1. ¹Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong SAR, China
2. ²Abgent Inc., San Diego, CA, USA
3. ³Century Biotech Limited, Hong Kong SAR, China
4. ⁴Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR, China
5. ⁵Department of Microbiology and School of Public Health, The Chinese University of Hong Kong, Hong Kong SAR, China
6. ⁶Department of Pathology, Princess Margaret Hospital, Hong Kong SAR, China

Correspondence: Dr AWI Lo, MBChB, PhD, Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong SAR, China. E-mail: awilo@cuhk.edu.hk

Received 9 January 2005; Revised 16 March 2005; Accepted 17 March 2005; Published online 13 May 2005.

Abstract

Severe acute respiratory syndrome (SARS) is a newly emerging infectious disease that haunted the world from November 2002 to July 2003. Little is known about the biology and pathophysiology of the novel coronavirus that causes SARS. The tissue and cellular distributions of coronaviral hypothetical and structural proteins in SARS were investigated. Antibodies against the hypothetical (SARS 3a, 3b, 6, 7a and 9b) and structural proteins (envelope, membrane, nucleocapsid and spike) of the coronavirus were generated from predicted antigenic epitopes of each protein. The presence of these proteins were first verified in coronavirus-infected Vero E6 tissue culture model. Immunohistochemical studies on different human tissues, including a cohort of nine autopsies, two liver biopsies and intestinal biopsies of SARS patients, further confirmed the existence of coronaviral hypothetical and structural proteins in the cytoplasm of pneumocytes and small intestinal surface enterocytes in SARS patients. With this vast array of antibodies, no signal was observed in other cell types including those organs in which reverse transcriptase-polymerase chain reactions were reported to be positive. Structural proteins and the functionally undefined hypothetical proteins were expressed in coronavirus-infected cells with distinct expression pattern in different organs in SARS patients. These antipeptide antibodies can be useful for the diagnosis of SARS at the tissue level.