Antibody Response of Patients with Severe Acute Respiratory Syndrome (SARS) Targets the Viral Nucleocapsid

• Published in: The Journal of Infectious Diseases Vol. 190; no. 2; pp. 379 - 386
• Main Authors: Leung, Danny Tze Ming, Chi Hang, Tam Frankie, Chun Hung, Ma, Sheung Chan, Paul Kay, Cheung, Jo Lai Ken, Niu, Haitao, Tam, John Siu Lun, Lim, Pak Leong
• Format: Journal Article Web Resource
• Language: English
• Published: Chicago, IL The University Chicago Press 15.07.2004; University of Chicago Press; Oxford University Press
• Subjects: Adolescent; Adult; Aged; Antibodies; Antibodies, Viral - blood; Antibody formation; Antigens; Antigens, Viral - immunology; Biological and medical sciences; Blotting, Western; Child; Enzyme linked immunosorbent assay; Female; Fluorescent Antibody Technique, Indirect; Fundamental and applied biological sciences. Psychology; Humans; Immunoglobulin G - blood; Infectious diseases; Major and Brief Reports; Male; Medical sciences; Membrane Glycoproteins - immunology; Microbiology; Middle Aged; Molecular Weight; Nucleocapsid; Nucleocapsid - immunology; SARS; SARS coronavirus; SARS Virus - immunology; Severe acute respiratory syndrome; Severe Acute Respiratory Syndrome - immunology; Severe Acute Respiratory Syndrome - virology; Spike Glycoprotein, Coronavirus; Vero cells; Viral Envelope Proteins - immunology; Viral pneumonia; Viruses; Human; Infection; Lung disease; Microbiology; Respiratory disease; Viral disease; Severe acute respiratory syndrome; Nucleocapsid; Humoral immunity
• DOI: 10.1086/422040
• ISSN: 0022-1899

The recent outbreak of severe acute respiratory syndrome (SARS) provided an opportunity to study the antibody response of infected individuals to the causative virus, SARS coronavirus. We examined serum samples obtained from 46 patients with SARS, 40 patients with non-SARS pneumonia, and 38 healthy individuals, by use of Western blotting (WB), enzyme-linked immunoassay (ELISA), and immunofluorescence assay, using both native and bacterially produced antigens of the virus. We found a highly restricted, immunoglobulin G-dominated antibody response in patients with SARS, directed most frequently (89% by ELISA) and predominantly at the nucleocapsid. Almost all of the subjects without SARS had no antinucleocapsid antibodies. The spike protein was the next most frequently targeted, but only 63% of the patients (by ELISA) responded. Other targets of the response identified by use of WB included antigens of 80 and 60 kDa. Several nonstructural proteins cloned were not antigenic, and the culture-derived nucleocapsid appeared to be specifically degraded.