A previously unknown safety mechanism in our immune system keeps the body free from autoimmune diseases. Researchers from Karolinska Institutet have discovered that a cell in our inherited immune system can prevent our adaptive (learned) immune system from reacting to the body's native cells, which can otherwise lead to autoimmune diseases such as SLE. The study is published in the academic journal Nature Immunology. Autoimmune diseases and allergies, in which the immune system triggers an immunological reaction in sufferers, are becoming increasingly common. In some cases, such as the rheumatic disease SLE, the immune system reacts to the body's own cells. One of the most important components of our learned (adaptive) immune system is the white blood cells called B lymphocytes, which are one of the main causal factors of many autoimmune diseases, including SLE, since it is these cells that start to react to the body's native structures, giving rise to the symptoms....