title: Molecular characterization and immune modulation properties of Clonorchis sinensis-derived RNASET2.
abstract: BACKGROUND
  Clonorchis sinensis (C. sinensis, Cs) is a trematode parasite that often causes chronic cumulative infections in the hepatobiliary ducts of the host and can lead to pathological changes by continuously released excretory/secretory proteins (ESPs). A T2 ribonuclease in trematode ESPs, has been identified as a potent regulator of dendritic cell (DCs) modulation. We wondered whether there was a counterpart present in CsESPs with similar activity. To gain a better understanding of CsESPs associated immune responses, we identified and characterized RNASET2 of C. sinensis (CsRNASET2) in this paper.
  
  
  METHODS
  We expressed CsRNASET2 in Pichia pastoris and identified its molecular characteristics using bioinformatic analysis and experimental approaches. The immune modulation activities of CsRNASET2 were confirmed by evaluating cytokine production and surface markers of recombinant CsRNASET2 (rCsRNASET2) co-cultured DCs, and monitoring levels of IgG isotypes from rCsRNASET2 administered BALB/c mice.
  
  
  RESULTS
  CsRNASET2 appeared to be a glycoprotein of T2 ribonuclease family harboring conserved CAS motifs and rich in B-cell epitopes. Furthermore, CsRNASET2 was present in CsESPs and was able to modulate cytokine production of DCs. In addition, rCsRNASET2 could significantly suppress the expression of lipopolysaccharide-induced DCs maturation markers. In addition, when subcutaneously administered with rCsRNASET2 there was a marked effect on IgG isotypes in mouse sera.
  
  
  CONCLUSIONS
  Collectively, we revealed that CsRNASET2, a T2 ribonuclease present in CsESPs, could modulate DCs maturation and might play an important role in C. sinensis associated immune regulation in the host.
authors.forename: Yanquan
authors.initials: Y
authors.lastname: Xu
authors.forename: Wenjun
authors.initials: W
authors.lastname: Chen
authors.forename: Meng
authors.initials: M
authors.lastname: Bian
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Wang
authors.forename: Jiufeng
authors.initials: J
authors.lastname: Sun
authors.forename: Hengchang
authors.initials: H
authors.lastname: Sun
authors.forename: Feifei
authors.initials: F
authors.lastname: Jia
authors.forename: Chi
authors.initials: C
authors.lastname: Liang
authors.forename: Xuerong
authors.initials: X
authors.lastname: Li
authors.forename: Xiaonong
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, People's Republic of China. huang66@mail.sysu.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
authors.forename: Xinbing
authors.initials: X
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001854:Bone Marrow Cells; D003004:Clonorchis sinensis / Q000201:enzymology* / Q000378:metabolism; D016207:Cytokines; D003713:Dendritic Cells; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D007074:Immunoglobulin G / Q000097:blood; D007132:Immunoglobulin Isotypes; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D051381:Rats; D017207:Rats, Sprague-Dawley; D012260:Ribonucleases / Q000235:genetics / Q000378:metabolism*
chemical_list: D016207:Cytokines; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D012260:Ribonucleases