friedrichstrasse 24, 35392, Giessen, Germany.
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25
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Wilson IBH, Paschinger K. Sweet secrets of a therapeutic worm: mass-spectrometric N-glycomic analysis of Trichuris suis. Anal Bioanal Chem 2015; 408:461-71. [PMID: 26650734 DOI: 10.1007/s00216-015-9154-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 10/23/2015] [Accepted: 10/27/2015] [Indexed: 01/15/2023]
Abstract
Trichuris suis, a nematode parasite of pigs, has attracted attention as its eggs have been administered to human patients as a potential therapy for inflammatory diseases. The immunomodulatory factors remain molecularly uncharacterised, but in vitro studies suggest that glycans on the parasite's excretory/secretory proteins may play a role. Using an off-line LC-MS approach in combination with chemical and enzymatic treatments, we have examined the N-linked oligosaccharides of T. suis. In addition to the paucimannosidic and oligomannosidic N-glycans typical of many invertebrates, a number of glycans carry N,N'-diacetyllactosamine (LacdiNAc) modified by fucose and/or phosphorylcholine. Such antennal epitopes are similar to ones previously associated with immunomodulation by helminths; here we propose phosphorylcholine modifications predominantly of terminal N-acetylgalactosamine but also of subterminal α1,3-fucosylated N-acetylglucosamine. Exact knowledge of the glycome of T. suis will facilitate more targeted studies on glycan receptors in the host as well as the engineering of cell lines to produce correctly glycosylated recombinant forms of candidate proteins for future studies on immunomodulation.
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Affiliation(s)
- Iain B H Wilson
- Department of Chemistry, Universität für Bodenkultur, Muthgasse 18, 1190, Wien, Austria.
| | - Katharina Paschinger
- Department of Chemistry, Universität für Bodenkultur, Muthgasse 18, 1190, Wien, Austria
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26
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Yan S, Brecker L, Jin C, Titz A, Dragosits M, Karlsson NG, Jantsch V, Wilson IBH, Paschinger K. Bisecting Galactose as a Feature of N-Glycans of Wild-type and Mutant Caenorhabditis elegans. Mol Cell Proteomics 2015; 14:2111-25. [PMID: 26002521 DOI: 10.1074/mcp.m115.049817] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Indexed: 01/15/2023] Open
Abstract
The N-glycosylation of the model nematode Caenorhabditis elegans has proven to be highly variable and rather complex; it is an example to contradict the existing impression that "simple" organisms possess also a rather simple glycomic capacity. In previous studies in a number of laboratories, N-glycans with up to four fucose residues have been detected. However, although the linkage of three fucose residues to the N,N'-diacetylchitobiosyl core has been proven by structural and enzymatic analyses, the nature of the fourth fucose has remained uncertain. By constructing a triple mutant with deletions in the three genes responsible for core fucosylation (fut-1, fut-6 and fut-8), we have produced a nematode strain lacking products of these enzymes, but still retaining maximally one fucose residue on its N-glycans. Using mass spectrometry and HPLC in conjunction with chemical and enzymatic treatments as well as NMR, we examined a set of α-mannosidase-resistant N-glycans. Within this glycomic subpool, we can reveal that the core β-mannose can be trisubstituted and so carries not only the ubiquitous α1,3- and α1,6-mannose residues, but also a "bisecting" β-galactose, which is substoichiometrically modified with fucose or methylfucose. In addition, the α1,3-mannose can also be α-galactosylated. Our data, showing the presence of novel N-glycan modifications, will enable more targeted studies to understand the biological functions and interactions of nematode glycans.
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Affiliation(s)
- Shi Yan
- From the ‡Department für Chemie, Universität für Bodenkultur, 1190 Wien, Austria
| | - Lothar Brecker
- §Institut für Organische Chemie, Universität Wien, 1090 Wien, Austria
| | - Chunsheng Jin
- ¶Institutionen för Biomedicin, Göteborgs universitet, 405 30 Göteborg, Sweden
| | - Alexander Titz
- From the ‡Department für Chemie, Universität für Bodenkultur, 1190 Wien, Austria
| | - Martin Dragosits
- From the ‡Department für Chemie, Universität für Bodenkultur, 1190 Wien, Austria
| | - Niclas G Karlsson
- ¶Institutionen för Biomedicin, Göteborgs universitet, 405 30 Göteborg, Sweden
| | - Verena Jantsch
- ‖Department für Chromosomenbiologie, Max F. Perutz Laboratories, Universität Wien, 1030 Wien, Austria
| | - Iain B H Wilson
- From the ‡Department für Chemie, Universität für Bodenkultur, 1190 Wien, Austria;
| | - Katharina Paschinger
- From the ‡Department für Chemie, Universität für Bodenkultur, 1190 Wien, Austria
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Timm T, Lenz C, Merkel D, Sadiffo C, Grabitzki J, Klein J, Lochnit G. Detection and site localization of phosphorylcholine-modified peptides by NanoLC-ESI-MS/MS using precursor ion scanning and multiple reaction monitoring experiments. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:460-471. [PMID: 25487775 DOI: 10.1007/s13361-014-1036-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 10/17/2014] [Accepted: 10/22/2014] [Indexed: 06/04/2023]
Abstract
Phosphorylcholine (PC)-modified biomolecules like lipopolysaccharides, glycosphingolipids, and (glyco)proteins are widespread, highly relevant antigens of parasites, since this small hapten shows potent immunomodulatory capacity, which allows the establishment of long-lasting infections of the host. Especially for PC-modified proteins, structural data is rare because of the zwitterionic nature of the PC substituent, resulting in low sensitivities and unusual but characteristic fragmentation patterns. We have developed a targeted mass spectrometric approach using hybrid triple quadrupole/linear ion trap (QTRAP) mass spectrometry coupled to nanoflow chromatography for the sensitive detection of PC-modified peptides from complex proteolytic digests, and the localization of the PC-modification within the peptide backbone. In a first step, proteolytic digests are screened using precursor ion scanning for the marker ions of choline (m/z 104.1) and phosphorylcholine (m/z 184.1) to establish the presence of PC-modified peptides. Potential PC-modified precursors are then subjected to a second analysis using multiple reaction monitoring (MRM)-triggered product ion spectra for the identification and site localization of the modified peptides. The approach was first established using synthetic PC-modified synthetic peptides and PC-modified model digests. Following the optimization of key parameters, we then successfully applied the method to the detection of PC-peptides in the background of a proteolytic digest of a whole proteome. This methodological invention will greatly facilitate the detection of PC-substituted biomolecules and their structural analysis.
