Immunologic tolerance (null)

Immunologic tolerance refers to the state or process by which the immune system is unresponsive or non-reactive to specific antigens, particularly one’s own tissues (self-antigens), and certain harmless environmental antigens. It is essential for preventing autoimmune diseases and regulating excessive immune responses. Tolerance is established centrally (in primary lymphoid tissues like thymus/bone marrow) and peripherally (in secondary lymphoid tissues and other organs), mediated by processes such as clonal deletion, anergy, and induction of regulatory T cells and B cells. Failure of tolerance can result in autoimmune diseases, while overactive tolerance mechanisms can allow cancer cells or chronic infections to persist. While immunologic tolerance itself is not a discrete molecular target, its restoration is a therapeutic goal in numerous immune-mediated diseases, and multiple molecular pathways involved in tolerance induction are being targeted by immunomodulatory therapies.

Other names

Immune toleranceimmunotoleranceimmunological tolerance

Induction of regulatory T cells or regulatory B cells (Treg, Breg); Deletion or anergy of autoreactive lymphocytes (central/peripheral tolerance); Immune checkpoint modulation (PD-1, CTLA-4 pathways); Tolerogenic antigen presentation and/or cytokine milieu (e.g., IL-10, TGF-β)