SLAMF7 (CS1/CD319)

Class

Monoclonal antibody (immunostimulatory, NK-cell-mediated ADCC)

Pathway

Dual mechanism — directly activates NK cells via SLAMF7 engagement and tags SLAMF7-expressing myeloma cells for NK-cell-mediated antibody-dependent cellular cytotoxicity

SLAMF7 (also known as CS1 or CD319) is a cell-surface protein belonging to the signaling lymphocytic activation molecule (SLAM) family of immune receptors. It is expressed at high, fairly uniform density on malignant plasma cells in multiple myeloma, and its normal expression is largely restricted to hematopoietic cells such as natural killer (NK) cells, plasma cells, and some other lymphocytes. This restricted distribution makes SLAMF7 a useful tumor-associated marker that can be targeted without broadly affecting tissues outside the blood and immune system. Monoclonal antibodies directed against SLAMF7 act through a dual mechanism. First, by coating myeloma cells with antibody, they mark these cells for destruction through antibody-dependent cellular cytotoxicity (ADCC), a process in which NK cells recognize the antibody bound to the tumor surface and kill it. Second, because NK cells themselves carry SLAMF7, the same antibody can engage and directly activate these effector cells, increasing their cytotoxic capacity independently of tumor recognition. This combination of tagging the tumor and priming the immune cells responsible for eliminating it is particularly relevant in multiple myeloma, where enhancing NK-cell-mediated clearance of malignant plasma cells complements therapies that work through other mechanisms.