title: Regulated expression of Ly-6A.2 is important for T cell development.
abstract: Ly-6A.2 is a surface protein on T cells that may play a role in lymphocyte activation. The regulation of Ly-6A.2 expression during T cell lymphopoiesis has been intriguing. It is one of the earliest markers expressed on pluripotent hemopoietic stem cells and is present on both primitive and mature T cells, but its expression is extinguished in the thymus during key developmental stages. To determine whether Ly-6A.2 is active on developing T cells, as well as the significance of its developmental regulation, Ly-6A.2 was expressed throughout T cell development under control of the T cell-specific human CD2 enhancer in transgenic mice. The constitutive overexpression of Ly-6A.2 in vivo led to a marked impairment in the generation of thymocytes. Development was arrested at the time in thymic development when Ly-6A.2 expression is normally turned off. These results indicate that the regulated expression of Ly-6A.2 in thymocytes may be important for normal development. Moreover, these findings demonstrate that Ly-6A.2 is active in the thymic microenvironment.
authors.affiliation: Dana-Farber Cancer Institute, Boston, MA 02115, USA.
authors.forename: A
authors.initials: A
authors.lastname: Bamezai
authors.forename: D
authors.initials: D
authors.lastname: Palliser
authors.forename: A
authors.initials: A
authors.lastname: Berezovskaya
authors.forename: J
authors.initials: J
authors.lastname: McGrew
authors.forename: K
authors.initials: K
authors.lastname: Higgins
authors.forename: E
authors.initials: E
authors.lastname: Lacy
authors.forename: K L
authors.initials: KL
authors.lastname: Rock
mesh_terms: D000818:Animals; D000950:Antigens, Ly / Q000096:biosynthesis* / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology*; D005314:Embryonic and Fetal Development / Q000276:immunology; D005434:Flow Cytometry; D018507:Gene Expression Regulation, Developmental / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000196:embryology*
chemical_list: D000950:Antigens, Ly