eLife good news! The placenta lacks the main molecule used by the SARS-CoV-2 virus to cause infection.

July 19, 2020 /PRNewswire/ -- The placenta membrane containing fetal and amniotic fluid lacks the messenger RNA (mRNA) molecules needed to make ACE2 receptors, the main cell surface receptors that cause infection semblets caused by the SARS-CoV-2 virus, according to a study by researchers at the National Institutes of HealthTheir findings were published in the journal eLifeThese placental tissues also lack mRNAs to make an enzyme called TMPRSS2, which SARS-CoV-2 can use to enter cellsThe study authors say the very low levels of ACE2 receptors and TMPRS2 enzymes in the placenta may explain why SARS-CoV-2 is rarely found in the fetuses or newborns of pregnant women infected with the virusPhoto Source: eLife, led by DRRoberto Romero, director of the perinatal research chapter of the NIH Younis Kennedy Shriver National Institute for Child Health and Human Development (NICHD), found that the placenta contains molecules that previous studies have suggested are possible for SARS-CoV-2 infection pathways, including CD147 receptor synteraseL L and Flynn proteaseThey also detected a macrophage (immune cell) with ACE2 receptors in the placenta and membrane tissueHowever, they point out that there is little evidence that infected macrophages can spread the SARS-CoV-2 virus to the placenta, cell membranes and fetuses during normal pregnancyFinally, the researchers found that the placenta contains a large number of receptors used to infect the Zika virus and the cytomegalovirus, both of which are known to pose serious health risks when passed from a woman to a fetus during pregnancyRelated: Placenta lacks s mains used by SARS-CoV-2 virus to roger el Pais Pique-Regi et alDoes this human placenta express the canonical cell rt rt mediators for SARS-CoV-2? , eLife (2020)DOI: 10.1101/2020.05.18.101485.