American scientists have discovered in the human body an unknown type of cell called X-lymphocytes. They are able to function like the other two types of cells and can cause type 1 diabetes. This is reported by the publication Live Science.
According to the researchers, there are about seven X immune cells for ten thousand white blood cells. At the same time, they can play a large role in the development of autoimmune reactions. In type 1 diabetes, the immune system begins to destroy the beta cells of the pancreas that produce insulin. An important role in the pathological process is played by a protein complex called the main histocompatibility complex (MHC).
MHC is located on the surface of immune cells and binds to antigens - foreign substances. In this form, antigens are presented to T-lymphocytes, which begin to destroy infected cells and stimulate other types of lymphocytes to fight the infection. It has been shown that insulin becomes a likely antigen in the case of type 1 diabetes. At the same time, it was shown that MHC weakly binds to insulin, which in theory should not cause a strong immune response.
The results of a new study show that X immune cells have receptors for T-lymphocytes and B-lymphocytes, which play an important role in the presentation of antigen to T cells. X cells cause lymphocytes that attack beta cells to divide at a high rate, which greatly enhances the autoimmune process. However, it is not yet known what exactly causes this process.