Matching Items (28)
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 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.
ContributorsHaller, Sarah S. (Author) / Hogue, Brenda (Thesis director) / Liu, Wei (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor) / Biodesign Institute (Contributor)
Created2017-05
Description
Despite the safe and effective use of attenuated vaccines for over fifty years, measles virus (MV) remains an insidious threat to global health. Problematically, infants less than one year of age, who are the most prone to severe infection and death by measles, cannot be immunized using current MV vaccines. For this dissertation, I generated and performed preclinical evaluation of two novel MV vaccine candidates. Based on data from clinical trials that showed increasing the dosage of current MV vaccines improved antibody responses in six-month-old recipients, I hypothesized that increasing the relevant antigenic stimulus of a standard titer dose would allow safe and effective immunization at a younger age. I generated two modified MVs with increased expression of the hemagglutinin (H) protein, the most important viral antigen for inducing protective neutralizing immunity, in the background of a current vaccine-equivalent. One virus, MVvac2-H2, expressed higher levels of full-length H, resulting in a three-fold increase in H incorporation into virions, while the second, MVvac2-Hsol, expressed and secreted truncated, soluble H protein to its extracellular environment. The alteration to the virion envelope of MVvac2-H2 conferred upon that virus a measurable resistance to in vitro neutralization. In initial screening in adult mouse models of vaccination, both modified MVs proved more immunogenic than their parental strain in outbred mice, while MVvac2-H2 additionally proved more immunogenic in the gold standard MV-susceptible mouse model. Remarkably, MVvac2-H2 better induced protective immunity in the presence of low levels of artificially introduced passive immunity that mimic the passive maternal immunity that currently limits vaccination of young infants, and that strongly inhibited responses to the current vaccine-equivalent. Finally, I developed a more physiological infant-like mouse model for MV vaccine testing, in which MV-susceptible dams vaccinated with the current vaccine-equivalent transfer passive immunity to their pups. This model will allow additional preclinical evaluation of the performance of MVvac2-H2 in pups of immune dams. Altogether, in this dissertation I identify a promising candidate, MVvac2-H2, for a next generation measles vaccine.
ContributorsJulik, Emily (Author) / Reyes del Valle, Jorge (Thesis advisor) / Chang, Yung (Committee member) / Blattman, Joseph (Committee member) / Hogue, Brenda (Committee member) / Nickerson, Cheryl (Committee member) / Arizona State University (Publisher)
Created2016
Description
Poxviruses such as monkeypox virus (MPXV) are emerging zoonotic diseases. Compared to MPXV, Vaccinia virus (VACV) has reduced pathogenicity in humans and can be used as a partially protective vaccine against MPXV. While most orthopoxviruses have E3 protein homologues with highly similar N-termini, the MPXV homologue, F3, has a start codon mutation leading to an N-terminal truncation of 37 amino acids. The VACV protein E3 consists of a dsRNA binding domain in its C-terminus which must be intact for pathogenicity in murine models and replication in cultured cells. The N-terminus of E3 contains a Z-form nucleic acid (ZNA) binding domain and is also required for pathogenicity in murine models. Poxviruses produce RNA transcripts that extend beyond the transcribed gene which can form double-stranded RNA (dsRNA). The innate immune system easily recognizes dsRNA through proteins such as protein kinase R (PKR). After comparing a vaccinia virus with a wild-type E3 protein (VACV WT) to one with an E3 N-terminal truncation of 37 amino acids (VACV E3Δ37N), phenotypic differences appeared in several cell lines. In HeLa cells and certain murine embryonic fibroblasts (MEFs), dsRNA recognition pathways such as PKR become activated during VACV E3Δ37N infections, unlike VACV WT. However, MPXV does not activate PKR in HeLa or MEF cells. Additional investigation determined that MPXV produces less dsRNA than VACV. VACV E3Δ37N was made more similar to MPXV by selecting mutants that produce less dsRNA. By producing less dsRNA, VACV E3Δ37N no longer activated PKR in HeLa or MEF cells, thus restoring the wild-type phenotype. Furthermore, in other cell lines such as L929 (also a murine fibroblast) VACV E3Δ37N, but not VACV WT infection leads to activation of DNA-dependent activator of IFN-regulatory factors (DAI) and induction of necroptotic cell death. The same low dsRNA mutants demonstrate that DAI activation and necroptotic induction is independent of classical dsRNA. Finally, investigations of spread in an animal model and replication in cell lines where both the PKR and DAI pathways are intact determined that inhibition of both pathways is required for VACV E3Δ37N to replicate.
