title: Differential processing of self-antigens by subsets of thymic stromal cells.
abstract: The stromal network of the thymus provides a unique environment that supports the development of mature CD4(+) and CD8(+) T cells expressing a very diverse repertoire of T cell receptors (TCR) with limited reactivity to self-antigens. Thymic cortical epithelial cells (cTECs) are specialized antigen-presenting cells (APCs) that promote the positive selection of developing thymocytes while medullary thymic epithelial cells (mTECs) and thymic dendritic cells (tDCs) induce central tolerance to self-antigens. Recent studies showed that cTECs express a unique set of proteases involved in the generation of self-peptides presented by major-histocompatibility encoded molecules (pMHC) and consequently may express a unique set of pMHC complexes. Conversely, the stromal cells of the medulla developed several mechanisms to mirror as closely as possible the constellation of self-peptides derived from peripheral tissues. Here, we discuss how these different features allow for the development of a highly diverse but poorly self-reactive repertoire of functional T cells.
authors.affiliation: Centre de Physiopathologie de Toulouse Purpan, Université Toulouse III Paul-Sabatier, Toulouse F-31300, France. sylvie.guerder@inserm.fr
authors.forename: Sylvie
authors.initials: S
authors.lastname: Guerder
authors.forename: Christophe
authors.initials: C
authors.lastname: Viret
authors.forename: Hervé
authors.initials: H
authors.lastname: Luche
authors.forename: Laurence
authors.initials: L
authors.lastname: Ardouin
authors.forename: Bernard
authors.initials: B
authors.lastname: Malissen
mesh_terms: D017951:Antigen Presentation / Q000276:immunology*; D000938:Antigen-Presenting Cells / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D004847:Epithelial Cells / Q000276:immunology; D006801:Humans; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology*
chemical_list: D001324:Autoantigens; D011948:Receptors, Antigen, T-Cell