Scientists have discovered a mechanism that slows down aging
It will also help to cope with serious diseases and infections in the long term.
An international team of scientists from the UK, Italy, China and America has identified a new mechanism that slows down and can even prevent the natural aging of immune cells. In an article published in the journal Nature Cell Biology, the researchers write that the new data will not only help people live healthier and longer, but also help them cope with serious diseases, such as cancer and dementia.
Dr Alessio Lanna, professor at University College London, explains: “Immune cells are constantly on high alert to fight pathogens. To remain effective, they must be preserved in the body for decades, but this is impossible. In this study, we sought to find out what mechanisms exist that ensure the longevity of cells of the immune system, known as T cells, when initiating an immune response against an antigen – a foreign and potentially dangerous substance.”
At the ends of the “tails” of chromosomes are telomeres — protective “caps” that determine the DNA sequence. It, in turn, protects the coding regions of chromosomes, prevents their damage and acts as a biological clock that controls the number of replications (cell divisions). In T cells, over time, telomeres are erased to a critical size: that’s when the cell stops dividing and enters the aging process. The immune system is gradually destroyed or remains in a static, dysfunctional state.
During the research, a group of scientists initiated the reaction of T-lymphocytes to a microbe and unexpectedly discovered the transfer of telomeres between two types of leukocytes in extracellular vesicles (small particles that facilitate intercellular communication). The antigen-presenting cell (APC) becomes a kind of telomere donor for T cells, which increases their working life, strengthens them and protects the body from lethal infection in the long term.
The transfer lengthens some telomeres by about 30 times, which telomerase cannot do — it is the only DNA-synthesizing enzyme that is responsible for maintaining telomeres in stem cells and cells of the immune system. However, it does not perform this function in other cells, which leads to telomere depletion.
Scientists have found that extracellular vesicles “rejuvenate” the immune system in both mice and humans. Drugs created on the basis of this method can be administered separately or in combination with a vaccine, which will improve immune protection. Due to this, revaccination will not be necessary.
Recently, scientists from the University of Aberdeen began studying the immune system of sharks in order to create new drugs to fight cancer and rheumatoid arthritis in the future.
