Evaluation of antibody responses against SARS coronaviral nucleocapsid or spike proteins by immunoblotting or ELISA.

Abstract

Severe acute respiratory syndrome (SARS)-CoV is a newly emerging virus that causes SARS with high mortality rate in infected people. To study the humoral responses against SARS-CoV, we evaluated nucleocapsid (N) and spike (S) proteins-specific antibodies in patients' sera by Western blotting and enzyme-linked immunosorbent assay (ELISA). Recombinant N and S proteins of SARS-CoV were purified from transformed E. coli. Serum specimens from 40 SARS-CoV-infected patients in the convalescent phase were analyzed by Western blotting using the purified antigens. Serial serum specimens from 12 RT-PCR-confirmed SARS patients were assayed by ELISA using the recombinant N protein as coated antigen. By Western blotting, 97.5% of the SARS patients were positive for N protein-specific antibodies whereas only 47.5% of the samples were positive for S protein-specific antibodies. Using N protein-based ELISA, 10 out of the 12 patients were positive for N protein-specific antibodies and 6 of them showed seroconversion at mean of 16 days after onset of fever. Immunoblotting was useful for detecting the humoral immune response after SARS-CoV infection. Antibodies against SARS-CoV N protein appear at the early stage of infection, therefore, N protein-based ELISA could serve as a simple, sensitive, and specific test for diagnosing SARS-CoV infection.

• Authors: Li-Rung Huang, Chi-Ming Chiu, Shiou-Hwei Yeh, Wen-Hung Huang, Po-Ren Hsueh, Wen-Zieh Yang, Jyh-Yuan Yang, Ih-Jen Su, Shan-Chwen Chang, Pei-Jer Chen
• Journal: Journal of medical virology (J Med Virol) Vol. 73 Issue 3 Pg. 338-46 (Jul 2004) ISSN: 0146-6615 [Print] United States
• PMID: 15170626 (Publication Type: Evaluation Study, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright 2004 Wiley-Liss, Inc.

Chemical References

• Antibodies, Viral
• Antigens, Viral
• Coronavirus Nucleocapsid Proteins
• Membrane Glycoproteins
• Nucleocapsid Proteins
• Recombinant Fusion Proteins
• Spike Glycoprotein, Coronavirus
• Viral Envelope Proteins
• spike glycoprotein, SARS-CoV
• spike protein, mouse hepatitis virus

Topics

• Amino Acid Sequence
• Antibodies, Viral (biosynthesis, blood)
• Antibody Formation
• Antigens, Viral (genetics, immunology)
• Blotting, Western
• Cloning, Molecular
• Coronavirus Nucleocapsid Proteins
• Enzyme-Linked Immunosorbent Assay
• Escherichia coli (genetics, metabolism)
• Humans
• Membrane Glycoproteins (genetics, immunology)
• Molecular Sequence Data
• Nucleocapsid Proteins (genetics, immunology)
• Recombinant Fusion Proteins (immunology, isolation & purification)
• Severe acute respiratory syndrome-related coronavirus (immunology)
• Severe Acute Respiratory Syndrome (diagnosis, immunology)
• Spike Glycoprotein, Coronavirus
• Viral Envelope Proteins (genetics, immunology)