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Affiliation(s)
- Thomas Timm
- Protein Analytics, Institute of Biochemistry, Faculty of Medicine, Justus-Liebig-University Giessen, 35392, Giessen, Germany
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28
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Pineda MA, Lumb F, Harnett MM, Harnett W. ES-62, a therapeutic anti-inflammatory agent evolved by the filarial nematode Acanthocheilonema viteae. Mol Biochem Parasitol 2014; 194:1-8. [PMID: 24671112 DOI: 10.1016/j.molbiopara.2014.03.003] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/07/2014] [Accepted: 03/12/2014] [Indexed: 01/29/2023]
Abstract
Filarial nematodes cause long-term infections in hundreds of millions of people. A significant proportion of those affected develop a number of debilitating health problems but, remarkably, such infections are often unnoticed for many years. It is well known that parasitic worms modulate, yet do not completely inhibit, host immunological pathways, promoting their survival by limiting effective immune mechanisms. Such immunoregulation largely depends on molecules released by the worms, termed excretory-secretory products (ES). One of these products is the molecule ES-62, which is actively secreted by the rodent filarial nematode Acanthocheilonema viteae. ES-62 has been shown to exert anti-inflammatory actions thorough its phosphorylcholine (PC)-containing moiety on a variety of cells of the immune system, affecting intracellular signalling pathways associated with antigen receptor- and TLR-dependent responses. We summarise here how ES-62 modulates key signal transduction elements and how such immunomodulation confers protection to mice subjected to certain experimental models of inflammatory disease. Finally, we discuss recent results showing that it is possible to synthetise small molecule analogues (SMAs) that mimic the anti-inflammatory properties of ES-62, opening an exciting new drug development field in translational medicine.
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Affiliation(s)
- Miguel A Pineda
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK
| | - Felicity Lumb
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0NR, UK
| | - Margaret M Harnett
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK
| | - William Harnett
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0NR, UK.
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29
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Roberts B, Antonopoulos A, Haslam SM, Dicker AJ, McNeilly TN, Johnston SL, Dell A, Knox DP, Britton C. Novel expression of Haemonchus contortus vaccine candidate aminopeptidase H11 using the free-living nematode Caenorhabditis elegans. Vet Res 2013; 44:111. [PMID: 24289031 PMCID: PMC4176091 DOI: 10.1186/1297-9716-44-111] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 11/19/2013] [Indexed: 11/28/2022] Open
Abstract
With the problem of parasitic nematode drug resistance increasing, vaccine development offers an alternative sustainable control approach. For some parasitic nematodes, native extracts enriched for specific proteins are highly protective. However, recombinant forms of these proteins have failed to replicate this protection. This is thought to be due to differences in glycosylation and/or conformation between native and recombinant proteins. We have exploited the free-living nematode Caenorhabditis elegans to examine its suitability as an alternative system for recombinant expression of parasitic nematode vaccine candidates. We focussed on Haemonchus contortus aminopeptidase H11 glycoprotein, which is enriched in a gut membrane fraction capable of inducing significant protection against this important ovine gastrointestinal nematode. We show that H. contortus H11 expressed in C. elegans is enzymatically active and MALDI mass spectrometry identifies similar di- and tri-fucosylated structures to those on native H11, with fucose at the 3- and/or 6-positions of the proximal GlcNAc. Some glycan structural differences were observed, such as lack of LDNF. Serum antibody to native H11 binds to C. elegans recombinant H11 and most of the antibody to rH11 or native H11 is directed to glycan moieties. Despite these similarities, no reduction in worm burden or faecal egg count was observed following immunisation of sheep with C. elegans-expressed recombinant H11 protein. The findings suggest that the di- and tri-fucosylated N-glycans expressed on rH11 do not contribute to the protective effect of H11 and that additional components present in native H11-enriched extract are likely required for enhancing the antibody response necessary for protection.
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Affiliation(s)
- Brett Roberts
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bearsden Road, Glasgow G61 1QH, UK.
