Purpose: CD20 is one of B-lymphocyte antigens, and is known as an effective target for B cell lymphomas. Although anti-CD20 monoclonal antibody (mAb) drugs have brought significant survival benefits to B cell lymphoma patients, some patients have shown no clinical response in a second treatment of anti-CD20 mAbs; therefore, more effective treatment of B cell lymphomas should be developed. In this study, we aimed to develop useful anti-CD20 mAbs for treatment or research of B cell lymphoma.
Methods: For the anti-CD20 mAb development, we used Cell-Based Immunization and Screening (CBIS) method. CD20-overexpressed LN229 cells (LN229/CD20) were used for immunization. The screening of hybridomas was performed by flow cytometry (FCM) using CD20-overexpressed CHO cells.
Results: We used 8 Balb/c mice for the hybridoma development, and obtained 18 anti-CD20 mAbs. Of those clones, C₂₀Mab-11 (IgM, kappa) was shown to be useful for FCM and western blot (WB) for endogenous CD20-expressing cell lines. Furthermore, C₂₀Mab-11 strongly stained B cells of the lymph follicle via immunohistochemistry (IHC).
Conclusion: Using CBIS method, we successfully developed a sensitive and specific anti-CD20 mAb C₂₀Mab-11, which is useful for FCM, WB, and IHC.