Laboratory animals help solve the complex puzzles of diseases:
The COVID-19 pandemic has seen scientists around the globe come together to study how the infection affects the body and to develop new treatments and vaccines. To do this, scientists often use human cells donated from patients. However, these represent only small pieces of the complex puzzle which is the human body. Diseases, such as COVID-19, attack different pieces of the puzzle and only by examining the whole picture we can see the extent of disruption. Similarly, only by inspecting the whole body, can doctors and researchers’ asses if a treatment or vaccine is beneficial or if there are dangerous side effects. Where possible and humane, scientists recreate the complete puzzle by using animals that mimic the human disease.
Laboratory mice cannot catch COVID-19:
A widely used approach is to use laboratory mice. Unfortunately, using mice to understand and test treatments for COVID-19 has turned out to be trickier than usual. The COVID-19 virus can only enter and infect lungs that are covered in a specific particle called ACE2 which is very different between humans and mice. Without human version of ACE2 the virus cannot infect mice, making reliable and easy drug-development experiments useless.
A harmless virus can help the scientists:
A group of scientists in Yale, led by the scientist Akiko Iwasaki, might now have found a solution for this problem. Benjamin Israelow and Eric Song, the lead scientists on the study, used a different and harmless virus to deliver the human ACE2 directly into adult mouse lungs. Two weeks after delivery, mice were able to catch COVID-19 and the infection indeed resembled the human disease. These scientists therefore created a way of using mice that not only harbours potential to test therapies for unwanted side effects, but also to help figure out the extent of overall disruption in COVID-19 disease.
Why is it useful?
The importance of this study is the creation of a simple way to infect mice with COVID-19. Scientists all around the world can now, for example, focus on how COVID-19 acts on elderly, diabetic or obese mice. This will help understand why these pre-existing conditions play such an important role in human patients.
Original Paper: Israelow et al, 2020, bioRxiv (https://www.biorxiv.org/content/10.1101/2020.05.27.118893v1)
Oximmuno summary for researchers: https://www.nature.com/articles/s41577-020-0369-3
These summaries were created by the OxImmuno Literature initiative and are simplified views which are meant to help to explain the concept/ideas behind the research papers and not every single detail. They should not be considered as an endorsement or otherwise of the research. For more information on the initiative and its work please see our first blog post.