Enhanced T-lymphocyte reconstitution with G-CSF/AMD3100 treatment before FV vector injection. (A) Schematic of experiment involving G-CSF/AMD3100 treatment before FV vector injection. (B) Flow cytometry plot of peripheral blood CD34⁺ cells in nonmobilized (H866) or mobilized (H867) newborn canines at 6 hours posttreatment. (C) Kinetics of gene marking based on fluorophore expression in circulating lymphocytes from dogs treated with different FV vectors with or without G-CSF/AMD3100 mobilization. Lymphocyte population was defined based on forward and side scatter (SSC). (D) Kinetics of lymphocyte reconstitution (lymphocytes per microliter of peripheral blood) in the same animals described in panel C. (E) Kinetics of CD3⁺ cells reconstitution (cells per microliter of peripheral blood) in the same animals described in panel C during the first 7 months posttreatment. In panels D and E, normal range of lymphocyte/CD3⁺ cell counts is shown by horizontal dashed lines. Animal R2203 only survived for 119 days posttreatment. (F) FV vector copy number measured longitudinally in peripheral blood leukocytes from unmobilized animals R2258/R2260 and mobilized animals H864/H867. BID, twice per day.