Mechanisms of deadly and infectious viruses: Learning how lipid enveloped viruses assemble
thesisposted on 07.05.2020, 03:32 by Monica Leigh Husby
Viruses are pathogenic agents which affect all varieties of organisms, including plants, animals and humans. These microscopic particles are genetically simple organisms which encode a limited number of proteins that undertake a wide range of functions. While structurally distinct, viruses often share common characteristics that have evolved to aid in their infectious life cycles. A commonly underappreciated characteristic of many deadly viruses is a lipid envelope coat that surrounds them. Lipid enveloped viruses comprise a diverse range of pathogenic viruses, known to cause disease in both animals and human which often leads to high fatality rates, many of which lack effective and approved therapeutics. This report focuses on learning how a multifunctional protein within lipid enveloped viruses, the matrix protein, interacts with the plasma membrane of cells to enter and exit cells. Specifically, four viruses are investigated, Measles virus and Nipah virus (within the Paramyxoviridae family) and Ebola virus and Marburg virus (within the Filoviridae family). Through numerous in vitro experiments, functional cellular assays, a myriad of microscopy techniques, and experiments in high containment bio-safety level 4 settings, this report identifies specific lipids at play during the viral assembly process for each virus. Moreover, mechanistic insight is presented as to how each matrix protein interacts with the plasma membrane to facilitate: membrane association, viral matrix protein oligomerization and assembly, the rearrangement of lipids within the plasma membrane, and viral production. Lastly, numerous small molecule inhibitors targeting specific lipids, (e.g. phosphatidylserine and phosphatidylinositol 4,5 bisphosphate) within the cell were investigated for their efficacy in inhibiting matrix protein-dependent viral like particle production and viral spread in cells. As a whole, these projects lend credence to the significant role that lipids and the plasma membrane play throughout lipid enveloped viral life cycles, and provide compelling evidence for the merit of future drug-development research geared at targeting the matrix protein-plasma membrane interaction.