Track 11: Poliovirus Attack
The terrible enterovirus family, which includes numerous common colds, includes the poliovirus. Since technology has not yet enabled us to see thus deeply within the cells, it has been known for some time that enteroviruses significantly reorganize the inside of infected hosts. Virologists have now been able to capture three-dimensional pictures of how the poliovirus develops and colonizes human cells for the first time thanks to a recent study. By observing areas with half-assembled viruses, the virologists were able to pinpoint the location in the cell where the poliovirus creates new virus particles. This " factory" in the cell, which resembled autophagy, a normally occurring cellular process, turned out to be present. The 2016 Nobel Prize in Physiology or Medicine was awarded for the discovery of the cell mechanism called autophagy.
Autophagy often works to destroy substances that the cell wishes to get rid of, such as virus particles. However, the poliovirus can rewire this anti-virus defensive system such that it instead creates additional viruses. The scientists discovered that some proteins are particularly significant. The virus uses the VSP34 protein to create new particles. When the virologists blocked VSP34, they could observe that the virus could mainly only form half particles and could seldom assemble whole viruses. ULK1, another significant protein, inhibits the development of viruses. The number of viruses multiplied, as the virologists could observe when this protein was suppressed. Given that the illness was seen as nearly eliminated, a fall in vaccination rates as well as rising vaccine resistance may be contributing factors in wealthy nations where polio has returned.