β-Estradiol treatment does not diminish VEX⁺PDCs, impair PDC function, or perturb their developmental kinetics. (A) Following 14 days of treatment, placebo and β-estradiol (E2 Rx) treated 10-week-old H2-VEX mice were analyzed for the presence of VEX⁺cells within the CLP and PDC fractions of the BM. The mean percentage of VEX⁺cells within either progenitor population is shown in panel B (○ indicates E2 Rx mice; •, placebo controls). (C) Placebo and β-estradiol (E2 Rx)–treated 10-week-old C57BL/6 mice were inoculated with BrdU at 12-hour intervals for 1 to 4 days as described in “Materials and methods” beginning 14 days after transplantation with placebo or β-estradiol pellets. On days 1 to 4 cohorts of 3 mice per group were examined for BrdU incorporation in BM (CD19^–Ly6C⁺CD11c⁺B220⁺) and splenic (CD19^–CD3ϵ^–CD11c⁺CD11c⁺Ly6C⁺B220⁺) PDCs. ▵ indicates E2 Rx mice; □, placebo controls. (D) ELISA analysis of IFN-α production following stimulation was performed on PDCs isolated from placebo and β-estradiol–treated mice demonstrate no loss of functional activity following estrogen administration. Data from triplicate cultures were used to calculate the mean and SEM for each condition.