How Disruption of the Body's Defense System Leads to Aging?

A group of researchers has succeeded in identifying one of the reasons for the imbalance in the immune system structure that leads to its aging. This finding, which has currently been studied among laboratory organisms, could potentially provide a perspective for prolonging the functioning of the immune system and increasing lifespan. Time leaves its effects in various forms on humans and other living beings. The process, which we have yet to find an escape from, is known as aging and senescence, but it is not a phenomenon formed by a single component. Just like a finely woven carpet that depicts a complex scene with thousands of threads, thousands of known and unknown factors come together to express the aging process, ultimately overcoming the force of life and the will to live in living beings. However, this complex picture does not deter researchers and scientists from striving to understand and identify the reasons for aging. They have focused on this issue through various pathways and are trying to recognize it similarly and provide multifaceted ways to combat it. Today, we know that a large part of the aging process results from genetic encoding recorded within the intertwined double strands of DNA in our bodies, which interrupts or reduces the expected instructions based on the processes of cellular repair and division over a specified period. Meanwhile, our various organs require more continuous repair over time and, with increased lifespan, are exposed to more risks and attacks from inside or outside the body. Therefore, the immune system must take on a more active role during this period. However, one of the problems of aging is that the structure and defense system of the human body weakens with age and cannot respond appropriately to pathogens. This weakness in the immune structure not only exposes our body to greater damage from attacks but also provides an opportunity for the invading agent to continue living within the body, allowing it to grow and evolve to adapt better to the human body. Now, a group of scientists from the University of Southern California (USC) has reported in a study published in the journal 'Cellular and Molecular Immunology' that they have identified one of the puzzles related to the aging of the immune system structure through experiments conducted on laboratory mice. Unlike drug and therapeutic tests conducted on mice, which usually require a long path before they can be implemented on humans, research aimed at understanding the functions of structures like the defense system has a high degree of generalizability to other species, including humans. In this research, the scientists introduced a subset of stem cells found in the blood as the cause of damage to the immune system structure due to aging. Generally, the human defense system consists of two defensive layers. The first part comprises cells belonging to the front line of defense, known as the innate immune system. This collection of cells is responsible for quickly and generally attacking the invading agents in the face of pathogens. The second layer of the body's defense consists of cells such as T cells and B cells, which are known for their adaptive defense system that relies on its cellular memory to target infections previously encountered rather than launching a general counterattack against attacks. This is the part that is trained in processes like vaccination to make the body resistant to future attacks. Researchers have now found that a subset of blood stem cells, for various reasons, produces an excessive number of immune cells of the innate defense structure, disrupting the necessary balance against external attacks. With the increase in general attacks from this part of the defense system, healthy organs are also attacked, ultimately leading to a state known as immune system aging and a reduction in the lifespan of organisms. We still do not know exactly why such a mechanism exists in the body, particularly with age, where this subset of immune cells excessively produces this part of the body's defensive cells. Perhaps an evolutionary mechanism for strengthening the body evolved during a time when our knowledge of the surrounding environment was less; however, this group of researchers has stated that by inhibiting this group of stem cells and controlling the excessive production of the comprehensive defense cells of the human innate defense system, the performance of the defense structure can be improved and the consequences of aging can be prevented. They have also tested this theory on mice and observed positive results. If these researchers can confirm their experimental results through repetition and reproduction—which is part of the verification process and increasing confidence in new scientific findings—and implement them in humans, there is hope that beyond directly combating aging, solutions for strengthening the immune system and perhaps preventing the development of autoimmune diseases can be found. Identifying the conditions that lead to this event and controlling it may help maintain our body's defense structure in its optimal state, which could assist in treating many of today's chronic diseases.