Highly infectious SARS-CoV pseudotyped virus reveals the cell tropism and its correlation with receptor expression.

Studies of SARS coronavirus (SARS-CoV)-the causative agent of severe acute respiratory syndrome (SARS)-have been hampered by its high transmission rate and the pathogenicity of this virus. To permit analysis of the host range and entry mechanism of SARS-CoV, we incorporated the humanized SARS-CoV spike (S) glycoprotein into HIV particles to generate a highly infectious SARS-CoV pseudotyped virus. The infection on Vero E6-a permissive cell line to SARS-CoV-could be neutralized by sera from convalescent SARS patients, and the entry was a pH-dependent process. With these highly infectious SARS-CoV pseudotypes, several cell lines derived from various tissues were revealed as susceptible to SARS-CoV, which were highly corresponding to the expression pattern of virus's receptor angiotensin-converting enzyme 2 (ACE2). In addition, we also demonstrated angiotensin 1 converting enzyme (ACE)-the homologue of ACE2 could not function as a receptor for SARS-CoV.