title: NKT cells derive from double-positive thymocytes that are positively selected by CD1d.
abstract: CD1d-reactive NKT cells are a separate T cell sublineage. Instructive models propose that NKT cells branch off the mainstream developmental pathway because of their T cell antigen receptor specificity, whereas stochastic models would propose that they develop from precursor cells committed to this sublineage before variable-gene rearrangement. We show here that immature double-positive (DP) thymocytes form the canonical rearranged Valpha gene of NKT cells at nearly equivalent frequencies in the presence or absence of CD1d expression. After interacting with CD1d in the thymus, these cells give rise to expanded populations of NKT cells-including both CD4+ and double-negative lymphocytes in the thymus and periphery-that express this alpha chain. These results confirm the existence of a DP intermediate for CD1d-reactive NKT cells. They also show that the early developmental stages of these T cells are not governed by a distinct mechanism, which is consistent with the TCR-instructive model of differentiation.
authors.affiliation: La Jolla Institute for Allergy and Immunology, 10355 Science Center Drive, San Diego, CA 92121, USA.
authors.forename: L
authors.initials: L
authors.lastname: Gapin
authors.forename: J L
authors.initials: JL
authors.lastname: Matsuda
authors.forename: C D
authors.initials: CD
authors.lastname: Surh
authors.forename: M
authors.initials: M
authors.lastname: Kronenberg
mesh_terms: D000818:Animals; D018949:Antigens, CD1 / Q000032:analysis* / Q000235:genetics; D055610:Antigens, CD1d; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002454:Cell Differentiation; D019070:Cell Lineage; D002478:Cells, Cultured; D005699:Galactosylceramides / Q000378:metabolism; D015332:Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor; D007133:Immunoglobulin Joining Region / Q000096:biosynthesis / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000096:biosynthesis / Q000235:genetics; D016130:Immunophenotyping; D008213:Lymphocyte Activation; D051379:Mice; D018345:Mice, Knockout; D012333:RNA, Messenger / Q000096:biosynthesis; D013234:Stem Cells / Q000166:cytology; D016176:T-Lymphocyte Subsets / Q000145:classification / Q000276:immunology*; D013950:Thymus Gland / Q000254:growth & development / Q000276:immunology*
chemical_list: D018949:Antigens, CD1; D055610:Antigens, CD1d; D005699:Galactosylceramides; D007133:Immunoglobulin Joining Region; D007135:Immunoglobulin Variable Region; D012333:RNA, Messenger