Grant: Early Career Investigator Awards - Circulatory and Respiratory Health

Heart failure and cardiomyopathy are diseases that cause great mortality in Canada. These are caused by a progressive worsening of heart function, due to several causes that are not always well understood. Virus infection is thought to be a major cause of heart disease development. Virus infections of the heart are not too uncommon among the population, as they are often confused by a simple viral process, such as a cold. However, in some individuals infections of the heart can be much severe and cause hospitalization. Whether a person has had a heart infection with clears signs or not, there exists an important chance that they will slowly progress to heart disease. The reason for that is unknown. In some cases, the damage caused by the virus is too big for the heart to adapt and keep functioning well. In other cases, the virus cannot be completely removed and causes the immune system to keep fighting it in the heart, causing important collateral damage. Finally, sometimes, a virus infection of the heart is accompanied by the wrongful activation of protective cells of the body that learn to attack the heart instead of the virus. In the studies proposed here, we will investigate the functions of a specific subset of protective cells, referred to as CD4 T cells because they express a protein called CD4. These CD4 T cells are the major designers of the fights against infections, by deciding which other defensive cells and mechanisms will be used to fight. Unfortunately, we know very little of how these cells behave during viral infection of the heart and what determines a good strategy against the virus. We believe that studying these cells we can better understand why some people are unable to beat the virus and limit heart injury, which otherwise can lead to a lethal heart disease.