ARID3a is Required for CpG-Induced Expression of IFNα. HSPCs were stimulated with CpG for 6 days and assessed by flow cytometry for ARID3a and IFNα.(A) Representative flow cytometric plots of ARID3a and IFNα expression with and without CpG stimulation show percentages in each quadrant. (B) Cells were infected with ARID3a shRNA or unrelated scramble shRNA-expressing lentivirus prior to stimulation with CpG and analyzed by flow cytometry for ARID3a and IFNα expression. A representative histogram showing ARID3a inhibition (left panel). MFIs: CpG-9.74, Scramble-11.3, ARID3a shRNA- 3.78. Data from 4 samples were evaluated for numbers of ARID3a expressing cells (right panel). (C) Similar analyses as shown in B are presented for IFNa. MFIs: CpG-11.2, Scramble-9.37, ARID3a shRNA- 5.48. Open circles are cultures stimulated with CpG. Averages and error bars are shown. Significance was assessed by paired T test, *, p < 0.05; **, p < 0.01, ***, p < 0.001.