Rare Immune Cells Surge in People Over One Hundred, Boosting Longevity Defense
Researchers discovered that individuals past age 100 show a sharp rise in CD4 cytotoxic T lymphocytes, a rare immune cell that actively destroys harmful targets.
In a new investigation, scientists examined immune profiles of 28 individuals split into three age brackets—those in their 70s, centenarians and supercentenarians—and identified a marked growth of CD4 cytotoxic T lymphocytes in the oldest group. These rare white-blood cells not only coordinate immune activity but also directly eliminate infected or damaged cells, and they were found to clone themselves more frequently in people over a century old.
A machine-learning review of 1,500 subjects across all ages mirrored this pattern, indicating the phenomenon is not limited to a small sample. Kosuke Hashimoto, a biologist at the University of Osaka, interprets the rise as an active, adaptive response to persistent antigens. Immunologists Rahul Sharma and Alon Monsonego, who were not involved in the work, praised the study while emphasizing the need to clarify whether these cells truly benefit health in extreme age. Future research aims to pinpoint the specific targets of these cells and explore their presence in younger populations.
Why it matters
Understanding how rare immune cells expand in the very old could inform new strategies to combat age-related diseases.
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