People who live to 110 and beyond — known as supercentenarians — have a remarkable cellular defense that may help explain their extraordinary longevity: an unusually high abundance of rare cancer-fighting immune cells.
A study published in Nature and covered by ScienceAlert on August 19-20 found that among 28 Japanese participants aged 110 or older, those with the highest share of a rare type of immune cell called CD4 cytotoxic T lymphocytes (CD4 CTLs) showed the strongest resistance to age-related immune decline. These cells, which are typically found in very low numbers even in healthy adults, appear to be a cellular signature of supercentenarians.
Unlike ordinary CD4 helper T cells, which coordinate immune responses, CD4 CTLs can directly kill cancer cells and virus-infected cells — functioning more like the body's elite combat troops than its generals. The researchers discovered that supercentenarians carry not just more of these cells, but also that their CD4 CTLs show signs of continued adaptation and activity even at extreme old age.
"Despite their advanced age, many centenarians show relatively preserved immune function and resistance to conditions linked to immunosenescence," the study noted. The finding builds on previous research showing that centenarians tend to have immune profiles that resemble those of much younger adults — but the specific role of CD4 CTLs was not well understood until now.
The discovery has potential implications for cancer treatment and healthy aging research. If scientists can understand what triggers the production and maintenance of these rare cells, it could lead to new therapies that boost cancer-fighting immunity in the general population — or treatments that mimic the longevity-associated immune profile of supercentenarians.
The research was conducted by an international team and published in Nature.
