Fyn Plays a Pivotal Role in Fetomaternal Tolerance Through Regulation of Th17 Cells.

Problem: Spontaneous abortion is a poorly understood phenomenon, although fetomaternal intolerance is known to play an important role in its pathogenesis. The tyrosine-specific phosphotransferase Fyn has been reported as a significant regulator in immune response. However, its role in fetomaternal immune tolerance and contribution to spontaneous abortion remains unclear.

Methods Of Study: Fyn expression was evaluated at the fetomaternal interface of normal pregnant and abortion-prone mice, as well as in decidual tissue obtained from normal human pregnancies and idiopathic miscarriages. A Fyn inhibitor was administrated into the LPS-induced abortion mice to investigate the variation of embryo resorption and local immunity.

Results: Fyn expression fluctuated with the progress of normal pregnancy and was elevated in abortion-prone mice and patients with recurrent spontaneous abortion. The Fyn inhibitor reversed LPS-induced embryo absorption and aberrant inflammatory status including redundant expression of IRF4 and increased proportion of Th17 cells.

Conclusion: Fyn is confirmed as a negative regulator in fetomaternal immune tolerance, through promoting Th17 cell expansion and proinflammatory factors expression.