Expression of eGFP in transduced CD34⁺ and SRC-derived cells.

(A) FACS analysis of transgenic eGFP (GFP) and CD34⁺expression 6 days after lentiviral transduction. Cells were stained with an anti–CD34-PE/Cy5 monoclonal antibody. Mock-transduced CD34⁺ cells are shown on the left and cells transduced with eGFP in the absence of cytokine stimulation at an MOI of 3 are shown at the right. Almost identical results were seen after lentiviral transduction in the presence of cytokine stimulation (data not shown). Quadrants were set according to isotype-matched negative controls. (B) Lymphohematopoietic engraftment of SRC-derived cells in NOD/SCID mice 6 to 7 weeks after transplantation. Expression of eGFP in subpopulations of cells is shown. Engraftment was quantitated using anti–human CD45-PE/Cy5 and anti–murine CD45 PE antibodies (left 2 panels). Expression of eGFP (x-axis) was analyzed in CD34⁺, CD33⁺, CD38⁺, and CD19⁺ human cells (from left to right, y-axis). Quadrants were set according to isotype-matched negative controls. These data are representative of 28 mice (mock n = 9, eGFP-transduction n = 19). The numbers refer to the upper left and upper right quadrants, respectively. PE indicates phycoerythrin; PE/Cy5, phycoerythrin-cyanin 5.1.