Viruses have undoubtedly always existed, and many of them have caused illnesses that have been known to humankind for thousands of years.
Viruses have undoubtedly always existed, and many of them have caused illnesses that have been known to humankind for thousands of years. The COVID-19 pandemic has gripped the entire world for more than a year, reinforcing the fact that there is still a lot we don’t understand about viruses, how they work, and how to stop them.
But recently, a team of researchers from the University of Leeds was able to determine the process through which certain viruses — such as the common cold virus and polioviruses — can manage to become so infectious.
Their findings were published earlier this month in the journal PLOS Pathogens. Identifying the way that these viruses package their genetic code could potentially lead to new advancements in the way they are combated, and new drugs and treatments could be developed to be more efficient against these pathogens.
When a virus infects a cell, it seeks to spread its genetic material to other cells. In order to do so, the virus creates virions, which are daughter particles that contain the virus’ nucleic acid genome (RNA or DNA) and transmit this genetic information to infect more cells. Each virion has an outer shell made of protein, which is called a capsid. While the existence of virions and their importance in viral transmission has been known for decades, researchers hadn’t been able to discover how viruses assemble these infectious particles — until now.
The research study was supervised by Professor Peter Stockley, former Director of the Astbury Centre for Structural Molecular Biology at Leeds and Professor Reidun Twarock from York. Experts in the fields of molecular structure of viruses, electron microscopy and mathematical biology collaborated in the research.
Professor Stockley remarked: “This study is extremely important because of the way it shifts our thinking about how we can control some viral diseases. If we can disrupt the mechanism of virion formation, then there is the potential to stop an infection in its tracks.”
“Our analysis suggests that the molecular features that control the process of virion formation are genetically conserved, meaning they do not mutate easily – reducing the risk that the virus could change and make any new drugs ineffective.”
Why viral RNA is so important
The study analyzed the bovine virus enterovirus-E; this virus isn’t dangerous to humans, but it acts as the universally adopted research surrogate for the poliovirus. Poliovirus, on the other hand, causes polio or poliomyelitis, a disease that paralyzed or killed hundreds of thousands of people each year until effective vaccines were developed to prevent it.
Poliovirus, enterovirus-E, and human rhinovirus (which causes the common cold) are all part of the enterovirus genus. Other significant viruses in this genus include coxsackievirus A, which causes hand, foot, and mouth disease; coxsackievirus B viruses, which can cause pericarditis, myocarditis, and meningitis; and echoviruses, which can cause nonspecific viral infections that can range from mild to fatal in severity.
The study examined the function of RNA Packaging Signals or RNA-PS, which are short regions of viral RNA that guarantee the formation of infectious virions. The study found evidence to support the theory that RNA-PS are conserved in an evolutionary manner between pathogens of the same family. The research team used advanced electron microscopes at the Astbury Biostructure Laboratory at the University of Leeds to observe this process, which marks the first time this has been possible for any virus.
The fact that RNA-PS are common to different viruses within the same family could signify that future antiviral treatments could target these RNA regions; likewise, they could also be manipulated to develop new vaccines.
