title: Cutting edge: identification of the targets of clonal deletion in an unmanipulated thymus.
abstract: Autoreactive thymocytes can be eliminated by clonal deletion during their development in the thymus. The precise developmental stage(s) at which clonal deletion occurs in a normal thymus has been difficult to assess, in large part because of the absence of a specific marker for TCR-mediated apoptosis. In this report, we reveal that Nur77 expression can be used as a specific marker of clonal deletion in an unmanipulated thymus and directly identify TCRintCD4+CD8+ and semimature CD4+CD8- thymocytes as the principal targets of deletion. These data indicate that clonal deletion normally occurs at a relatively late stage of development, as cells mature from CD4+CD8+ thymocytes to single-positive T cells.
authors.affiliation: Department of Biology, Haverford College, Haverford, PA 19041, USA.
authors.forename: Hyung J
authors.initials: HJ
authors.lastname: Cho
authors.forename: Samuel G
authors.initials: SG
authors.lastname: Edmondson
authors.forename: Arden D
authors.initials: AD
authors.lastname: Miller
authors.forename: MacLean
authors.initials: M
authors.lastname: Sellars
authors.forename: Shawn T
authors.initials: ST
authors.lastname: Alexander
authors.forename: Selin
authors.initials: S
authors.lastname: Somersan
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Punt
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D015704:CD4 Antigens / Q000096:biosynthesis; D016827:CD8 Antigens / Q000096:biosynthesis; D002454:Cell Differentiation / Q000276:immunology; D017637:Clonal Deletion / Q000276:immunology*; D004268:DNA-Binding Proteins / Q000096:biosynthesis; D005434:Flow Cytometry; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D018160:Receptors, Cytoplasmic and Nuclear; D011987:Receptors, Steroid; D016176:T-Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D014157:Transcription Factors / Q000096:biosynthesis
chemical_list: D015415:Biomarkers; D015704:CD4 Antigens; D016827:CD8 Antigens; D004268:DNA-Binding Proteins; C539818:Nr4a1 protein, mouse; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D018160:Receptors, Cytoplasmic and Nuclear; D011987:Receptors, Steroid; D014157:Transcription Factors