Declining T cell immunity in the elderly

Declining T cell immunity in the elderly

A study expands the understanding of the molecular pathways that control T cell function and survival and how it relates to declining T cell immunity in the elderly.

The findings outline that the increased metabolism of T cells observed with advanced age was an indication that they were working harder merely to survive.

The study published in Nature Communications contradicts previous knowledge, which suggested an increased metabolism was indicative of T cell function, and will have implications for the development of targeted interventions such as vaccines or immunotherapies to treat age-related immune dysfunction.

T cells play an important role in the body's immune response to viral infections and tumors, but T cell immunity wanes as we age, thus increasing our susceptibility to these diseases.

The authors investigated virtual memory T (TVM) cell metabolism and its association with longevity and functionality. Elevated spare respiratory capacity (SRC) is a feature of TVM, but not antigen-experienced memory T (TMEM), cells and it increases with age in both subsets. The elevated SRC observed in aged mouse TVM cells and human CD8+ T cells from older individuals is associated with a heightened sensitivity to IL-15. 

"We've shown that an amped-up metabolism, rather than arming cells to fight pathogens better, is associated with T cell survival over a lifespan. The cells need to substantially increase their metabolism just to survive in the relatively hostile environment of the elderly," the senior author said.

"This work is important because one of the hallmarks of immune aging is the loss of T cells. So it provides clues on how we might promote T cell survival in the elderly, and so boost T cell immunity," the senior author said.