A Message from the Human Placenta: Structural and Immunomodulatory Defense against SARS-CoV-2.
Nina-Naomi KreisAndreas RitterFrank LouwenJuping YuanPublished in: Cells (2020)
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 and structural defense against viral infections. We further discuss the potential molecular mechanisms, 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-regulated placental immune defense and modulation strategies. Particularly, immunomodulatory mechanisms employed by the placenta may mitigate violent immune response, maybe soften cytokine storm tightly associated with severely ill COVID-19 patients, possibly minimizing cell and tissue damages, and potentially reducing SARS-CoV-2 transmission.
Keyphrases
- sars cov
- respiratory syndrome coronavirus
- public health
- coronavirus disease
- nuclear factor
- pregnant women
- immune response
- type iii
- toll like receptor
- innate immune
- physical activity
- preterm birth
- pregnancy outcomes
- mental health
- endothelial cells
- cell death
- emergency department
- dendritic cells
- gestational age
- electronic health record
- cell therapy
- inflammatory response
- stem cells
- human health
- risk assessment
- body mass index
- binding protein
- multidrug resistant
- gram negative
- artificial intelligence
- anti inflammatory