Monday, March 20, 2017

Asian vs African Strains of Zika: Effects on Fetal Development

In a recent study from the University of Missouri, researchers looked into how two different strains of Zika Virus affect the placental cells of pregnant women. W know that many women who are infected with Zika virus experience fetuses with teratogenic effects, or fetal death and abortion as a result of their infection. Previously, most evidence put out in the past two years of research has laid large blame on the Asian strain of the virus. In particular it has been shown that the Asian strain of Zika can produce brain abnormalities and other teratogenic effects in fetuses. Until now, researchers have been less sure of the effects that the African strain of Zika has on pregnant women and their fetuses. It seems that the African strain is more dangerous than we believed, and that this version of the virus may cause more cell death than the Asian strain does.

The researchers showed these effects by transforming stem cell lines into placental cells, and then inoculating them with either the Asian strain or the African strain of Zika. They also inoculated full-term placental cells to see if a difference in reactions depended on age of the cells. They found that the African strain was highly trophic towards the early placental cells, and that it caused more cell lysis than the Asian strain did. Both strains had less of an effect on the older placental cells. The researchers have used this evidence to suggest that infection with an African strain of Zika early on in pregnancy may lead to the high rates of fetal abortion that we are observing in Zika infected pregnant women. So now we think that the Asian strain is the main cause for microcephaly, and the African strain could be responsible for fetal death.

Elisa Hofmeister ‘18

See here for more info:
Sheridan, M. A., Yunusov, D., Balaraman, V., Alexenko, A. P., Yabe, S., Verjovski-Almeida, S., . . . Roberts, R. M. (2017). Vulnerability of primitive human placental trophoblast to Zika virus. Proceedings of the National Academy of Sciences, 114(9). doi:10.1073/pnas.1616097114

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