Canonical Wnt signaling activity in hematopoietic cells ex vivo as measured with lentiviral Wnt reporters. (A) Scheme of lentiviral Wnt reporters, which contain multimerized TCF binding sites in front of a minimal promoter driving expression of Venus (a yellow shifted variant of GFP) and a constitutive expression cassette of the PGK promoter driving expression of human CD2 (hCD2), Wnt1 or a fusion of LEF-1 and the C-terminal transactivation domain of β-catenin (LEF/β-cat). (B) Histograms show Venus expression (Wnt signaling) in control (hCD2 expression) or Wnt-stimulated (Wnt1 or LEF/β-cat expression) activated peripheral T cells of control and β-/γ-catenin double-deficient chimeras or 293T cells 48 hours after viral transduction. Numbers indicate the percentage of cells in the indicated gate. (C) The bar graph shows Wnt reporter activity in 293T cells stimulated with different doses of LRP6Δex, Wnt1 or LEF/β-catenin on expression of nontargeting RNAi () or RNAi targeting β-catenin (). The RNAi does not target the C-terminal β-catenin domain contained in the LEF/β-catenin fusion construct. Error bars are SD. All data are from 3 to 5 independent experiments, and representative histograms are shown.