Malignant cells often exhibit aberrant surface glycosylation patterns, potentially altering recognition by immune cells. NK cells, sentinels of cancer immunosurveillance, express multiple receptors that allow for discrimination between healthy and malignant cells. We determined that ligands of the inhibitory sialic acid-binding lectins Siglec-7 and Siglec-9 are expressed on the surface of multiple tumor cell types including leukemia and melanoma, and that expression of these ligands protects tumor cells from NK cell responses. Evaluation of NK cells in healthy donors revealed the presence of a Siglec-9-expressing cytotoxic NK cell population with a mature phenotype and enhanced chemotactic potential. Interestingly, the Siglec-9-expressing NK cell population was reduced in peripheral blood from cancer patients. These data suggest that targeting Siglec-7 and Siglec-9 ligand-receptor interactions may enhance NK cell-based cancer therapies.
Speaker: Stephan von Gunten
Institute of Pharmacology, INO-F, Inselspital, CH-3010 Bern, Switzerland
Time: Wednesday, 27 January 2016, 13:00