Figure 4. HBZ directly induces Foxp3 expression in CD4⁺ T cells.

(A) Schematic diagrams of retrovirus vectors used in this study. (B) Mouse CD4⁺CD25⁻ T cells transduced with retrovirus vector encoding HBZ or empty vector with or without TGF-β were stained with anti-Foxp3 antibody and analyzed by flow cytometry. (C) To study the effect of HBZ on promoter activity of the Foxp3 gene, EL4 cells were transfected with Foxp3 reporter plasmid and/or HBZ expressing plasmid. Representative data shown are firefly luciferase activities normalized to those of renilla luciferase (mean ± SD).