November 22, 2024

The COVID-19 Trojan Horse: How the Virus Breaks Into the Placental Fortress

Placenta cells (syncytiotrophoblast, in green) contaminated with the SARS-CoV-2 infection (COVID-19, in red); blue locations are cell nuclei identifying the multinucleated syncytiotrophoblasts. Credit: Monash University
The Australian research study team grew placenta tissue in the laboratory, utilizing a modern technique established by Professor Polo and coworkers where human skin cells are “reprogrammed” into trophoblast stem cells (the cells that help an establishing embryo connect to the wall of the uterus, forming part of the placenta). They discovered that ACE2, a protein that acts as the entrance for SARS-CoV-2 to go into organs such as the lung, exists in specific placental cells, like syncytiotrophoblasts (ST cells).
Importantly, ST cells were prone to the virus– a major finding as these placental cells produce the essential hormone for preserving pregnancy (hCG).
Dr. Joseph Chen, a stem cell biologist at Monash University and co-first author of the report, said this discovery describes several scientific reports showing swelling of the placenta due to COVID-19.
” We observed that SARS-CoV-2 infection led to a significant decrease in the survival and differentiation of ST cells, which in turn resulted in lower production of hCG,” he said. “It suggests that this is how COVID-19 might affect pregnancy, though further examinations are required.”
Teacher Jose Polo. Credit: Mike Rutherford
Virologist at Doherty Institute and co-first author of the study Dr Jessica Neil said, “our team also discovered that anti-ACE2 antibodies and antiviral drugs were efficient in preventing SARS-CoV-2 infection and bring back normal ST distinction and function”.
Teacher Subbarao said that this study is a substantial advance for the wider understanding of viral infections in pregnancy.
” Our research study provides valuable insights into the link in between SARS-CoV-2 infection and placenta pathology. This is a video game changer as we are now geared up to check out how the early placenta might be impacted by other viruses also,” she said.
Teacher Polo stressed the significance of the research in developing a platform to study early placental cell types.
” This research study not only assists us to understand what happens when the placenta is contaminated with the COVID-19 virus during pregnancy, it also implies we have developed a wider, scalable and tractable platform to study early placental cell types,” he stated.
Referral: “A placental model of SARS-CoV-2 infection reveals ACE2-dependent vulnerability and differentiation problems in syncytiotrophoblasts” 13 July 2023, Nature Cell Biology.DOI: 10.1038/ s41556-023-01182-0.

Australian scientists have discovered how COVID-19 can infect human placenta, exposing that the virus affects the syncytiotrophoblast cells, which are important for keeping pregnancy. The study also found that anti-ACE2 antibodies and antiviral drugs can efficiently avoid this infection, supplying a substantial development in understanding and potentially mitigating the impacts of viral infections on pregnancy.
Human skin cells reprogrammed into placental stem cells shows how COVID infects placenta– and how it can be stopped.
In a landmark research study published today (July 13) in the journal Nature Cell Biology, Australian researchers, led by Professor Jose Polo from Monash University and the University of Adelaide and University of Melbournes Professor Kanta Subbarao from the Peter Doherty Institute for Infection and Immunity (Doherty Institute), have actually revealed how COVID-19 can contaminate the human placenta.
Research study has shown that COVID-19 infections during pregnancy might cause negative outcomes, but little is learnt about the systems behind the results of SARS-CoV-2 infection in pregnancy.