Flow cytometric analyses of engraftment and transgene expression in human cells in chimeric NOD/SCID and NOD/SCID/β2m^–/– mice. Panels A-D indicate how flow cytometry gates were set to analyze human granulocytes arising in mice that received transplants. The gate shown in panels A (control mouse not receiving transplant) and B (mouse receiving transplant of human CD34⁺ PBSCs) confines human cells (human CD45⁺) with high side scatter characteristics, whereas the gate in panels C and D confines human CD45⁺/CD13⁺ cells. The analyses shown in panels E-G are delimited to cells that satisfy the characteristics confined to both gates and define a human granulocyte gate. In panels E-G, the gp91^phox-positive (E-F) and CFP-positive (G) regions are indicated by the horizontal bars. The percentages indicate the percentage of cells in that region. Panels B and D demonstrate representative analyses of bone marrow from a mouse that received transplants of human RD114-MFGS-gp91^phox–transduced X-CGD CD34⁺ PBSCs, in which total human cell engraftment (all human CD45⁺ irrespective of side scatter) was 36% (B) and the percentage of CD45⁺/CD13⁺ cells was 17% (D). Panels A and C show representative analyses of bone marrow from a mouse not receiving a transplant, indicating that the combined gating eliminates almost all murine cell background signal. Panels E-F show representative analyses of gp91^phox expression in the human granulocyte gate in the bone marrow of mice that received transplants of RD114-MFGS-gp91^phox–transduced X-CGD CD34⁺ PBSCs or RD114-MFGS-CFP–transduced normal CD34⁺ PBSCs (the latter used to demonstrate expression of native gp91^phox in normal human cells). Panel G shows a representative analysis of CFP transgene expression in the human granulocyte gate in the bone marrow of a NOD/SCID mouse that received transplants of RD114-MFGS-CFP–transduced normal CD34⁺ PBSCs. Naive human X-CGD CD34⁺ PBSCs transplanted into NOD/SCID/β2m^–/– mice gave rise to human granulocytes that did not express gp91^phox or CFP (nonfilled overlays in panels E-G).