Int. J. Dev. Biol. 49: 137 - 142 (2005)

https://doi.org/10.1387/ijdb.041959js

Vol 49, Issue 2-3

Special Issue: The Nogent Institute

Regulatory T cells in the establishment and maintenance of self-tolerance: role of the thymic epithelium

Published: 1 May 2005

Josselyne Salaün*, Catherine Corbel¹ and Nicole M. Le Douarin

Laboratoire d'Embryologie Cellulaire et Moléculaire, Nogent-sur-Marne cedex, France and ¹Institut Cochin, Département Hématologie, Paris, France

Abstract

The thymus constitutes the microenvironment for T lymphocyte differentiation and acquisition of self-tolerance. Aiming to specify the contributions of the two essential parts of the thymus, namely hemopoietic and epithelial, we have devised experimental models in birds and mice. Chimeric thymuses, xenogeneic in birds and allogeneic in mice, were constructed early in development. In both models we could demonstrate a critical role of the epithelial component of the thymic stroma in induction and maintenance of self-tolerance. These experiments showed that suppression mechanisms are also implicated in these events, strongly suggesting the existence of regulatory T cells in both models. Before these experiments the control of self-tolerance was usually attributed to suppressive cells. However, as the cell phenotypes were not identified, the role of these cells was disregarded. Numerous studies since our investigations argue in favour of regulatory mechanisms. The work we initiated several years ago represents a contribution to our understanding of the two linked and opposite aspects of immune-responded control, namely self-tolerance and autoimmunity

Keywords

embryo, thymus, graft, self-recognition, regulatory T-cell