title: Intracellular phenotype screen of MHC1 W632 in SPPL3ko
design: Various glycosphingolipids (GSLs) are expressed all over the cell surface, however their functions are currently mostly unknown. Here, the cell surface GSL-repertoire is identified as a new regulatory layer of HLA class I-directed immune responses. Specifically the protease SPPL3 controls the HLA class I-affecting GSL-repertoire by inhibiting the enzyme B3GNT5.