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Surveillance of Influenza Virus Spread on the Arizona State University Campus

Description

The 2017-2018 Influenza season was marked by the death of 80,000 Americans: the highest flu-related death toll in a decade. Further, the yearly economic toll to the US healthcare system and society is on the order of tens of billions

The 2017-2018 Influenza season was marked by the death of 80,000 Americans: the highest flu-related death toll in a decade. Further, the yearly economic toll to the US healthcare system and society is on the order of tens of billions of dollars. It is vital that we gain a better understanding of the dynamics of influenza transmission in order to prevent its spread. Viral DNA sequences examined using bioinformatics methods offer a rich framework with which to monitor the evolution and spread of influenza for public health surveillance. To better understand the influenza epidemic during the severe 2017-2018 season, we established a passive surveillance system at Arizona State University’s Tempe Campus Health Services beginning in January 2018. From this system, nasopharyngeal samples screening positive for influenza were collected. Using these samples, molecular DNA sequences will be generated using a combined multiplex RT-PCR and NGS approach. Phylogenetic analysis will be used to infer the severity and temporal course of the 2017-2018 influenza outbreak on campus as well as the 2018-2019 flu season. Through this surveillance system, we will gain knowledge of the dynamics of influenza spread in a university setting and will use this information to inform public health strategies.

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2019-05

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Coronavirus Envelope Protein Transmembrane Domain: Impact of Positive Charges on Virus-like Particle Assembly

Description

Coronaviruses are a significant group of viruses that cause enteric and respiratory infections in a variety of animals, including humans. Outbreaks of Severe Acute Respiratory Syndrome (SARS) and Middle Eastern Respiratory Syndrome (MERS) in the past 15 years has increased

Coronaviruses are a significant group of viruses that cause enteric and respiratory infections in a variety of animals, including humans. Outbreaks of Severe Acute Respiratory Syndrome (SARS) and Middle Eastern Respiratory Syndrome (MERS) in the past 15 years has increased research into coronaviruses to gain an understanding of their structure and function so one day therapies and vaccines may be produced. These viruses have four main structural proteins: the spike, nucleocapsid, envelope, and membrane proteins. The envelope (E) protein is an integral membrane protein in the viral envelope that acts as a viroporin for transport of cations and plays an important role in pathogenesis and viral assembly. E contains a hydrophobic transmembrane domain with polar residues that is conserved across coronavirus species and may be significant to its function. This experiment looks at the possible role of one polar residue in assembly, the 15th residue glutamine, in the Mouse Hepatitis Virus (MHV) E protein. The glutamine 15 residue was mutated into positively charged residues lysine or arginine. Plasmids with these mutations were co-expressed with the membrane protein (M) gene to produce virus-like particles (VLPs). VLPs are produced when E and M are co-expressed together and model assembly of the coronavirus envelope, but they are not infectious as they do not contain the viral genome. Observing their production with the mutated E protein gives insight into the role the glutamine residue plays in assembly. The experiment showed that a changing glutamine 15 to positive charges does not appear to significantly affect the assembly of the VLPs, indicating that this specific residue may not have a large impact on viral assembly.

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2017-05

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Genetic Trends in the Vertical Transmission of the Clone-13 Variant of LCMV

Description

Among wild rodent populations, vertical transmission is believed to constitute the primary route of infection for Lymphocytic Choriomeningitis Virus (LCMV), a non-lytic arenavirus with both acute and chronic forms. When carrier mice infected at birth with the acute Armstrong strain

Among wild rodent populations, vertical transmission is believed to constitute the primary route of infection for Lymphocytic Choriomeningitis Virus (LCMV), a non-lytic arenavirus with both acute and chronic forms. When carrier mice infected at birth with the acute Armstrong strain reproduce, they generate congenital carrier offspring containing a quasispecies of LCMV that includes Armstrong as well as its chronic Clone-13 variant. This study examined the genetic trends in the vertical transmission of LCMV from mothers infected perinatally with Clone-13. Viral isolates obtained from the serum of congenital carrier offspring were partially sequenced to reveal residue 260 in the glycoprotein-encoding region of their S segment, the site of a major amino acid change differentiating the chronic and acute strains. It was found that the phenylalanine-to-leucine mutation associated with Clone-13 was present in 100% of the isolates, strongly indicating that the offspring of Clone-13 carriers contain exclusively the chronic variant. This research has broad implications for the epidemiology of the virus, and, given the predominance of Armstrong in the wild, suggests that there must be a biological cost associated with Clone-13 infection in non-carriers.