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30
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Yan 闫石 S, Serna S, Reichardt NC, Paschinger K, Wilson IBH. Array-assisted characterization of a fucosyltransferase required for the biosynthesis of complex core modifications of nematode N-glycans. J Biol Chem 2013; 288:21015-21028. [PMID: 23754284 DOI: 10.1074/jbc.m113.479147] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Fucose is a common monosaccharide component of cell surfaces and is involved in many biological recognition events. Therefore, definition and exploitation of the specificity of the enzymes (fucosyltransferases) involved in fucosylation is a recurrent theme in modern glycosciences. Despite various studies, the specificities of many fucosyltransferases are still unknown, so new approaches are required to study these. The model nematode Caenorhabditis elegans expresses a wide range of fucosylated glycans, including N-linked oligosaccharides with unusual complex core modifications. Up to three fucose residues can be present on the standard N,N'-diacetylchitobiose unit of these N-glycans, but only the fucosyltransferases responsible for transfer of two of these (the core α1,3-fucosyltransferase FUT-1 and the core α1,6-fucosyltransferase FUT-8) were previously characterized. By use of a glycan library in both array and solution formats, we were able to reveal that FUT-6, another C. elegans α1,3-fucosyltransferase, modifies nematode glycan cores, specifically the distal N-acetylglucosamine residue; this result is in accordance with glycomic analysis of fut-6 mutant worms. This core-modifying activity of FUT-6 in vitro and in vivo is in addition to its previously determined ability to synthesize Lewis X epitopes in vitro. A larger scale synthesis of a nematode N-glycan core in vitro using all three fucosyltransferases was performed, and the nature of the glycosidic linkages was determined by NMR. FUT-6 is probably the first eukaryotic glycosyltransferase whose specificity has been redefined with the aid of glycan microarrays and so is a paradigm for the study of other unusual glycosidic linkages in model and parasitic organisms.
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Affiliation(s)
- Shi Yan 闫石
- From the Department für Chemie, Universität für Bodenkultur, A-1190 Wien, Austria and
| | - Sonia Serna
- the Biofunctional Nanomaterials Unit, CICbiomaGUNE, 20009 San Sebastian, Spain
| | | | - Katharina Paschinger
- From the Department für Chemie, Universität für Bodenkultur, A-1190 Wien, Austria and
| | - Iain B H Wilson
- From the Department für Chemie, Universität für Bodenkultur, A-1190 Wien, Austria and.
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31
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Schiller B, Hykollari A, Yan S, Paschinger K, Wilson IBH. Complicated N-linked glycans in simple organisms. Biol Chem 2013; 393:661-73. [PMID: 22944671 DOI: 10.1515/hsz-2012-0150] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 04/07/2012] [Indexed: 11/15/2022]
Abstract
Although countless genomes have now been sequenced, the glycomes of the vast majority of eukaryotes still present a series of unmapped frontiers. However, strides are being made in a few groups of invertebrate and unicellular organisms as regards their N-glycans and N-glycosylation pathways. Thereby, the traditional classification of glycan structures inevitably approaches its boundaries. Indeed, the glycomes of these organisms are rich in surprises, including a multitude of modifications of the core regions of N-glycans and unusual antennae. From the actually rather limited glycomic information we have, it is nevertheless obvious that the biotechnological, developmental and immunological relevance of these modifications, especially in insect cell lines, model organisms and parasites means that deciphering unusual glycomes is of more than just academic interest.
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Affiliation(s)
- Birgit Schiller
- Department für Chemie, Universität für Bodenkultur, A-1190 Wien, Austria
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32
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Microbial modulation of host immunity with the small molecule phosphorylcholine. Infect Immun 2012; 81:392-401. [PMID: 23230294 DOI: 10.1128/iai.01168-12] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
All microorganisms dependent on persistence in a host for survival rely on either hiding from or modulating host responses to infection. The small molecule phosphorylcholine, or choline phosphate (ChoP), is used for both of these purposes by a wide array of bacterial and parasitic microbes. While the mechanisms underlying ChoP acquisition and expression are diverse, a unifying theme is the use of ChoP to reduce the immune response to infection, creating an advantage for ChoP-expressing microorganisms. In this minireview, we discuss several benefits of ChoP expression during infection as well as how the immune system fights back against ChoP-expressing pathogens.
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Talabnin K, Aoki K, Saichua P, Wongkham S, Kaewkes S, Boons GJ, Sripa B, Tiemeyer M. Stage-specific expression and antigenicity of glycoprotein glycans isolated from the human liver fluke, Opisthorchis viverrini. Int J Parasitol 2012; 43:37-50. [PMID: 23174105 DOI: 10.1016/j.ijpara.2012.10.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 09/16/2012] [Accepted: 10/15/2012] [Indexed: 10/27/2022]
Abstract
Infection by Opisthorchis viverrini (liver fluke) is a major public health problem in southeastern Asia, resulting in hepatobiliary disease and cholangiocarcinoma. Fluke surface glycoconjugates are prominently presented to the host, thereby constituting a crucial immunological interface that can determine the parasite's success in establishing infection. Therefore, N- and O-linked glycoprotein glycan profiles of the infective metacercarial stage and of the mature adult were investigated by nanospray ionisation-linear ion trap mass spectrometry (NSI-MS(n)). Glycan immunogenicity was investigated by immunoblotting with serum from infected humans. Metacercariae and adult parasites exhibit similar glycan diversity, although the prevalence of individual glycans and glycan classes varies by stage. The N-glycans of the metacercaria are mostly high mannose and monofucosylated, truncated-type oligosaccharides (62.7%), with the remainder processed to complex and hybrid type glycans (37.3%). The N-linked glycan profile of the adult is also dominated by high mannose and monofucosylated, truncated-type oligosaccharides (80.0%), with a smaller contribution from complex and hybrid type glycans (20.0%). At both stages, complex and hybrid type glycans are detected as mono-, bi-, tri-, or tetra-antennary structures. In metacercariae and adults, O-linked glycans are detected as mono- to pentasaccharides. The mucin type core 1 structure, Galβ1-3GalNAc, predominates in both stages but is less prevalent in the adult than in the metacercaria. Immunogenic recognition of liver fluke glycoproteins is reduced after deglycosylation but infected human serum was unable to recognise glycans released from peptides. Therefore, the most potent liver fluke antigenic epitopes are mixed determinants, comprised of glycan and polypeptide elements.
