Organoid models reveal how coronavirus SARS-CoV-2 infects human intestinal cells
Researchers from the Hubrecht Institute in Utrecht, Erasmus MC University Medical Center Rotterdam, and Maastricht University in the Netherlands using human intestinal organoids, have found that the coronavirus SARS-CoV-2, which causes COVID-19, can infect cells of the intestine and multiply there.
These findings could explain the observation that approximately one third of COVID-19 patients experiences gastrointestinal symptoms such as diarrhea, and the fact that the virus often can be detected in stool samples. The results of this study were published in the scientific journal Science on the 1st of May 2020.
Intestinal organoids, the right one infected with coronavirus SARS-CoV-2. The coronavirus is colored white, the organoids themselves are colored blue and green. Credit: Joep Beumer, copyright Hubrecht Institute
The researchers used human intestinal organoids: tiny versions of the human intestine that can be grown in the lab. Hans Clevers (Hubrecht Institute): "These organoids contain the cells of the human intestinal lining, making them a compelling model to investigate infection by SARS-CoV-2."
When the researchers added the virus to the organoids, they were rapidly infected. The virus enters a subset of the cells in the intestinal organoids, and the number of cells that are infected increases over time. Using electron microscopy, an advanced way to visualize different components of the cell in great detail, the researchers found virus particles inside and outside the cells of the organoids.
The researchers also cultured the organoids in different conditions that result in cells with higher and lower levels of the ACE2 receptor, through which SARS-CoV-2 can enter the cells. To their surprise, they found that the virus infected cells with both high and low levels of the ACE2 receptor. Ultimately, these studies may lead to new ways to block the entry of the virus into our cells.
The current study is in line with other recent studies that identified gastrointestinal symptoms in a large fraction of Covid-19 patients and virus in the stool of patients free of respiratory symptoms. Special attention may be needed for those patients with gastrointestinal symptoms. More extensive testing using not only nose and throat swabs but also rectal swabs or stool samples may thus be needed.
Source: Hubrecht Institute