title: [Vaccination of rhesus monkeys with recombinant antigen fragments and protection from hepatitis E virus infection].
abstract: OBJECTIVE
  To observe anti-HEV IgG response to vaccination of recombinant antigen fragments and evaluate its protection from Hepatitis E Virus infection in rhesus monkeys (Macaca mulatta).
  
  
  METHODS
  Twelve monkeys were divided into three groups and immunized respectively with three different recombinant antigens: namely Ag1 (carboxyl terminal 431 amino acids of ORF2), Ag2 (128aa fragment at the carboxyl terminal of ORF2), and Ag3 (full length ORF3 ligated with two ORF2 fragments encoded by 6743-7126nt and 6287-6404nt). The monkeys were challenged intravenously with fecal suspension from experimentally infected rhesus monkeys, and the other three monkeys served as the placebo group for challenge with HEV. The dynamic changes of the levels of ALT and anti-HEV IgG were examined. Pathological changes of liver tissue were observed by light microscope. Excretion of virus was detected by RT-nPCR.
  
  
  RESULTS
  Hepatic histopathology of two monkeys in the placebo group was consistent with acute viral hepatitis, and ALT was elevated 3-4 weeks after inoculated with virus, up to 10-20 times higher than normal level. The liver tissue of monkeys immunized with antigen kept normal, ALT in several monkeys elevated mildly, and anti-HEV IgG conversation occurred at 1-2 weeks after vaccination, with the titer reaching 1:12,800. The virus RNA could be detected by RT-nPCR from days 7 to 50 in monkeys of control group, and from days 7 to 21 in vaccinated monkeys after challenged with virus.
  
  
  CONCLUSIONS
  The recombinant antigens could induce the production of anti-HEV IgG, which protected rhesus monkeys from acute Hepatitis symptoms related to HEV infection.
authors.affiliation: Department of Molecular Biology, Institute of Medical Biology, CAMS, PUMC, Kunming 650118, China. mayanbing1969@163.net
authors.forename: Yan-bing
authors.initials: YB
authors.lastname: Ma
authors.forename: Tian-hong
authors.initials: TH
authors.lastname: Xie
authors.forename: Guang-ming
authors.initials: GM
authors.lastname: Zhang
authors.forename: Chun-hong
authors.initials: CH
authors.lastname: Li
authors.forename: Xie-Jie
authors.initials: XJ
authors.lastname: Dai
authors.forename: Chang-bai
authors.initials: CB
authors.lastname: Dai
authors.forename: Mao-sheng
authors.initials: MS
authors.lastname: Sun
authors.forename: Jian
authors.initials: J
authors.lastname: Lu
authors.forename: Sheng-li
authors.initials: SL
authors.lastname: Bi
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000276:immunology*; D016751:Hepatitis E / Q000517:prevention & control*; D016752:Hepatitis E virus / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology; D008253:Macaca mulatta; D012367:RNA, Viral / Q000097:blood; D011994:Recombinant Proteins / Q000276:immunology; D014611:Vaccination; D014761:Viral Hepatitis Vaccines / Q000276:immunology*
chemical_list: D000956:Antigens, Viral; D007074:Immunoglobulin G; D012367:RNA, Viral; D011994:Recombinant Proteins; D014761:Viral Hepatitis Vaccines