It's been known for many years that when a virus such as influenza infects respiratory cells there is an immediate antiviral response at the cellular level -- the first barrier for protecting the body from the virus. Most of the changes that occur are a result of antiviral gene expression.
About 10 years ago, scientists first learned about small RNA pathways called microRNAs, which regulate gene expression. This led Horvath to want to investigate the role of microRNAs in influenza virus infection and determine what they are contributing to the antiviral response. Exactly which genes might the microRNAs be targeting?
In their current study, Horvath and his team used human lung cells, infected them with the influenza A virus and looked to see which microRNAs were activated in response to the virus. They focused on six microRNAs that were found to increase in abundance during flu infection.
The researchers found the virus activated two microRNAs that turned on the genes IRAK1 and MAPK3. This resulted in a decrease in the amount of proteins that help turn on the immune response.
Essentially, the virus uses the cell mechanisms to its advantage, disarming parts of the natural antiviral system. The flu takes over the expression of microRNAs for its own purposes. The flu increases the expression of microRNA, which decreases the amount of protein and diminishes the immune response.
Having identified a specific set of microRNAs whose expression in host respiratory cells is changed by the influenza virus, Horvath next is interested at looking at the clinical outcomes. He is working with Pedro C. Avila, M.D., professor of medicine-allergy-immunology at the Feinberg School to see if the microRNAs are di
|Contact: Megan Fellman|