Zika scientists had established that these antiviral proteins, known as type I interferon, were required to fight Zika infection in mothers. But it was not clear what role interferon played in providing an immune defense for the fetus.
‘Antiviral proteins known as type I interferon that blocks the Zika virus replication in mothers may affect the fetal growth and development.’
To investigate, the team led by immunobiologist Akiko Iwasaki studied two different types of mouse models. One type lacked the receptor for type 1 interferon altogether, and the other had only one copy of the interferon receptor gene. Only the latter showed signs of abnormal placental development, restricted fetal growth and death, the scientists said.
The finding demonstrates that the damaging effects of the immune response to Zika virus can outweigh the benefits for foetuses, said the research team, noting that although type 1 interferon is critical to blocking replication of the virus, too much of it can be detrimental during pregnancy. The study results may have implications for other infection-related pregnancy complications and possible interventions.