Endothelial cell mobilization. Cell markers of endothelial lineage were tested on PB MNCs of 4 baboons mobilized with G-CSF + SCF. Analysis could not be performed in animals not administered with cytokines, given the too-low number of CD34⁺ cells in the circulation. Comparison was performed with mobilized MNCs from 6 healthy human donors administered with G-CSF alone. (A) Flow cytometric analysis: 4 biparametric dot plots show double-labeling with anti-CD133-PE MoAb and anti-CD34-FITC MoAb (top left), anti-CD117-PE MoAb and anti-CD34-FITC MoAb (bottom left), anti-CD34-PE MoAb and anti-FLK-1-FITC mAb (top right), anti-CD34-PE MoAb and anti-GATA2-FITC MoAb (bottom right), respectively. Bottom right dot plot displays overlapping negative control (gray dots, performed with anti-CD34-PE MoAb and nonspecific mouse MoAb) and positive test (black dots). The 3 other dot plots show positive tests. Results are representative of both baboon and human mobilized cell samples (except CD133/CD34 labeling, which can only be evaluated with human cells). (B) RT-PCR analysis: Analyzed samples are issued from baboons and healthy donors as indicated earlier in the legend for flow cytometric analysis. mRNA expression levels of GATA-2 and Flk-1 were analyzed by reverse transcription and real-time PCR. Transcription factors' mRNA levels, normalized against cyclophylin-A mRNA, are expressed as percentages of averaged mRNA levels of mobilized CD34^- cells (error bars indicate standard deviation). Flk-1 mRNA was tested in CD34⁺ cells and was detectable only at a low level, 50 to 100 times weaker than in HUVEC control cells.