Longevity & AgingScientists Map Why Your Immune System Ages and How to Reverse It
The thymus, the organ responsible for producing T cells, begins shrinking early in life and accelerates with age — a process called thymic involution. This leads to fewer naïve T cells, a narrowed T cell receptor repertoire, and accumulation of senescent T cells that fuel chronic inflammation. The result is weakened defenses against infections, cancer, and poor vaccine responses. This review from the Centre d'Immunologie de Marseille-Luminy synthesizes the cellular and molecular mechanisms driving involution — including hormonal shifts, inflammaging, and stromal cell dysfunction — and evaluates rejuvenation strategies such as sex steroid ablation, growth hormone, RANKL signaling, IL-7 therapy, and FOXN1-reprogrammed cell transfer. These approaches show genuine promise for restoring thymic architecture and renewing the peripheral T cell pool in aging individuals.
