Development and Characterization of Ea7Mab-10: A Novel Monoclonal Antibody Targeting EphA7

Eph receptor-ephrin system is essential for embryonic, neural, and vascular development, and also plays important roles in tumor promotion or suppression. EphA7 was described as a tumor suppressor that is frequently lost in lymphomas. In contrast, EphA7 mutations have been suggested to be a driver gene in several cancers. However, the detailed molecular function has not been clarified. Therefore, monoclonal antibody (mAb) against EphA7 is essential for basic research and clinical applications. In this study, we developed a novel anti-human EphA7 mAb, Ea7Mab-10, using the Cell-Based Immunization and Screening (CBIS) method. Ea7Mab-10 reacted with EphA7-overexpressed Chinese hamster ovary-K1 (CHO/EphA7) and EphA7-overexpressed LN229 (LN229/EphA7) in flow cytometry. The binding affinities were determined as 3.1×10-9 M for CHO/EphA7 and 6.9×10-9 M for LN229/EphA7. Furthermore, Ea7Mab-10 did not show cross-reactivity with other Eph family members. Furthermore, Ea7Mab-10 is suitable for western blotting and immunohistochemistry. These results indicate that Ea7Mab-10, established by the CBIS method, facilitates basic studies of EphA7 and is expected for future therapeutic applications, including mAb-based targeted therapy.