Monoclonal antibody K312-based depletion of pluripotent cells from differentiated stem cell progeny prevents teratoma formation

Human pluripotent stem cells (PSCs) have been utilized as a promising source in regenerative medicine. However, the risk of teratoma formation that comes with residual undifferentiated PSCs in differentiated cell populations is most concerning in the clinical use of PSC derivatives. Here, we report that a mono-clonal antibody (mAb) targeting PSCs could distinguish undiffer-entiated PSCs, with potential teratoma-forming activity, from differentiated PSC progeny. A panel of hybridomas generated from mouse immunization with H9 human embryonic stem cells (hESCs) was screened for ESC-specific binding using flow cyto-metry. A novel mAb, K312, was selected considering its high stem cell-binding activity, and this mAb could bind to several human induced pluripotent stem cells and PSC lines. Cell-bind-ing activity of K312 was markedly decreased as hESCs were differentiated into embryoid bodies or by retinoic acid treatment. In addition, a cell population negatively isolated from undiffer-entiated or differentiated H9 hESCs via K312 targeting showed a significantly reduced expression of pluripotency markers, in-cluding Oct4 and Nanog. Furthermore, K312-based depletion of pluripotent cells from differentiated PSC progeny completely prevented teratoma formation. Therefore, our findings suggest that K312 is utilizable in improving stem cell transplantation safety by specifically distinguishing residual undifferentiated PSCs. [BMB Reports 2022; 55(3): 142-147]

Automated summary

In this study, researchers developed a monoclonal antibody K312 that can distinguish undifferentiated pluripotent stem cells (PSCs) from differentiated PSC progeny. By targeting with K312, pluripotent cells can be depleted from differentiated PSC progeny, effectively preventing teratoma formation.