Tracking and Modeling of HSC Clonal Dynamics by Vector Marking

Despite their extensive use in transplantation and gene therapy, there is currently limited information on the life span, number and biological properties of human hematopoietic stem cells that every day sustain the generation of billions of new blood cells. We previously showed in ADA-SCID gene therapy that gene-corrected blood stem cells engraft long-term without aberrant expansions. In this context, upon retroviral mediated gene transfer into blood stem cell, each single clone is univocally marked by a specific vector integration site and its fate can be followed long-term. The goal of this proposal is to study the survival and differentiation potential of human hematopoietic stem cells using the information derived from the analyses of retroviral insertions in clinical gene therapy studies. This work will be coupled with in vitro assays and in vivo experiments on animal models to further corroborate evidences collected from clinical trials. The results of these investigations will provide crucial information on the clonal dynamics of blood stem cells and will allow to improve current treatment approaches.