免疫疾病 z-bo 2020-10-26 348

　　Although stressful events in life are likely to cause autoimmune diseases, scientists still do not understand the potential chain reaction of these events. A mouse study published this week in the journal mSystems suggests that the gut microflora may play an important role in this regard. Researchers have found that the appearance of stress can cause changes in intestinal bacteria, which in turn stimulates the activity of immune cells and increases the possibility of them attacking themselves. An autoimmune disease is a disease in which the body's immune system attacks its own tissues and systems, and it is difficult to determine the root cause. Part of the reason is that the severity and symptoms of these diseases are different. They include multiple sclerosis, swelling, rheumatoid arthritis, juvenile diabetes, scleroderma and pulmonary fibrosis. The National Institutes of Health estimates that more than 20 million people in the United States suffer from autoimmune diseases, most of whom are women.

　　Researchers have identified several genetic risks, but autoimmune diseases are thought to be caused by a complex interaction between genetic and environmental factors. In this research published in the journal mSystems, BarIlan University (BarIlan University) immunologist Dr. Orly Avni collaborated with graduate student Michal Werbner and other collaborators on psychological and social stress. We investigated such environmental risks. Potential treatments provide opportunities.

　　"We know that there is a strong interaction between the immune system and microbes," Avni said. She said that an important step in understanding how stress causes autoimmune diseases is to determine the genetic response of bacteria. Research conducted by her team has shown that social stress can change the composition and transcription of the flora. She said: "The subsequent immune response to this threat weakened self tolerance." The researchers studied two groups of mice. A rat is exposed to daily stress and has dangerous contact with other major and aggressive rats. There are no other groups. Ten days later, the researchers analyzed the intestinal flora of each group of mice and found that the stressed mice had higher levels of certain bacteria. These microorganisms include Bifidobacterium and desalting bacteria, which are abundant in patients with multiple sclerosis.

　　But Avni said that interest in bacterial behavior is far greater than interest in ingredients. Studies have shown that stress leads to the activation of bacterial genes. Bacterial genes are related to potentially violent behaviors, such as growth, movement, and signals transmitted between pathogens and hosts. Microorganisms with these characteristics can spread to other parts of the body, including lymph nodes, and trigger an immune response. When the researchers analyzed the lymph nodes of stressed mice, they found an increase in the number of certain known pathogenic bacteria. They also found that a higher proportion of effector T cells are known to play a role in autoimmunity. These findings indicate that stress can cause changes in intestinal microbial activity, which in turn affects the immune response and ultimately causes physical attacks.

　　This study shows that intestinal bacteria can sense and respond to social stress, but Avni is studying how this long-term interaction between the bacteria and the host works. Point out the need for better understanding.

　　She said: "It is not enough to study the composition of species, increase or decrease. We also need to understand how microbes perceive us and change the'behavior' in response. She said this knowledge has led to tailored microbial interventions Control diseases caused by autoimmunity and other stress.