Virology Commons^™

Role Of Tetraspanins In Sars-Cov-2 Fusion And Entry, Marcos Saul Santiago Figueroa

Master's Theses

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the pandemic the world has been facing in recent years. Even as new countermeasures are developed, there is still much we don’t know in terms of its entry into host cells. Tetraspanins are transmembrane proteins that are near ubiquitous amongst cell types. They fulfill numerous roles, including that of a viral co-receptor. Here, we considered whether tetraspanins, specifically CD9, CD63, and CD81 influence SARS-CoV-2 fusion and entry. Using ACE2-LgBit and tetraspanin overexpressing EVs and HeLa cells, we find that the presence of excess tetraspanins inhibit fusion and entry. However, we …

Bisacodyl Limits Chikungunya Virus In Vitro And Is Broadly Antiviral, Natalie June Lomascolo

Master's Theses

Identifying novel antivirals requires significant time and resource investment, and the continuous threat of viruses to human health necessitates commitment to antiviral identification and development. Developing antivirals requires years of research and validation, and recent outbreaks have highlighted the need for preparedness in counteracting pandemics. One way to facilitate development is to repurpose molecules already used clinically. By screening such compounds, we can accelerate antiviral development. Here, we screened compounds from the National Institutes of Health’s Developmental Therapeutic Program for activity against chikungunya virus, an alphavirus that is responsible for a significant outbreak in the Americas in 2013. Using this …

Characterizing A Novel Cocksackievirus B3 Protease Mutant And Its Response To Polyamine Depletion, Bridget Hulsebosch

Master's Theses

Enteroviruses, including Coxsackievirus B3 (CVB3), are pervasive pathogens that cause significant disease, including cardiomyopathies. Unfortunately, no treatments or vaccines are available for infected individuals. We identified the host polyamine pathway as a potential drug target, as inhibiting polyamine biosynthesis significantly reduces enterovirus replication in vitro and in vivo. Here, we show that CVB3 is sensitive to polyamine depletion through the polyamine analog diethylnorspermidine (DENSpm) which enhances polyamine catabolism through induction of polyamine acetylation. We demonstrate that CVB3 acquires resistance to DENSpm via mutation of the 2A protease, which enhances proteolytic activity in the presence of DENSpm. Resistance to DENSpm occurred …

Assessing The Role Of The Interaction Between Polyamines And Heparan Sulfate In Coxsackievirus B3 Viral Infection, Oreoluwa Omoba

Master's Theses

Non-polioenteroviruses are highly infectious viruses that typically cause mild asymptomatic cases but can cause severe disease such as aseptic meningitis and dilated cardiomyopathy. Coxsackievirus B3 (CVB3) is a member of this group and is prevalent in the United States and Eastern Asia. Viruses like CVB3 rely on the host cell for many molecules in order to replicate. One such set of molecules is the polyamines. Polyamines are small, positively charged molecules that play a role in a multitude of cellular processes including RNA/DNA stabilization, gene expression, translation, and regulating membrane fluidity. Previous studies have shown CVB3 relies on polyamines for …

Development Of An Attenuated Zika Virus By Editing The 5’ Untranslated Region, E. Ashley Thompson

Master's Theses

Zika Virus (ZIKV) is a mosquito-transmitted flavivirus that usually causes no symptoms to mild febrile in humans, and it has been regarded as an insignificant pathogen to public health. However, recent outbreaks of ZIKV infection have revealed that ZIKV can cause severe neurological effects in adults, such as Guillain-Barre Syndrome (GBS), and in infants whose mothers acquired the virus during pregnancy, causing Congenital Zika Syndrome (CZS). Currently, no approved vaccine is available and there is a critical need to develop an effective and safe vaccine. While most vaccine developmental strategies target the viral prM-E protein of ZIKV, we aimed to …

Zika Virus Inactivates Polyamine Catabolism Via Alternative Splicing To Enhance Infection, Marion Lea Graham

Master's Theses

During viral infection, the virus and host must compete for resources inside the cell. One of these resources is polyamines. Polyamines are small, positively charged molecules that are found in all eukaryotic cells. They play a key role in several cellular functions including growth and proliferation, transcription and translation, and membrane stability. Viruses also rely polyamines for productive replication, utilizing them during DNA/RNa polymerization, nucleic acid packaging, and protein synthesis. in response to a virus infecting a host cell, the host cell will begin to regulate polyamine levels as a way to combat the infection. Polyamine levels are regulated by …

