title: High expression of small hepatitis D antigen in Escherichia coli and ELISA for diagnosis of hepatitis D virus.
abstract: Hepatitis D virus (HDV) infection is often accompanied by hepatitis B virus (HBV) infection. Co-infection of HDV and HBV may lead to more severe symptoms and even death. Current methods for HDV diagnosis have high false-positive rates and show significant result discrepancies. The Abbott AxSYM AUSAB test, currently a standard test for HDV detection, is too laborious and expensive for routine application. Therefore, new sensitive and cost-efficient methods for HDV diagnosis are urgently needed. In this study, S-HDAg protein was produced in high yield in Escherichia coli. Optimal protein production was achieved by optimization of S-HDAg gene codons according to the codon preference of E. coli and using host cells with appropriate cell density. Under optimal expression conditions, the S-HDAg protein expression yield (30mg/l) was the highest among any proteins expressed in E. coli. A standard enzyme-linked immunosorbent assay (ELISA) for HDV was developed using the purified S-HDAg protein, which showed high specificity against hepatitis B, C, D and E viruses. Overall, the ELISA had superior specificity and sensitivity compared with the Abbott AxSYM AUSAB test and was also more convenient and cost-efficient.
authors.affiliation: Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping District, Beijing 102206, China.
authors.forename: Junying
authors.initials: J
authors.lastname: Ding
authors.affiliation: Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping District, Beijing 102206, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Yi
authors.affiliation: Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping District, Beijing 102206, China.
authors.forename: Qiudong
authors.initials: Q
authors.lastname: Su
authors.affiliation: Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping District, Beijing 102206, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Qiu
authors.affiliation: Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping District, Beijing 102206, China.
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Jia
authors.affiliation: Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping District, Beijing 102206, China. Electronic address: Shengli_Bi@163.com.
authors.forename: Shengli
authors.initials: S
authors.lastname: Bi
mesh_terms: D003001:Cloning, Molecular; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D006508:Hepatitis Antibodies / Q000097:blood*; D003699:Hepatitis D / Q000175:diagnosis*; D003698:Hepatitis Delta Virus / Q000276:immunology*; D035923:Hepatitis delta Antigens / Q000235:genetics; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D011994:Recombinant Proteins / Q000235:genetics; D012680:Sensitivity and Specificity
chemical_list: D006508:Hepatitis Antibodies; D035923:Hepatitis delta Antigens; D007074:Immunoglobulin G; D011994:Recombinant Proteins
keywords: Diagnosis; Enzyme-linked immunosorbent assay; Expression; Hepatitis delta virus; Purification; S-HDAg