A new study conducted by the MRC-University of Glasgow Center for Virus Research has for the first time discovered that viruses can fuse together inside human cells to create a new type of pathogen that can evade the human immune system.
The researchers, who published the paper on Monday, co-infected human lung cells with influenza A virus (IAV) and respiratory syncytial virus (RSV) and found that instead of competing, they fused into a new palm-tree-shaped hybrid virus.
This new hybrid was then able to infect neighboring cells, despite the presence of antibodies against influenza that is meant to block infection. Researchers say that the antibodies still stuck to the influenza proteins on the hybrid virus’ surface, but the virus simply used RSV proteins to infect lung cells instead, akin to a ‘Trojan horse’.
Researchers are now trying to find out if this newly discovered hybrid virus plays a role in triggering a hard-to-treat and potentially fatal lung disease known as viral pneumonia, which is usually believed to be caused by influenza, RSV, and coronaviruses.
Professor Pablo Murcia, who supervised the research, says that what the team observed has never been described before. “We are talking about viruses from two completely different families combining together with the genomes of the external proteins of both viruses. It is a new type of virus pathogen,” he was quoted as saying by The Guardian.
Although co-infections in humans are believed to be quite common, the researchers say that before now, there has been little to no data on how viruses react when they find themselves inside the same cell.
Since the study was conducted using cultured layers of cells, scientists now look to study if hybrid viruses can form in actual patients with co-infections.
“We need to know if this happens only with influenza and RSV, or does it extend to other virus combinations as well?” Murcia said, adding that he believes it does and can even extend to animal viruses as well. “This is just the start of what I think will be a long journey, of hopefully very interesting discoveries.”