An international team led by scientists from University College London, UK, published a paper in Nature Cell Biology, saying that they had discovered a new mechanism that could slow down or even prevent the natural aging of immune cells - one of the nine signs of aging. Researchers believe that using this mechanism can prolong the life span of the immune system, make people live healthier and longer, and have clinical practical value in treating cancer, dementia and other diseases. Dr. Alessio Lanner, the main author of the research paper and emeritus professor of the medical department of University College London, said that the immune cells have always been on high alert and are ready to fight against pathogens. Their "combat readiness" lasts for decades in the body, but the mechanism to maintain this lifelong protection is still unknown to a large extent. In T cells, with each cell division, telomeres become shorter and shorter (telomere wear). Once telomeres are short enough, cells stop dividing and begin to age. This is mainly reflected in the immune system. As the immune system no longer works effectively, it will lead to chronic infection, cancer and death. Telomere wear is considered as one of the "signs of aging". In this study, the researchers started the immune response of T lymphocytes to microorganisms (foreign infection) in vitro. To their surprise, they observed telomere transfer between two types of leukocytes in extracellular vesicles (small particles that promote intercellular communication). An antigen presenting cell (APC), consisting of B cells, dendritic cells, or macrophages, that acts as a telomere donor on T lymphocytes (telomere receptor cells). After telomere transfer, receptor T cells become long-lived and have memory and stem cell properties, which enable T cells to protect the host from fatal infection for a long time. Professor Lanner explained that the telomere transfer reaction between immune cells showed that cells could exchange telomeres before the start of telomerase action, as a way to regulate the length of chromosomes. "It is possible to delay or cure aging simply by transferring telomeres". After discovering a new anti-aging mechanism, the research team confirmed that telomere extracellular vesicles can be purified from blood, and when added to T cells, they can show anti-aging activity in human and mouse immune systems. The study also found that it can directly promote the "telomere donor" transfer reaction in cells. (Outlook New Times)