Structural characterization of glycans on omega-1, a major Schistosoma mansoni egg glycoprotein that drives Th2 responses.
Soluble egg antigens (SEA) of the human parasite Schistosoma mansoni are among the strongest natural stimuli of Th2 responses. Omega-1, a major glycoprotein in SEA, initiates these characteristic Th2 responses through conditioning of dendritic cells (DCs). In view of the reported immunomodulatory potential of SEA glycans, we have investigated omega-1 glycosylation, using an approach combining mass spectrometric techniques and enzyme treatments at the glycopeptide level. We demonstrate that omega-1 has two fully occupied N-glycosylation sites, each mainly carrying core-difucosylated diantennary glycans with one or more Lewis X motifs in the antennae. Using a specific approach of nanoscale LC-MS(/MS) and MALDI-TOF(/TOF) MS in combination with exoglycosidase treatments of tryptic glycopeptides, we were able to provide a detailed, site-specific glycosylation analysis of a single, native S. mansoni glycoprotein. The obtained knowledge of the glycans present on omega-1 contributes to a full understanding of the mode of action of this immunomodulatory glycoprotein.
Meevissen
Moniek H J
MH
Department of Parasitology, Leiden University Medical Centre, 2333 ZA Leiden, The Netherlands.
Wuhrer
Manfred
M
Doenhoff
Michael J
MJ
Schramm
Gabriele
G
Haas
Helmut
H
Deelder
André M
AM
Hokke
Cornelis H
CH
D000818:Animals; D000947:Antigens, Helminth / Q000737:chemistry* / Q000276:immunology; D004527:Egg Proteins / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D006023:Glycoproteins / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D006031:Glycosylation; D056724:Immunity, Humoral / Q000187:drug effects; D010446:Peptide Fragments / Q000032:analysis / Q000378:metabolism; D011134:Polysaccharides / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D012550:Schistosoma mansoni / Q000737:chemistry* / Q000276:immunology; D053719:Tandem Mass Spectrometry; D018418:Th2 Cells / Q000187:drug effects / Q000276:immunology; D014357:Trypsin / Q000378:metabolism; D005644:alpha-L-Fucosidase / Q000378:metabolism; D001616:beta-Galactosidase / Q000378:metabolism
D000947:Antigens, Helminth; D004527:Egg Proteins; D006023:Glycoproteins; D010446:Peptide Fragments; D011134:Polysaccharides; D001616:beta-Galactosidase; D005644:alpha-L-Fucosidase; D014357:Trypsin