Cytotoxic Activity of CD48 Monoclonal Antibodies Against Human Lymphoma Cells

CD48 is a cell surface, glycosylphosphatidylinositol-linked glycoprotein, and a potential target for treatment of leukemia and lymphoma. Two anti-CD48 mAbs, murine HuLy-m3 and human IgG1-N2A, were compared in cellular assays using a human lymphoma cell line (Raji) for their ability to inhibit cell growth and induce apoptosis. In vitro studies revealed both HuLy-m3 and IgG1-N2A mAbs were able to induce potent growth inhibition, reflected by a reduction in viable cells of approximately 70% compared to controls after 90 h. Furthermore, Raji cells treated with IgG1-N2A showed evidence of apoptosis, including increased ethidium bromide uptake, cell shrinkage and chromosomal DNA degradation.