Figure 3. B7-H4 on AHSC inhibits T cell proliferation.
(A) AHSC were transfected with FITC-labeled siRNA or mock, and uptake of siRNA was evaluated by flow cytometry. (B) AHSC transfected with either B7-H4 siRNA or control siRNA were analyzed for the B7-H4 RNA expression using qualitative and (C) quantitative RT-PCR. Results are shown as fold difference of B7-H4 amplification over GAPDH control. (D) Mock or control siRNA or B7-H4 siRNA transfected HSC were pulsed with gp33 peptide and cocultured with CFSE labeled P14 CD8+ T cells for 3 days and T cell proliferation assayed by flow cytometry. Numbers indicate percent divided cells. (E) CFSE-labeled CD8+ T cells were added to plate-bound anti-CD3/CD28 along with the indicated concentrations of B7-H4-Ig or control-Ig and cultured for three days. Proliferation was assessed by CFSE dilution. Representative data is shown from six independent experiments.