Garaudé S (2024) Engineering an antibody-discernible and functional CD45 variant on hematopoietic stem and progenitor cells via base editing. Univ Basel Thesis.
Objective: To develop a system for a cell surface marker present on all hematopoietic cell to deplete malignant cells. Authors screened CD45’s extracellular domain regions with base editors and generated multiple CD45 protein variants altering the binding of antibodies.
Summary: Authors selected the CD45 K352E/G variant profile and improved its base editing rate as it showcased loss of binding of a unique anti-CD45 antibody while still maintaining the surface marker’s expression, stability, and function in human hematopoietic stem and progenitor cells (HSPCs). The resulting loss of antibody binding prompted the modification and humanization of the anti-CD45 antibody, culminating in the development of an anti-CD45 antibody-drug conjugate (CD45-ADC; CIM053-SG3376). In an AML mouse models xenografted with HSPCs, administration of the CD45-ADC selectively depleted human leukemia and HSPCs wt cells while preserving the healthy hematopoietic system derived from the transplanted base edited HSPCs.
Usage: In vitro antibody-drug-conjugate (ADC) mediated killing assays. For ADC killing assays involving saporin, a 100 nM stock was prepared by incubating the biotinylated antibody and Streptavidin-ZAP at a 1:1 molar ratio for 30 min at room temperature
Related Products: Streptavidin-ZAP (Cat. #IT-27), Anti-CD45.2-SAP (Cat. #IT-91)