A recent study has revealed distinctive characteristics of the immune system in centenarians, noting a significant increase in the number of tumor-destroying T cells, which opens up prospects for studying longevity and cancer prevention.
According to experts, this study opens new horizons for studying the mechanisms of longevity and cancer prevention
According to the results of this study, centenarians (100 years and older) have a significantly higher number of CD4 cytotoxic T lymphocytes (CD4 CTLs)—specialized immune cells capable of destroying cancer cells. Scientists analyzed blood samples from 28 adults across three age groups: 70–99 years, 100–109 years, and 110 years and older. The study revealed that the proportion of CD4 cytotoxic T cells increases with age, averaging 4 percent in the first age group, 9.6 percent in the second age group, and 17.6 percent in the 110 years and older group.
Researchers discovered that this increase was due to clonal expansion—a process by which immune cells multiply in response to threats. The most common cell type accounted for an average of 33.3 percent of the CD4 cytotoxic T cells, and in one instance, 53.8 percent. Comparing the receptor sequences of the major cell types to a database revealed approximately 30 matches from individuals with lung, breast, and liver cancer. None of the centenarians in the study had been diagnosed with these types of cancer, suggesting that the increase in cells may reflect early immune responses to hidden threats.
The researchers say, "Aging of the immune system is not simply a process of deterioration in its functions. The selective increase in certain T cells indicates that the immune system, even in old age, is able to continue to adapt to age-related changes."
According to them, this data is preliminary and does not prove that elevated numbers of CD4 cytotoxic T cells directly prevent cancer or prolong life. Therefore, the next step will be to study the behavior of these cells in tissues.
