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Published on: September 20, 2016
Does the human placenta express the canonical cell entry mediators for SARS-CoV-2?
Roger Pique-Regi1,2,3, Roberto Romero1,2,4,5,6,7, Adi L Tarca1,3,8
1Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, <italic>Eunice Kennedy Shriver</italic> National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Detroit, United States.
The placenta shows minimal expression of ACE2 and TMPRSS2, key entry mediators for SARS-CoV-2. This suggests vertical transmission of COVID-19 is unlikely during pregnancy.
Area of Science:
- Reproductive biology
- Virology
- Genomics
Background:
- The COVID-19 pandemic, caused by SARS-CoV-2, has impacted pregnant women globally.
- Concerns exist regarding potential vertical transmission of SARS-CoV-2 to fetuses.
- The canonical cell entry pathway for SARS-CoV-2 involves ACE2 and TMPRSS2 receptors.
Purpose of the Study:
- To investigate the expression of ACE2 and TMPRSS2 in placental and chorioamniotic tissues during pregnancy.
- To assess the potential for SARS-CoV-2 cell entry into placental cells.
- To compare SARS-CoV-2 receptor expression with that of other vertically transmitted viruses.
Main Methods:
- Analysis of single-cell/nuclei RNA-sequencing data from placental and chorioamniotic tissues.
- Quantification of ACE2 and TMPRSS2 co-transcription levels.
- Evaluation of expression patterns for known congenital infection viral receptors.
Main Results:
- Co-transcription of ACE2 and TMPRSS2 is negligible in the placenta.
- The placenta exhibits minimal expression of canonical SARS-CoV-2 cell-entry mediators.
- Receptors for Zika virus and cytomegalovirus are highly expressed in placental cell types.
Conclusions:
- The placenta's low expression of ACE2 and TMPRSS2 makes it an unlikely route for SARS-CoV-2 vertical transmission.
- Congenital infection risk from SARS-CoV-2 via placental cell entry appears low.
- Placental cell tropism differs significantly between SARS-CoV-2 and viruses known to cause congenital infections.
