CpG ODN Enhances the Efficacy of Rituximab in Non-Hodgkin Lymphoma

The anti-CD20 monoclonal antibody rituximab (RTX) has been applied to the therapy of B-cell proliferative disease, but a number of factors, such as the expression level of its target antigen, modulate its efficacy. Since unmethylated CpG-containing DNA sequences activate members of the immune systems, including B lymphocytes, their benefit to RTX treatment was determined on human lymphoma B-cell line cells. These Daudi cells expressed high endosomal level of the CpG Toll-like receptor 9, but CpG had effects neither on the viability, nor on the proliferation of the cells. In contrast, there appeared to be an increase in the expression of CD20, resulting in a higher efficiency of RTX for the killing of malignant Daudi cells.