A Yale research team has revealed how cells in different parts of the human airway vary in their response to the common cold virus. Their finding, published in Cell Reports, could help solve the mystery of why some people exposed to the cold virus get ill while others don’t, said the researchers.
The research team used epithelial cells from healthy human donors. The cells were derived from either the nasal passages or the lungs. They exposed both cell types, maintained under the same conditions in cell culture, to rhinovirus. Unexpectedly, the researchers observed a more robust antiviral response in nasal cells. To investigate further, the researchers triggered the virus surveillance pathway — known as the RIG-I pathway — in both nasal and lung cells. They found that both cell types generated an antiviral response and a defences response against oxidative stress and other inhaled irritants such as cigarette smoke or tree pollen. In nasal cells, the antiviral response was stronger, but in bronchial cells, defence against oxidative stress was more pronounced.
In additional experiments, the research team found evidence for a trade-off: The defence response against oxidative stress shut off antiviral defences. To investigate this further, the team exposed nasal cells to oxidative stress in the form of cigarette smoke, and then to the cold virus, and found that the nasal cells were more susceptible to the virus. This finding points to a delicate balance between the body’s different defence mechanisms.
The study shows a mechanistic link between environmental exposures and susceptibility to the common cold, and also may explain why smokers tend to be more susceptible to rhinovirus infection. The researchers hope the finding will lead to the discovery of new strategies to combat respiratory viruses, which cause an estimated 500 million colds and 2 million hospitalizations in the United States per year.
Story Source:
Materials provided by Yale University. Original written by Ziba Kashef.
Journal Reference:
Valia T. Mihaylova, Yong Kong, Olga Fedorova, Lokesh Sharma, Charles S. Dela Cruz, Anna Marie Pyle, Akiko Iwasaki, Ellen F. Foxman. Regional Differences in Airway Epithelial Cells Reveal Tradeoff between Defense against Oxidative Stress and Defense against Rhinovirus. Cell Reports, September 11, 2018 DOI: 10.1016/j.celrep.2018.08.033
