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.

Tolerance and Autoimmunity

Tolerance and Autoimmunity

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

Tolerance and Autoimmunity Establishment and Maintenance of Tolerance

Tolerance and Autoimmunity Regulatory T cells (Treg cells)

Tolerance and Autoimmunity

Tolerance and Autoimmunity

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

Tolerance and Autoimmunity Proposed mechanisms for induction of autoimmunity

Autoimmunity Molecular mimicry

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