Glycoproteomic analysis of MGL binding protein on acute T cell leukemia cells

O-glycosylation is generally initiated by the transfer of a N-acetylgalactosamine to Ser/Thr residues of proteins, forming the Tn antigen. This truncated surface glycan is expressed at high levels by tumor cells and is associated with higher metastatic behaviour and poor prognosis of patients. The Tn antigen is recognised by the C-type macrophage galactose lectin (MGL), which induces the activation of immunosuppressive responses. Here, we investigated the MGL binding proteins in Jurkat cells. The optimization of pull-down assays and subsequent glycoproteomic analysis by mass spectrometry, allowed us to identify 17 cell surface proteins as novel MGL-ligands.