Non-Th2 regulatory T-cell control of Th1 autoimmunity

The Th1/Th2 concept brought an attractive explanation of the active self to lerance which appears to control the onset of pathogenic autoimmunity. New data coming from various independent horizons indicate that self immunoregu lation could also depend to a large extent on non-Th2 cells. Original data derived from the day-3-thymectomy model, selective T-cell lymphocytopenia a nd nonobese diabetic mice are discussed in an effort to analyze similaritie s and differences in phenotype (CD25, CD62L and CD45RB) and cytokine patter n (notably interleukin (IL)-4, IL-10 and transforming growth factor (TGF)be ta) of regulatory cells involved in these models. The relationship of these cells with Th3, Tr1 and natural killer (NK) T cells are also discussed. Th e hypothesis is proposed that CD25 CD62L T cells mediate the physiologic re gulation of self regulation whereas Th2 and Th3 cells are essentially induc ed following sensitization against autoantigens.