title: Immunoproteomics Identification of Major IgE and IgG4 Reactive Schistosoma japonicum Adult Worm Antigens Using Chronically Infected Human Plasma.
abstract: Immunoepidemiological studies from endemic areas have revealed age-dependent resistance correlation with increased level of IgE and decreased level of IgG4 antibodies in responses to schistosomes' soluble worm antigen. However, there have been limited studies on analyses of major antigens that provoke IgE and IgG4 immune response during chronic stage of schistosomiasis. In this study, for the first time, immunoproteomics approach has been applied to identify S. japonicum worm antigens in liquid fractions that are recognized by IgE and IgG4 antibody using plasma from chronically infected population. ProteomeLabPF 2D fractionated 1-D and 2-D fractions of SWA antigens were screened using pooled high IgE/IgG4 reactive plasma samples by dot-blot technique. In 1-D fractions, IgE isotype was detected by fewer antigenic fractions (43.2%). The most recognized isotype was IgG3 (79.5%) followed by IgG1 (75.0%) and IgG4 (61.4%). Liquid chromatography MS/MS protein sequencing of reactive 2-D fractions revealed 18 proteins that were identified, characterized and gene ontology categories determined. 2-D fractions containing proteins such as zinc finger, RanBP2-type, domain-containing protein were strongly recognized by IgE and moderately by IgG4 whereas fractions containing proteins such as ubiquitin-conjugating enzyme and cytosolic II 5'-nucleotidase strongly recognizing by IgG subclasses (IgG1, IgG3 and IgG4) but not IgE. By this study, a simple and reproducible proteomic method has been established to identify major immunoreactive S. japonicum antigens. It is anticipated that this will stimulate further research on the immunogenicity and protective potential of proteins identified as well as discovery of novel compounds that have therapeutic importance.
authors.affiliation: Department of Immunogenetics and Global Centre of Excellence, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki City, Nagasaki 852-8523, Japan.
authors.forename: Daniel
authors.initials: D
authors.lastname: Boamah
authors.forename: Mihoko
authors.initials: M
authors.lastname: Kikuchi
authors.forename: Nguyen Tien
authors.initials: NT
authors.lastname: Huy
authors.forename: Kenta
authors.initials: K
authors.lastname: Okamoto
authors.forename: Honggen
authors.initials: H
authors.lastname: Chen
authors.forename: Irene
authors.initials: I
authors.lastname: Ayi
authors.forename: Daniel Adjei
authors.initials: DA
authors.lastname: Boakye
authors.forename: Kwabena Mante
authors.initials: KM
authors.lastname: Bosompem
authors.forename: Kenji
authors.initials: K
authors.lastname: Hirayama