Constitutive CD257 production enhances leukemia development. (A) Flow cytometric analysis of blood cells from different mouse strains (TCL1×BAFF-Tg mice labeled as BAFF/TCL1; TCL1-Tg, as -/TCL1; and BAFF-Tg, as BAFF/-) collected at different ages as indicated and stained with CD5 and B220 antibodies. Each analysis was done in triplicate. One representative blot for each analysis is shown. (B) Representative contour plots of blood cells from 9-month-old mice (n = 3 in each cohort) stained with CD5 and hTCL1 antibodies. (C) Blood-derived CD3−CD5+ cells in the indicated mouse strains at different ages were measured by flow cytometry using CD3 and CD5 antibodies (n = 12 mice per cohort; error bars indicate SD). (D) Clonal expansion of TCL1-Tg and TCL1×BAFF-Tg mice splenocytes (n = 2 per cohort per indicated age) as determined by Southern blot analysis of genomic DNA using a JH-probe. (E) Survival (Kaplan-Meier) plots of cohorts of 12 age- and sex-matched mice of the indicated strains. Mean survival times were TCL1×BAFF-Tg mice, 11.2 ± 3.4; TCL1-Tg, 20.7 ± 3.9; and BAFF-Tg, 21.0 ± 3.8 months. More than 50% of WT mice were still alive at the end of the 25-month observation period.
