… and it seems that a human enzyme facilitates the invasion. The National Institute of Allergy and Infectious Diseases press release explains:
“This new research sheds light on the mechanism Ebola virus uses to enter cells,” notes NIAID Director Anthony S. Fauci, M.D. “These findings raise the possibility of a broad-spectrum antiviral therapy that could be effective against multiple hemorrhagic fever viruses.”
Senior author James M. Cunningham, M.D., of Brigham and Women’s Hospital and Harvard Medical School in Boston, and his colleagues discovered two cellular enzymes that the Ebola virus co-opts and uses to cut up one of the virus’ surface proteins. Once this protein is snipped apart, the virus is free to begin multiplying. The scientists applied broad-spectrum enzyme inhibitors to mammalian cells before exposing them to Ebola virus. When one specific cellular enzyme, cathepsin B, was inhibited, the infectivity of Ebola virus dropped to near zero. An accessory role is played by another cellular enzyme, cathepsin L, the scientists determined.
Inhibitors of cathepsins are already under clinical development as anti-cancer drugs. The authors write, “Further investigation of the antiviral efficacy of [enzyme] inhibitors may…be warranted. The wealth of existing knowledge regarding the design and in vivo pharmacology of these inhibitors may facilitate development of an anti-Ebola-virus therapy.”