Arteriviruses are poised for spillover to humans: Study
According to new University of Colorado Boulder research published online September 30, a mysterious family of viruses, which are already endemic to wild African primates and known to cause fatal Ebola-like symptoms in some monkeys, are “prepared to spread” to humans. in the magazine cell.
While such arterioviruses are already considered a serious threat to macaques, no human infections have been reported to date. It is not certain what effect the virus would have on humans if the species jumped.
But the authors, invoking parallels with HIV (whose ancestor originated in African monkeys), call for vigilance nonetheless: By monitoring arterial viruses now, in both animals and humans, the global health community could avoid another pandemic, they said. .
This animal virus has figured out how to get into human cells, multiply itself, and escape some of the important immune mechanisms we expect to protect us from an animal virus. This is very rare, said senior author Sarah Sawyer, professor of molecular, cellular and developmental biology at the University of Colorado Boulder. “We have to watch her.”
There are thousands of unique viruses circulating among animals around the world, and most of them do not cause any symptoms. In recent decades, increasing numbers have jumped into humans, wreaking havoc on naive immune systems without any experience in combating them: these include Middle East Respiratory Syndrome (MERS) in 2012, severe acute respiratory syndrome coronavirus (SARS-CoV) in 2003, and SARS-CoV-2 (the virus that causes COVID-19) in 2020.
For 15 years, Sauer’s lab has used laboratory techniques and tissue samples from wildlife from around the world To explore animal viruses that may be susceptible to transmission to humans.
For the latest study, she and first author Cody Warren, then a postdoctoral fellow at the BioFrontiers Institute in CU, focused on arterial viruses that are common in pigs and horses but have not been well studied among non-human primates. They specifically looked at monkey hemorrhagic fever virus (SHFV), which causes a deadly disease similar to Ebola virus disease and has caused fatal outbreaks in captive macaque colonies dating back to the 1960s.
The study demonstrates that the molecule, or receptor, called CD163, plays a key role in the biology of monkey arterioviruses, enabling the virus to invade and infect target cells. Through a series of lab experiments, the researchers discovered, to their surprise, that the virus was also remarkably adept at capturing the human copy of CD163, getting into human cells and quickly making copies of it.
Like the human immunodeficiency virus (HIV) and its precursor monkey immunodeficiency virus (SIV), simian arterial viruses also appear to attack immune cells, disrupt key defense mechanisms, and persist in the body over the long term.
“The parallels between this virus and the monkey viruses that led to the HIV pandemic are profound,” said Warren, who is now an assistant professor at the Ohio State University College of Veterinary Medicine.
The authors stress that another pandemic is not imminent, and the public has no need for concern.
But they suggest that the global health community prioritize further study of monkey arterioviruses, develop blood antibody tests for them, and consider monitoring human populations in close contact with animal vectors.
A wide range of African monkeys already carry large amounts of diverse arterial viruses, often asymptomatic, and some species interact frequently with humans and have been known to bite and scratch people.
“Just because we haven’t diagnosed human arterial virus infection yet doesn’t mean that no human has been exposed,” Warren said.
Warren and Sawyer noted that in the 1970s, no one had heard of HIV either.
Researchers now know that HIV likely originated from SIVs that infected non-human primates in Africa, and likely jumped to humans sometime in the early 20th century.
When I started killing young men in the 1980s in the United States, there was no serological testing, and no treatment was in place.
There is no guarantee that these simian arterial viruses will be transmitted to humans, Sawyer said. But one thing is certain: more viruses will pass to humans and cause disease.
“COVID is just the latest in a long chain of spillover events from animals to humans, some of which have turned into global catastrophes,” Sawyer said. “Our hope is that by raising awareness of the viruses that we have to look out for, we can move forward so that if human infections start to occur, we deal with them quickly.”