Can an protein be tolerized against if it doesn't have an MHCII epitope? - (Mar/04/2014 )
In the classical paradigm of immunological tolerance, the majority of Tregs develop within the thymus upon presentation of MHCII epitopes from mTECs and medullary DCs. Does this mean that if a protein in the periphery doesn't have an MHCII epitope, then it can't be tolerized against?
Not sure that i understood the question correctly.
Tolerance can be induced against a protein without MHCII. T cells undergo positive selection in the thymus in that they only survive when they bind strongly enough to MHC I or MHC II (CD8 and CD4 positive T cells respectively), and negative selection in that they only survive when they do not bind strongly to the self-antigens ectopically expressed by mTECs and DCs. IIRC T regs are supposed to have an intermediate affinity here, although I'm not sure if this is just a theory or already proven.