Matching Items (38)
Description
Plants are a promising upcoming platform for production of vaccine components and other desirable pharmaceutical proteins that can only, at present, be made in living systems. The unique soil microbe Agrobacterium tumefaciens can transfer DNA to plants very efficiently, essentially turning plants into factories capable of producing virtually any gene. While genetically modified bacteria have historically been used for producing useful biopharmaceuticals like human insulin, plants can assemble much more complicated proteins, like human antibodies, that bacterial systems cannot. As plants do not harbor human pathogens, they are also safer alternatives than animal cell cultures. Additionally, plants can be grown very cheaply, in massive quantities.
In my research, I have studied the genetic mechanisms that underlie gene expression, in order to improve plant-based biopharmaceutical production. To do this, inspiration was drawn from naturally-occurring gene regulatory mechanisms, especially those from plant viruses, which have evolved mechanisms to co-opt the plant cellular machinery to produce high levels of viral proteins. By testing, modifying, and combining genetic elements from diverse sources, an optimized expression system has been developed that allows very rapid production of vaccine components, monoclonal antibodies, and other biopharmaceuticals. To improve target gene expression while maintaining the health and function of the plants, I identified, studied, and modified 5’ untranslated regions, combined gene terminators, and a nuclear matrix attachment region. The replication mechanisms of a plant geminivirus were also studied, which lead to additional strategies to produce more toxic biopharmaceutical proteins. Finally, the mechanisms employed by a geminivirus to spread between cells were investigated. It was demonstrated that these movement mechanisms can be functionally transplanted into a separate genus of geminivirus, allowing modified virus-based gene expression vectors to be spread between neighboring plant cells. Additionally, my work helps shed light on the basic genetic mechanisms employed by all living organisms to control gene expression.
In my research, I have studied the genetic mechanisms that underlie gene expression, in order to improve plant-based biopharmaceutical production. To do this, inspiration was drawn from naturally-occurring gene regulatory mechanisms, especially those from plant viruses, which have evolved mechanisms to co-opt the plant cellular machinery to produce high levels of viral proteins. By testing, modifying, and combining genetic elements from diverse sources, an optimized expression system has been developed that allows very rapid production of vaccine components, monoclonal antibodies, and other biopharmaceuticals. To improve target gene expression while maintaining the health and function of the plants, I identified, studied, and modified 5’ untranslated regions, combined gene terminators, and a nuclear matrix attachment region. The replication mechanisms of a plant geminivirus were also studied, which lead to additional strategies to produce more toxic biopharmaceutical proteins. Finally, the mechanisms employed by a geminivirus to spread between cells were investigated. It was demonstrated that these movement mechanisms can be functionally transplanted into a separate genus of geminivirus, allowing modified virus-based gene expression vectors to be spread between neighboring plant cells. Additionally, my work helps shed light on the basic genetic mechanisms employed by all living organisms to control gene expression.
ContributorsDiamos, Andy (Author) / Mason, Hugh S (Thesis advisor) / Mor, Tsafrir (Committee member) / Hogue, Brenda (Committee member) / Stout, Valerie (Committee member) / Arizona State University (Publisher)
Created2017
Description
Single-particle diffraction from X-ray Free Electron Lasers offers the potential for molecular structure determination without the need for crystallization. In an effort to further develop the technique, we present a dataset of coherent soft X-ray diffraction images of Coliphage PR772 virus, collected at the Atomic Molecular Optics (AMO) beamline with pnCCD detectors in the LAMP instrument at the Linac Coherent Light Source. The diameter of PR772 ranges from 65–70 nm, which is considerably smaller than the previously reported ~600 nm diameter Mimivirus. This reflects continued progress in XFEL-based single-particle imaging towards the single molecular imaging regime. The data set contains significantly more single particle hits than collected in previous experiments, enabling the development of improved statistical analysis, reconstruction algorithms, and quantitative metrics to determine resolution and self-consistency.
