Part 7: Tolerance And Autoimmunity Flashcards
What is tolerance?
A state of the immune system usually associated with self-recognition, the immune system does not respond to self antigens”
How is tolerance developed?
Developed to self antigens during fetal development and continues to a lesser degree throughout life
When does central tolerance occur?
During lymphocyte development
What is an example of central tolerance for T cells?
Thymic education when positive/negative selection in thymus results in mature cells
What are 3 mechanisms that exist to prevent auto-reactivity of lymphocytes after they leave the thymus/bone marrow?
- Deletion
- Anergy
- Suppression
What is deletion of lymphocytes in peripheral tolerance?
Process of killing auto-reactive cells, apoptosis
What is anergy of lymphocytes in peripheral tolerance?
Lack of reaction by body’s defense mechanisms to antigens due to inadequate activation of T cells
What is suppression of lymphocytes in peripheral tolerance?
A population fo T cells, call T regulatory cells, exists that prevents other T cells from recognizing self-antigens
What is autoimmunity?
Immune system reacting to self antigens
Autoimmunity is usually characterized by the production of
Autoantibodies
