Development of Monoclonal Antibody 281-mG 2a -f Against Golden Hamster Podoplanin.

Golden (Syrian) hamster ( Mesocricetus auratus ) is a small animal model of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Pathological analyses of the tissues are required to understand the pathogenesis of SARS-CoV-2 and the evaluation of therapeutic modalities, including neutralizing monoclonal antibodies (mAbs). However, mAbs that recognize the golden hamster-derived antigens and distinguish specific cell types, such as the pneumocytes, are limited. Podoplanin (PDPN) is an essential marker of lung type I alveolar epithelial cells, kidney podocytes, and lymphatic endothelial cells. In this study, an anti-Chinese hamster ( Cricetulus griseus ) PDPN mAb PMab-281 (IgG 3 , kappa) was established using the Cell-Based Immunization and Screening (CBIS) method. A defucosylated mouse IgG 2a version of PMab-281 (281-mG 2a -f) was also developed. The 281-mG 2a -f strongly recognized both the Chinese hamster and the golden hamster PDPN using flow cytometry and could detect lung type I alveolar epithelial cells, lymphatic endothelial cells, and Bowman's capsules in the kidney from the golden hamster using immunohistochemistry. These results suggest the usefulness of 281-mG 2a -f for analyzing the golden hamster-derived tissues and cells for SARS-CoV-2 research.