tolerogen

A tolerogen is a substance that induces a state of immune tolerance, meaning the immune system learns not to react against it. This is a form of specific immune unresponsiveness. Unlike immunogens, which provoke an immune response, tolerogens are designed to prevent one. This can be achieved through various mechanisms, often involving the induction of regulatory T cells (Tregs) or the deletion of self-reactive immune cells.

The concept of tolerogens is particularly relevant in the context of transplantation and autoimmune diseases. In transplantation, the immune system normally recognizes foreign donor organs as a threat and mounts an attack. Tolerogens could potentially be used to pre-treat recipients or donor organs to make the immune system accept the transplant without the need for broad immunosuppression, which carries significant side effects.

Similarly, in autoimmune diseases, the immune system mistakenly attacks the body's own tissues. Tolerogens derived from self-antigens could be administered to retrain the immune system to recognize these tissues as "self" and cease the autoimmune attack. Research into tolerogens involves identifying specific antigens and developing methods to deliver them in a way that promotes tolerance rather than immunity. This is an active area of immunological research with potential therapeutic applications.