title: [Antigencity identification of recombinant hepatitis E virus ORF2 protein expressed in Pichia pastoris].
abstract: BACKGROUND
  To determine the antigenicity of recombinant hepatitis E virus ORF2 (rHEV ORF2) protein expressed in Pichia pastoris (P. pastoris).
  
  
  METHODS
  By using the rHEV ORF2 protein from E.coli as control, an indirect ELISA was adopted to identify the sensitivity, specificity and stability of rHEV ORF2 protein from P. pastoris in detection of HEV IgM and IgG antibody in sera from patients with hepatitis E. The reactivity of the rHEV ORF2 against 5 HEV ORF2 monoclonal antibodies (McAbs) was also tested.
  
  
  RESULTS
  The minimum concentration of coated antigen with which HEV IgG could be detected was 12.5 ng/ml, while the highest serum dilution to detect both IgM and IgG antibodies against HEV was 1:5 120. No cross-reaction was found with sera from patients with any other types of hepatitis. The 37 degree C acceleration test showed that the rORF2 was highly stable within 12 months at 4 degrees C. The 5 HEV ORF2 McAbs showed better reaction with the rORF2 from P. pastoris, especially that 4B2, 2E2, whose reaction against the rORF2 were 125 and 25 times respectively higher than that of rORF2 from E.Coli.
  
  
  CONCLUSIONS
  There may be more extensive conformational epitopes in the rHEV ORF2 from P. pastoris. The excellent antigenicity, sensitivity and stability suggest that it can be served as a new candidate antigen for the development of diagnostic reagents of hepatitis E.
authors.affiliation: The No. 261 Hospital of PLA, Beijing,100094, China.
authors.forename: Yu-pin
authors.initials: YP
authors.lastname: Tong
authors.forename: Sheng-li
authors.initials: SL
authors.lastname: Bi
authors.forename: Jian
authors.initials: J
authors.lastname: Lu
authors.forename: Yong-zhen
authors.initials: YZ
authors.lastname: Jiang
authors.forename: Mei-yun
authors.initials: MY
authors.lastname: Zhan
mesh_terms: D015870:Gene Expression; D006508:Hepatitis Antibodies / Q000097:blood; D018963:Hepatitis Antigens / Q000235:genetics* / Q000276:immunology; D016751:Hepatitis E / Q000276:immunology*; D016752:Hepatitis E virus / Q000235:genetics / Q000276:immunology*; D006801:Humans; D010843:Pichia / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: D006508:Hepatitis Antibodies; D018963:Hepatitis Antigens; C400971:ORF2 protein, Hepatitis E virus; D011994:Recombinant Proteins; D014764:Viral Proteins