Protein critical to Ebola virus infection identified

Scientists have identified a protein in host cells that appears critical in facilitating infection by the Ebola virus.

The study, which appears in the journal Nature, showed that cells lacking the protein remained unharmed despite exposure to the virus, according to the New York Times.

Genetically altered laboratory mice that were created to be partially deficient in the protein became sick, but generally did not die after exposure.

Judith White, a cell biologist and virologist at the University of Virginia, called the results of the study astounding. It is the first time scientists have been able to show that a genetically engineered animal can survive an infection by the mostly lethal virus.

White said the research points to a potential target for the development of anti-Ebola drugs. The study, according to White, has greatly added to scientists' understanding of how the virus is able to enter cells and subsequently cause havoc.

Researchers from Harvard Medical School, the Whitehead Institute for Biomedical Research Institute in Cambridge, Massachusetts, and Albert Einstein College of Medicine in New York began by introducing random mutations to a large collection of cells, then exposing them to a virus designed to mimic Ebola.

"We asked the virus to find us cells it couldn't infect," Kartik Chandran, a professor of microbiology and immunology at Albert Einstein College of Medicine, said, the New York Times reports.

When the scientists found a series of Ebola-resistant cells, they noticed that a protein called NPC1 was missing from them. NPC1 is usually found inside a cellular compartment known as an endosome, which helps introduce cholesterol into a cell's cytoplasm. Humans without the protein usually develop Niemann-Pick disease, in which cholesterol builds up in the brain, liver and spleen.

Cells from patients with Niemann-Pick disease that were exposed to the Ebola-like virus also survived, further indicating a link.

"Scientists never like to say something is definitively it, because a new discovery always comes along," Dr. Erica Ollmann Saphire of the Scripps Research Institute said, the New York Times reports. "But NPC1 is the most convincing target we've seen yet for Ebola."