Does aging begin with lymphocytes?

How immunity accelerates aging

Kirill Stasevich, Science and Life (nkj.ru )

With age, the immune system begins to work worse – it reacts less to vaccines, fights infections poorly, etc.; one of the reasons for this is that mitochondria – cellular organelles that provide the cell with energy - work worse in aging immune cells. Poorly functioning mitochondria do not provide enough energy and at the same time produce many dangerous by-products; such mitochondria are generally considered one of the main causes of aging.

But at the same time, old immune cells themselves accelerate the aging of other tissues and organs. Elderly people and animals develop chronic inflammation, which is sometimes called age–related inflammation. As a defense tool, the inflammatory response should help fight infections and diseased cells, but inflammation itself can harm healthy tissues. And if inflammation begins by mistake, due to the fact that the immune mechanism of inflammatory control has broken down, then healthy tissues begin to suffer. And with age, such background inflammation can accelerate the aging of the entire body.

Researchers from the Autonomous University of Madrid, the Supreme Council for Scientific Research of Spain and other scientific centers have shown what role defective T cells play in such age-related inflammation. Normally, T lymphocytes chase pathogens, destroy infected and cancer cells, regulate the strength of the immune response, help B cells synthesize antibodies, and also synthesize inflammatory signals - as much as necessary. But if the mitochondria of the T cells started to mess up, then the T cells began to secrete too many inflammatory molecules.

The authors of the work used genetic engineering methods to spoil the mitochondria of mouse T-lymphocytes, and by seven months such mice looked not like ordinary young animals, but like very old people. They were sluggish, slow, their muscles weakened and decreased in volume, their heart worked worse, they lost weight, not to mention that their immunity struggled worse with infections. According to the passport, so to speak, the animals were still very young, but due to energy disturbances in T-lymphocytes, they aged before their time. In other words, defective T cells are indeed responsible for general aging, at least in part.

At the same time , in an article in Science (Desdín-Micó et al., T cells with dysfunctional mitochondria induce multimorbidity and premature senescence) states how such immune aging can be reversed. Firstly, mice with damaged T cells were given a substance that blocks the TNF-α protein (tumor necrosis factor alpha) - this is one of the signaling molecules that stimulates the inflammatory response and which is abundantly secreted by T lymphocytes. If the inflammatory signal was suppressed, the grip in the paws of the mice increased (that is, the muscles strengthened), the heart began to pump blood better, and the animals themselves began to navigate the maze better (that is, cognitive functions improved).

Secondly, mice were given a substance called nicotinamide adenine dinucleotide, or NAD. It is one of the most important intermediary molecules involved in the energy reactions of mitochondria. With the help of additional NAD, lymphocytes had to partially compensate for the lack of energy that they had due to defective mitochondria, and stop acting to the detriment of the body. The mice that got OVER became more active and their heart function improved.

TNF protein blockers are now prescribed for chronic inflammation, such as rheumatoid arthritis; there are also commercial drugs that increase the level of NAD. Perhaps they can be used to slow down aging not only in mice, but also in humans. However, according to News from Science (Defective immune cells could make us old), the mice in the experiment aged unnaturally – earlier than usual and due to a special mutation in the mitochondrial protein of T cells. As a result, we found out that T-cells may be directly related to aging, but it is not a fact that the same methods that inhibited aging in experimental mice will work in people who have aged in the usual way.

Portal "Eternal youth" http://vechnayamolodost.ru