Unformatted text preview: :-elimination of thymocytes that bind to self MHC with high affinity (bind too tight activation)-thymocytes here intereact w/ APC (DC + Macrophage) & medullary epithelial cells that express self Ag + MHCI/II-strong binding to self+MHC too strongly TCR signaling, activation of T cell (bad) apoptosis-some t cells reactive w/ self molec outside of thymus (problem) How to rid t cells that recognize peptides from tissue specific proteins sometimes presented by medullary thymic epithelial cells? AIRE = tf How TCR lead to either +/- selection?-TCR with diff affinities for diff peptides-avidity of TCR for particular peptide: affinity + number of peptides-avidity for diff peptides distinct signals + vs – selection...
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- Spring '08
- Epithelial cells, T Cell, Thymus, self MHC