Prosaposin hyperglycosylation: a novel tumor immune escape mechanism and implications for cancer immunotherapy

In a recent article published in Science , Sharma et al. describes the essential role of saposins in cross-presentation of tumor membrane-associated antigens by dendritic cells (DC) to CD8 + T cells. 1 However, antigen cross-presentation, which is fundamental in cancer cell elimination, is hindered in tumor DC by hyperglycosylation of the common saposin precursor prosaposin (pSAP) leading to impaired T cell tumor immunity—yet, the potential of recombinant pSAP to re-establish T cell responses may offer a novel way to counteract immune evasion in a therapeutic approach.