Tolerance

Definition

Tolerance refers to the immune system's ability to recognize and avoid attacking the body's own cells and tissues. It is essential for preventing autoimmune disorders where the body mistakenly targets its own components.

5 Must Know Facts For Your Next Test

1. Tolerance is established through central and peripheral mechanisms in the immune system.
2. Central tolerance occurs in primary lymphoid organs such as the thymus and bone marrow.
3. Peripheral tolerance involves regulatory T cells (Tregs) that suppress immune responses outside primary lymphoid organs.
4. Failure of tolerance mechanisms can lead to autoimmune diseases such as rheumatoid arthritis, lupus, and multiple sclerosis.
5. Autoantigens are self-antigens that are normally tolerated by the immune system but can become targets in autoimmune disorders.

Review Questions

• What are the two main types of tolerance mechanisms in the immune system?
• How does peripheral tolerance differ from central tolerance?
• Why is tolerance important in preventing autoimmune diseases?

Related terms

Autoantigen: A normal protein or complex of proteins that is recognized by the immune system of patients with specific autoimmune diseases.

Regulatory T Cells (Tregs): A subset of T cells that maintain tolerance to self-antigens and prevent autoimmune disease.

Autoimmune Disorder: A condition arising from an abnormal immune response targeting a normal body part.