Presence of leukemia cells in the peripheral blood of mice engrafted with primary T-ALL.

Mice were preconditioned with 10 × 10⁶ cord blood MNCs before injection with 1.6 × 10⁶ primary T-ALL cells. For the mouse presented here, the levels of T-ALL engraftment in bone marrow and spleen were 93% and 87%, respectively, followed both as CD5⁺CD7⁺ cells and Vβ2⁺CD7⁺ cells (not shown). Peripheral blood obtained from this mouse was analyzed by flow cytometry for the presence of human T-ALL cells. As indicated, T-ALL in the peripheral blood was similarly followed both as CD5⁺CD7⁺cells and as Vβ2⁺CD7⁺ cells. Isotype-matched control mAbs were used to determine appropriate cursor settings for analysis. Percentages of human CD5⁺CD7⁺ (A) and Vβ2⁺CD7⁺ (B) double-positive cells in mouse peripheral blood were determined to be 95% and 92%, respectively.