Anti‐ergotypic Immunoregulation

T‐cell vaccination (TCV) controls pathogenic autoimmune T‐cell responses via two different regulatory cell populations: anti‐idiotypic and anti‐ergotypic T cells. Anti‐idiotypic T cells recognize clone‐specific determinants, like the CDR3 region of the T‐cell receptor. Anti‐ergotypic T cells recognize antigenic determinants derived from activation markers, which are upregulated by activated T cells, like CD25. In this review, we analyse the different components of the anti‐ergotypic response: (1) the target T cells, which can be CD8 + or CD4 + T cells that express TCR α β or TCR γ δ ; (2) the ergotope, which can be a T cell‐restricted ergotope not expressed by other cell types or a widely expressed, shared ergotope and (3) the anti‐ergotypic T cells, which are detectable in the naive immune system, but whose numbers can be expanded during the induction of an immune response against, or as a result of TCV or specific, anti‐ergotypic vaccination. Finally, we discuss possible interactions between anti‐ergotypic regulators and other regulatory T cells. We propose that the expression of major histocompatibility complex class II molecules by regulatory CD4 + CD25 + T cells may make possible the cross‐regulation of anti‐ergotypic and CD4 + CD25 + regulatory T cells, fine‐tuning immunoregulation in the mature immune system.