Regulation of PKB activity in human CD34⁺ hematopoietic progenitors affects lineage development in β2-microglobulin (−/−) NOD/SCID mice. (A) CD34⁺ cells, cultured in presence of the cytokines SCF, FLT-3, ligand and TPO, were transduced with empty vector alone, myrPKB, or PKBcaax. After 3 days of culture, cells were injected into β2-microglobulin (−/−) NOD/SCID mice. Six weeks after injection, mice were killed, eGFP-positive human cells were sorted, and cytospins were made. Cytospins were stained with May-Grunwald Giemsa solution. Lineage development was depicted as the percentage of (B) neutrophils, (C) monocytes, (D) CD14-positive cells, (E) erythrocytes, and (F) eosinophils within the human, eGFP-positive bone marrow–derived cells. (G) To determine eosinophil development, the eGFP-positive population was sorted from the nontransduced cells and cytospins were made. The percentage of cells differentiated toward eosinophils was determined by Luxol Fast Blue staining, a dye specifically staining for eosinophilic granules. (H) The percentage of CD19-positive cells was determined by FACS analysis to determine B-cell development. Error bars represent SEM.