Immune tolerance

Definition

Immune tolerance is the immune system's ability to recognize and not attack the body's own cells and tissues. It prevents autoimmune diseases by distinguishing between self and non-self antigens.

5 Must Know Facts For Your Next Test

1. Immune tolerance is critical for preventing autoimmune reactions where the body attacks its own tissues.
2. Central tolerance occurs in the thymus and bone marrow, where T-cells and B-cells that react against self-antigens are eliminated.
3. Peripheral tolerance takes place outside primary lymphoid organs and involves mechanisms such as anergy, regulatory T-cells, and deletion to control self-reactive cells.
4. Breakdown of immune tolerance can lead to autoimmune diseases like type 1 diabetes, rheumatoid arthritis, and multiple sclerosis.
5. Immunological memory does not form against self-antigens due to immune tolerance mechanisms.

Review Questions

• What are the two main types of immune tolerance and where do they occur?
• How does peripheral tolerance prevent autoimmunity?
• Name three autoimmune diseases that can result from a failure in immune tolerance.

Related terms

Autoimmune Disease: A condition in which the immune system mistakenly attacks the body's own tissues.

Regulatory T-Cells (Tregs): A subset of T-cells involved in maintaining peripheral tolerance by suppressing immune responses against self-antigens.

Anergy: A state of unresponsiveness to antigen stimulation typically used as a mechanism in peripheral tolerance to prevent autoimmunity.