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34
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Yan S, Bleuler-Martinez S, Plaza DF, Künzler M, Aebi M, Joachim A, Razzazi-Fazeli E, Jantsch V, Geyer R, Wilson IBH, Paschinger K. Galactosylated fucose epitopes in nematodes: increased expression in a Caenorhabditis mutant associated with altered lectin sensitivity and occurrence in parasitic species. J Biol Chem 2012; 287:28276-90. [PMID: 22733825 DOI: 10.1074/jbc.m112.353128] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The modification of α1,6-linked fucose residues attached to the proximal (reducing-terminal) core N-acetylglucosamine residue of N-glycans by β1,4-linked galactose ("GalFuc" epitope) is a feature of a number of invertebrate species including the model nematode Caenorhabditis elegans. A pre-requisite for both core α1,6-fucosylation and β1,4-galactosylation is the presence of a nonreducing terminal N-acetylglucosamine; however, this residue is normally absent from the final glycan structure in invertebrates due to the action of specific hexosaminidases. Previously, we have identified two hexosaminidases (HEX-2 and HEX-3) in C. elegans, which process N-glycans. In the present study, we have prepared a hex-2;hex-3 double mutant, which possesses a radically altered N-glycomic profile. Whereas in the double mutant core α1,3-fucosylation of the proximal N-acetylglucosamine was abolished, the degree of galactosylation of core α1,6-fucose increased, and a novel Galα1,2Fucα1,3 moiety attached to the distal core N-acetylglucosamine residue was detected. Both galactosylated fucose moieties were also found in two parasitic nematodes, Ascaris suum and Oesophagostomum dentatum. As core modifications of N-glycans are known targets for fungal nematotoxic lectins, the sensitivity of the C. elegans double hexosaminidase mutant was assessed. Although this mutant displayed hypersensitivity to the GalFuc-binding lectin CGL2 and the N-acetylglucosamine-binding lectin XCL, the mutant was resistant to CCL2, which binds core α1,3-fucose. Thus, the use of C. elegans mutants aids the identification of novel N-glycan modifications and the definition of in vivo specificities of nematotoxic lectins with potential as anthelmintic agents.
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Affiliation(s)
- Shi Yan
- Department für Chemie, Universität für Bodenkultur, A-1190 Wien, Austria
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Harnett W, Rzepecka J, Houston KM. How do nematodes transfer phosphorylcholine to carbohydrates? Trends Parasitol 2010; 26:114-8. [DOI: 10.1016/j.pt.2009.12.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 11/25/2009] [Accepted: 12/14/2009] [Indexed: 10/19/2022]
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Grabitzki J, Lochnit G. Immunomodulation by phosphocholine--biosynthesis, structures and immunological implications of parasitic PC-epitopes. Mol Immunol 2009; 47:149-63. [PMID: 19864025 DOI: 10.1016/j.molimm.2009.09.035] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Accepted: 09/24/2009] [Indexed: 11/28/2022]
Abstract
Phosphocholine (PC) as a small haptenic molecule present on antigens of parasites can provoke various effects on immune cells leading to immunomodulation of the host's immune system. This immunomodulation not only allows long-term persistence but also prevents severe pathology due to down-regulation of cellular immune responses. Additionally, PC plays an important role for development and fertility of the parasites. To fully understand the mechanisms of immunomodulation the detailed knowledge of the biosynthesis of the PC-epitopes, their molecular structure and biological function has to be elucidated. The implication of parasite-specific transferases in the biosynthesis of the PC-epitopes and the sensitivity of parasites towards disruption of the choline metabolism offers new perspectives for the development of anti-parasitic drugs and therapies. Furthermore, the immunomodulation provoked by PC-epitopes preventing inflammatory reactions may be useful in the treatment of inflammatory diseases. This review summarizes the current knowledge on the biosynthesis of PC-epitopes, their structures and immunological implications.
