Toll-Like Receptor-Dependent Antiviral Responses at the Maternal-Fetal Interface

The maternal-fetal interface is a key barrier to protect the fetus from infection. Toll-like receptors (TLRs) at the maternal-fetal interface are involved in antiviral responses. TLRs are expressed in both maternal decidua and fetal trophoblasts. Virus-induced activation of TLR signaling pathways triggers the release of interferon-related antiviral molecules and other inflammatory cytokines and/or chemokines by the host innate immune system, which may disrupt immune tolerance at the maternal-fetal interface and lead to pregnancy complications. In this review, we summarize the state of knowledge on the most common viral infections during pregnancy, antiviral TLR responses at the maternal-fetal interface, and TLR-associated pregnancy complications.