Table 1.

High levels of HbF in erythroblasts derived from PB CD34⁺ cells transduced with γ-globin lentiviral vectors

Vector	Cell proliferation*	CD235+,† %	GFP+,‡ %	CFU-C, % vector+§	Vector copy no.‖	HbF,¶ %
Mock	250 ± 126	87 ± 11	ND	ND	ND	1.4 ± 0.4
GFP	230 ± 94	91 ± 9	87 ± 6	ND	3.5 ± 1.6	1.9 ± 0.5
V5m3	319 ± 149	93 ± 7	ND	77 ± 3	0.9 ± 0.2	11.1 ± 3.1
V5m3–400	259 ± 112	92 ± 5	ND	91 ± 9	1.0 ± 0.1	15.4 ± 4.9

Data are mean ± SD.

ND indicates not done.

^*Fold increase in viable cells from day of transduction to culture day 11 or 12.

^†Erythroid differentiation was monitored by flow cytometric analysis of bulk cell populations for expression of CD235 (Glycophorin A) on culture day 14.

^‡GFP⁺ fraction of bulk cell population determined by flow cytometry on culture days 12 to 14.

^§PCR analysis for the presence of vector sequences in clonogenic progenitors grown in methylcellulose supplemented with cytokines.

^‖Genomic DNA was isolated from the bulk cell population on day 8 of culture and copy number determined by quantitative PCR or Southern blot analysis.

^¶Percentage of fetal hemoglobin production quantified by HPLC and normalized per vector copy for V5m3 and V5m3–400 transduced cell populations.