Preferential transduction of NOD/SCID repopulating cells by TPO- and SCF- or TPO/SCF-displaying LVs. NOD/SCID mice that received 2 × 105 CD34+ CB cells transduced with TPO- (G/TPOHA), SCF- (G/SCFSUx), TPO/SCF- (G/TPOHA/SCFSUx), or VSV-G–pseudotyped vectors were analyzed for human engraftment in femur BM (hCD45+) at 7 weeks after transplantation. (A) FACS analysis of multilineage engraftment by CB CD34+ cells transduced for 24 hours at an MOI of 4 with TPO/SCF-displaying lentiviral (G/TPOHA/SCFSUx) or unmodified vectors in absence (VSV-G) or presence of rTPO (10 ng/mL) and rSCF (50 ng/mL). The upper right quadrant shows the GFP+ cells within the CD19+, CD14+, CD34+, CD13+ cells in the human graft (hCD45+ cells). The FACS profiles are representative of each transduction condition. (B) CB hCD34+ cells were transduced for 24 hours at an MOI of 4 with TPO- (G/TPOHA), SCF- (G/SCFSUx), TPO/SCF- (G/TPOHA/SCFSUx), or VSV-G–pseudotyped vectors in the absence (–) or presence of the counterpart cytokines. After repopulation into NOD/SCID mice, transduction levels of total SRCs (hCD45+) and the subpopulation of human progenitor cells (hCD34+) were compared.