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Affiliation(s)
- Julia Grabitzki
- Institute of Biochemistry, Faculty of Medicine, University of Giessen, Germany
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van Die I, Cummings RD. Glycan gimmickry by parasitic helminths: a strategy for modulating the host immune response? Glycobiology 2009; 20:2-12. [PMID: 19748975 DOI: 10.1093/glycob/cwp140] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Parasitic helminths (worms) co-evolved with vertebrate immune systems to enable long-term survival of worms in infected hosts. Among their survival strategies, worms use their glycans within glycoproteins and glycolipids, which are abundant on helminth surfaces and in their excretory/ secretory products, to regulate and suppress host immune responses. Many helminths express unusual and antigenic (nonhost-like) glycans, including those containing polyfucose, tyvelose, terminal GalNAc, phosphorylcholine, methyl groups, and sugars in unusual linkages. In addition, some glycan antigens are expressed that share structural features with those in their intermediate and vertebrate hosts (host-like glycans), including Le(X) (Galbeta1-4[Fucalpha1-3]GlcNAc-), LDNF (GalNAcbeta1-4[Fucalpha1-3]GlcNAc-), LDN (GalNAcbeta1-4GlcNAc-), and Tn (GalNAcalpha1-O-Thr/Ser) antigens. The expression of host-like glycan determinants is remarkable and suggests that helminths may gain advantages by synthesizing such glycans. The expression of host-like glycans by parasites previously led to the concept of "molecular mimicry," in which molecules are either derived from the pathogen or acquired from the host to evade recognition by the host immune system. However, recent discoveries into the potential of host glycan-binding proteins (GBPs), such as C-type lectin receptors and galectins, to functionally interact with various host-like helminth glycans provide new insights. Host GBPs through their interactions with worm-derived glycans participate in shaping innate and adaptive immune responses upon infection. We thus propose an alternative concept termed "glycan gimmickry," which is defined as an active strategy of parasites to use their glycans to target GBPs within the host to promote their survival.
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Affiliation(s)
- Irma van Die
- Department of Molecular Cell Biology & Immunology, VU University Center, Amsterdam, The Netherlands.
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38
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Li X, Cowles EA, Cowles RS, Gaugler R, Cox-Foster DL. Characterization of immunosuppressive surface coat proteins from Steinernema glaseri that selectively kill blood cells in susceptible hosts. Mol Biochem Parasitol 2009; 165:162-9. [PMID: 19428663 DOI: 10.1016/j.molbiopara.2009.02.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Revised: 01/05/2009] [Accepted: 02/01/2009] [Indexed: 11/30/2022]
Abstract
Surface coat proteins (SCPs) of entomopathogenic nematodes are implicated in the suppression/evasion of host immune responses, which is required for successful host colonization. Steinernema glaseri NC strain SCPs suppressed immune responses in oriental beetle larvae (Exomala orientalis), a susceptible host for S. glaseri, in a dosage-dependent manner, thus protecting Heterorhabditis bacteriophora from being killed in the same host. Melanization of H. bacteriophora decreased from 92+/-5% in the untreated check to 1+/-3% when protected by injection of 230ng of S. glaseri SCPs. As the SCPs dosage increased, freely moving H. bacteriophora increased from 3+/-4% in the untreated group to 57+/-15% with an SCPs dose of 940ng. At 2h and in the absence of SCPs, 8% and 11% of hemocytes of E. orientalis were stained by propidium iodide and Hoechst, respectively. When exposed to 300ng/microl SCPs, 70% and 96% were stained, respectively. At 6h, propidium iodide stained 37% and 92% of the hemocytes without and with SCPs, respectively. In contrast, more than 90% of the cells were stained by Hoechst with or without SCPs. As native proteins, two isolated S. glaseri SCPs had an immunosuppressive effect; they were each composed of 38kDa (PI=4.6) and 56kDa (PI=3.6) subunits. SCP peptides were sequenced using LC-MS/MS and the mass fingerprints obtained with MALDI-TOF-MS; there were no significant matches found in peptide databases, which suggests that the SCPs studied are novel proteins. Twelve cDNA sequences were derived based on short peptides and 7 of them had no significant match against the Caenorhabditis elegans protein database. One of the cDNA matched an unknown C. elegans protein and the remaining 4 cDNAs matched proteins of C. elegans and Brugia malayi.
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Affiliation(s)
- Xinyi Li
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA
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Schachter H. The functions of paucimannose N-glycans in Caenorhabditis elegans. TRENDS GLYCOSCI GLYC 2009. [DOI: 10.4052/tigg.21.131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
SUMMARYInfection with parasitic helminths takes a heavy toll on the health and well-being of humans and their domestic livestock, concomitantly resulting in major economic losses. Analyses have consistently revealed bioactive molecules in extracts of helminths or in their excretory/secretory products that modulate the immune response of the host. It is our view that parasitic helminths are an untapped source of immunomodulatory substances that, in pure form, could become new drugs (or models for drug design) to treat disease. Here, we illustrate the range of immunomodulatory molecules in selected parasitic trematodes, cestodes and nematodes, their impact on the immune cells in the host and how the host may recognize these molecules. There are many examples of the partial characterization of helminth-derived immunomodulatory molecules, but these have not yet translated into new drugs, reflecting the difficulty of isolating and fully characterizing proteins, glycoproteins and lipid-based molecules from small amounts of parasite material. However, this should not deter the investigator, since analytical techniques are now being used to accrue considerable structural information on parasite-derived molecules, even when only minute quantities of tissue are available. With the introduction of methodologies to purify and structurally-characterize molecules from small amounts of tissue and the application of high throughput immunological assays, one would predict that an assessment of parasitic helminths will yield a variety of novel drug candidates in the coming years.
