UT Health San Antonio scientists have identified a key hormone that may help maintain thymus function as we age, offering hope for stronger immune systems in older adults.
Scientists at The University of Texas Health Science Center at San Antonio (UT Health San Antonio) have made a groundbreaking discovery that could enhance immune system function in older adults. Their study, published in the February issue of Nature Aging, reveals that fibroblast growth factor FGF21, a peptide hormone, plays a vital role in preserving thymic tissue, crucial for fighting infections.
The thymus, a small gland under the breastbone, is essential for training T-cells, the body’s defenders against infections. However, this gland diminishes in size and function with age, leading to a weakened immune system.
By increasing levels of FGF21 in mouse models, the researchers were able to maintain both the size and efficacy of the thymus, promoting a more diverse development of T-cells.
“This research could be pivotal in developing a way to preserve strong immune responses across a lifetime,” Ann Griffith, an assistant professor in the Department of Microbiology, Immunology and Molecular Genetics at UT Health San Antonio, said in a news release. “This is an exciting step forward in finding targets that can durably restore thymic function in older people and improve their immune response.”
The study, spearheaded by Griffith, builds on previous research that explores the genetic changes occurring during thymic regeneration. Previous findings highlighted the role of FGF21 in thymic growth, and Griffith’s team further elucidated its effect on the gland’s cellular morphology.
“FGF21 can signal directly to the stromal cells inside the thymus and may also be signaling to other cells in a way that impacts the morphology,” Griffith added.
As we age, the thymus’ ability to regenerate and support young T-cells declines, making older adults more prone to infections and cancer recurrence. While increasing FGF21 levels appears promising in mitigating thymic atrophy, it does not entirely prevent it.
Nevertheless, FGF21 showed potential in reducing inflammation and autoimmunity, which escalate as thymic function decreases.
“Part of the T-cells’ education in this ‘school’ is to make sure that if they are recognizing our own tissues, we remove these cells,” added Griffith. “We’ve seen this function diminish with age, and this protein was able to mitigate that to potentially allow for better tolerance in T-cells that come out of the thymus.”
Source: University of Texas Health Science Center at San Antonio