Regulation of galectin-3-induced apoptosis of Jurkat cells by both O-glycans and N-glycans on CD45.

Galectin-3 has been reported to induce apoptosis of Jurkat cells through binding receptors such as CD45. CD45RABC is heavily O-glycosylated and N-glycosylated, while CD45RO is only N-glycosylated. In this study, no apoptosis induced by galectin-3 was detected in CD45RO-transfected cells, whereas apoptosis of CD45RABC-transfected cells was observed, implying that O-glycans on CD45 might play roles in galectin-3-induced apoptosis. O-Glycosylation inhibition assay further suggests the role of O-glycans on CD45 in regulation of galectin-3-induced apoptosis. We also found that deglycosylation at N327 of CD45RO resulted in increased binding to galectin-3 without affecting apoptosis, while deglycosylation at N36 or N109 of CD45RO enhanced galectin-3-induced apoptosis. These data demonstrate that galectin-3-induced apoptosis of Jurkat cells is regulated by both O-glycans and N-glycans on CD45.