Regulated expression of Ly-6A.2 is important for T cell development.
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.
Bamezai
A
A
Dana-Farber Cancer Institute, Boston, MA 02115, USA.
Palliser
D
D
Berezovskaya
A
A
McGrew
J
J
Higgins
K
K
Lacy
E
E
Rock
K L
KL
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*
D000950:Antigens, Ly