Establishment of CMab-11, a novel anti-CD20 monoclonal antibody, for the detection of B cells.

CD20 is one of several B-lymphocyte antigens that has been shown to be an effective target for the detection and treatment of B-cell lymphomas. Sensitive and specific monoclonal antibodies (mAbs) are required for every application used for the diagnosis of B-cell lymphoma. Although many anti-CD20 mAbs have been established, the types of applications, those anti-CD20 can be used in, are limited. In this study, we aimed to establish novel anti-CD20 mAbs to be used for broad applications, such as flow cytometry, western blot, and immunohistochemical analyses, using the Cell-Based Immunization and Screening (CBIS) method. One of the established mAbs, CMab-11 (IgM, kappa), detected overexpression of CD20 in CHO-K1 or LN229 cell lines, indicating that CMab-11 is specific for CD20. In western blot analyses, CMab-11 detected not only overexpression of CD20 in CHO-K1 or LN229 cell lines, but also CD20 of BALL-1 and Raji cells with both sensitivity and specificity. Furthermore, CMab-11 strongly stained B cells of the lymph follicle and B cell lymphomas in immunohistochemical analyses. These results indicate that CMab-11 develped by CBIS method, is useful for the detection of CD20 in lymphoma tissues by flow cytometry, western blot, and immunohistochemical analyses and potentially could be beneficial for the treatment of B cell lymphomas.