Neutrophil recovery in the tissues and in the circulation after BMT. (A) Neutrophil recovery in the tissues after BMT. This plot shows the mean percentage of E-GFP (percentage of total cells) donor neutrophils recovered in the spleen and the lungs of SV129/black recipient mice after BMT. Flow cytometry was used to determine the percentage of E-GFP neutrophils present in single-cell suspensions of the lungs and spleen of mice that received a transplant. Tissue neutrophil engraftment is defined by the day from which the numeric values of donor E-GFP neutrophil counts begin to rise steadily, reflecting the beginning of neutrophil recovery in the tissues after BMT. In this study, tissue engraftment (TE) in the lungs and spleen occurred, on average, on day 4 after BMT, on average 2 days earlier than in the blood circulation of mice that received a transplant not treated with G-CSF (see panel B). Data are shown as mean ± SD (3-12 mice per day after BMT). (B) Neutrophil recovery in the circulation, with and without G-CSF treatment after BMT. This plot shows the mean blood neutrophil counts over time (absolute neutrophil counts, ANCs) in SV129/black recipient mice with and without G-CSF treatment after BMT. Blood neutrophils were quantified by a HEMAVET multispecies hematology analyzer (Drew Scientific). Blood neutrophil engraftment is defined by the day from which the numeric values of donor E-GFP neutrophil counts begin to rise steadily, reflecting the beginning of neutrophil recovery in the blood after BMT. Day of blood engraftment (BE) for the +G-CSF and -G-CSF treatment groups occurs, on average, on day 5 and day 6 after BMT, respectively. G-CSF accelerates blood neutrophil engraftment on average by 1 day, and neutrophil levels reach pretreatment levels much faster in the +G-CSF treatment group than in the -G-CSF group. Data are shown as mean ± SD (3-12 mice per day after BMT).