Immunological Tolerance and Autoimmunity

Which process eliminates immature T cells that recognize self-antigens with high affinity in the thymus?

What is the primary function of T regulatory cells in peripheral tolerance?

Which of the following is NOT a mechanism of peripheral tolerance?

What is the term for the breakdown of immunological tolerance leading to an immune response against self-antigens?

Which of the following autoimmune diseases is an example of an organ-specific autoimmune disease?

What is the primary role of immunological tolerance in preventing autoimmune diseases?

Which of the following is a hormonal influence that can contribute to autoimmunity?

What is the term for the process by which immature T cells that recognize self-antigens with low affinity are spared and mature?

Central Tolerance

Occurs in the thymus
Immature T cells that recognize self-antigens with high affinity are eliminated through apoptosis (negative selection)
T cells that recognize self-antigens with low affinity are spared and mature (positive selection)

Peripheral Tolerance

Occurs in peripheral tissues
Involves mechanisms to prevent autoimmune responses:
- T regulatory cells (Tregs) suppress autoreactive T cells
- Activation-induced cell death (AICD) eliminates autoreactive T cells
- Immune privilege: certain tissues (e.g., eye, brain) have reduced immune surveillance
- Immune suppression: cytokines (e.g., TGF-β, IL-10) and cells (e.g., Tregs) suppress immune responses

Autoimmunity

Occurs when tolerance is broken, and the immune system attacks self-antigens
Can be caused by:
- Genetic predisposition
- Environmental triggers (e.g., infections, toxins)
- Hormonal influences
- Immune system dysfunction
Examples of autoimmune diseases:
- Rheumatoid arthritis
- Lupus
- Hashimoto's thyroiditis
- Multiple sclerosis

Immunological Tolerance and Autoimmunity

Immunological tolerance is crucial for preventing autoimmune diseases
Autoimmune diseases occur when immunological tolerance is broken
Understanding tolerance mechanisms can provide insights into autoimmune disease pathogenesis and potential therapeutic targets

Understand the mechanisms of central and peripheral tolerance, and how their breakdown can lead to autoimmune diseases. Learn about the different types of tolerance, their importance, and examples of autoimmune diseases. Test your knowledge on immunological tolerance and autoimmunity!