Tissue transglutaminase on trophoblast cells as a possible target of autoantibodies contributing to pregnancy complications in celiac patients.

Abstract

Women with celiac disease (CD) are often affected by atypical presentations of the disease associated with reproductive disorders as a main extra-digestive complaint. Here, we analyzed if autoantibodies against tissue transglutaminase (tTG) in sera from CD patients with reproductive disorders could display direct effects through their interaction with tTG expressed on trophoblast cells and phagocytes inducing tissue damage and interfering in the clearance of trophoblast apoptotic bodies. Sera from CD women with reproductive disorders were obtained, and their ability to induce apoptosis of Swan-71 (cytotrophoblast cell line) and to modulate the wound-healing and phagocytes process was tested. Swan-71 cells expressed tTG and CD sera displayed a significant decrease in trophoblast cell migration and a delay in injury healing on trophoblast cells, compared with those observed with control sera. Moreover, CD sera significantly reduced trophoblast cell proliferation and increased apoptosis levels in comparison with those observed in the control sera. Finally, autoantibodies against tTG interfere in the clearance of trophoblast apoptotic bodies through a mechanism involving MFG-E8 (milk fat globulin-EGF factor 8)-tTG binding. The anti-tTG antibodies might contribute to trophoblast damage and disrupt the phagocytosis process of apoptotic bodies that could promote a pro-inflammatory microenvironment.