ContributorsCotsmire, Samantha (Author) / Jacobs, Bertram L (Thesis advisor) / Varsani, Arvind (Committee member) / Hogue, Brenda (Committee member) / Haydel, Shelley (Committee member) / Arizona State University (Publisher)
Created2021
Description
Macromolecular structural biology advances the understanding of protein function through the structure-function relationship for applications to scientific challenges like energy and medicine. The proteins described in these studies have applications to medicine as targets for therapeutic drug design. By understanding the mechanisms and dynamics of these proteins, therapeutics can be designed and optimized based on their unique structural characteristics. This can create new, focused therapeutics for the treatment of diseases with increased specificity — which translates to greater efficacy and fewer off-target effects. Many of the structures generated for this purpose are “static” in nature, meaning the protein is observed like a still-frame photograph; however, the use of time-resolved techniques is allowing for greater understanding of the dynamic and flexible nature of proteins. This work advances understanding the dynamics of the medically relevant proteins NendoU and Taspase1 using serial crystallography to establish conditions for time-resolved, mix-and-inject crystallographic studies.
ContributorsJernigan, Rebecca Jeanne (Author) / Fromme, Petra (Thesis advisor) / Hansen, Debra (Thesis advisor) / Chiu, Po-Lin (Committee member) / Hogue, Brenda (Committee member) / Arizona State University (Publisher)
Created2022
Description
An electric field can be applied to a microfluidic device in order to stop particle flow. Electroosmosis, electrophoresis, and dielectrophoresis act on the particles in different directions in the microfluidic channel, and when these forces create zero net force, the particle stops in the channel. The goal of the performed experiments is to investigate whether hydrostatic pressure generated by a syringe pump could help concentrate these particles and separate them from other contents. Introducing precise, adjustable hydrostatic pressure from the syringe pump provides another mechanism for controlling particle behavior. A microfluidic channel was crafted into a device connected to a syringe pump, and videos of 1 µm silica particles in the device were recorded under a microscope in order to show that samples could be infused into the device and concentrated or captured at a specific location in the channel using hydrostatic pressure. Capture of the particles occurred with and without controlled hydrostatic pressure, but these events occurred somewhat consistently at different voltages. In addition, particle movement in the channel with the syringe pump off was originally attributed to the electrokinetic forces. However, when compared to experiments without the syringe pump connected to the device, it became evident that the electrokinetic forces should have moved the particles in the opposite direction and that, in actuality, there is an inherent pressure in the device also affecting particle movement even when the syringe pump is not turned on.
ContributorsRuddle, Kallen (Author) / Hayes, Mark (Thesis director) / Guo, Jia (Committee member) / Hogue, Brenda (Committee member) / Barrett, The Honors College (Contributor) / School of Molecular Sciences (Contributor)
Created2022-12
Description
Human Papillomavirus (HPV) is the most commonly transmitted STI and isresponsible for an estimated 5% of cancer cases worldwide. HPV infection is implicated
in 70% of cervical cancer incidence and is also responsible for a variety of oropharyngeal
and anogenital cancers. While vaccination has greatly reduced the cervical cancer
burden in developed countries, HPV infection remains high in developing countries due
to high cost and poor access to healthcare. Several studies have highlighted the
presence of anti-HPV antibodies following infection and their potential use as
biomarkers for developing novel screening methods. Progression from initial infection to
cancer is slow, thus presenting an opportunity for effective screening programs.
Biomarker screening is an important area of cancer detection and Lateral Flow Assays
(LFA) are a low cost, easy to use alternative to other screening methods that require
extensive training and laboratory space. Therefore, this project proposes as a hypothesis
that the development of an LFA screening for HPV specific IgG can provide clinically
relevant data for the early detection of cervical dysplasia. This project adapts an LFA in a
multiplexed format for fluorescence-based serologic detection of HPV specific IgG in
patient plasma.
