March 25, 2022
Keio University School of Medicine
A joint research group, led by the Department of Dermatology at the Keio University School of Medicine, has discovered a new mechanism for controlling self-reactive B cells, which produce antibodies that attack the body.
The human body has B cells that produce antibodies to attack pathogens such as viruses and bacteria, protecting us from foreign invaders. A diverse range of B cells are produced in the body to create antibodies that can respond to various pathogens. In this process, B cells that attack the body's own tissues can sometimes arise, resulting in autoimmune diseases. In healthy individuals, the activity of these self-reactive B cells is suppressed, preventing the onset of autoimmune diseases. Elucidating this mechanism is crucial for understanding the pathology of autoimmune diseases.
In the context of the pathology of pemphigus vulgaris, an autoimmune disease caused by IgG antibodies against desmoglein 3 (Dsg3)—a molecule involved in adhesion between epidermal cells—this study used mice to reveal how Dsg3-reactive B cells are controlled in vivo. Specifically, the researchers discovered a unique immune state where, under normal conditions, Dsg3-reactive B cells are kept in a state of producing non-pathogenic IgM antibodies, and autoimmunity is controlled by preventing a class switch to the production of pathogenic IgG antibodies. These findings are expected to lead to the development of new therapeutic and preventive methods for autoimmune diseases involving autoantibodies, including pemphigus.
The results of this research were published in the American scientific journal "Journal of Immunology" on February 1, 2022 (U.S. Central Time).
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