Epilepsy 4 (EL-4) cells transducted with protein transduction domain (PTD) recombinant proteins. (a) EL-4 cells were incubated with increasing doses of PTD-mouse forkhead box protein 3 (mFoxP3) (320 nM, 640 nM and 1280 nM) for 4 h. The expression of intracellular FoxP3 in PTD-mFoxP3-transduced EL-4 cells was detected by staining with anti-FoxP3-phycoerythrin (PE) using flow cytometry. (b) Cells were transduced with 640 nM PTD-enhanced green fluorescent protein (eGFP)- mouse forkhead box protein 3 (mFoxP3) for 2 h (a), the nuclei were stained with propidium iodide (PI) (b), and merged (c,d) examined by confocal microscopy. (c) EL-4 cells co-cultured with or without mFoxP3, PTD-mFoxP3 for 2 h at 640 nM, then cytoplasm and nucleus proteins were extracted and probed for the presence of recombinant proteins with anti-6 × His-Tag monoclonal antibody (mAb) (1 : 1000). (d) EL-4 cells were cultured with 640 nM PTD-mFoxP3 and harvested at 2 and 12 h, then cytoplasm and nucleus proteins were extracted and probed for the presence of recombinant proteins with anti-6 × His-Tag monoclonal antibody (mAb) (1 : 1000).