VSV-G pseudotyped infection of CD34+ HPCs results in developmental pathology in multiple hematopoietic lineages. (A) The NL4_HSA-eGFP vector is based on the NL4-3 strain of HIV-1. The vector is deficient in env and vpr because of the insertion of marker genes and was pseudotyped with VSV-G to produce viral vector particles. (B) FACS strategy for differentiating GFP-positive and GFP-negative CD34+ hematopoietic progenitor cells 48 hours after transduction. (C) Quantitative PCR analysis for copies of HIV per GFP+ cell indicates a single integrant on average for each donor. (D) Colonies grown in methylcellulose derived from NL4_HSA-eGFP–transduced cells (right) are in general much smaller than those derived from nontransduced cells (left). (E) CD34+ hematopoietic progenitors transduced with NL4-HSA-eGFP generate far fewer colonies than do nontransduced cells. Each mark represents an individual methylcellulose plate and the data represent the mean ± the standard error of the mean (SEM). (F) There is a skewing of lineages in NL4-_HSA-eGFP–transduced cultures compared with nontransduced. Erythroid colonies are particularly impacted. (G) Megakaryocyte colonies are likewise diminished from transduced progenitors. Each mark represents an individual plate and the data represent the mean ± SEM. LTR, long terminal repeat; SSC, side scatter.