Antiviral Drug Targets Host Cell Membrane Phospholipids

Bavituximab is a chimeric mouse-human monoclonal antibody that specifically binds to anionic phospholipids (phosphotidylserine) exposed on the membrane surface of virus-infected cells.

In the current study, which was published in the November 23, 2008, online issue of the journal Nature Medicine, guinea pigs were infected with Pichinde virus (a model for Lassa fever virus, a potential bioterrorism agent). While the virus killed all the animals in the control group, 50% of the guinea pigs treated with bavituximab survived. When bavituximab was administered together with the antiviral medication ribavirin, 63% of guinea pigs survived.

"When injected into the bloodstream, bavituximab circulates in the body until it finds these inside-out lipids and then binds to them,” said senior author Dr. Philip Thorpe, professor of pharmacology at the University of Texas Southwestern Medical Center. "In the case of virus infection, the binding raises a red flag to the body's immune system, forcing the deployment of defensive white blood cells to attack the infected cells. This approach reduces the ability of the virus to escape attack by a drug. Viruses often dodge drugs by mutating into a different form that the drug is ineffective against. A host cell is a more immutable target.”

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University of Texas Southwestern Medical Center