Researchers at West Virginia University discovered what makes respiratory syncytial virus (RSV) such a severe and persistent illness. Senior author Giovanni Piedimonte, MD, and his team found that RSV prompts the release of a molecule that keeps the invaded cells alive despite the infection. This mechanism allows infected cells to survive for a longer period of time while they continue to produce viral particles, thus contributing to the severity and persistence of the infection.
“Viruses must find a way to survive inside the host, and in this case RSV has found a way of keeping alive the cells that they infect,” Piedimonte said. “The virus invades the cell, which then produces a small molecule called NGF, or nerve growth factor. NGF allows the cell to survive while the virus reproduces itself. Finally, the cell explodes releasing new viral particles ready to infect the neighboring cells.”
“There is still no effective therapy or medical treatment for RSV infection. While often mild, it still is responsible for the deaths of hundreds of infants in the United States each year,” said Piedimonte, chair of the WVU department of pediatrics, in an announcement about the study. “The virus also strikes in nursing homes and causes deaths in the elderly population, so understanding how it works is critical.”
Piedimonte said that in determining how the virus instructs the infected cell to prolong its life, the researchers might have established a blueprint for development of new antiviral drugs aimed at interfering with the action of NGF. He added that RSV might prefer the lower respiratory tract specifically because the smaller airways there allow for more efficient production of NGF.
“The interesting part of the RSV infection is that the viruses induce NGF production within an hour of coming into contact with the human cells— that is, even before they start multiplying,” said lead author, Sreekumar Othumpangat, PhD, a researcher in the WVU Pediatric Research Institute.
Piedimonte’s team is now proceeding with other studies to see if they can pinpoint the same mechanism in common cold and influenza viruses.
The article, “NGF Is an Essential Survival Factor for Bronchial Epithelial Cells during Respiratory Syncytial Virus Infection,” appears in the current issue of the journal PLoS ONE.