Figure 1. Effect of different mutated forms of C/EBPα on human progenitors.

A) Analysis of effect of expression of WT C/EBPα , mutated C/EBPα on N-terminal and on C-terminal on Human Hematopoietic progenitors by Colony Forming Units assay. 2×10³ human hematopoietic progenitors (Lin⁻ cells) after transduction were plated in H4434 medium; two weeks later number, type of CFUs and expression or not of GFP were determinate using an inverted fluorescent microscope. The number of erythroid (grey) and myeloid (black) colonies per transduced cells (GFP+) are reported. (B) Maintenance of Human Hematopoietic Progenitors by expression of C/EBPα mutant. Serial replating from primary or Secondary CFU assays were done to evaluate Secondary or Tertiary CFUs respectively. Each CFU assays was plated in H4434 medium and quantify after two weeks. Numbers of transduced CFU for Control, WT C/EBPα, N-terminal and C-terminal are represented. (C) Differences in Hematopoietic Stem Cells after transduction were determinate by Long Term Culture Initiating Cells (LTC-IC) assay. 1×10⁴ Human Lin⁻ cells, after transduction, were plated on irradiated stromal cell layer (M2-10B4 cell line) for five weeks, then preserved progenitors was evaluated by CFU assay in H4435 medium. Results are shown as mean ± standard deviation (SD), with significant differences of p ≤ 0.05, p ≤ 0.01 or p ≤ 0.001 are indicating by (*), (**) or (***) respectively. All the data are from a minimum of triplicates of two independent experiments.