An obscure family of viruses, already endemic to wild primates in Africa and known to cause deadly Ebola-like symptoms in some monkeys, is ‘ready to spread’ to humans, according to new research from the University of Colorado Boulder published online September 30 in the journal Cell.
While these arteriviruses are already considered a critical threat to macaques, no human infections have been reported to date. And we do not know what the impact of the virus on humans would be if he changed species.
But the authors, evoking parallels with HIV (whose precursor was born in African monkeys), nevertheless call for vigilance: By monitoring arteriviruses now, both in animals and in humans, the global health community might potentially avert another pandemic, they say.
“This animal virus was able to enter human cells, multiply and evade some of the important immune mechanisms that should protect us once morest an animal virus. It’s pretty rare,” said lead author Sara Sawyer, a professor of molecular, cellular, and developmental biology at CU Boulder. “We should pay attention to that.”
Thousands of unique viruses circulate among animals around the world, most of them causing no symptoms. In recent decades, an increasing number of them have passed to humans, wreaking havoc on naïve immune systems that are not used to fighting them: This is the case with the respiratory syndrome of the Middle East (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, Dr. Sawyer’s lab has used laboratory techniques and tissue samples from wild animals around the world to determine which animal viruses are likely to jump to humans.
For the latest study, she and first author Cody Warren, then a postdoctoral fellow at CU’s BioFrontiers Institute, focused on arteriviruses, which are common in pigs and horses but little studied in nonhuman primates. They looked specifically at the simian hemorrhagic fever virus (SHFV), which causes a deadly illness similar to Ebola virus disease and which has caused deadly outbreaks in colonies of captive macaques since the 1960s.
The study demonstrates that a molecule, or receptor, called CD163 plays a key role in the biology of simian arteriviruses, allowing 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 capable of latching onto the human version of CD163, entering human cells and quickly making copies.
Like the human immunodeficiency virus (HIV) and its precursor, the simian immunodeficiency virus (SIV), simian arteriviruses also seem to attack immune cells, neutralizing the main defense mechanisms and establishing themselves permanently in the organism.
“There are profound similarities between this virus and the simian viruses that gave rise to the HIV pandemic,” said Warren, now an assistant professor at the Ohio State University College of Veterinary Medicine.
The authors stress that another pandemic is not imminent and that the public should not be alarmed.
But they suggest the global health community should prioritize further studies of simian arteriviruses, develop tests to detect antibodies in the blood, and consider surveillance of human populations in close contact with simian arteriviruses. carrier animals.
A wide range of African monkeys already carry high viral loads of various arteriviruses, often without symptoms, and some species frequently interact with humans and are known to bite and scratch people.
“Just because we haven’t yet diagnosed human arterivirus infection doesn’t mean no humans have been exposed. We didn’t search,” Warren said.
Warren and Sawyer note that in the 1970s no one had heard of HIV either.
Researchers now know that HIV likely originated from SIV infecting non-human primates in Africa, and likely jumped to humans in the early 1900s.
When he started killing young men in the 1980s in the United States, no serological tests existed and no treatment was in preparation.
Sawyer said there’s no guarantee these simian arteriviruses will jump to humans. But one thing is certain: other viruses will pass to humans, and they will cause disease.
“COVID is just the latest in a long line of animal-to-human transmission events, some of which have resulted in global catastrophes,” Sawyer said. “Our hope is that by raising awareness of the viruses we need to watch out for, we can take the lead so that if human infections start to occur, we will be on the hook quickly. »
Source :
University of Colorado Boulder
Journal reference:
10.1016/j.cell.2022.09.022