For the research from the University of Leeds, viruses like poliovirus and the common cold virus were studied. The virologists were able to identify how viruses ‘package up’ their genetic code. This physical process enables the viruses to infect cells.
It has long been established that once a cell is infected, a virus needs to spread its genetic material to other cells. This process requires the creation of virions. This is the complete, infective form of a virus outside a host cell, with a core of RNA and a capsid and they serve as newly-formed infectious genetic copies of the virus. A virus is composed of a central core of nucleic acid called genome (either DNA or RNA) plus the protein coat surrounding is called as capsid. The virions have the capacity to infect other cells and cause disease.
What has not been established, until now, is the mechanism by which a virus assembles virions. For the study, the researchers modelled a bovine virus called Enterovirus-E. This virus is used as a surrogate for the poliovirus.
This revealed an important role played by RNA packaging signals. These are short regions of the RNA molecule. Working with proteins from the virus’s casing, these drive the formation of the virion. This was shown through a series of electron microscopy images.
What is good news is that the molecular features that shape the process of virion formation are genetically conserved. This means they do not mutate significantly. This lowers the possibility that the virus can mutate and therefore lead to new drugs becoming ineffective. It follows that the importance of the research is that it could lead to new anti-viral agents to be developed to help to prevent infections.
The research has been published in the journal PLOS Pathogens. The article is titled “Assembly of infectious enteroviruses depends on multiple, conserved genomic RNA-coat protein contacts.”
