It has been established that people who have lived to be 110 years or older may possess an unusually active immune system capable of identifying and eliminating potentially dangerous cells. According to the results of a study conducted by Japanese scientists, centenarians show a noticeable increase in rare T-cells that are capable of destroying various cells, including those that could become cancerous.
Biologist Kosuke Hashimoto and a team from Osaka University analyzed blood samples from 28 individuals, including ten centenarians aged 110 years and older. The data showed that in individuals over 100 years old, the proportion of cytotoxic CD4 T-cells was significantly higher than in the group of participants aged 70 to 90 years: about 10% compared to 4%. In people exceeding 110 years, this figure reached approximately 18%.
Scientists hypothesize that this transformation of the immune system begins around the age of one hundred. Since abnormal and damaged cells accumulate in the body over time, which can trigger the development of oncological diseases, the strengthening of this specific type of immune cell may be an adaptive mechanism of the body to these age-related changes.
Nevertheless, researchers cannot yet definitively state that these cells are what ensures longevity. They recorded signs that some of these cells react to specific immune threats but were unable to determine which tissues or cells serve as their targets. Although similarities with T-cell receptors identified in cancer patients suggest a possible anti-tumor function, there is no direct confirmation of this mechanism at present.
The unusually active immunity of centenarians is viewed by scientists as one of the possible factors contributing to their resistance to age-related pathologies. It remains unclear whether this immune restructuring is the primary cause of exceptional longevity or if it is a consequence of the unique characteristics of the bodies of people who managed to live over one hundred years.
In another study, it was previously established that the current Ebola fever outbreak in the DR Congo and Uganda likely originated from a new transmission of the rare Bundibugyo virus strain from animals to humans, after which the infection spread among people for several months. Genetic analysis confirmed the difference between the current variant and viruses from past epidemics, but the source of infection and the exact start of the outbreak remain undetermined.