from Lenore Pereira, Takako Tabata, Matthew Petitt and June Fang-Hoover writing in Cytomegaloviruses: From Molecular Pathogenesis to Intervention:
During human pregnancy, HCMV spreads from the infected mother to the fetus, navigating the complex architecture of the human placenta, which anchors the fetus to the uterus. Primary sites of virus replication in the placenta include cytotrophoblast progenitor cells in chorionic villi and differentiating/invading cytotrophoblasts that breach uterine blood vessels and form a hybrid vasculature, increasing blood flow to the surface of the placenta. Focal virus replication and induction and release of paracrine factors result in pathology and a hypoxic intrauterine environment that stimulates compensatory development of vascularized floating villi. This review summarizes recent insights into the molecular changes that occur during virus replication, strategies to rescue development of the human placenta and the utility of placental villous explants and xenografts in SCID mice for quantifying infection in vitro and pathogenesis in vivo.
Further reading: Cytomegaloviruses: From Molecular Pathogenesis to Intervention