Corona: How Covid-19 destroys the lungs

Although the coronavirus “Sars-CoV-2” is currently grabbing the attention of global research, it was not yet clearly clear how exactly “Covid-19” attacks the cells of our lungs.

Scientists from the “University of Cambridge” have now for the first time been able to see what happens at the cellular level during a “Sars-CoV-2” infection.

Corona infection: the course of the disease simulated in the laboratory

The “Sars-CoV-2” coronavirus not only affects the lungs and airways, but also the tissue of other organs such as the heart, intestines, brain and the nervous system. For most of these organs, doctors have already found a way to successfully view a corona infection in the laboratory.

Of all things, the alveoli that are particularly badly affected by “Covid-19” have so far lacked the information to track exactly how an infection is taking place in cells. “We still know surprisingly little about how” Sars-CoV-2 “affects the lungs and makes them sick,” explains Joo-Hyeon Lee, doctoral student at the Institute for Stem Cell Research in Cambridge.

Researchers at the “University of Cambridge” have now succeeded in examining the course of the disease and the effects of “Sars-CoV-2” on the lungs. To do this, the scientists developed so-called organoids, a miniature image of an organ grown from stem cells, in this case a lung.

The researchers cultivated the lung organoids from the stem cells of healthy donors and then infected them with “Sars-CoV-2”. The scientists published their observations and results in the specialist magazine for stem cell research Cell Stem Cell.

Protective mechanism: Corona drives cells to suicide

Contact with a single virus particle is enough to infect a lung cell, according to the researchers. According to the study, 61 percent of the organoid’s lung cells were infected with corona just one day after initial contact with “Covid-19”. The body immediately started producing interferons, an immune messenger that puts cells on alert.

But although the cells changed after just a few hours and mutated into small “virus factories”, the virus defense mechanism only began after 48 hours: On the third day after infection, the cells had increased the production of antiviral molecules to the maximum, according to the researchers.

In most cases, however, the body’s own cell defense is not sufficient to defeat “Sars-CoV-2”. This means that apoptosis messenger substances are produced around 60 hours after infection, the scientists report.

According to research, apoptosis is a kind of suicide command for cells: “A cell goes into apoptosis when signals that it needs for survival are withdrawn from it, or when other signals order suicide. […] This prevents genome defects from being passed on to daughter cells, ”says the“ Federal Ministry for Education and Research ”.

Coronavirus study: organoids provide a good representation of reality

According to the scientists, the study provides valuable insight into the course and stages of a “Covid-19” disease – from the viral takeover of the cell machinery and the first alarm signals to the mobilization of the cell’s own resistance to the failure of defense measures and death of the cell.

One can assume that an infection in the human body proceeds very similarly. Since Corona usually only causes serious lung damage after about ten days after infection, it can be assumed that the cellular response to “Sars-CoV-2” in humans occurs with a time delay compared to the organoid.

According to the study, this could be because it takes the coronavirus a few days to travel from the upper airways to the lungs.

As a radiologist, Christopher Herzog has already dealt with numerous people who have contracted the coronavirus. In the interview he explains what is going on in the lungs and why a “CT” can be important.