For centuries, explorers have searched for the fountain of youth. Surprisingly, the secret to staying young might have been within us all along. Amor, a scientist, and colleagues have discovered that T cells can be reprogrammed to fight aging, so to speak.
Given the right genetic changes, these white blood cells can attack another group of cells known as senescent（衰老的）cells, which are thought to be responsible for many of the diseases we fight with later in life. Senescent cells are those that stop replicating（再生）. As we age, they build up in our bodies, resulting in some diseases.
While several existing drugs can eliminate these cells, many must be taken repeatedly over time. As an alternative, Amor and colleagues turned to a "living" drug called CAR（chimeric antigen receptor）T cells.
They discovered CAR T cells could be used to rid of senescent cells in mice. As a result. the mice ended up living healthier lives. They had lower body weight, improved metabolism（新陈代谢）, and increased physical activity. All these came without any tissue damage or side effects.
Perhaps the greatest power of CAR T cells is their long-lasting effects. The team found that just one dose（一剂）at a young age can have lifelong effects. That single treatment can protect against conditions that commonly occur later in life.
"T cells have the ability to develop memory and exist in your body for really long periods. which is very different from a chemical drug," Amor explained.
Amor's lab is now investigating whether CAR T cells let mice live not only healthier but also longer. If so, society will be one step closer to the fountain of youth.