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Grabitzki J, Ahrend M, Schachter H, Geyer R, Lochnit G. The PCome of Caenorhabditis elegans as a prototypic model system for parasitic nematodes: Identification of phosphorylcholine-substituted proteins. Mol Biochem Parasitol 2008; 161:101-11. [DOI: 10.1016/j.molbiopara.2008.06.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Revised: 06/13/2008] [Accepted: 06/16/2008] [Indexed: 11/16/2022]
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Gene inactivation confirms the identity of enzymes involved in nematode phosphorylcholine-N-glycan synthesis. Mol Biochem Parasitol 2008; 157:88-91. [DOI: 10.1016/j.molbiopara.2007.08.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Revised: 08/27/2007] [Accepted: 08/28/2007] [Indexed: 11/30/2022]
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Paschinger K, Gutternigg M, Rendić D, Wilson IBH. The N-glycosylation pattern of Caenorhabditis elegans. Carbohydr Res 2007; 343:2041-9. [PMID: 18226806 DOI: 10.1016/j.carres.2007.12.018] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 12/07/2007] [Accepted: 12/17/2007] [Indexed: 01/21/2023]
Abstract
Determining the exact nature of N-glycosylation in Caenorhabditis elegans, a nematode worm and genetic model organism, has proved to have been an unexpected challenge in recent years; a wide range of modifications of its N-linked oligosaccharides have been proposed on the basis of structural and genomic analysis. Particularly mass spectrometric studies by a number of groups, as well as the characterisation of recombinant enzymes, have highlighted those aspects of N-glycosylation that are conserved in animals, those which are seemingly unique to this species and those which are shared with parasitic nematodes. These data, of importance for therapeutic developments, are reviewed.
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Affiliation(s)
- Katharina Paschinger
- Department für Chemie, Universität für Bodenkultur, Muthgasse 18, A-1190 Wien, Austria.
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Hall AJ, Quinnell RJ, Raiko A, Lagog M, Siba P, Morroll S, Falcone FH. Chitotriosidase deficiency is not associated with human hookworm infection in a Papua New Guinean population. INFECTION GENETICS AND EVOLUTION 2007; 7:743-7. [PMID: 17765019 PMCID: PMC2080692 DOI: 10.1016/j.meegid.2007.07.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 06/27/2007] [Accepted: 07/23/2007] [Indexed: 11/23/2022]
Abstract
Human chitotriosidase (CHIT1) is a chitinolytic enzyme with suggested anti-fungal properties. Previous studies have suggested that chitotriosidase may also protect individuals against filarial nematode infections and malaria. A mutant allele, which renders chitotriosidase unstable and enzymatically inactive, is found at a frequency of >20% in Caucasians and other populations. This allele is found at much lower frequency in parts of West Africa where malarial and intestinal helminth infections are endemic. Here, we investigate whether there is a significant association between chitotriosidase genotype and the intensity of hookworm infection in 693 individuals from five villages in Papua New Guinea. Individuals were genotyped for chitotriosidase using a PCR-based assay. There was no association between CHIT1 genotype and the intensity of hookworm infection as determined by faecal egg counts. The frequency of the mutant allele was 0.251, very similar to that found in non-endemic countries. The extent of geographical variation in allele frequencies across worldwide populations was not high (F(st)=0.11), and does not provide evidence for directional selection at this locus between different geographical areas. We conclude that the CHIT1 genotype does not play a crucial role in protection against hookworm infection. This does not correlate with a previous study that linked the mutant CHIT1 genotype to filariasis susceptibility. The possible reasons for this discrepancy are discussed.
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Affiliation(s)
- Andrew J. Hall
- Immune Modulation Research Group, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Rupert J. Quinnell
- Institute of Integrative and Comparative Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Andrew Raiko
- Papua New Guinea Institute of Medical Research, PO Box 60, Goroka EHP 441, Papua New Guinea
| | - Moses Lagog
- Papua New Guinea Institute of Medical Research, PO Box 60, Goroka EHP 441, Papua New Guinea
| | - Peter Siba
- Papua New Guinea Institute of Medical Research, PO Box 60, Goroka EHP 441, Papua New Guinea
| | - Shaun Morroll
- Immune Modulation Research Group, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Franco H. Falcone
- Immune Modulation Research Group, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Corresponding author. Tel.: +44 115 84 66073; fax: +44 115 95 15102.
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Gutternigg M, Kretschmer-Lubich D, Paschinger K, Rendić D, Hader J, Geier P, Ranftl R, Jantsch V, Lochnit G, Wilson IBH. Biosynthesis of truncated N-linked oligosaccharides results from non-orthologous hexosaminidase-mediated mechanisms in nematodes, plants, and insects. J Biol Chem 2007; 282:27825-40. [PMID: 17636254 PMCID: PMC2850174 DOI: 10.1074/jbc.m704235200] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
In many invertebrates and plants, the N-glycosylation profile is dominated by truncated paucimannosidic N-glycans, i.e. glycans consisting of a simple trimannosylchitobiosyl core often modified by core fucose residues. Even though they lack antennal N-acetylglucosamine residues, the biosynthesis of these glycans requires the sequential action of GlcNAc transferase I, Golgi mannosidase II, and, finally, beta-N-acetylglucosaminidases. In Drosophila, the recently characterized enzyme encoded by the fused lobes (fdl) gene specifically removes the non-reducing N-acetylglucosamine residue from the alpha1,3-antenna of N-glycans. In the present study, we examined the products of five beta-N-acetylhexosaminidase genes from Caenorhabditis elegans (hex-1 to hex-5, corresponding to reading frames T14F9.3, C14C11.3, Y39A1C.4, Y51F10.5, and Y70D2A.2) in addition to three from Arabidopsis thaliana (AtHEX1, AtHEX2, and AtHEX3, corresponding to reading frames At1g65590, At3g55260, and At1g05590). Based on homology, the Caenorhabditis HEX-1 and all three Arabidopsis enzymes are members of the same sub-family as the aforementioned Drosophila fused lobes enzyme but either act as chitotriosidases or non-specifically remove N-acetylglucosamine from both N-glycan antennae. The other four Caenorhabditis enzymes are members of a distinct sub-family; nevertheless, two of these enzymes displayed the same alpha1,3-antennal specificity as the fused lobes enzyme. Furthermore, a deletion of part of the Caenorhabditis hex-2 gene drastically reduces the native N-glycan-specific hexosaminidase activity in mutant worm extracts and results in a shift in the N-glycan profile, which is a demonstration of its in vivo enzymatic relevance. Based on these data, it is hypothesized that the genetic origin of paucimannosidic glycans in nematodes, plants, and insects involves highly divergent members of the same hexosaminidase gene family.
