Thymic selection reinterpreted.
To summarize, I have attempted to present evidence that the unselected thymocyte TCR repertoire has such a propensity to recognize MHC/peptide at high affinity that it is likely that, were tolerance induction to be invariably dominant over positive selection, all T cells would be deleted or anergized. If this is true it follows that positive selection must in fact be capable of being the dominant process. I have further suggested that the existence of peptides capable of antagonizing T-cell activation in the thymus could inhibit deletion, and that this might correspond to positive selection.
Elliot
J I
JI
Section of Transplantation Biology, Clinical Research Centre, Harrow, Middx., U.K.
D000818:Animals; D006182:H-Y Antigen; D006801:Humans; D008285:Major Histocompatibility Complex / Q000502:physiology*; D008954:Models, Biological; D010446:Peptide Fragments / Q000276:immunology; D017634:Self Tolerance / Q000502:physiology*; D013601:T-Lymphocytes / Q000502:physiology*; D013950:Thymus Gland / Q000166:cytology*
D006182:H-Y Antigen; D010446:Peptide Fragments