Comparative engraftment and clonality of macaque HSPCs expanded on human umbilical vein endothelial cells versus non-expanded cells

• Published in: Molecular therapy. Methods & clinical development 2021-03, Vol.20, p.703-715
• Main Authors: Srivastava, Sandeep K., Truitt, Lauren L., Wu, Chuanfeng, Glaser, Adam, Nolan, Daniel J., Ginsberg, Michael, Espinoza, Diego A., Koelle, Samson, Yabe, Idalia M., Yu, Kyung-Rok, Hong, Sogun, Sellers, Stephanie, Krouse, Allen, Bonifacino, Aylin, Metzger, Mark, Dagur, Pradeep K., Donahue, Robert E., Dunbar, Cynthia E., Panch, Sandhya R.
• Format: Article
• Language: English
• Subjects: clonal expansion; ex-vivo expansion; genetic barcoding; hematopoiesis; HUVECs; Original; rhesus macaque
• ISSN: 2329-0501; 2329-0501
• DOI: 10.1016/j.omtm.2021.02.009

Ex vivo hematopoietic stem and progenitor cell (HSPC) expansion platforms are under active development, designed to increase HSPC numbers and thus engraftment ability of allogeneic cord blood grafts or autologous HSPCs for gene therapies. Murine and in vitro models have not correlated well with clinical outcomes of HSPC expansion, emphasizing the need for relevant pre-clinical models. Our rhesus macaque HSPC competitive autologous transplantation model utilizing genetically barcoded HSPC allows direct analysis of the relative short and long-term engraftment ability of lentivirally transduced HSPCs, along with additional critical characteristics such as HSPC clonal diversity and lineage bias. We investigated the impact of ex vivo expansion of macaque HSPCs on the engineered endothelial cell line (E-HUVECs) platform regarding safety, engraftment of transduced and E-HUVEC-expanded HSPC over time compared to non-expanded HSPC for up to 51 months post-transplantation, and both clonal diversity and lineage distribution of output from each engrafted cell source. Short and long-term engraftment were comparable for E-HUVEC expanded and the non-expanded HSPCs in both animals, despite extensive proliferation of CD34+ cells during 8 days of ex vivo culture for the E-HUVEC HSPCs, and optimization of harvesting and infusion of HSPCs co-cultured on E-HUVEC in the second animal. Long-term hematopoietic output from both E-HUVEC expanded and unexpanded HSPCs was highly polyclonal and multilineage. Overall, the comparable HSPC kinetics of macaques to humans, the ability to study post-transplant clonal patterns, and simultaneous multi-arm comparisons of grafts without the complication of interpreting allogeneic effects makes our model ideal to test ex vivo HSPC expansion platforms, particularly for gene therapy applications. [Display omitted] The rhesus macaque barcoded autologous competitive repopulation preclinical transplantation model was utilized to study the engraftment and safety of hematopoietic stem and progenitor cells expanded in co-culture with E4ORF-1 gene transduced human umbilical vein endothelial cell as compared to non-expanded cells, documenting polyclonal long-term multilineage hematopoiesis.