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Affiliation(s)
- Martin Gutternigg
- Department für Chemie, Universität für Bodenkultur, Muthgasse 18, A-1190 Wien, Austria
| | | | - Katharina Paschinger
- Department für Chemie, Universität für Bodenkultur, Muthgasse 18, A-1190 Wien, Austria
| | - Dubravko Rendić
- Department für Chemie, Universität für Bodenkultur, Muthgasse 18, A-1190 Wien, Austria
| | - Josef Hader
- Department für Chemie, Universität für Bodenkultur, Muthgasse 18, A-1190 Wien, Austria
| | - Petra Geier
- Department für Chemie, Universität für Bodenkultur, Muthgasse 18, A-1190 Wien, Austria
| | - Ramona Ranftl
- Department für Chemie, Universität für Bodenkultur, Muthgasse 18, A-1190 Wien, Austria
| | - Verena Jantsch
- Abteilung für Chromosomenbiologie, Vienna Biocenter II, A-1030 Wien, Austria
| | - Günter Lochnit
- Institut für Biochemie, Justus-Liebig-Universität, D-35292 Gießen, Germany
| | - Iain B. H. Wilson
- Department für Chemie, Universität für Bodenkultur, Muthgasse 18, A-1190 Wien, Austria
- To whom correspondence should be addressed: ; Tel: +43-1-36006-6541; Fax: +43-1-36006-6076
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Pöltl G, Kerner D, Paschinger K, Wilson IBH. N-glycans of the porcine nematode parasite Ascaris suum are modified with phosphorylcholine and core fucose residues. FEBS J 2006; 274:714-26. [PMID: 17181538 PMCID: PMC2850173 DOI: 10.1111/j.1742-4658.2006.05615.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
In recent years, the glycoconjugates of many parasitic nematodes have attracted interest due to their immunogenic and immunomodulatory nature. Previous studies with the porcine roundworm parasite Ascaris suum have focused on its glycosphingolipids, which were found, in part, to be modified by phosphorylcholine. Using mass spectrometry and western blotting, we have now analyzed the peptide N-glycosidase A-released N-glycans of adults of this species. The presence of hybrid bi- and triantennary N-glycans, some modified by core alpha1,6-fucose and peripheral phosphorylcholine, was demonstrated by LC/electrospray ionization (ESI)-Q-TOF-MS/MS, as was the presence of paucimannosidic N-glycans, some of which carry core alpha1,3-fucose, and oligomannosidic oligosaccharides. Western blotting verified the presence of protein-bound phosphorylcholine and core alpha1,3-fucose, whereas glycosyltransferase assays showed the presence of core alpha1,6-fucosyltransferase and Lewis-type alpha1,3-fucosyltransferase activities. Although, the unusual tri- and tetrafucosylated glycans found in the model nematode Caenorhabditis elegans were not found, the vast majority of the N-glycans found in A. suum represent a subset of those found in C. elegans; thus, our data demonstrate that the latter is an interesting glycobiological model for parasitic nematodes.
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Lochnit G, Grabitzki J, Henkel B, Tavernarakis N, Geyer R. First identification of a phosphorylcholine-substituted protein from Caenorhabditis elegans: isolation and characterization of the aspartyl protease ASP-6. Biol Chem 2006; 387:1487-93. [PMID: 17081123 DOI: 10.1515/bc.2006.186] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Caenorhabditis elegans is a widely accepted model system for parasitic nematodes, drug screening and developmental studies. Similar to parasitic worms, C. elegans expresses glycosphingolipids and glycoproteins carrying, in part, phosphorylcholine (PCho) substitutions, which might play important roles in nematode development, fertility and, at least in the case of parasites, survival within the host. With the exception of a major secretory/excretory product from Acanthocheilonema viteae (ES-62), no protein carrying this epitope has been studied in detail yet. Here we report on the identification, characterization and localization of the aspartyl protease ASP-6 of C. elegans, which is excreted by the nematode in a PCho-substituted form. Within the worm, most prominent expression of the protein is observed in the intestine, while muscle and epithelial cells express asp-6 to a lesser extent. In animals harboring an ASP-6::GFP fusion protein, diffuse fluorescence throughout the body cavity of adult worms indicates that the chimeric protein is secreted.
