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 membraneassociated 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.