In a first, researchers identify how viruses affect human cells by 'packaging up' their genetic code

11-01-2021

Viruses are a large group of microbes that are known to cause some of the most deadly, dangerous infections around the world. Viruses such as Ebola, Zika, HIV, and others have caused global health crisis. Even the pathogen that has caused the current pandemic, COVID-19, is a virus. Even as viral infections and diseases are so common and such a big concern, researchers have not yet discovered how these viruses are able to infect cells. For the first time, researchers have identified how viruses such as the poliovirus, and the common cold virus are able to 'package up' their genetic code, allowing them to infect cells. The findings of the study were published in the journal PLOS Pathogens. The study was conducted by a team from the University of Leeds and York. The results open up the possibility of that medication or anti-viral agents would help stop such infections.

How viral infections spread within human cells
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Once a cell is infected, a virus needs to spread within cells in order to infect more parts of the body. This is a complex process. It involves the production of virions � the newly-formed infectious copies of the virus. Each such unit is a protein shell, that contains a complete code of the virus's genetic code. The virions can then infect other cells, and cause disease. Till now, it has not been clear how the virus assembles these daughter virions. As per Professor Peter Stockley, former Manager of the Astbury Centre for Structural Molecular Biology at Leeds, who part supervised the study with Professor Reidun Twarock from York, �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�s the capability to stop an infection in its tracks.� Our analysis suggests that the molecular characteristics that control the process of virion formation are genetically conserved, meaning they don�t mutate readily reducing the risk that the virus could change and make any new medication ineffective. The study at Leeds and York brings together experts in the molecular structure of viruses, electron microscopy and mathematical biology. The analysis focuses on a harmless bovine virus that is non-infectious in people, Enterovirus-E, that�s the universally embraced surrogate for the poliovirus. The poliovirus is a dangerous virus that infects people, causing polio and is the goal of a virus eradication initiative by the World Health Organization. The enterovirus group also includes human rhinovirus, which causes the common cold. The study published today details the role of what is called RNA packaging signals, short regions of the RNA molecule which together with proteins in the virus�s casing ensure the accurate and efficient formation of an infectious virion. The researchers could determine potential sites on the RNA molecule which could act as packaging signals. Using advanced electron microscopes at the Astbury Biostructure Laboratory in the University of Leeds, scientists were able to directly visualize this process. This is the first time this has been possible with any kind of virus.