In a bid to better understand interactions between viruses during infections, scientists have studied the fusion of two viruses, influenza A and respiratory syncytial virus (RSV). In a lab-based experiment designed to analyze the clinical outcomes and pathogen behavior of co-inhibiting viruses, scientists observed the formation of a new virus has some parts of RSV and another portion of of Influenza A, and as a whole appears to be shaped like a gecko’s foot.
In the experiments conducted by Dr. Joanne Haney of the University of Glasgow, human cells were first exposed to both viruses together and then individually in a controlled setting, contrary to expectations, rather than competing with each other they fused together.
Supervisor of the research Prof.Pablo Murcia said, “This kind of hybrid virus has never been described before, we are talking about viruses from two completely different families combining together with the genomes and the external proteins of both viruses. It is a new type of virus pathogen.”
When both these viruses joined forces it was revealed that influenza A was able to infect a broad range and a higher number of human cells, by displaying the surface proteins of RSV, influenza A particles were able to evade the immune system, increasing their survival chances. While typically influenza only infects the nose, throat, and windpipe, RSV generally attacks the lung cells and windpipe.
Once the hybrid cells have been formed they can easily spread to adjoining cells and even the presence of antibodies to block the influenza is unable to stop the infection from spreading. The hybrid virus makes use of RSV proteins to tackle the threat of antibodies that attack influenza proteins and therefore are able to infect lung cells.
It was also observed that the hybrid cells were able to travel further along the respiratory tract to cause more severe lung infections. This is the first time such viral cooperation has been observed and thus explains why co-infections lead to significantly worse outcomes for patients. According to a virologist at the University of Leeds, Dr. Stephen Griffin, this phenomenon could increase the chances of a possibly fatal viral pneumonia.
The research team also revealed that the hybrid cells were also able to infiltrate through cultured layers of cells. This is noteworthy because, unlike individual respiratory cells, these cells are connected to each other in an authentic way which would mean that in order to get in and out the virus particles will have to go a certain way.
Researchers are guessing that the formation of these hybrid viruses is not just limited to RSV and influenza and there is a likelihood that similar results can be observed with animal viruses. In order to confirm this hypothesis experiments in patients with co-infections will have to be conducted.
