'Mini lungs' grown from tissue donated to Cambridge hospitals in the United Kingdom have provided much-needed insight into the way that COVID-19 infects and damages the lungs of people with the disease.
A group of researchers from South Korea and the UK has published a research paper in the journal Cell Stem Cell, detailing their findings on the mechanisms underlying SARS-COV-2 infection, the virus that causes COVID-19.
3D models of key lung tissue
Having passed the grim tallies of over 40 million cases of COVID-19 worldwide and more than 1 million deaths from the disease, we are still in the process of building practical knowledge of what exactly the virus does to the human body.
"We still know surprisingly little about how SARS-COV-2 infects the lungs and causes disease," Dr. Joo-Hyeon Lee, co-senior author, and a Group Leader at the Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, explained in a press release.
"Our approach has allowed us to grow 3D models of key lung tissue – in a sense, ‘mini-lungs’ – in the lab and study what happens when they become infected," he continued.
Gaining a better understanding of SARS-COV-2 infection
The team used the tissue donated to tissue banks at the Royal Papworth Hospital NHS Foundation Trust and Addenbrooke’s Hospital, Cambridge University NHS Foundations Trust, UK, and Seoul National University Hospital to extract a type of lung cell known as human lung alveolar type 2 cells.
Their aim was to gain a better understanding of how SARS-COV-2 infects the lungs and causes disease.
By reprogramming the alveolar type 2 cells back to their earlier ‘stem cell’ stage, the researchers were able to grow self-organizing alveolar-like 3D structures that mimic the behavior of key lung tissue.
Tackling unanswered key questions
The team infected the organoids with a strain of SARS-COV-2 taken from a patient in South Korea. Using fluorescence imaging and single-cell genetic analysis, they were able to study how the cells responded to the virus.
"Based on our model, we can tackle many unanswered key questions, such as understanding genetic susceptibility to SARS-COV-2, assessing relative infectivity of viral mutants, and revealing the damage processes of the virus in human alveolar cells," said Dr. Young Seok Ju, co-senior author, and an Associate Professor at Korea Advanced Institute of Science and Technology.
"Most importantly, it provides the opportunity to develop and screen potential therapeutic agents against SARS-COV-2 infection."
It's not the first time that "mini lungs" have been used to model the effects of COVID-19 on human tissue: back in July, USC stem cell scientists tested experimental COVID-19 treatments on human “mini-lungs” and lung models.
Researchers from Duke University have also just unveiled their findings based on lung organoids, which they say allow them to "watch the battle between the SARS-CoV-2 coronavirus and lung cells at the finest molecular scale."
In the near future, the researchers from the UK and South Korea study hope to use their technique to grow 3D models from cells of patients who are particularly vulnerable to infection, such as the elderly, and find out what exactly happens to their lung tissue.