Transduction of human CD34⁺ cells.

Examples of hematopoietic colonies derived from CD34⁺progenitors transduced by CGPMAPΔBel and stained with X-Phos to produce dark-colored AP⁺ cells (A) as compared to untransduced controls (B), or transduced by CGPMscvF and examined by fluorescence microscopy for GFP expression (C-D). Original magnification 25 × in panels A-D. (E) Transduction rates of CD34⁺ cells by GFP vector CGPMscvF as measured by flow cytometry of liquid cultures 5 days after infection, or by progenitor colony assays. The average results of 4 experiments at MOIs ranging from 5 to 23 are shown (with SDs). Total as well as burst-forming units-erythrocytes (BFU-E), colony-forming units-granulocyte/macrophage (CFU-GM), and colony-forming units-granulocyte, erythrocyte, macrophage, megakaryocyte (CFU-GEMM) colonies were enumerated.