Trudeau Institute researchers have found a key mechanism that limits damage from the immune response to the influenza virus. The findings should help improve vaccines against influenza, which causes about 36,000 deaths in the United States each year. The findings will appear in the April 1 edition of The Journal of Immunology and is currently available on the publication’s website, jimmunol.org.
The paper, titled, “Antigen-specific memory Treg control memory responses to influenza virus infection,” was authored by Erik L. Brincks, Alan D. Roberts, Tres Cookenham, Stewart Sell, Jacob E. Kohlmeier, Marcia A. Blackman, and David L. Woodland.
When infected by influenza virus, the body mounts an inflammatory response and activates white blood cells that attack infected cells to eliminate the virus. This vigorous immune response typically controls the influenza infection but can cause unwanted damage to the infected individual even after the virus is eliminated. However, the body possesses other specialized white blood cells, known as regulatory T cells, or Treg, that can limit unwanted damage. In the reported study, Trudeau investigators were able to closely follow Treg-specific cells for the virus during the course of experimental flu infection in laboratory mice.
During an initial mild exposure to influenza virus, from which they recovered, the mice produced Treg. When the mice were re-infected with flu, the Treg quickly came into play. They controlled inflammation and limited the multiplication and potential damage that white blood cells can cause as they combat the virus.
By fine-tuning immune responses during a second influenza infection, Treg control the extent of damage, while still allowing the infected individual to eliminate the infection. Future studies will examine how vaccines might induce and expand an influenza-specific Treg population for protection against highly harmful influenza viruses.