Isolation of a cDNA encoding thymic shared antigen-1. A new member of the Ly6 family with a possible role in T cell development

Abstract

We have previously characterized a novel mouse thymocyte marker, defined as thymic shared Ag-1 (TSA-1), present on both immature thymocytes and a subset of thymic medullary epithelial cells. MTS 35, a mAb specific for TSA-1, alters T cell differentiation when added to fetal thymic organ cultures, suggesting TSA-1 may be important for T cell development in the thymus. In this study, we describe the isolation of a cDNA encoding TSA-1 using transient expression of COS-7 cells and selection with MTS 35. The predicted amino acid sequence of this cDNA encodes a 15 to 17-kDa protein and the expressed protein is linked to the membrane via a phosphatidylinositol moiety. TSA-1 is transcriptionally act..