Microbiology Commons^™

The Effect Of Environmental Selection Pressure On The Rate Of Recombination To An Advantageous Receptor Mutation In Bovine Coronavirus, Gavin Schroter, Sally Hall, Mona Hwang, Monica Borucki

STAR Program Research Presentations

Bovine Coronavirus (BCoV) is an important analogue in understanding the effectiveness of zoonotic, single-stranded, positive sense RNA viruses. Many of the most recent viral outbreaks have been attributed to RNA viruses that have one, or more, animal reservoirs [1]. BCoV is such a great candidate for studying these types of viruses because they are from the family Coronaviridae, which also contains the viruses that cause severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). The goal of this study was to observe changes in genetic makeup of the virus’ outer membrane Spike protein via recombination between two …

Host Species Restriction Of Middle East Respiratory Syndrome Coronavirus Through Its Receptor, Dipeptidyl Peptidase 4, Neeltje Van Doremalen, Kerri L. Miazgowicz, Shauna Milne-Price, Trenton Bushmaker, Shelly Robertson, Dana Scott, Joerg Kinne, Jason S. Mclellan

Dartmouth Scholarship

Middle East respiratory syndrome coronavirus (MERS-CoV) emerged in 2012. Recently, the MERS-CoV receptor dipeptidyl peptidase 4 (DPP4) was identified and the specific interaction of the receptor-binding domain (RBD) of MERS-CoV spike protein and DPP4 was determined by crystallography. Animal studies identified rhesus macaques but not hamsters, ferrets, or mice to be susceptible for MERS-CoV. Here, we investigated the role of DPP4 in this observed species tropism. Cell lines of human and nonhuman primate origin were permissive of MERS-CoV, whereas hamster, ferret, or mouse cell lines were not, despite the presence of DPP4. Expression of human DPP4 in nonsusceptible BHK and …

Orca Project By Danny Catts And Dr. Johnson, Danny Catts, Dr. Johnson

Journal of Undergraduate Research

After we successfully characterized our virus, we proceeded to investigate the variant’s viral behavior in hopes of finding a difference in comparison to that of the standard. After preliminary steps showed little variation, we took a different direction with the project.

Biosorption Of Heavy Metals Onto The Surface Of Bacteriophage T4, Zheng Huan Tan

School of Biological Sciences: Dissertations, Theses, and Student Research

Biosorption of heavy metals by bacterial and eukaryotic cell surfaces and the subsequent transport in aqueous environments is well recognized. However, very little is known about the roles viruses play in biosorption. Viruses outnumber prokaryotes and eukaryotes in environmental systems. These organisms represent abundant nanoparticulate organic colloids with reactive surfaces. Here we conducted a series of experiments to assess the biosorption potential of Escherichia coli bacteriophage T4. Adsorption of a heavy metal, Zn²⁺, to the surface of phage T4 was tested in a series of purified phage/metal solutions (0 µM – 1000 µM at 23°C). The Langmuir isotherm …

The Innate Antiviral Effects Of Extracellular Viral Dsrna In Rainbow Trout Cells, Sarah J. Poynter

Theses and Dissertations (Comprehensive)

Viral double-stranded RNA (dsRNA) molecules are a potent pathogen-associated molecular pattern and play a crucial role in the innate immune response. During a viral infection, extracellular and intracellular dsRNA can initiate pathways resulting in the production of type I interferons (IFNs) and interferon-stimulated genes (ISGs). The accumulation of ISGs within a cell results in a protective antiviral state. This study used both commercially available dsRNA (poly I:C) and in vitro transcribed dsRNA molecules, based on the viral hemorrhagic septicemia virus (VHSV) genome sequence, as stimuli to investigate the effects of these molecules on the innate immune response in rainbow trout …

Phi X 174, David J. Hall

Infectious Pathogens

Phi X 174 database number # 1CD3. Phi X 174 is a virus that infects bacteria and was the first DNA-based genome to be sequenced in 1977. This bacteriophage has a [+] circular single-stranded DNA genome. The assembly of the capsid has been successfully done in vitro and is the focus of many studies on self-assembly, drug delivery and nanotechnology.

Dengue Virus, David J. Hall

Infectious Pathogens

Dengue virus, database # 1THD Dengue fever, is an infectious tropical disease caused by the dengue virus and transmitted by mosquito. Symptoms include fever, headache, muscle and joint pains, and a characteristic skin rash that is similar to measles. In a small proportion of cases the disease develops into the life-threatening dengue hemorrhagic fever. Dengue is a positive strand RNA virus that is part of the flavivirus family. Dengue is an enveloped virus meaning it has a nucleocapsid protecting the RNA and the nucleocapsid is surrounded by lipids (hence the name enveloped).

