LEF-1 rescue of CD34⁺ cells from 2 patients with CN restores diminished ELA2/NE synthesis. (A-B) mRNA expression of LEF-1 (A) and C/EBPα (B) in BM CD33⁺ cells of studied groups: CN, severe congenital neutropenia; CyN, cyclic neutropenia; Ctrl, control; all treated with G-CSF. Data represent means ± SDs and were measured in triplicate; **P < .01 compared with Ctrl. (C-E) CD34⁺ cells from 2 patients with CN were transduced with LEF-1 lv GFP or ctrl lv GFP and subsequently incubated without or with G-CSF for 4 days. (C) ELA2 mRNA expression was measured by qRT-PCR normalized to β-actin and is presented as AUs; data represent means ± SDs of 2 experiments measured in triplicates (*P < .05 to ctrl lv samples). (D) NE protein secretion into culture supernatants was assessed with the use of NE-specific ELISA. Data represent means ± SDs and are derived from 2 independent experiments each measured in triplicate (**P < .01 to ctrl lv samples). (E) CD34⁺ cells from 2 patients with CN were transduced with LEF-1 lv GFP; on day 2 GFP⁺ cells were sorted depending on the intensity of GFP expression (low, medium, high) and subsequently incubated without or with G-CSF for 4 days. ELA2 mRNA expression was measured by qRT-PCR normalized to β-actin and is presented as AUs; data represent means ± SDs of 2 independent experiments each measured in triplicates.