If virus can infect us, why can’t the intelligent humans design something that can trick the virus to self-destruct? This question regarding the ability of self-destruct was raised in one of the casual conversations I had last week. My immediate answer was that in the case of RNA viruses, some progeny viruses go through self-destruction due to the high mutation rate because of the absence of proofreading in the RNA Polymerase. But if the error is prevented, self-destruction will not happen, unless you change the cellular components (i.e. increasing the expression of antiviral mechanisms, or just reducing the expression of replication machinery that the virus needs). In sum, my answer was yes in some conditions, but no in the perfect scenario when virus can replicate without problems.
After researching for papers regarding the self-destructive virus, I came across an article about a researcher, Bently Fane, from University of Arizona, and also several publications from Dr. Fane on pubmed.com. In short, they basically engineered bacteria to keep producing the mutated virus’s coat protein. So why is it important for them to make mutated protein? The mutated protein serves as a decoy. Due to the high abundance of mutated and un-mutated coat proteins within the virus-infected bacteria, newly synthesized viruses incorporated both proteins by mistake. These viruses probably do not have a proper structure to withstand the external environment (i.e. pH changes and high termperature). As a result, these viruses were destroyed due to instability. The bottom line is that viruses can be made to self-destruct by making decoy coat proteins. So now let’s step back a little. Theoretically, if we can make our infected cells to keep making mutated coat proteins, the progeny viruses will self-destruct because they incorporate some mutated coat proteins.
So, can this be a cure for viral infection? If we can somehow express mutated coat protein, can we evade infection? Sadly, the answer is no. Self-destruction can only be induced for a short period of time. The abundance of mutated coat proteins exerted pressure to select for a subgroup of viruses that can form a proper structure with mutated and un-mutated coat proteins. After a few generations, the fitter subgroup survives and becomes the dominant virus. Therefore, this surviving subgroup will continue without self-destructing (meaning we can never outrun viruses!).
J Virol. 2011 Jul;85(13):6589-93. Epub 2011 Apr 13. From resistance to stimulation: the evolution of a virus in the presence of a dominant lethal inhibitory scaffolding protein. Cherwa JE Jr, Fane BA.
J Virol. 2009 Nov;83(22):11746-50. Epub 2009 Sep 2. Viral adaptation to an antiviral protein enhances the fitness level to above that of the uninhibited wild type.Cherwa JE Jr, Sanchez-Soria P, Wichman HA, Fane BA.
Self-destructiv virus – A tool to learn how viruses work. University Communications.