Specific GFP expression in DR.GFP-transduced blood CD34⁺ cells and their progeny differentiated in vitro.

(A) Human CD34⁺ PBSCs were transduced with DR.GFP or EF.GFP LV at an MOI of 10. GFP and MHC II (HLA-DR) expression of these transduced CD34⁺ cells was analyzed 3 days after transduction. (B) Human DCs were differentiated from the above-transduced CD34⁺ cells for 16 days in the presence of human GM-CSF, IL-4, and TNF-α. Expression of the DC cell surface markers and the correlation of GFP with MHC II expression in these human DCs were examined by FACS analysis. The histogram of staining with each specific antibody (filled lines) overlays on the background staining (open lines) using the corresponding isotype-matched control antibody. (C) Transduced cells were differentiated in methylcellulose for erythroid/myeloid CFC assays. CFC-derived differentiated cells (non-DCs) were harvested on day 14 and examined for GFP, MHC II, myeloid (CD13 and CD33), and erythroid (glycophorin A, GlyA) cell lineage marker expression. (D) The SF of each vector to direct MHC II⁻-specific transgene expression (see “Materials and methods”) in transduced CD34⁺ cells, DCs, and non-DCs derived from the transduced CD34⁺ cells.