Simply put, the immune system allows us to avoid serious damage and the destruction of foreign microorganisms, and even helps our body repair damaged and damaged tissues, and maintain normal body functions to the maximum extent. For example, if we have a wound on our skin and bacteria grow here, an infection has occurred. After infection, the body activates the immune system, and immune inflammatory response occurs through immune cells. We will notice a typical change is the phenomenon of local redness, swelling, heat and pain. If the infection is severe and the inflammatory response is severe, reactions such as abscesses will occur, and finally infection It gradually subsided, and the wound became scarred or completely returned to normal. If this process fails, the bacteria will spread from the wound to the whole body, which can cause sepsis and even death of the whole body.

           In this process, the immune system is basically good. But despite this, the inflammation caused by the immune response can also cause pain, temporary or permanent damage to the tissue structure, and changes in the body's energy metabolism, such as fever. Therefore, the immune response has the function of fighting against injury and infection, and it also needs to pay a certain price.

               What's more troublesome is that the immune system itself can also be disturbed. The more common one is allergic reactions caused by over-immune reactions. Generally, allergic reactions are caused by our body's over-sensitive response to foreign antigens such as pollen mites that are not seriously harmful. Another more harmful problem is autoimmune disease. The core of the problem is that the immune system has an immune attack on the body's own components and cells, and treats itself as an enemy. The immune system, regardless of enemy or enemy, is extremely harmful. Typical examples include rheumatoid arthritis, systemic lupus erythematosus, and type 1 diabetes. In this case, the immune system is out of control or over-activated. If it is to further improve the function, isn't it just for the chaos.

           Therefore, from the perspective that the immune system may cause harm to the body itself, improving immunity is not a very good description, and it is easy to cause misunderstandings. At least the academic community does not like to use this expression. Is there a better situation for improving immunity? If the human body experiences a decline in immune system function, and if this decreased immune function is restored, this situation is similar to boosting immunity. There are two situations in which the immune system will decline in the population as a whole. One is a child who is just 6 months old, because the immune antibodies from the mother are gradually inactivated, but their own immune system has not been fully established, and the immune function is relatively poor. Bacteria and virus infections are very prone to occur at this stage.

          The other is that with age, the immune function will gradually decline in the old age, and the immune response will be slow. If an infection occurs at this time, it is not easy to overcome it smoothly, and it is easy to spread throughout the body and even bring serious consequences. Is there any way to overcome this problem? People have actually taken a lot of countermeasures. The basic logic of the clinical use of human blood immunoglobulin injection is based on this reason.

              A recent study has provided new ideas for restoring the decline in immune function caused by aging. The decline in immune function of the elderly can be said to be a feature of the aging of the immune system. If aging can be reversed, then the declining immune function can be restored to normal. On August 29, 2019, Professor Simon's group from the Kennedy Institute of Rheumatology, Oxford University Medical School (Dr. Zhang Hanlin is the first author of the paper) published an article Polyamines Control eIF5AHypusination, TFEB Translation, and Autophagy in Molecular Cell. to Reverse B Cell Senescence, reported their new discoveries in the direction of immune aging.

             The study found that the antibody response of normal aging mice to the immunogen was very weak, and when the mice were given spermidine through drinking water throughout the experiment, their antibody production increased several times. Subsequent studies conducted research on the cytological basis that caused this change and found that spermidine activated the autophagy signaling pathway to produce this effect. Blood samples from healthy volunteers of different ages were tested. Similar to the results observed in aging mice, the immune cells of the elderly also showed a significant decrease in spermidine content and autophagy signaling pathway protein expression. When immune cells are activated in vitro, old-derived cells also have lower levels of autophagy and antibody secretion. These defects can be improved by adding spermidine to the culture medium.

           This shows that spermidine can also promote the function of immune cells in the elderly and has clear clinical application potential. Of course, whether spermidine can be used to improve the immunity of the elderly, there are still many problems that need to be resolved. However, this recovery of immune function in the case of aging is the best explanation for improving immunity. A big inspiration for us is that Hydrogen, as a function of repairing the decline of aging immunity, may be a subject worthy of study.