title: [Immune tolerance].
abstract: Immune tolerance reflects the absence of immune reactions to self-antigens (natural tolerance) or exogenous antigens, at least in experimental models (acquired tolerance). It results in part from central mechanisms leading to the elimination or deletion of auto-reactive B or T cell clones by apoptosis in primary lymphoid organs. In the periphery, this is reflected by more-or-less reversible states of anergy, which arise from a time or spatial discordance between the different signals required for lymphocyte activation, or from a network of interactions between lymphocytes leading to the production of antagonistic signals. The reversibility of anergy-inducing mechanisms, a deregulation of the production of certain cytokines, or incomplete clonal deletion mechanisms could explain the emergence of autoimmune diseases by a rupture of self-tolerance. As these mechanisms are not fully understood, clinical induction of tolerance by the use of nonspecific immunodepressive agents is not yet possible.
authors.affiliation: Laboratoire d'immunodifférenciation, Institut Jacques-Monod, CNRS-Université Paris 7.
authors.forename: M
authors.initials: M
authors.lastname: Seman
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology* / Q000502:physiology; D007111:Immunity, Cellular / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
vernacular_title: La tolérance immunitaire.