Immune tolerance

Immune tolerance is the selective suppression of immune responses to particular antigens, especially the body’s own tissues and harmless substances. It is maintained by mechanisms that delete, disable, or regulate reactive immune cells.

Central tolerance: The elimination or alteration of self-reactive lymphocytes during their development in primary immune organs. It removes many self-reactive T cells in the thymus and B cells in the bone marrow.
Antigen: A molecule or molecular structure that can be specifically recognized by antibodies or lymphocyte receptors. Tolerance is specific to antigens rather than a general shutdown of immunity.
Autoimmunity: An immune response directed against the body's own molecules, cells, or tissues. Autoimmunity arises when tolerance fails to prevent damaging self-directed responses.
Oral tolerance: Reduced immune responsiveness to an antigen encountered through the gastrointestinal tract. It helps prevent unnecessary responses to food proteins and other gut antigens.
Immune tolerance therapy: A treatment strategy designed to suppress immune responses to selected antigens while preserving broader immunity. The central challenge is achieving reliable antigen specificity without weakening protection against infection.
Peripheral tolerance: The control of mature self-reactive lymphocytes outside primary immune organs. It restrains autoreactive cells that escape central screening.
T cell receptor: A receptor on T cells that recognizes antigen fragments displayed by major histocompatibility complex molecules. Self-reactive T-cell receptors are screened during development and controlled afterward.
Autoimmune disease: A disease caused by immune responses against the body's own tissues. These disorders are clinical consequences of breakdowns in self-tolerance.
Allergen immunotherapy: Treatment that repeatedly exposes a person to an allergen to reduce allergic reactions over time. It seeks to establish lasting tolerance to otherwise harmless environmental antigens.
Antigen-specific immunotherapy: An immune treatment directed at a defined antigen rather than the immune system as a whole. It offers a route to restoring tolerance while minimizing generalized immune suppression.

Linked from 16 pages