The Role Of Polyamines In Enteroviral Attachment, Thomas Mckenzie Kicmal

Master's Theses

Polyamines are small polycationic molecules with flexible carbon chains that are found in all eukaryotic cells. Polyamines are involved in the regulation of many host processes and have been shown to be implicated in viral replication. Depletion of polyamine pools in cells with FDA approved drugs restricts replication of diverse RNA viruses. Viruses can exploit host polyamines to facilitate packaging, transcription, translation, and protease activity but other mechanisms remain largely unknown. Picornaviruses, including Coxsackievirus B3 (CVB3), are sensitive to depletion of polyamines and remain a significant public health threat. We employed CVB3 as a model system to investigate a potential …

Dissecting A Role For Polyamines In Rift Valley Fever Virus Infection, Vincent Mastrodomenico

Master's Theses

Bunyaviruses are emerging viral pathogens that cause encephalitis, hemorrhagic fevers, and meningitis. Rift Valley fever virus is a particularly devastating bunyavirus, infecting both humans and livestock with significant morbidity and mortality. By coordinating several host and viral processes Rift Valley fever virus is able to produce infectious virions. Polyamines are small, positively-charged host-derived molecules that play diverse roles in human cells and in infection. We previously demonstrated that polyamines are crucial for RNA viruses; however, the mechanisms by which polyamines function remain unknown. Here, we investigated polyamines' role in the replication of the Rift Valley fever virus (vaccine strain MP-12). …

Engineering Yeast To Evaluate Human Proteins Involved In Selective Rna Packaging During Hiv Particle Production, Ryan M. Bitter

Master's Theses

Despite recent advances in antiretroviral therapy, nearly 37 million people continue to live with human immunodeficiency virus (HIV). Basic and applied research on the assembly of HIV could be enhanced by using a genetically tractable organism, such as yeast, rather than mammalian cells. While previous studies showed that expression of the HIV Gag polyprotein in Saccharomyces cerevisiae spheroplasts resulted in the production of virus-like particles (VLPs), many questions regarding the utility of yeast in HIV assembly remain uninvestigated. Here, we report use of S. cerevisiae for both the production of VLPs with selectively packaged RNA and to evaluate the human …

Characterizing Immune Response To Hiv-1 Infection In Bicd2-Knockout Cells, Omar Abdel-Rahim

Master's Theses

An important part of the HIV-1 infection cycle is the attachment of the intracellular viral core to the host microtubule network, facilitated by attachment of the viral capsid to cargo adaptor proteins. One such cargo adaptor is Bicaudal D Homolog Protein 2 (BICD2). BICD2 can attach to both the HIV-1 capsid and the dynein/dynactin complex and facilitate the trafficking of the viral core towards the host nucleus. Removal of BICD2 can disrupt this viral translocation, resulting in an elevated immune response that impairs productive HIV-1 infection. In my research, we investigated what viral particles are detected in the absence of …

Immunobiology Of Adenovirus-Vector Vaccines For Mrsa, Emily Orvis

Master's Theses

Staphylococcus aureus is a gram-positive, extracellular bacterium that has emerged as an

important human pathogen. This bacterium is a leading cause of skin and soft tissue infections

(SSTIs) in humans, often leading to invasive and life-threatening infections. Treatment of S.

aureus infections is becoming more complicated due to the rise of methicillin-resistant S. aureus

(MRSA) strains, which are becoming increasingly resistant to a number of antibiotics. In the

United States, invasive MRSA infections result in more deaths annually than any other infectious

agent.

Despite a dire need, there is currently no vaccine against S. aureus infections. The failure

of past …

Surveying Host Innate Immune Responses To Interferon Antagonist-Deficient Murine Coronaviruses, Aaron Brian Volk

Master's Theses

Two coronaviruses (CoVs)—severe acute respiratory syndrome (SARS) virus and Middle East respiratory syndrome (MERS) virus—have emerged in the 21st century from animal reservoirs into the human population, each causing an epidemic associated with significant disease and mortality. CoV epidemics are currently only controllable by rigorous public health measures; no targeted therapeutics or vaccines exist to treat or prevent any human CoV infection. One method of generating attenuated CoV strains to be studied as vaccine candidates involves specifically disrupting CoV-encoded interferon (IFN) antagonists, thereby rendering the virus vulnerable to host innate antiviral immunity. Deubiquitinating (DUB) activity encoded within CoV nonstructural protein …