ContributorsReddy, Hemanth K. N. (Author) / Yoon, Chun Hong (Author) / Aquila, Andrew (Author) / Awel, Salah (Author) / Ayyer, Kartik (Author) / Barty, Anton (Author) / Berntsen, Peter (Author) / Bielecki, Johan (Author) / Bobkov, Sergey (Author) / Bucher, Maximilian (Author) / Carini, Gabriella A. (Author) / Carron, Sebastian (Author) / Chapman, Henry (Author) / Daurer, Benedikt (Author) / DeMirci, Hasan (Author) / Ekeberg, Tomas (Author) / Fromme, Petra (Author) / Hajdu, Janos (Author) / Hanke, Max Felix (Author) / Hart, Philip (Author) / Hogue, Brenda (Author) / Hasseinizadeh, Ahmad (Author) / Kim, Yoonhee (Author) / Kirian, Richard (Author) / Kurta, Ruslan P. (Author) / Larsson, Daniel S. D. (Author) / Loh, N. Duane (Author) / Maia, Filipe R. N. C. (Author) / Mancuso, Adrian P. (Author) / Muhlig, Kerstin (Author) / Munke, Anna (Author) / Nam, Daewoong (Author) / Nettelblad, Carl (Author) / Ourmazd, Abbas (Author) / Rose, Max (Author) / Schwander, Peter (Author) / Seibert, Marvin (Author) / Sellberg, Jonas A. (Author) / Song, Changyong (Author) / Spence, John (Author) / Svenda, Martin (Author) / van der Schot, Gijs (Author) / Vartanyants, Ivan A. (Author) / Williams, Garth J. (Author) / Xavier, P. Lourdu (Author) / ASU Biodesign Center Immunotherapy, Vaccines and Virotherapy (Contributor) / Biodesign Institute (Contributor) / Applied Structural Discovery (Contributor) / College of Liberal Arts and Sciences (Contributor) / School of Molecular Sciences (Contributor) / School of Life Sciences (Contributor) / Department of Physics (Contributor)
Created2017-06-27
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
Description
Women with breast cancer often experience weight gain during and after treatment, significantly increasing risk for recurrence as well as all-cause mortality. Based on a growing body of evidence, meditative movement practices may be effective for weight management. First, we describe the effects of stress on factors associated with weight gain for breast cancer survivors. Then, a model is proposed that utilizes existing evidence to suggest how meditative movement supports behavioral, psychological, and neurohormonal changes that may explain weight loss. Application of the model suggests how a novel “mindful-body-wisdom” approach may work to help reduce weight for this at-risk group.
ContributorsLarkey, Linda (Author) / Vega Lopez, Sonia (Author) / Keller, Colleen (Author) / McClain, Darya (Author) / Ainsworth, Barbara (Author) / Ohri-Vachaspati, Punam (Author) / Smith, Lisa (Author) / Jeong, Mihyun (Author) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor) / College of Health Solutions (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2014-12-24
Description
Serial femtosecond crystallography (SFX) using X-ray free-electron lasers has produced high-resolution, room temperature, time-resolved protein structures. We report preliminary SFX of Sindbis virus, an enveloped icosahedral RNA virus with ∼700 Å diameter. Microcrystals delivered in viscous agarose medium diffracted to ∼40 Å resolution. Small-angle diffuse X-ray scattering overlaid Bragg peaks and analysis suggests this results from molecular transforms of individual particles. Viral proteins undergo structural changes during entry and infection, which could, in principle, be studied with SFX. This is an important step toward determining room temperature structures from virus microcrystals that may enable time-resolved studies of enveloped viruses.
