Pangolins are missing the genes mammals use to detect viruses

In a new study published by Frontiers, experts have discovered how pangolins are able to tolerate coronaviruses. The animals lack two genes that humans and all other mammals rely on to detect viruses and trigger the body’s immune response. 

Pangolins were recently identified as a potential source of COVID-19 infection. The scaly mammals are believed to have served as an “intermediate host,” passing SARS-CoV-2 from horseshoe bats to humans. 

The findings of the new study may ultimately help experts develop treatments that can make the human body more resistant to the coronavirus. 

The researchers analyzed the genome sequence of pangolins and compared it to other mammals such as humans, dogs, and cattle.

Study co-author Dr. Leopold Eckhart is an expert at the Medical University of Vienna in Austria.

“Our work shows that pangolins have survived through millions of years of evolution without a type of antiviral defense that is used by all other mammals,” said Dr. Eckhart.

“Further studies of pangolins will uncover how they manage to survive viral infections, and this might help to devise new treatment strategies for people with viral infections.”

In humans, the coronavirus can send the body’s immune system into overdrive, unleashing an inflammatory response called a cytokine storm that does much more harm than good. 

The study authors suggest that the suppression of gene signaling may be a possible treatment option for severe cases of COVID-19. 

However, Professor Eckhart cautions though that such a remedy could open the door to secondary infections. 

“The main challenge is to reduce the response to the pathogen while maintaining sufficient control of the virus.” Professor Eckhart explained that an over-activated immune system can be prevented by changing the timing or reducing the intensity of the immune response.

The study identified genetic differences between pangolins and other mammals, but did not investigate the impact of those differences on the antiviral response. It is not yet clear how exactly pangolins are so resilient to SARS-CoV-2, but the lack of the two signaling genes is most likely involved. 

Professor Eckhart pointed to another gene called RIG-I that acts as a sensor against viruses, noting that it could possibly defend against coronaviruses.

The research offers a starting point to better understand certain characteristics of SARS-CoV-2, as well as the body’s response to the virus. 

The study is published in the journal Frontiers in Immunology.

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By Chrissy Sexton, Earth.com Staff Writer