title: Cystic fibrosis and bacterial colonization define the sputum N-glycosylation phenotype.
abstract: Although mucin O-glycosylation of sputum from individuals suffering from cystic fibrosis (CF) is known to be altered relative to their unaffected counterparts, protein N-glycosylation of CF sputum remains structurally and functionally under-characterized. We report the first N-glycome of soluble proteins in sputum derived from five CF patients, two pathogen-free and two pathogen-infected/colonized non-CF individuals suffering from other pulmonary conditions. N-Glycans were profiled using porous graphitized carbon-liquid chromatography-negative ion-tandem mass spectrometry following enzymatic release from sputum proteins. The composition, topology and linkage isomers of 68 N-glycans were characterized and relatively quantified. Recurring structural features in all sputum N-glycomes were terminal α2,6-sialylation, α1,6-core fucosylation, β1,4-bisecting GlcNAcylation and compositions indicating paucimannosylation. Despite covering different genotypes, age, gender and microbial flora, the sputum N-glycomes showed little interpatient and longitudinal variation within CF patients. Comparative N-glycome analysis between inter-patient group revealed that lung infection/colonization, in general, extensively enriches the CF sputum N-glycosylation phenotype with paucimannose with simultaneous over-sialylation/fucosylation and under-bisecting GlcNAcylation of complex/hybrid N-glycans. In contrast, the sputum from CF patients had only slightly increased abundance of paucimannose N-glycans relative to pathogen-infected/colonized non-CF individuals. Similar to mucin O-glycosylation, protein N-glycosylation appears to be regulated primarily as a secondary effect of bacterial infection and inflammation rather than the CF pathogenesis in sputum. This study provides new structural N-glycan information to help understand the complex cellular and molecular environment of the CF affected respiratory tract.
authors.affiliation: Biomolecular Frontiers Research Centre, Department of Chemistry and Biomolecular Sciences, Macquarie University, North Ryde, Sydney 2109, Australia.
authors.forename: Vignesh
authors.initials: V
authors.lastname: Venkatakrishnan
authors.affiliation: Biomolecular Frontiers Research Centre, Department of Chemistry and Biomolecular Sciences, Macquarie University, North Ryde, Sydney 2109, Australia.
authors.forename: Morten
authors.initials: M
authors.lastname: Thaysen-Andersen
authors.affiliation: Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR-Pathology West, Westmead Hospital, Sydney 2006, Australia.
authors.forename: Sharon C A
authors.initials: SC
authors.lastname: Chen
authors.affiliation: Biomolecular Frontiers Research Centre, Department of Chemistry and Biomolecular Sciences, Macquarie University, North Ryde, Sydney 2109, Australia.
authors.forename: Helena
authors.initials: H
authors.lastname: Nevalainen
authors.affiliation: Biomolecular Frontiers Research Centre, Department of Chemistry and Biomolecular Sciences, Macquarie University, North Ryde, Sydney 2109, Australia nicki.packer@mq.edu.au.
authors.forename: Nicolle H
authors.initials: NH
authors.lastname: Packer
mesh_terms: D000117:Acetylglucosamine / Q000737:chemistry / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001232:Aspergillus fumigatus / Q000737:chemistry / Q000187:drug effects / Q000254:growth & development*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D003550:Cystic Fibrosis / Q000188:drug therapy / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D005260:Female; D005643:Fucose / Q000737:chemistry / Q000378:metabolism; D054794:Glycomics; D006031:Glycosylation; D054884:Host-Pathogen Interactions; D006801:Humans; D008297:Male; D008358:Mannose / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D009077:Mucins / Q000737:chemistry / Q000378:metabolism; D010641:Phenotype; D011134:Polysaccharides / Q000737:chemistry* / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000737:chemistry / Q000187:drug effects / Q000254:growth & development*; D012471:Salivary Proteins and Peptides / Q000737:chemistry / Q000378:metabolism; D012794:Sialic Acids / Q000737:chemistry / Q000378:metabolism; D013183:Sputum / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000737:chemistry / Q000187:drug effects / Q000254:growth & development*
chemical_list: D000900:Anti-Bacterial Agents; D009077:Mucins; D011134:Polysaccharides; D012471:Salivary Proteins and Peptides; D012794:Sialic Acids; D005643:Fucose; D008358:Mannose; D000117:Acetylglucosamine
keywords: N-glycans; bacterial colonization; cystic fibrosis; paucimannose; sputum