Coronaviruses are found in a wide range of animal species, including bats (chiropteans). In this regard, the scientific literature has long highlighted the high resilience of some chiropteran species to viral infection.
The immune system of these flying mammals is in a “pre-alert” state, which makes it easier for them to fight off viral infections. Having an immune system in a continual state of pre-alert would cause inflammatory problems in other mammals, but not in bats, which is why they are the subject of several worldwide epidemiological and immunological investigations.
As part of the study, led by the experts Nolwenn Jouvenet and Laurent Dacheux, from the Institute Pasteur in Paris, includes the collaboration of experts from research institutions in France, the Czech Republic and Switzerland, the group looked at how well primary cells from different species of bats could help SARS-CoV-2 spread.
The findings of the research published in the Journal of Virology show “that none of these cells,” according to the lead author, “was permissive to the infection, not even those expressing detectable levels of angiotensin-converting enzyme 2 (ACE2), a metallopeptidase that serves as a viral receptor in many mammal species.”
“The cells,” adds the researcher, “did not allow the infection in the species Rhinolophus ferrumequinum, a chiropteran from the same genus as the Asian bat in which the BANAL-52 virus was found, a potential ancestor of SARS-CoV-2. Specifically, the genetic sequences of the BANAL-52 virus are 96.8% similar to that of SARS-CoV-2.”
In humans, it is known that the SARS-CoV-2 spike protein interacts with the cell membrane receptor ACE2 before infecting the cell. But emphasizes that “in the case of the chiropteran cells, either the amount of ACE2 enzyme is small and it no longer enters the cell or, if the virus binds to ACE2, it cannot infect the cell.”
This study advances our knowledge of the defense systems against viral infections on a larger scale. This area of study has been pursued for many years by the team at the UB and IRBio led by Serra-Cobo, and it is currently gathering momentum within the scope of the EvoDevo-Cat research group at the UB Faculty of Biology.
“Specifically, our team is working to understand the adaptations of the chiropterans regarding viral infections,” adds the author.
“An important number of zoonotic viruses circulate in chiropter populations without causing symptoms of the disease in the carriers,” notes the researcher.
“Over the course of the evolutionary history of chiropterans — about 64 million years,” according to the Jordi Serra-Cobo, “there have been processes of coevolution between bats and viruses.
“One example of these processes is in the adaptation to coronaviruses. The study of the evolutionary adaptations of living beings to deal with viral infections is of great interest, since they provide information that can have medical applications.”
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