Myeloid cells' evasion of melanoma immunity.

An immune-suppressive role of myeloid-derived suppressor cells (MDSCs) in melanoma has long been speculated, whereas molecular mechanisms underlying this role are not well understood. Here, Chung and colleagues show that dendritic cell-associated, heparan sulfate proteoglycans-dependent integrin ligand (DC-HIL), a cell surface immune-modulatory molecule, is highly expressed on tumor-associated MDSCs. Genetic ablation or antibody blockade of DC-HIL delays the growth of transplantable B16 melanoma in syngeneic mice, which is accompanied by enhanced antitumor T-cell activities. These findings support a role for DC-HIL in immune evasion within the melanoma microenvironment.