CD4⁺ CD25⁺ lymphocyte and dendritic cell mobilization with intermediate doses of recombinant human granulocyte colony-stimulating factor in healthy donors

We prospectively conducted a quantitative and phenotypic analysis of T, B, natural killer (NK), NKT, type 1 and 2 dendritic cells (DC), and regulatory T cells, before and after mobilization with intermediate doses of granulocyte colony-stimulating factor (G-CSF) (16 μg/kg per day). Between November, 2003, and December, 2004, we collected stem cells from 25 HLA identical sibling donors for allogeneic hematopoietic stem cell transplantation. Before mobilization and 3 h after the fourth and fifth doses of G-CSF, blood samples were taken for blood counts and flow cytometry. The median number of regulatory T cells before and after G-CSF was statistically different (69 ± 41 × 10⁶/L versus 161 ± 159 × 10⁶/L, p < 0.01). We observed a 1.7-fold increase in NK and NKT cells (p < 0.009 and p < 0.02, respectively). DC were mobilized with a 11.5-fold increase in type 2 (p < 0.004) and a 8.5-fold increase in type 1 DC (p < 0.003). The patients received a mean of: 2.2 × 10⁷/kg ± 1.4 × 10⁷/kg of NK cells, 0.95 × 10⁷/kg ± 0.81 × 10⁷/kg of NKT cells, 0.43 × 10⁷/kg ± 0.53 × 10⁷/kg of type 1 DC, 0.3 × 10⁷/kg ± 0.45 × 10⁷/kg of type 2 DC and 1.4 × 10 ⁷/kg ± 1.2 × 10⁷/kg of regulatory T cells. Using intermediate doses of G-CSF, we have demonstrated the mobilization of different lymphocyte subsets, in particular regulatory T cells and DC, which can be expanded later and used in the treatment of cancer and autoimmune diseases.