Phenotyping Temperature-Sensitive Coronaviruses, Amani Eddins

Master's Theses

Coronaviruses (CoVs) can cause a range of symptoms; from a mild common cold to life threatening acute respiratory distress syndrome (ARDS) upon infection. These emerging viruses have the ability to be highly pathogenic and detrimental to the human population. Two prime examples of CoV emergence, SARS-CoV (Severe Acute Respiratory Syndrome) and MERS-CoV, (Middle Eastern Respiratory Syndrome), which exhibits the pandemic potential of emerging CoVs that gain human tropism. Given the increasing potential of an emerging CoV outbreak there is a state of urgency to develop vaccines that will help protect the human population against current and future circulating strains. The …

Detection Of Hcmv Viral Il-10 (Vil-10) In Healthy Blood Donors, Vivian P. Young

Master's Theses

Human cytomegalovirus (HCMV) is widespread in the general population and can establish lifelong latency with expression of a limited subset of viral genes. The UL111A gene is expressed during both lytic and latent infection, and at least two protein isoforms are produced. During lytic infection, the full length transcript yields cmvIL-10, a potent immunosuppressive viral ortholog of human IL-10 (hIL-10). Alternative splicing of the UL111A transcript yields a truncated protein, LAcmvIL-10, which is expressed during both lytic and latent infection but with a limited range of immunosuppressive functions. The two viral cytokines, collectively termed viral IL-10 (vIL-10), are identical in …

The Effects Of Stress And Alcohol On Hiv-1 Latency, Sarah Ilene Talley

Master's Theses

A major barrier to HIV eradication is the persistence of latent viral reservoirs that exist despite antiretroviral therapy. In order to develop effective therapeutics, a comprehensive understanding of latency and factors driving the formation of the latent reservoir is needed. As stress and alcohol are common comorbidities associated with HIV infection, the goal of this research was to determine how stress and alcohol could affect HIV-latency. Specifically, we hypothesized that the ability of latent proviruses to be reactivated by “shock and kill” approaches would be altered by glucocorticoid and ethanol treatments, and prolonged ethanol exposure would affect the size of …

The Role Of Pidd Protein In Adenoviral Induction Of Apoptosis, Iris Teresa Figueroa

Master's Theses

The Adenovirus E1A gene sensitizes cells to genetic insults and apoptosis, most notably in response to cytotoxic factors from innate immune cells. The mechanisms by which E1A sensitizes cells to apoptotic stressors have not been fully elucidated, however E1A actively represses NF-κB anti-apoptotic defenses, thereby sensitizing cells to alternative apoptotic cascades. Recent studies alternatively indicate that E1A also actively induces Caspase-2 activation and mitochondrial injury in the presence of certain cytotoxic injuries.

Caspase-2 is cleaved and activated in a large complex consisting of p53-inducible protein with a death domain (PIDD), an adaptor protein RAIDD, and pro-caspase 2. PIDD auto-proteolyzes into …

Malaria Transmission Blocking Vaccines, Lukasz Jacek Sewera

Master's Theses

Malaria affects 198 million people and kills 584,000 each year, predominantly in Sub-Saharan Africa (WHO). The most severe form of malaria is caused by the protozoan parasite Plasmodium falciparum. Development of a vaccine against P. falciparum has been hindered by its complex life cycle with multiple antigenically distinct human and mosquito stages. To effectively prevent disease and reduce the parasite burden in populations, a vaccine will need to target multiple stages, including blocking transmission at the mosquito stage.

Antibodies generated against P. falciparum mosquito stage antigen Pfs25 can prevent parasite transmission from humans to mosquitoes. However, Pfs25 is poorly immunogenic …

Reconsidering The Model Of Trim5Α Assembly: The Role Of The Linker2 (L2) Region In Trim5Α Assembly, Laura Johnsen

Master's Theses

The TRIM5α protein from rhesus macaques (TRIM5αrh) exhibits a remarkable ability to potently inhibit infection by Human Immunodeficiency Virus Type-1 (HIV-1). Extensive studies have shown that TRIM5α is capable of self-associating at many levels, eventually leading to the formation of a hexameric assembly that can superimpose on the hexameric lattice of the HIV-1 capsid. The mechanism underlying the self-association of TRIM5α and the molecular determinants of self-association remain to be completely understood. In this study, we show that the Linker 2 (L2) region of TRIM5rh is important for dimerization and higher order self-association, both of which are independent processes. Additionally, …