Human Papilloma Virus 16, David J. Hall

Infectious Pathogens

Human Papilloma virus 16, database# 1DZL Infection by most papillomaviruses is either asymptomatic or causes small benign tumors, known as papillomas or warts (e.g. human papillomavirus HPV6 or HPV11). Papillomas caused by some types, however, such as human papillomaviruses 16 and 18, carry a risk of becoming cancerous. Human papilloma virus is a non-enveloped, double stranded, circular DNA virus.

Hepatitis B, David J. Hall

Infectious Pathogens

Hepatitis B, database # 2g33. Hepatitis B is an infectious inflammatory illness of the liver caused by the hepatitis B virus (HBV). Hepatitis B virus (HBV) is a member of the Hepadnavirus family.The virus particle, (virion) consists of an outer lipid envelope and an icosahedral nucleocapsid core composed of protein. These virions are 42 nM in diameter. The nucleocapsid encloses the viral DNA and a DNA polymerase that has reverse transcriptase activity.

Innate Immune Responses To Respiratory Syncytial Virus: Age-Associated Changes, Terianne Maiko Wong

USF Tampa Graduate Theses and Dissertations

Respiratory syncytial virus (RSV) infection causes ~64 million cases of respiratory disease and 200,000 deaths annually worldwide, yet there is no broadly effective prophylactic or treatment regimen. RSV can produce acute respiratory illness in patients of all ages but strikes the age extremes, infants and the elderly, with highest frequency presumably due to innate immune deficiencies. A higher morbidity and mortality has been reported for the elderly above 65 years of age, which has been attributed to immune senescence. Efforts to generate an effective vaccine have thus far been unsuccessful.

The innate immune system provides the first line of defense …

The Crispr/Cas Adaptive Immune System Of Pseudomonas Aeruginosa Mediates Resistance To Naturally Occurring And Engineered Phages, Kyle C. Cady, Joe Bondy-Denomy, Gary E. Heussler, Alan R. Davidson, George A. O'Toole

Dartmouth Scholarship

Here we report the isolation of 6 temperate bacteriophages (phages) that are prevented from replicating within the laboratory strain Pseudomonas aeruginosa PA14 by the endogenous CRISPR/Cas system of this microbe. These phages are only the second identified group of naturally occurring phages demonstrated to be blocked for replication by a nonengineered CRISPR/Cas system, and our results provide the first evidence that the P. aeruginosa type I-F CRISPR/Cas system can function in phage resistance. Previous studies have highlighted the importance of the protospacer adjacent motif (PAM) and a proximal 8-nucleotide seed sequence in mediating CRISPR/Cas-based immunity. Through engineering of a protospacer …

Virus Capsids As Nanoscale Delivery Vessels Of Photoactive Compounds For Site-Specific Photodynamic Therapy, Brian Alexander Cohen

Legacy Theses & Dissertations (2009 - 2024)

The research presented in this work details the use of a viral capsid as an addressable delivery vessel of photoactive compounds for use in photodynamic therapy. Photodynamic therapy is a treatment that involves the interaction of light with a photosensitizing molecule to create singlet oxygen, a reactive oxygen species. Overproduction of singlet oxygen in cells can cause oxidative damage leading to cytotoxicity and eventually cell death. Challenges with the current generation of FDA-approved photosensitizers for photodynamic therapy primarily stem from their lack of tissue specificity. This work describes the packaging of photoactive cationic porphyrins inside the MS2 bacteriophage capsid, followed …

Therapeutic Peptide-Based Vaccination Strategies Against Hpv-Induced Cancers, Kelly Barrios Marrugo

USF Tampa Graduate Theses and Dissertations

There is an urgent need for the development of an effective therapeutic vaccine against cancer caused by human papilloma virus (HPV). We focused on HPV-induced malignancies because of their high worldwide prevalence (e.g., cervical carcinoma and head & neck cancer). A successful therapeutic vaccine could prevent the 250 000 deaths/year worldwide and the 2.25 billion dollars that

are expended in related care in the US.

We used an HPV-induced mouse cancer model to test vaccines

composed of a CD8 T cell peptide epitope administered with potent adjuvants designed to generate vast numbers of high avidity cytotoxic T lymphocytes specific for …

Primary Human Mammary Epithelial Cells Endocytose Hiv-1 And Facilitate Viral Infection Of Cd4+ T Lymphocytes, Stephanie M. Dorosko, Ruth I. Connor

Dartmouth Scholarship

The contribution of mammary epithelial cells (MEC) to human immunodeficiency virus type 1 (HIV-1) in breast milk remains largely unknown. While breast milk contains CD4(+) cells throughout the breast-feeding period, it is not known whether MEC directly support HIV-1 infection or facilitate infection of CD4(+) cells in the breast compartment. This study evaluated primary human MEC for direct infection with HIV-1 and for indirect transfer of infection to CD4(+) target cells. Primary human MEC were isolated and assessed for expression of HIV-1 receptors. MEC were exposed to CCR5-, CXCR4- and dual-tropic strains of HIV-1 and evaluated for viral reverse transcription …

