Researchers at the University of Osaka have identified a rare type of immune cell that becomes more abundant in people who live beyond 110 years. Known as CD4 cytotoxic T lymphocytes (CD4 CTLs), these cells appear to combine the ability to recognize threats with the capacity to destroy infected or abnormal cells.

The study found that these cells remain relatively uncommon throughout most of life but increase significantly after the age of 100. In supercentenarians, they can account for a substantial proportion of circulating T cells and remain highly active, suggesting that the immune system may undergo important changes even in extreme old age.

Interestingly, many of these cells showed molecular features similar to T cells involved in cancer recognition, raising the possibility that they may help detect and respond to cancerous cells and other persistent threats.

The findings also challenge the idea that the immune system simply declines with age. Instead, they suggest that immune cells may reorganize and adapt in people who achieve exceptional longevity, potentially strengthening their ability to respond to long-term health threats.

Although the researchers caution that CD4 CTLs have not been proven to directly promote longevity, the findings offer new insights into how immune adaptation may contribute to disease resistance, healthy aging, and exceptional lifespan.

Source: https://www.asiaresearchnews.com/content/immune-remodeling-extreme-old-age-how-supercentenarians-reshape-their-immune-system