Glycosylation changes in hFUT1 transgenic mice increase TCR signaling and apoptosis resulting in thymocyte maturation arrest

Abstract

Glycosylation of cell surface proteins is important in thymocyte maturation. In particular, the level of sialylation of key glycoproteins such as CD45 is believed to play a major role in regulating TCR signaling, adhesion and apoptosis of developing thymocytes. We show here that transgenic expression of human α1-2 fucosyltransferase (hFUT1) in mice resulted in a marked shift from sialylation to fucosylation of thymocyte glycoproteins. This was associated with a significant reduction in thymocyte number, an increased rate of apoptosis in double positive and single positive thymocytes, and a maturation arrest at TCR-dependent developmental transitions reminiscent of CD45 deficiency. Indeed, CD..