title: Modest cortex and promiscuous medulla for thymic repertoire formation.
abstract: Recent advances in the understanding of medullary thymic epithelial cell biology, and especially of their promiscuous gene expression, have highlighted the indispensable role of thymic medulla in shaping a self-tolerant T-cell repertoire. Additionally, our recent results have shown that cortical thymic epithelial cells possess a unique proteasome (the so-called thymoproteasome), which seems to possess limited protein degradation capability for generating peptides that are loaded onto class I major histocompatibility complex molecules. We discuss here the unique role of thymoproteasomes in the development and repertoire formation of CD8+ T cells, focusing on the stepwise and contrasting roles of cortical epithelial cells and medullary epithelial cells. These results could offer fundamental new insights into the molecular mechanisms of T-cell repertoire selection.
authors.affiliation: Division of Experimental Immunology, Institute for Genome Research, University of Tokushima, Tokushima 770-8503, Japan. takahama@genome.tokushima-u.ac.jp <takahama@genome.tokushima-u.ac.jp>
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Takahama
authors.forename: Keiji
authors.initials: K
authors.lastname: Tanaka
authors.forename: Shigeo
authors.initials: S
authors.lastname: Murata
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D004848:Epithelium / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000096:biosynthesis / Q000276:immunology*; D015870:Gene Expression / Q000276:immunology; D006801:Humans; D008285:Major Histocompatibility Complex / Q000276:immunology; D009842:Oligopeptides / Q000096:biosynthesis / Q000276:immunology*; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D011487:Protein Conformation; D017634:Self Tolerance; D037182:T-Cell Antigen Receptor Specificity / Q000235:genetics / Q000276:immunology; D013950:Thymus Gland / Q000254:growth & development / Q000276:immunology*
chemical_list: D018984:Epitopes, T-Lymphocyte; C408902:MHC binding peptide; D009842:Oligopeptides; D010455:Peptides