Human amnion epithelial cells (hAECs) induce regulatory T cell (Treg) maturation via transforming growth factor-beta 1 (TGF-β1). (A) Co-culture of FoxP3- non-Tregs with hAECs induced FoxP3 transcription and green fluorescent protein (GFP) expression. This was wholly ameliorated by the addition of an anti-TGFβ blocking antibody (1 mg/mL). TGFβ was used as a positive control to induce FoxP3+ transcription (*P <0.05, ****P <0.001). (B) Levels of human TGF-β1 levels in the supernatant of hAECs were significantly elevated after 5 days co-cultured with non-Tregs (*P <0.05). (C) Stimulation with interferon-gamma (IFNγ) and tumour necrosis factor-alpha (TNFα) significantly increased gene expression of TGF-β1 (*P <0.05).