1. Tolerance and Autoimmunity
Autoimmunity – inappropriate response of the immune system against self component.
Tolerance – mechanisms that exist to protect an individual from potentially self-reactive lymphocytes.

2. Tolerance and Autoimmunity

3. Tolerance and Autoimmunity

4. Tolerance and Autoimmunity
Establishment and Maintenance of Tolerance
Factors that promote tolerance:
 High doses of antigen
 Persistence of antigen in host
 Intravenous or oral introduction
 Absence of adjuvants
 Low levels of costimulators

5. Tolerance and Autoimmunity
Establishment and Maintenance of Tolerance

6. Tolerance and Autoimmunity
Regulatory T cells (Treg cells)

7. Tolerance and Autoimmunity

8. Tolerance and Autoimmunity

9. Tolerance and Autoimmunity
Contributors to autoimmunity:
 CD4+ T cell
 MHC
 TCR

10. Tolerance and Autoimmunity
Proposed mechanisms for induction of autoimmunity

11. Autoimmunity
Molecular mimicry

12. Autoimmunity Current Treatments:  Immunosuppressive drugs
 Thymectomy
 Plamapheresis
 TNF-a blockers