Residual public repertoires to self

The consensus view about the constitution of the T cell receptor repertoire has shifted greatly even during this decade. Although the discovery of aut oimmunity in the fifties had clearly shown that a repertoire must exist dir ected against self antigens, the extent of this repertoire was not fully ap preciated. In our work we have tried to elucidate the nature of the antigen ic specificities against which this self-directed repertoire is directed. T he non-tolerized (residual) self-directed repertoire is a direct consequenc e of the hierarchy of antigenic determinant display, and is the most import ant influence in the organism's choice of which T cells to delete. Certain determinants remain "silent" and are neither displayed in the thymus nor in the periphery: these are a heterogeneous group which are invisible to T ce lls for a variety of reasons. One reason relates to the processing and pres entation of determinants, and a second derives from the nature of the T cel l receptor (TcR) and the avidity of the T cell for its target specificity. (C) 2000 Published by Elsevier Science B.V. All rights reserved.