Analysis of the repopulating capacity of human MNCs isolated from G-CSF– or G-CSF plus SCF–mobilized PB.

(A-B) Summary of the level of human engraftment in NOD/SCID EMV^null mice that received transplants of PB MNCs isolated following (A) G-CSF or (B) G-CSF plus SCF mobilization. Mouse BM was extracted 6 to 8 weeks after transplantation and analyzed for human engraftment by flow cytometry and Southern blot analysis. Each symbol (▪) represents a single mouse recipient of transplanted MNCs (5 to 50 × 10⁶ cells) derived from a total of 6 independent G-CSF–mobilized samples (n = 18) and 9 independent G-CSF plus SCF–mobilized samples (n = 27). Horizontal lines represent the average level of engraftment for each cell dose and did not show a statistical difference between mobilization regimes. LDA showed a similar frequency of SCID repopulating cells (1 SRC in approximately 8 × 10⁶ MNCs) for both G-CSF– and G-CSF plus SCF–mobilized PB. (C-D) Representative analysis of multilineage stem cell repopulation assessed in human-engrafted mice receiving transplants of 25 × 10⁶ G-CSF– (C) or G-CSF plus SCF–mobilized PB MNCs (D). Mouse BM cells were stained with monoclonal antibody combinations for human-specific antibody against the panleukocyte marker CD45 (gated R1) (Ci,Di), and human cells were assayed for presence of mature B lymphoid cells (CD20, CD19) (Ciii,Diii), mature myeloid cells (CD33, CD15) (Civ,Div), primitive cells (CD34, CD38) (Cv,Dv), and mature T-lymphoid cells (CD4 and CD38) (Cvi,Dvi). Limits for quadrants were established with the use of FITC isotype and PE isotype controls (Cii,Dii), and statistics display the frequency of subsets representative of human hematopoietic differentiation in the BM of NOD/SCID recipients of transplants of either G-CSF– or G-CSF plus SCF–mobilized PB MNCs.