ContributorsJohns, William (Author) / Anderson, Karen (Thesis advisor) / Lake, Douglas (Committee member) / Hogue, Brenda (Committee member) / Arizona State University (Publisher)
Created2023
Description
Z-DNA binding protein 1 (ZBP1) is an interferon-inducible protein that plays a crucial role in antiviral defense by recognizing Z-form nucleic acid (Z-NA), a left-handed conformer of double-stranded DNA/RNA. When ZBP1 binds to Z-NA, it can trigger programmed cell death pathways, including apoptosis and necroptosis, in collaboration with receptor interacting protein kinases 1 and 3 (RIPK1 and RIPK3). Z-NA positive viruses including poxviruses and influenza A virus (IAV) activate ZBP1-dependent cell death during replication. Little is known whether ZBP1 plays any role during Z-NA negative virus infection. Doxycycline-inducible A549 ACE2 Tet-On cells were constructed to express ZBP1 and were infected with Z-NA negative viruses. ZBP1-expressing cells infected with Sindbis virus (SINV), La Crosse virus (LACV), Vesicular stomatitis virus (VSV) and human coronavirus OC43 (hCoV-OC43) underwent extensive cell death, which could be rescued by a caspase inhibitor but not by JAK1/2 or RIPK1 kinase inhibitors. However, cell death was not observed upon Zika virus (ZIKV), Encephalomyocarditis virus (EMCV), Chikungunya virus (CHKV) or human coronavirus 229E (hCoV-229E) infection. ZBP1 expression did not impact the replication of all tested viruses. In addition, ZBP1-mediated cell death during infection depends on the Zα2 and RHIM1 domains and partially on the C-terminal domain. These findings suggest that Z-NA can be detected by the Zα2 domain to initiate cell death pathways during infection with some Z-NA negative viruses and that the RHIM1/C-terminal domains are necessary for ZBP1-induced cell death. Further research is needed to determine the Z-NA ligand and the precise mechanism of ZBP1-mediated antiviral responses and how they can be exploited for the development of novel antiviral therapies.
ContributorsLa Rosa, Bruno Andres (Author) / Li, Yize (Thesis advisor) / Jacobs, Bertram (Committee member) / Hogue, Brenda (Committee member) / Arizona State University (Publisher)
Created2023
Description
Alpha herpesviruses are a family of neuroinvasive viruses that infect multiplevertebrate species. Alpha herpesviruses are responsible for human and livestock infections, most notably Herpes Simplex Virus (HSV), Varicella Zoster virus (VZV), and Pseudorabies Virus (PRV). PRV is a potent swine virus that can infect other mammals, and results in lethal encephalitis that can be devastating to livestock and of great financial expense to farmers. HSV, types 1 and 2, and VZV are widespread throughout the global human population, with estimates of the HSV-1 burden at about 60% of people worldwide. The hallmark of alpha herpesvirus infection is a persistent, lifelong infection that can reactivate throughout the lifespan of the host. Currently, the precise mechanisms of how these viruses undergo intracellular trafficking to emerge from the infected cell in epithelial tissues is not well understood. Many insights have been made with PRV in animal neurons, both in culture systems and animal models, about the viral genes and host factors involved in these processes. However, understanding of these mechanisms, and the interplay between viral and host proteins, in the human pathogen HSV-1 is even more lacking. Using recombinant fluorescent virus strains of HSV-1 and Total Internal Reflection Microscopy to image the transport of mature viral progeny in epithelial cells, it was determined that the egress of HSV-1 uses constitutive cellular secretory pathways. Specifically, the viral progeny traffic from the trans-Golgi network to the site of exocytosis at the plasma membrane via Rab6a secretory vesicles. This work will contribute to the understanding of how alpha herpesviruses complete their lifecycles in host cells, particularly at the sites where infection initially occurs and can spread to a new organism. Knowledge of these processes may lead to the development of therapeutics or prophylactics to reduce the burden of these viruses.
