Mesenchymal stromal cells improve the transplantation outcome of CRISPR-Cas9 gene-edited human HSPCs
Stefania Crippa, Anastasia Conti, Valentina Vavassori, Samuele Ferrari, Stefano Beretta, Silvia Rivis, Roberto Bosotti, Serena Scala, Stefania Pirroni, Raisa Jofra-Hernandez, Ludovica Santi, Luca Basso‐Ricci, Ivan Merelli, Pietro Genovese, Alessandro Aiuti, Luigi Naldini, Raffaella Di Micco, Maria Ester Bernardo
Abstract
Mesenchymal stromal cells (MSCs) have been employed in vitro to support hematopoietic stem and progenitor cell (HSPC) expansion and in vivo to promote HSPC engraftment. Based on these studies, we developed an MSC-based co-culture system to optimize the transplantation outcome of clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 gene-edited (GE) human HSPCs. We show that bone marrow (BM)-MSCs produce several hematopoietic supportive and anti-inflammatory factors capable of alleviating the proliferation arrest and mitigating the apoptotic and inflammatory programs activated in GE-HSPCs, improving their expansion and clonogenic potential in vitro. The use of BM-MSCs resulted in superior human engraftment and increased clonal output of GE-HSPCs contributing to the early phase of hematological reconstitution in the peripheral blood of transplanted mice. In conclusion, our work poses the biological bases for a novel clinical use of BM-MSCs to promote engraftment of GE-HSPCs and improve their transplantation outcome.