November 14, 2018
To cross the placenta, Zika virus may hijack the route by which acquired immunity is transferred from mother to fetus, new research suggests.
The results are scheduled for publication in Cell Host & Microbe.
Antibodies against dengue virus make it easier for Zika to infect certain immune cells in the placenta, called Hofbauer cells. This effect was observed in both cell culture and in explanted human placental tissue, says lead author Mehul Suthar, Ph.D., assistant professor of pediatrics at Emory University School of Medicine and Emory Vaccine Center.
Zika infection during pregnancy can lead to overt microcephaly—a smaller head and brain—in the developing fetus, as well as more subtle neurological problems detectable later.
Researchers had previously observed that syncytiotrophoblasts, cells that make up outermost layer of the placenta, are resistant to Zika infection. Yet studies of Zika-infected pregnant women show that the virus is present in the placenta in the majority of cases.
“We needed to know how the virus gets across the placenta,” Suthar says. “Previous studies have shown that Zika persists in the placenta for months. It’s clearly getting in there.”