Scientists at Harvard Medical School (USA) have uncovered the mechanism of aging of the immune system, due to which older people are at high risk of complications from infectious diseases. This is reported in a press release on MedicalXpress.
Researchers conducted experiments on mice and found that the body of old rodents is deficient in T-cells (T-lymphocytes), which attack the pathogens and also participate in the formation of immunological memory. Specialists simulated signals that warn the defense system of the penetration of pathogens to activate T-cells, but in older animals the functions of lymphocytes were impaired. In particular, cells grew slower, isolated few signaling molecules, and quickly died.
Scientists have determined that in T-cells of old rodents there is an insufficient activity of the metabolic pathway, called the metabolism of one-carbon fragments. It is a series of biochemical reactions that occur in the mitochondria and cytosol of cells. During this process, amino acids and nucleotides are formed, which are the building blocks of proteins and DNA, respectively. With the help of the metabolism of one-carbon fragments, T-lymphocytes restore themselves and divide.
The researchers added two components of one-carbon metabolism to the cells, including formate and glycine. This allowed T-cells to increase proliferation and reduce the risk of death.