Peripheral T cell Tolerance Modes of Tolerance Breakdown
  Immune ignorance Release of sequestered antigens
Aberrant expression of MHC class II
Increased expression of autoantigen/MHC class II Molecular mimicry
Epitope spreading
Anergy Release of inflammatory mediators
Increased expression or function of costimulatory molecules
Suppression of IDO
Regulatory T Cells Release of inflammatory mediators
  Apoptosis Defects in apoptosis signaling
Viral apoptosis inhibitors  
Table 4: Mechanisms of peripheral T cell tolerance.