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Affiliation(s)
- Günter Lochnit
- Institute of Biochemistry, Faculty of Medicine, Justus-Liebig-University, Friedrichstrasse 24, D-35392 Giessen, Germany
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Harvey DJ. Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update covering the period 1999-2000. MASS SPECTROMETRY REVIEWS 2006; 25:595-662. [PMID: 16642463 DOI: 10.1002/mas.20080] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
This review describes the use of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry for the analysis of carbohydrates and glycoconjugates and continues coverage of the field from the previous review published in 1999 (D. J. Harvey, Matrix-assisted laser desorption/ionization mass spectrometry of carbohydrates, 1999, Mass Spectrom Rev, 18:349-451) for the period 1999-2000. As MALDI mass spectrometry is acquiring the status of a mature technique in this field, there has been a greater emphasis on applications rather than to method development as opposed to the previous review. The present review covers applications to plant-derived carbohydrates, N- and O-linked glycans from glycoproteins, glycated proteins, mucins, glycosaminoglycans, bacterial glycolipids, glycosphingolipids, glycoglycerolipids and related compounds, and glycosides. Applications of MALDI mass spectrometry to the study of enzymes acting on carbohydrates (glycosyltransferases and glycosidases) and to the synthesis of carbohydrates, are also covered.
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Affiliation(s)
- David J Harvey
- Department of Biochemistry, Oxford Glycobiology Institute, University of Oxford, Oxford OX1 3QU, United Kingdom.
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Cipollo JF, Awad AM, Costello CE, Hirschberg CB. N-Glycans of Caenorhabditis elegans Are Specific to Developmental Stages. J Biol Chem 2005; 280:26063-72. [PMID: 15899899 DOI: 10.1074/jbc.m503828200] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have examined the N-glycans present during the developmental stages of Caenorhabditis elegans using two approaches, 1) a combination of permethylation followed by MALDI-TOF mass spectrometry (MS) and 2) derivatization with 2-aminobenzamide followed by separation by high-performance liquid chromatography and analyses by MALDI-TOF MS, post source decay (PSD) MS, and MALDI-QoTOF MS/MS. The N-glycan profile of each developmental stage (Larva 1, Larva 2, Larva 3, Larva 4, and Dauer and adult) appears to be unique. The pattern of complex N-glycans was stage-specific with the general trend of number and abundance of glycans being Dauer approximately = L1 > adult approximately = L4 > L3 approximately = L2. Dauer larvae contained complex N-glycans with higher molecular masses than those seen in other stages. MALDI-QoTOF MS/MS of Hex4HexNAc4 showed an N-acetyllac-tosamine substitution not previously observed in C. elegans. Phosphorylcholine (Pc)-substituted glycans were also found to be stage-specific. Higher molecular weight Pc-containing glycans, including fucose-containing ones such as difucosyl Pc-glycan (Pc1dHex2Hex5HexNAc6) seen in Dauer larvae, have not been observed in any organism. Pc2Hex4HexNAc3, from Dauer larvae, when subjected to PSD MS analyses, showed Pc may substitute both core and terminally linked GlcNAc; no such structure has previously been reported in any organism. C. elegans-specific fucosyl and native methylated glycans were found in all developmental stages. Taken together, the above results demonstrate that in-depth investigation of the role of the above N-glycans during C. elegans development should lead to a better understanding of their significance and the ways that they may govern interactions, both within the organism during development and between the mobile nematode and its pathogens.
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Affiliation(s)
- John F Cipollo
- Department of Molecular and Cell Biology, Boston University, Goldman School of Dental Medicine, Massachusetts 02118, USA
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50
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Lochnit G, Bongaarts R, Geyer R. Searching new targets for anthelminthic strategies: Interference with glycosphingolipid biosynthesis and phosphorylcholine metabolism affects development of Caenorhabditis elegans. Int J Parasitol 2005; 35:911-23. [PMID: 15885697 DOI: 10.1016/j.ijpara.2005.02.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2004] [Revised: 02/07/2005] [Accepted: 02/22/2005] [Indexed: 11/17/2022]
Abstract
Nematode infections are amongst the most abundant diseases of man and animals. They are characterised by a low mortality but high morbidity, thus reflecting the adaptation of these parasites to their hosts. Resistance as well as severe side-effects and efficacies restricted to distinct larval stages or parasites of the anthelmithics used at present require the urgent development of new and more nematode-specific drugs, targeting enzymes of parasite restricted biosynthetic routes. Caenorhabditis elegans has been found to be a good model system for parasitic nematodes, drug screening and developmental studies. Structural analyses have revealed nematode-specific glycosphingolipid structures of the arthro-series, carrying in part, phosphorylcholine substituents. These biomolecules appear to play important roles in nematode development, fertility and survival within the host and are, therefore, good target-candidates for the development of new anthelminthic strategies. Here we show that RNAi experiments targeting enzymes of glycosphingolipid biosynthesis or choline metabolism result, in part, in a drastic reduction of fertility. We further tested various chemical inhibitors of these pathways and found significant effects on the development of the worms, resulting in developmental arrest, sterility and, in part, lethality. Such inhibitors can, therefore, help to define new classes of anthelminthics.
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Affiliation(s)
- Günter Lochnit
- Faculty of Medicine, Institute of Biochemistry, University of Giessen, Friedrichstrasse 24, D-35392 Giessen, Germany.
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