The human body has the ability to ward off viruses by activating a naturally occurring protein at the cellular level, setting off a chain reaction that disrupts the levels of cholesterol required in cell membranes to enable viruses to enter cells. The findings, discovered by researchers in molecular microbiology and immunology at the Keck School of Medicine of the University of Southern California (USC), hold promise for the development of therapies to fight a variety of viral infections.
“Previous studies have shown that our bodies are already equipped to block viruses such as Ebola, influenza, West Nile, and SARS,” said Jae U. Jung, principal investigator and distinguished professor and chair of the Department of Molecular Microbiology and Immunology. The study, “The antiviral effector IFITM3 disrupts intracellular cholesterol homeostasis to block viral entry,” was published in the journal Cell Host & Microbe on April 17, 2013.
“We showed how this occurs,” Jung said. “When a virus tries to enter, the immune system gets stimulated by interferon, which produces almost 300 host proteins, including IFITM3. This protein then disrupts the interaction between two other proteins, which, in turn, significantly increases the level of cholesterol in cells, and thereby blocks the virus.”