Self-tolerance

Self-tolerance refers to the immune system's ability to distinguish between the body's own tissues and foreign substances, preventing the immune system from attacking the body itself. This intricate process is crucial for maintaining health and preventing autoimmune diseases, where the immune system mistakenly targets the body's own cells. It involves multiple mechanisms that suppress or eliminate self-reactive immune cells, ensuring that the immune response is directed towards external threats and not towards self-antigens. This process starts during the development of immune cells and continues throughout life to maintain immunologic balance. Without self-tolerance, chronic inflammation, tissue damage, and various autoimmune conditions would be widespread, making self-tolerance a fundamental principle of immunology. This is mainly due to the absence of autoreactive cells.

Self-tolerance meaning with examples

• During embryonic development, the thymus plays a crucial role in establishing self-tolerance by eliminating or inactivating T cells that recognize self-antigens. This ensures that the body does not mount an immune response against its own cells, avoiding autoimmune reactions later in life. Disruptions to thymic function can lead to autoimmune disorders.
• Individuals with strong self-tolerance rarely experience autoimmune diseases. This is because their immune systems effectively identify and eliminate self-reactive cells, preventing the attack on their own tissues and maintaining a state of immune homeostasis. This immune equilibrium shields the body from self-inflicted harm.
• Research into enhancing self-tolerance is a key focus in treating autoimmune diseases. Therapies are being developed to restore or enhance self-tolerance by retraining the immune system to accept self-antigens and halt the progression of autoimmune conditions. This includes treatments to remove autoreactive cells.
• Exposure to specific antigens or treatments can sometimes induce self-tolerance. For example, administering certain proteins orally can, in some cases, tolerize the immune system, preventing it from attacking the body's own tissues and cells. This is one approach to tackling autoimmune diseases.