Hcmv Promotes Breast Cancer Metastasis: Impacts Of Cmvil-10 In The Tumor Microenvironment, Robin Bishop

Master's Theses

Human cytomegalovirus (HCMV) is a highly species-specific, common human pathogen. While a large majority of people are infected with HCMV worldwide, infection is typically asymptomatic in immune competent individuals. To enhance virus persistence and avoid immune detection by the host, HCMV exploits the strategy of encoding homologs of cellular cytokines. One factor produced by HCMV-infected cells is the viral cytokine cmvIL-10, which acts through the cellular IL-10 receptor to induce downstream cell signaling. In instances where HCMV-infected cells infiltrate the tumor microenvironment, the presence of cmvIL-10 in may initiate events that promote a more invasive tumor phenotype. Cancer cells that …

Identifying And Characterizing The Degradative Pathway Of The Retroviral Restriction Factor Rhtrim5Α, Rachel Nelson

Master's Theses

Human immunodeficiency virus 1 (HIV-1) is a lentivirus that progresses to acquired immunodeficiency syndrome (AIDS). The protein TRIM5alpha from rhesus macaques (rhTRIM5alpha) restricts HIV-1 by blocking infection after entry of the virion into cells. Treatment of rhTRIM5alpha expressing cells with inhibitors to a cellular degradation pathway, the proteasome, partially relieves restriction but does not inhibit rhTRIM5alpha protein turnover. The role of a second degradation pathway, the autophagy-lysosomal pathway, in TRIM5alpha mediated restriction has not been explored.

In the present study, we demonstrate that rhTRIM5alpha is degraded by chaperone mediated autophagy (CMA). Inhibition of CMA alters rhTRIM5alpha localization and turnover, while …

Exosomes: Antiviral Agents In The Human Lung, Jennifer Alexandra Novak

Master's Theses

Hundreds of interferon effectors comprise the immediate host response to virus infection. One family of interferon stimulated genes is the IFITM (Interferon-Induced Transmembrane) proteins. IFITM3, in particular, has been shown to block virus cell entry of Influenza A Virus, SARS Coronavirus, and West Nile Virus, among others. IFITM3 has also been identified as an essential factor for host protection against Influenza A Virus in mice and humans. However, the mechanism by which IFITM3 functions remains unclear.

IFITM3 may function both intracellularly and extracellularly to block virus infection in the human lung. The extracellular milieu contains microscopic vesicles termed exosomes which …

Design Of A Tetracycline Operon Inducible System For The Control Of Vaccinia Virus Replication: Implications For Vaccine Development, Caitlin J. Hagen

Master's Theses

The use of vaccinia virus (VACV) as a vaccine resulted in the eradication of smallpox in 1979. Characteristics that contribute to the effectiveness of VACV as a vaccine and viral vector include its ability to elicit strong, long-lived humoral and cell-mediated immune responses as a live-replicating virus and to accept large inserts of DNA into its genome. However, adverse events associated with its use as the smallpox vaccine have constrained it from being more widely utilized in vaccines and therapies. We propose to improve the safety of VACV as a live-replicating vector by using elements of the tet operon to …

Role Of Type Ii Transmembrane Serine Proteases In Coronavirus Production, Gitanjali Cuckemane Subramanya

Master's Theses

Proteolytic cleavage of Coronavirus spike proteins at the appropriate time and location results in efficient virus entry activation. Type II transmembrane serine proteases (TTSPs), specifically, transmembrane protease serine 2 (TMPRSS2) when expressed on target cells, enhance SARS coronavirus entry by activating spike cleavage. This study investigated the effect of TTSPs expressed in Coronavirus producer cells. Murine Hepatitis Virus strain A59 (MHV A59) viruses produced in the absence of TMPRSS2 required target cell protease activity - either cell surface serine proteases or endosomal acidophilic proteases - for entry. MHV A59 viruses produced in the presence of TMPRSS2 were less infectious overall, …

The Inhibitory Effects Of The Extracts Of Zingiber Plants On The Adsorption, Growth, And Replication Of Phage Lpp-1 In Cyanobacterium, Ebby Paul Jido

Master's Theses

No abstract provided.