ContributorsBergeman, Melissa Hope (Author) / Hogue, Ian B (Thesis advisor) / Hogue, Brenda (Committee member) / Roberson, Robert (Committee member) / Varsani, Arvind (Committee member) / Arizona State University (Publisher)
Created2023
Description
Virus-like particles (VLPs) are optimum candidates for creating vaccines, as they are highly flexible, adaptable, safe, and similar to the structural proteins of the target cells. The COVID 19 pandemic has increased the need to create effective and safe vaccines that can be mass produced to stop the spread of COVID-19. Till now, various types of vaccine platforms have been utilized to create COVID-19 vaccines, each with unique characteristics and techniques. It is essential to use robust vaccine platforms that can deliver optimum results in a short period of time, with minimal risks. The structural proteins found in SARS-CoV-2, such as Spike (S) protein have been widely targeted to induce antibody response, also called a humoral response, which is a part of acquired immunity. The other structural proteins such as M (membrane) and E (envelope) can also be used as targets for antibodies. The S2 and glycoprotein (S full) can be used to induce an efficient IgG response. Therefore, the incorporation of structural proteins into VLPs can prove to be useful. Furthermore, double mosaic VLPs employs double epitopes, which can effectively cover the distances between the S proteins, thus optimizing the B cell activation process. This review describes the various developments that have taken place in the field of VLPs and more specifically, with regards to developing VLP vaccines against the SARS-CoV-2 virus.
ContributorsSharma, Anjali (Author) / Hogue, Brenda (Thesis director) / Li, Yize (Committee member) / Barrett, The Honors College (Contributor) / College of Health Solutions (Contributor)
Created2022-05
Description
CTB-MPR is a fusion protein between the B subunit of cholera toxin (CTB) and the membrane-proximal region of gp41 (MPR), the transmembrane envelope protein of Human immunodeficiency virus 1 (HIV-1), and has previously been shown to induce the production of anti-HIV-1 antibodies with antiviral functions. To further improve the design of this candidate vaccine, X-ray crystallography experiments were performed to obtain structural information about this fusion protein. Several variants of CTB-MPR were designed, constructed and recombinantly expressed in Escherichia coli. The first variant contained a flexible GPGP linker between CTB and MPR, and yielded crystals that diffracted to a resolution of 2.3 Å, but only the CTB region was detected in the electron-density map. A second variant, in which the CTB was directly attached to MPR, was shown to destabilize pentamer formation. A third construct containing a polyalanine linker between CTB and MPR proved to stabilize the pentameric form of the protein during purification. The purification procedure was shown to produce a homogeneously pure and monodisperse sample for crystallization. Initial crystallization experiments led to pseudo-crystals which were ordered in only two dimensions and were disordered in the third dimension. Nanocrystals obtained using the same precipitant showed promising X-ray diffraction to 5 Å resolution in femtosecond nanocrystallography experiments at the Linac Coherent Light Source at the SLAC National Accelerator Laboratory. The results demonstrate the utility of femtosecond X-ray crystallography to enable structural analysis based on nano/microcrystals of a protein for which no macroscopic crystals ordered in three dimensions have been observed before.
ContributorsLee, Ho-Hsien (Author) / Cherni, Irene (Author) / Yu, HongQi (Author) / Fromme, Raimund (Author) / Doran, Jeffrey (Author) / Grotjohann, Ingo (Author) / Mittman, Michele (Author) / Basu, Shibom (Author) / Deb, Arpan (Author) / Dorner, Katerina (Author) / Aquila, Andrew (Author) / Barty, Anton (Author) / Boutet, Sebastien (Author) / Chapman, Henry N. (Author) / Doak, R. Bruce (Author) / Hunter, Mark (Author) / James, Daniel (Author) / Kirian, Richard (Author) / Kupitz, Christopher (Author) / Lawrence, Robert (Author) / Liu, Haiguang (Author) / Nass, Karol (Author) / Schlichting, Ilme (Author) / Schmidt, Kevin (Author) / Seibert, M. Marvin (Author) / Shoeman, Robert L. (Author) / Spence, John (Author) / Stellato, Francesco (Author) / Weierstall, Uwe (Author) / Williams, Garth J. (Author) / Yoon, Chun Hong (Author) / Wang, Dingjie (Author) / Zatsepin, Nadia (Author) / Hogue, Brenda (Author) / Matoba, Nobuyuki (Author) / Fromme, Petra (Author) / Mor, Tsafrir (Author) / ASU Biodesign Center Immunotherapy, Vaccines and Virotherapy (Contributor) / Department of Chemistry and Biochemistry (Contributor) / College of Liberal Arts and Sciences (Contributor) / School of Life Sciences (Contributor) / Biodesign Institute (Contributor) / Infectious Diseases and Vaccinology (Contributor) / Department of Physics (Contributor)
Created2014-08-20