Figure 3: Costimulation blockade preferentially targets expansion of peptide stimulated non-regulatory T cells over regulatory T cells. BDC were activated in the absence (media only) or presence of stimulatory peptide without (peptide only) or with combined costimulation blockade (peptide+cCoB) for 1 and 3 days. Cells were evaluated by quantitative flow cytometry where absolute cell numbers were assessed using TruCount beads. CD3+ CD4+ T cells were identified (Total CD4+ T cells), or subpopulated based on FoxP3- and FoxP3+ CD4+ T cells. Shown are data from compiled from 3 independent experiments where T cell numbers were standardized to cells cultured without peptide and fold differences in the indicated subpopulations were calculated, and means and standard deviations (error bars) of these fold differences are displayed. Pairwise comparisons of the indicated T cell subpopulations were analyzed by Student’s t-Test and p values are shown.