TY  - JOUR
A1  - Kreis, Nina-Naomi
A1  - Ritter, Andreas Hans
A1  - Louwen, Frank
A1  - Yuan, Juping
T1  - A message from the human placenta: structural and immunomodulatory defense against SARS-CoV-2
T2  - Cells
N2  - The outbreak of the coronavirus disease 2019 (COVID-19) pandemic has caused a global public health crisis. Viral infections may predispose pregnant women to a higher rate of pregnancy complications, including preterm births, miscarriage and stillbirth. Despite reports of neonatal COVID-19, definitive proof of vertical transmission is still lacking. In this review, we summarize studies regarding the potential evidence for transplacental transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), characterize the expression of its receptors and proteases, describe the placental pathology and analyze virus-host interactions at the maternal-fetal interface. We focus on the syncytium, the barrier between mother and fetus, and describe in detail its physical andstructuraldefenseagainstviralinfections. Wefurtherdiscussthepotentialmolecularmechanisms, whereby the placenta serves as a defense front against pathogens by regulating the interferon type III signaling, microRNA-triggered autophagy and the nuclear factor-κB pathway. Based on these data, we conclude that vertical transmission may occur but rare, ascribed to the potent physical barrier, the fine-regulatedplacentalimmunedefenseandmodulationstrategies. Particularly,immunomodulatory mechanismsemployedbytheplacentamaymitigateviolentimmuneresponse,maybesoftencytokine storm tightly associated with severely ill COVID-19 patients, possibly minimizing cell and tissue damages, and potentially reducing SARS-CoV-2 transmission.
KW  - SARS-CoV-2
KW  - COVID-19
KW  - placenta
KW  - vertical transmission
KW  - immune defense
KW  - miRNA
KW  - interferon type III
KW  - NF-κB pathway
Y1  - 2020
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/55493
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-554938
SN  - 2073-4409
N1  - © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
VL  - 9
IS  - 8, art. 1777
SP  - 1
EP  - 24
PB  - MDPI
CY  - Basel
ER  -