La reconnaissance immunologique du soi : quelles frontières entre autoréactivité physiologique et pathologie autoimmune ?

Abstract

Il existe chez l' individu sain des cellules T et des cellules B autoreactives, dont l' activation et l' expansion sont etroitement controlees. L' expansion anormale de clones autoreactifs au cours d' une maladie auto-immune pourrait etre la consequence: (1) soit d' une stimulation du systeme immunitaire par un autoantigene qui se comporterait comme un immunogene; (2) soit d' une deregulation des processus moleculaires et cellulaires qui controlent normalement les cellules B et les cellules T autoreactives. Bien que la plupart - des maladies auto-immunes soient traitees par des strategies immunosuppressives non specifiques, les concepts presentes soulignent la necessite d' une utilisation plus large d' autres approches therapeutiques: immunoglobulines intraveineuses (IgIV), cytokines et antagonistes, anticorps monoclonaux diriges contre certaines molecules de surface des lymphocytes, induction de tolerance orale a l' auto-antigene.

Self reactive T and B cells are present in healthy individuals. Thus, activation and expansion of autoreactive cells in autoimmune disease may result either from the stimulation of the immune system by a self antigen that acquired immunogenic properties or from defective regulation of mechanisms that normally control autoreactivity. Most autoimmune diseases are currently treated with non-specific immunosuppressive strategies. However, the concepts discussed in the present review should encourage alternative therapeutic approaches such as intravenous immunoglobulins, cytokines and their antagonists, monoclonal antibodies directed toward immunoregulatory molecules of T and B lymphocytes and oral tolerance. [References: 40]