TGF-β–Induced Foxp3⁺ Tregs Loose Foxp3 Expression upon Restimulation

<div><p>(A) CD25⁻CD4⁺ T cells were cultured for 6 d in the presence of TGF-β as described in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0050038#pbio-0050038-g006" target="_blank">Figure 6</a>. On day 6, cultured cells were sorted by FACS for CD25⁺ cells and analyzed for intracellular Foxp3 expression by FACS (upper panel). Sorted CD25⁺ cells from the same TGF-β-cultures were restimulated for another 6 d in the absence of TGF-β. On day 6, cultured cells were analyzed for intracellular Foxp3 expression by FACS (lower panel). Numbers display frequency of cells within indicated populations.</p> <p>(B) Ex vivo isolated CD25⁺CD4⁺ Tregs were analyzed for intracellular Foxp3 expression before (upper panel) and after 6 d in vitro culture (lower panel) by FACS. Numbers display frequency of cells within indicated populations. One representative experiment out of two individual experiments is shown.</p>