CD319. also known as SLAMF7 or CRACC, is a cell surface glycoprotein belonging to the signaling lymphocytic activation molecule (SLAM) family. It is expressed on immune cells, including natural killer (NK) cells, activated T cells, and plasma cells, where it regulates cell adhesion, activation, and immune synapse formation. CD319 plays a critical role in modulating immune responses, particularly in NK cell-mediated cytotoxicity and plasma cell survival. Its overexpression on malignant plasma cells in multiple myeloma (MM) has made it a key therapeutic target.
CD319 antibodies, such as the clinically approved elotuzumab, are monoclonal antibodies designed to target this antigen. Elotuzumab, a humanized IgG1 antibody, binds CD319 on myeloma cells and Fcγ receptors on NK cells, enhancing antibody-dependent cellular cytotoxicity (ADCC) against tumor cells. Approved in combination with immunomodulatory drugs for relapsed/refractory MM, it demonstrates the therapeutic potential of CD319-targeted immunotherapy. Other investigational antibodies aim to exploit CD319’s role in immune regulation, either by blocking inhibitory signals or activating immune effector functions.
Research continues to explore CD319’s broader roles in autoimmune diseases and solid tumors, as well as strategies to optimize antibody engineering for improved efficacy and reduced toxicity. Challenges include understanding resistance mechanisms and identifying predictive biomarkers. CD319 antibodies represent a promising intersection of immune modulation and targeted cancer therapy.