Generation of biphenotypic B220⁺GR-1/MAC-1⁺ cells on overexpression of PAX5 in LSK cells. (A) Control and PAX5-transduced LSK cells were cultured under myeloid conditions as described in “Materials and methods” and total (GFP⁺ and GFP⁻ cells combined) cellular expansion was determined at different time points as indicated. Dashed and solid lines demonstrate expansion of control and PAX5 cultures, respectively. Shown are 2 patterns of growth. Left panel represents mean values of 3 individual transduction experiments (*P < .05), with typical exhaustion of control cultures. Right panel shows the experiment (of totally 15) with the longest sustained control culture. Stapled line indicates starting cell number (2 × 10⁴ cells). (B) GFP expression of control and PAX5-transduced LSK cells cultured under myeloid conditions at different time points. Percentages are mean values from 3 to 6 control and PAX5 experiments. (C) Expression of B220 and GR-1/MAC-1 on GFP⁺ cells in control (top panels) and PAX5-transduced (bottom panels) cultures. Values in quadrants show mean percentages from 3 experiments for control and PAX5-transduced cultures, respectively. (D) Percentages of total GFP⁺ control and PAX5-transduced cells coexpressing B220 and GR-1/MAC-1. One of 5 representative experiments is shown. The asterisk indicates statistically significant (P < .05) differences between control and PAX5-transduced cultures.