Autoreaktive

Autoreaktive is a term used to describe immune responses or components that target the body's own tissues, i.e., self-antigens. In immunology, autoreactive T cells and autoreactive antibodies can escape normal tolerance and recognize self-antigens, potentially contributing to autoimmune disease. Normally, central tolerance in the thymus and bone marrow, and peripheral tolerance mechanisms, delete or inactivate strongly self-reactive clones. When tolerance fails, autoreactive B cells may produce autoantibodies and autoreactive T cells may infiltrate tissues, leading to inflammation and tissue destruction. Several mechanisms promote autoreactivity, including molecular mimicry (pathogens sharing epitopes with self-antigens), bystander activation, epitope spreading, and release of sequestered antigens during tissue damage. Autoreactive responses may be organ-specific, as in type 1 diabetes (insulin, GAD65), or systemic, as in systemic lupus erythematosus (various nuclear antigens). Diagnosis often relies on detection of autoantibodies in serum or identification of autoreactive T cells, along with clinical symptoms. Autoreactive processes are central to many autoimmune diseases, but not all autoreactive cells cause disease; regulatory T cells, anergy, and immune checkpoint pathways help restrain them. Treatment focuses on reducing immune activity and inflammation, through immunosuppressants, targeted biologics (for example against TNF, IL-6), and therapies aimed at restoring tolerance in some contexts. The study of autoreactivity remains key to understanding and managing autoimmunity.