title: Identification of proteins inducing short-lived antibody responses from excreted/secretory products of Schistosoma japonicum adult worms by immunoproteomic analysis.
abstract: The excretory/secretory antigens of Schistosoma japonicum (Sj ESAgs) play important roles in host-parasite immune interactions. In this study, the antibody response patterns to Sj ESAgs in sera of individual rabbits at the healthy stage, 2-6 weeks post-infection and 4-16 weeks after treatment were examined. Antigens inducing short-lived antibody responses were selected by comparing differences in immune recognition of proteins in sera across the different stages by Western blotting and identified by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF/TOF-MS). The diagnostic value of these short-lived antibody responses for schistosomiasis was investigated. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was identified as a major antigen inducing a short-lived antibody response in Sj ESAgs. The antibody response against Sj GAPDH decreased at week 4 and disappeared between weeks 8-12 after effective chemical treatment of rabbits, and this response declined to negative levels in schistosomiasis patients one year after treatment. The intensity of the antibody response against Sj GAPDH was dependent on parasite load in mice. The sensitivity and specificity of IgG antibodies against recombinant Sj GAPDH for schistosomiasis diagnosis were 82.5% and 91.3%. Our findings suggest that Sj GAPDH induces short-lived antibody responses in the host, and detecting IgG against this antigen provides the basis for developing a potential method for diagnosis and evaluating treatment effects for schistosomiasis japonicum.
  
  
  CONCLUSIONS
  Schistosomiasis is one of the world's major public health problems. Developing effective diagnostic methods for detecting schistosome-specific antibodies to effectively identify active infections is part of a critical strategy for blocking transmission of the parasite and eradicating schistosomiasis. The excretory/secretory antigens of S. japonicum (Sj ESAgs) play important roles in host-parasite immune interactions. In our study, we examine the antibody response patterns to Sj ESAgs within individual rabbits at the healthy, schistosome infection and post-treatment stages by Western blotting. Proteins among the Sj ESAgs inducing short-lived antibody responses were identified by Matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF/TOF-MS), and their potential as immune markers for diagnosis and evaluating therapeutic effects in schistosomiasis was evaluated. Our findings suggest that S. japonicum glyceraldehyde-3-phosphate dehydrogenase (GAPDH) induces short-lived antibody responses in the host, and detecting IgG against this antigen provides the basis for developing a potential method for diagnosis and evaluating treatment effects for schistosomiasis japonicum.
authors.affiliation: Jiangsu Institute of Parasitic Diseases, Key Laboratory on Technology for Parasitic Disease Prevention and Control, Ministry of Health, Wuxi 214064, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.forename: Fei
authors.initials: F
authors.lastname: Zhao
authors.forename: Chuan-Xin
authors.initials: CX
authors.lastname: Yu
authors.forename: Di
authors.initials: D
authors.lastname: Xiao
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Song
authors.forename: Xu-Ren
authors.initials: XR
authors.lastname: Yin
authors.forename: Shuang
authors.initials: S
authors.lastname: Shen
authors.forename: Wan-Quan
authors.initials: WQ
authors.lastname: Hua
authors.forename: Jian-Zhong
authors.initials: JZ
authors.lastname: Zhang
authors.forename: Hui-fang
authors.initials: HF
authors.lastname: Zhang
authors.forename: Li-Hua
authors.initials: LH
authors.lastname: He
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Qian
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Yong-Liang
authors.initials: YL
authors.lastname: Xu
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000276:immunology / Q000378:metabolism*; D005260:Female; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) / Q000276:immunology / Q000378:metabolism*; D015801:Helminth Proteins / Q000276:immunology / Q000378:metabolism*; D007074:Immunoglobulin G / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008813:Mice, Inbred ICR; D040901:Proteomics / Q000379:methods; D011817:Rabbits; D012549:Schistosoma japonicum / Q000201:enzymology* / Q000276:immunology; D012554:Schistosomiasis japonica / Q000276:immunology / Q000378:metabolism*
chemical_list: D000909:Antibodies, Helminth; D015801:Helminth Proteins; D007074:Immunoglobulin G; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating)