The Role and Function of Regulatory T Cells in Toxoplasma gondii-Induced Adverse Pregnancy Outcomes

Figure 3

Mechanism of inhibiting Foxp3 by excreted-secreted antigens of T. gondii. ESA can inhibit the expression of Foxp3 by inducing the deactivation of IL-2R, inhibiting the expression of JAK3, and reducing the phosphorylation levels of STAT3 and STAT5. Furthermore, ESA may inactivate TβRII and further suppress the levels of p-Smad2, p-Smad3, and Smad4 in order to downregulate the expression of Foxp3. In addition, ESA can upregulate the expression of PI3K/AKT/mTOR via TLR4, resulting in the decrease of Foxp3 expression. ESA: excreted-secreted antigens; Foxp3: forkhead box p3; IL-2R: interleukin 2 receptor; JAK3: Janus kinase 3; STAT3: signal transducer and activator of transcription 3; TβRII: TGF-β type II receptor; TLR4: Toll-like receptor 4; PI3K: phosphatidylinositol 3-kinase; AKT: protein kinase B; mTOR: mammalian target of rapamycin.