Infection by Cold Virus Triggers Major Changes in Nasal Gene Activity

A team of molecular virologists from two universities and a major pharmaceutical company has identified the genes whose activities are transformed by infection with Rhinovirus, the most common cold virus.

Investigators from the University of Calgary (Alberta, Canada) infected a group of volunteers with a Rhinovirus serotype purified at the University of Virginia (Charlottesville, USA) in a nasal spray formulated at Procter & Gamble (Cincinnati, OH, USA). A control group was treated with only the virus-free nasal spray. Symptom scores and viral titers in nasal epithelial scrapings were measured, and changes in gene expression – as ascertained with high-throughput micro array technology – were assessed eight and 48 hours after inoculation. Real time reverse transcription-polymerase chain reaction for the antiviral protein viperin (virus inhibitory protein, endoplasmic reticulum-associated, interferon-inducible) and rhinoviruses was used in naturally acquired infections, and viperin mRNA levels and viral titers were measured in cultured cells.

Results published in the online edition of the November 1, 2008, issue of the American Journal of Respiratory and Critical Care Medicine revealed that no changes in gene expression were observed eight hours after viral infection, but 11,887 gene transcripts were significantly altered in scrapings obtained two days after infection. Major groups of up-regulated genes included chemokines, signaling molecules, interferon-responsive genes, and antivirals. The epithelial cells of the test group were found to produce an average of 6.5 times more viperin gene product that did the cells taken from the control group.

"This study shows that after rhinovirus infection, cold symptoms develop because parts of our immune system are in overdrive,” said contributing author Dr. Lynn Jump, principal researcher at Procter & Gamble. "The findings are important because they provide us a blueprint for developing the ideal cold treatment: one that maintains the body's natural antiviral response while normalizing the inflammatory response.”

"Rhinovirus is the major cause of the common cold, but it is also an important pathogen in more serious conditions, such as asthma and chronic obstructive pulmonary disease (COPD),” said first author Dr. David Proud, professor, of physiology and biophysics at the University of Calgary. "The study's findings are a major step toward more targeted cold prevention and treatment strategies while also serving as a valuable roadmap for the broader respiratory science community.”

Related Links:
University of Calgary
University of Virginia
Procter & Gamble