August 1, 2005

Penn Researchers Discover Key to How SARS Virus Infects Cells
Inhibitors of Cellular Enzymes Could Be Developed
For SARS Treatment

A proposed model of how SARS coronavirus enters the host cell. To gain entry, the virus binds to receptors on the cell surface as is taken up into a vesicle (endocytosis). Cathepsin L proteases facilitate fusion of the viral membrane and the vesicle membrane.

Credit: Graham Simmons, PhD and Paul Bates, PhD (University of Pennsylvania School of Medicine)

Comparison of how SARS enters the host cell versus Influenza and HIV. Unlike most known viruses, the SARS coronavirus needs to be cut by cathepsins in order to replicate within the host cell.

Credit: Graham Simmons, PhD and Paul Bates, PhD (University of Pennsylvania School of Medicine)

The cellular enzyme cathepsin inhibits SARS coronavirus infection. Infected cells fluoresce green.

Credit: Graham Simmons, PhD and Paul Bates, PhD (University of Pennsylvania School of Medicine); Proceedings of the National Academy of Sciences