Controlling thymus function to improve T-cell immunity in the aged.

The immune system protects us from invaders. As we age our immune system becomes compromised, leaving elderly individuals more susceptible to infection. The causes of this phenomenon, however, remain unclear. The thymus is essential for the development of critical immune cells, and progressively shrinks in size as we get old. Yet, it was unknown whether reduced thymic size causes immune aging defects. This is because we lacked experimental models in which we can reverse this process. I constructed mouse models that allow the thymus to be experimentally regrown and established that thymic atrophy underlies age-related immune defects. The aim of my project is to identify the mechanisms that cause thymic atrophy and explore how restored thymus function improves immunity in aging. The long-term goal of my proposal is to better understand the mechanisms underlying immune aging, so as to improve immune protection in aged individuals.