Figure 1

Potential mechanisms of milk exosome miR-155-mediated FoxP3 expression in Tregs. TCR activation upregulates CD25 and subsequent IL-2/STAT5 signaling, which cooperatively with TGFβ-activated SMAD5 stimulate the FOXP3 promoter. MiR-155 attenuates the expression of SOCS1, the inhibitor of STAT5, thus amplifying IL-2/STAT5-mediated FoxP3 expression. FoxP3 activates the bic promoter enhancing the synthesis of miR-155, which suppresses mRNAs of GATA3 and IL-4, pivotal transcription factors of Th2-mediated IgE-driven atopic immune responses.