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2015-05

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Display of Domain III from Dengue 2 Envelope Protein on HBsAg Virus-like Particles Vectored by Measles Virus

Description

Dengue virus infects millions of people every year. Yet there is still no vaccine available to prevent it. Here we use a neutralizing epitope determinant on the dengue envelope (E) protein as an immunogen to be vectored by a measles

Dengue virus infects millions of people every year. Yet there is still no vaccine available to prevent it. Here we use a neutralizing epitope determinant on the dengue envelope (E) protein as an immunogen to be vectored by a measles virus (MV) vaccine. However the domain III (DIII) of the dengue 2 E protein is too small to be immunogenic by itself. In order for it to be displayed on a larger particle, it was inserted into the amino terminus of small hepatitis B surface antigen (HBsAg, S) coding sequence. To generate the recombinant MV vector and verify the efficiency of this concept, a reverse genetics system was used where the MV vectors express one or two additional transcription units to direct the assembly of hybrid HBsAg particles. Two types of recombinant measles virus were produced: pB(+)MVvac2(DIII-S,S)P and pB(+)MVvac2(DIII-S)N. Virus recovered from pB(+)MVvac2(DIII-S,S)P was viable. An ELISA assay was performed to demonstrate the expression and secretion of HBsAg. Supernatant from MVvac2(DIII-S,S)P infected cells confirmed that hybrid HBsAg-domain III particles with a density similar to traditional HBsAg particles were released. Characteristics of the subviral particle have been analyzed for the successful incorporation of domain III. The replication fitness of the recombinant MV was evaluated using multi-step growth kinetics and showed reduced replication fitness when compared to the parental strain MVvac2. This demonstrates that viral replication is hindered by the addition of the two inserts into MV genome. Further analysis of MVvac2(DIII-S)N is needed to justify immune response studies in a small animal model using both of the generated recombinant vectors.

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Date Created
2014-05

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Stress Granule Formation in Poliovirus Infected Cells

Description

Stress granules are cytoplasmic foci that form in response to various types of cellular stress, including viral infection. They contain mRNA, translation initiation factors, the small ribosomal subunit, RNA binding proteins, and other unique components depending on the type of

Stress granules are cytoplasmic foci that form in response to various types of cellular stress, including viral infection. They contain mRNA, translation initiation factors, the small ribosomal subunit, RNA binding proteins, and other unique components depending on the type of stress the cell is under. Stress granules are thought to store these components until the stress as passed at which time the mRNA resumes translation. They also have an active role in the cell's antiviral response and are required for efficient induction of the interferon pathway. There are many viruses that induce or interfere with stress granules, including poliovirus. Poliovirus is a positive sense RNA virus that is part of the Picornaviridae family. Stress granules in poliovirus infected cells differ from stress granules in cells undergoing other types of stress because they contain the RNA binding protein Sam68, their formation is dependent on RNA export by the Crm1 pathway, and they are induced by poliovirus cleavage of eIF4G and PABP. It was found previously that Sam68 is found in the stress granules of poliovirus infected HeLa cells but not in oxidative stress of heat shock induced stress granules. My research shows that this finding is true in other cell lines and thus represents a biologically significant finding. The Crm1 pathway exports snRNAs and some mRNAs, rRNAs, and proteins. To determine which of these classes of RNA is necessary for stress granule formation in poliovirus infected cells but not in cells undergoing other types of stress, plasmids with modified PHAX protein were used to isolate the snRNA export pathway. More work needs to be done to determine the impact of snRNA export on stress granule formation. This research could eventually help us better understand the cell's anti-viral response and have implications for how we treat viral infections.

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Date Created
2016-12