Traditional retroviral gene transfer protocols for the genetic modification of hematopoietic stem and progenitor cells (HSPC) include a multiday ex vivo culture period, which can negatively affect the biology of the cells and is costly. As an alternative approach, we outline here a method for gene transfer into quiescent human HSPCs using lentiviral (LV) vectors and gamma-retroviral virus-like particles (eVLP). To achieve this, we use LV vectors and eVLPs pseudotyped with the modified baboon endogenous retroviral glycoprotein BaEVRLess, which targets the neutral amino acid transporters ASCT1 and ASCT2 on HSPCs. This envelope enables immediate transduction of freshly isolated or thawed, unstimulated HSPCs with higher gene transfer efficiencies than those obtained with VSVg-pseudotyped LV vectors and enables the transplantation of transduced HSPCs within less than 24 hr of cell isolation. These protocols provide detailed guidance on the production and titration of BaEVRLess-pseudotyped LV vectors and eVLPs and the cultivation and transduction of quiescent HSPCs, and highlights critical steps and potential pitfalls of these processes. © 2026 Wiley Periodicals LLC. Basic Protocol 1: Generation of BaEVRLess-pseudotyped lentiviral vectors Alternate Protocol: Generation of BaEVRLess-pseudotyped virus-like particles Support Protocol: Preparation and testing of polyethyleneimine solution for DNA transfection Basic Protocol 2: Transduction of quiescent human CD34+ hematopoietic stem and progenitor cells.
Klatt et al. (Thu,) studied this question.