title: Expression of SARS-coronavirus nucleocapsid protein in Escherichia coli and Lactococcus lactis for serodiagnosis and mucosal vaccination.
abstract: The nucleocapsid (N) protein of the severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) is an important antigen for the early diagnosis of SARS and the development of vaccines. It was expressed in Escherichia coli as a fusion with human glutathione S-transferase (hGST) and was confirmed by Western blotting analysis. This recombinant N protein (hGST-N) was purified and used to measure the SARS-CoV N-specific antibody in the sera of eight SARS patients by enzyme-linked immunosorbent assay. Specific antibody response to this purified recombinant N protein was 100% positive in the SARS patients' sera, while none of the control sera from 30 healthy people gave a positive reaction in the same assay. The SARS-CoV N protein was also expressed in Lactococcus lactis in the cytoplasm or secreted into the medium. The N-producing strain MG1363/pSECN and the purified hGST-N protein were respectively administered to mice, either orally or intranasally. Results indicated that orally delivered MG1363/pSECN induced significant N-specific IgG in the sera. In conclusion, our work provides a novel strategy to produce the SARS-CoV N protein for serodiagnosis and for L. lactis-based mucosal vaccines.
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, P.R. China.
authors.forename: Huadong
authors.initials: H
authors.lastname: Pei
authors.forename: Jingfang
authors.initials: J
authors.lastname: Liu
authors.forename: Yun
authors.initials: Y
authors.lastname: Cheng
authors.forename: Chaomin
authors.initials: C
authors.lastname: Sun
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.forename: Yueping
authors.initials: Y
authors.lastname: Lu
authors.forename: Jie
authors.initials: J
authors.lastname: Ding
authors.forename: Jian
authors.initials: J
authors.lastname: Zhou
authors.forename: Hua
authors.initials: H
authors.lastname: Xiang
mesh_terms: D000281:Administration, Intranasal; D000284:Administration, Oral; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000918:Antibody Specificity; D000086462:Coronavirus Nucleocapsid Proteins; D004926:Escherichia coli / Q000378:metabolism*; D005260:Female; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D013294:Lactococcus lactis / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D019590:Nucleocapsid Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000276:immunology / Q000302:isolation & purification; D045473:Severe acute respiratory syndrome-related coronavirus / Q000276:immunology*; D012698:Serologic Tests; D045169:Severe Acute Respiratory Syndrome / Q000175:diagnosis* / Q000276:immunology*; D014611:Vaccination; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage* / Q000276:immunology / Q000302:isolation & purification
chemical_list: D000914:Antibodies, Viral; D000086462:Coronavirus Nucleocapsid Proteins; D007074:Immunoglobulin G; D019590:Nucleocapsid Proteins; D011994:Recombinant Proteins; D014614:Vaccines, Synthetic; D014765:Viral Vaccines; D005982:Glutathione Transferase