Development of an Anti‐CDH15/M‐Cadherin Monoclonal Antibody Ca15Mab‐1 for Flow Cytometry, Immunoblotting, and Immunohistochemistry

Cadherins are key cell adhesion molecules that engage in extracellular homophilic binding. CDH15/M‐cadherin is localized to the apical surface of muscle satellite cells (SCs), which play a critical role in tissue regeneration after injury. Although CDH15 is considered a marker of SCs, there is no anti-CDH15 mAb suitable for flow cytometry. We developed anti-CDH15 monoclonal antibodies using the Cell-Based Immunization and Screening (CBIS) method containing a flow cytometry-based high-throughput screening. In flow cytometry, a clone Ca15Mab-1 (IgG1, κ) reacted with human CDH15-overexpressed Chinese hamster ovary-K1 (CHO/CDH15) cells. Furthermore, Ca15Mab-1 recognizes endogenous CDH15-expressing human osteosarcoma (Saos-2) and mouse myoblast (C2C12) cell lines. The dissociation constant values of Ca15Mab-1 for CHO/CDH15, Saos-2, and C2C12 were determined as 6.9 × 10⁻10 M, 8.4 × 10⁻10 M, and 1.6 × 10⁻⁹ M, respectively. Furthermore, Ca15Mab-1 can detect endogenous CDH15 in immunoblotting and immunohistochemistry. Ca15Mab-1, established by the CBIS method, is versatile for basic research and is expected to contribute to clinical studies such as antibody therapy.