Identification of a 16-kDa thymocyte membrane glycoprotein involved in the thymocyte/thymic medullary epithelial cell...

We have previously described a type of lymphoepithelial interaction involving CD4+ CD8+ thymocytes and a medullary epithelial cell line (E-5). This interaction is mediated by the recently described gp23/45 epithelial adhesion molecule and an as yet unknown thymocyte receptor. The present work describes a thymocyte surface glycoprotein of 16 kDa which binds both to E-5 cells and to the purified gp23/45 adhesion molecule. In addition, a thymic lymphoma cell line (Ti-6), which interacts with the E-5 cells via the gp23/45 receptor, also present a 16-kDa glycoprotein on its surface. Taken together, the data suggest that the 16-kDa thymocyte surface glycoprotein participates in the binding between these cells and the thymic epithelium.