ContributorsLawrence, Robert (Author) / Conrad, Chelsie (Author) / Zatsepin, Nadia (Author) / Grant, Thomas D. (Author) / Liu, Haiguang (Author) / James, Daniel (Author) / Nelson, Garrett (Author) / Subramanian, Ganesh (Author) / Aquila, Andrew (Author) / Hunter, Mark S. (Author) / Liang, Mengning (Author) / Boutet, Sebastien (Author) / Coe, Jesse (Author) / Spence, John (Author) / Weierstall, Uwe (Author) / Liu, Wei (Author) / Fromme, Petra (Author) / Cherezov, Vadim (Author) / Hogue, Brenda (Author) / Biodesign Institute (Contributor) / Infectious Diseases and Vaccinology (Contributor) / Applied Structural Discovery (Contributor) / Department of Chemistry and Biochemistry (Contributor) / College of Liberal Arts and Sciences (Contributor) / Department of Physics (Contributor) / School of Life Sciences (Contributor)
Created2015-08-20
Description
X-ray free-electron lasers (XFELs) provide new opportunities for structure determination of biomolecules, viruses and nanomaterials. With unprecedented peak brilliance and ultra-short pulse duration, XFELs can tolerate higher X-ray doses by exploiting the femtosecond-scale exposure time, and can thus go beyond the resolution limits achieved with conventional X-ray diffraction imaging techniques. Using XFELs, it is possible to collect scattering information from single particles at high resolution, however particle heterogeneity and unknown orientations complicate data merging in three-dimensional space. Using the Linac Coherent Light Source (LCLS), synthetic inorganic nanocrystals with a core–shell architecture were used as a model system for proof-of-principle coherent diffractive single-particle imaging experiments. To deal with the heterogeneity of the core–shell particles, new computational methods have been developed to extract the particle size and orientation from the scattering data to assist data merging. The size distribution agrees with that obtained by electron microscopy and the merged data support a model with a core–shell architecture.
ContributorsLi, Xuanxuan (Author) / Spence, John (Author) / Hogue, Brenda (Author) / Liu, Haiguang (Author) / College of Liberal Arts and Sciences (Contributor) / Department of Physics (Contributor) / Biodesign Institute (Contributor) / Applied Structural Discovery (Contributor)
Created2017-08-27
Description
Objective
Limited research has examined how aspects of religion and spirituality can be incorporated into community-based physical activity programs delivered outside of religious institutions. The purpose of this study was to qualitatively explore how spirituality and religion can be leveraged in the design of community-based physical activity programs for African American women delivered outside of faith-based or faith-placed settings.
Results
Three focus groups were conducted were conducted with 23 African American women (M age = 37.8 years, M BMI = 39.6 kg m[superscript 2]). Results showed that incorporating aspects of spirituality (i.e., words encouraging connectedness to a higher power, meditation, mind–body activities) into a physical activity program was universally accepted among participants, regardless of religious affiliation. In contrast, including concepts of religion (i.e., bible verses and/or quotes from religious leaders) was controversial and not recommended among women who did not identify with a religious faith. Findings indicate that when developing community-based physical activity interventions that will not be delivered through faith-based or faith-placed settings, researchers should avoid references to specific religious beliefs. Instead, interventions should focus on spirituality and emphasize the mind–body relationship between physical activity and an African American women’s inner-being and her connectedness with a higher power.
Limited research has examined how aspects of religion and spirituality can be incorporated into community-based physical activity programs delivered outside of religious institutions. The purpose of this study was to qualitatively explore how spirituality and religion can be leveraged in the design of community-based physical activity programs for African American women delivered outside of faith-based or faith-placed settings.
Results
Three focus groups were conducted were conducted with 23 African American women (M age = 37.8 years, M BMI = 39.6 kg m[superscript 2]). Results showed that incorporating aspects of spirituality (i.e., words encouraging connectedness to a higher power, meditation, mind–body activities) into a physical activity program was universally accepted among participants, regardless of religious affiliation. In contrast, including concepts of religion (i.e., bible verses and/or quotes from religious leaders) was controversial and not recommended among women who did not identify with a religious faith. Findings indicate that when developing community-based physical activity interventions that will not be delivered through faith-based or faith-placed settings, researchers should avoid references to specific religious beliefs. Instead, interventions should focus on spirituality and emphasize the mind–body relationship between physical activity and an African American women’s inner-being and her connectedness with a higher power.
ContributorsJoseph, Rodney (Author) / Ainsworth, Barbara (Author) / Mathis, LaTanya (Author) / Hooker, Steven (Author) / Keller, Colleen (Author) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor) / Center for Health Promotion and Disease Prevention (Contributor) / College of Health Solutions (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2017-10-23
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