BaEV-LVs transduce efficiently long-term reconstituting HSCs. Transduced cells were injected into the liver of irradiated newborn NSG mice. On reconstitution, the BM and spleen of these primary engrafted mice (first transplantation) were analyzed for transduced human cell engraftment (GFP⁺CD45⁺) in the BM and the spleen. Subsequently, the hCD34⁺ cells, isolated from the BM of these mice, were injected following the same procedure as for the primary NSG engraftments. Ten weeks after engraftment, these secondary recipient mice were analyzed for the percentage of transduced human cells (GFP⁺CD45⁺) in the BM and spleen. (A) Analysis of engraftment of transduced human cells (GFP⁺CD45⁺) in the BM and spleen of primary transplanted mice reconstituted with prestimulated (TPO+SCF+Flt-3L) hCD34⁺ cells and transduced with BaEVTR-LVs or BaEVRless-LVs in the presence of RetroNectin and of secondary recipient NSG mice. (B) Analysis of engraftment of transduced human cells (GFP⁺CD45⁺) in the BM and spleen of primary and secondary transplanted mice reconstituted with unstimulated hCD34⁺ cells transduced with BaEVTR-LVs or BaEVRless-LVs in the presence of RetroNectin and of secondary recipient NSG mice.