Human Uterine Natural Killer Cells But Not Blood Natural Killer Cells Inhibit Human Immunodeficiency Virus Type 1 Infection By Secretion Of Cxcl12, Teddy F. Mselle, Aexandra L. Howell, Mimi Ghosh, Charles R. Wira, Charles L. Sentman

Dartmouth Scholarship

Natural killer (NK) cells derived from the human female reproductive tract (FRT) are phenotypically and functionally distinct from those obtained from peripheral blood. Because the FRT is a primary site of human immunodeficiency virus type 1 (HIV-1) infection in women, we determined whether soluble factors secreted by uterine-derived NK (uNK) cells inhibit HIV-1 infection. Clonal populations of uNK cells were activated with interleukin-12 (IL-12) and IL-15, and conditioned media (CM) from these cultures evaluated for their ability to inhibit infection of cells by HIV-1_IIIB, HIV-1_NL4.3, and HIV-1_HC4 (X4-tropic) or HIV-1_BaL (R5-tropic) viruses. We found …

Bacteriophage Migration Via Nematode Vectors: Host-Parasite-Consumer Interactions In Laboratory Microcosms, John J. Dennehy, Nicholas A. Friedenberg, Yul W. Yang, Paul E. Turner

Dartmouth Scholarship

Pathogens vectored by nematodes pose serious agricultural, economic, and health threats; however, little is known of the ecological and evolutionary aspects of pathogen transmission by nematodes. Here we describe a novel model system with two trophic levels, bacteriophages and nematodes, each of which competes for bacteria. We demonstrate for the first time that nematodes are capable of transmitting phages between spatially distinct patches of bacteria. This model system has considerable advantages, including the ease of maintenance and manipulation at the laboratory bench, the ability to observe many generations in short periods, and the capacity to freeze evolved strains for later …

Investigation Of The Mechanisms Of Ozone-Mediated Viral Inactivation, Seiga Ohmine

Theses and Dissertations

Previous studies have established that ozone-oxygen mixtures can be used to inactivate a variety of microorganisms including bacteria, fungi and viruses. Ozone is a potent reactive oxygen species (ROS) that rapidly decays into a variety of additional short half-life ROS which have been shown to cause oxidative damage to biological molecules. I hypothesize that controlled ozone exposure and the subsequent generation of additional ROS would reduce viral infectivity by lipid and/or protein peroxidation. A proprietary ozone-oxygen delivery system was used to inactivate a series of enveloped [herpes simplex virus type-1 strain McIntyre (HSV-1), vaccinia strain Elstree (VAC), vesicular stomatitis virus …

Isolation And Characterization Of A Generalized Transducing Phage For Pseudomonas Aeruginosa Strains Pao1 And Pa14, Jonathan M. Budzik, William A. Rosche, Arne Rietsch, George A. O'Toole

Dartmouth Scholarship

A temperate, type IV pilus-dependent, double-stranded DNA bacteriophage named DMS3 was isolated from a clinical strain of Pseudomonas aeruginosa. A clear-plaque variant of this bacteriophage was isolated. DMS3 is capable of mediating generalized transduction within and between P. aeruginosa strains PA14 and PAO1, thus providing a useful tool for the genetic analysis of P. aeruginosa.

Cd40-Associated Traf 6 Signaling Is Required For Disease Induction In A Retrovirus-Induced Murine Immunodeficiency, Kathy A. Green, Cory L. Ahonen, W. James Cook, William R. Green

Dartmouth Scholarship

LP-BM5 retrovirus-infected C57BL/6 mice develop splenomegaly, lymphadenopathy, hypergammaglobulinemia, and immunodeficiency; thus, this disease has been named mouse AIDS. In this syndrome, CD154/CD40 interactions are required for but do not mediate disease by upregulation of CD80 or CD86. We report here that there is nonetheless a necessity for CD40 signaling competence, specifically an intact tumor necrosis factor receptor-associated factor 6 (TRAF 6) binding site.

Adoptive Transfer Of Polyclonal And Cloned Cytolytic T Lymphocytes (Ctl) Specific For Mouse Aids-Associated Tumors Is Effective In Preserving Ctl Responses: A Measure Of Protection Against Lp-Bm5 Retrovirus-Induced Immunodeficiency., William R. Green, Kathy A. Green, Karen M. Crassi

Dartmouth Scholarship

Cytolytic T lymphocytes (CTL) can be raised against C57BL/6 B-cell lymphomas from mice with LP-BM5 murine leukemia virus-induced AIDS (MAIDS). Adoptive transfer of polyclonal anti-MAIDS tumor CTL or two CTL clones specific for the B6-1710 MAIDS lymphoma caused preservation of major histocompatibility complex-restricted and allogeneic CTL responses, which may be interpreted as indices of protection from LP-BM5 murine leukemia virus-induced immunodeficiency.

The Amino-Terminal Functions Of The Simian Virus 40 Large T Antigen Are Required To Overcome Wild-Type P53-Mediated Growth Arrest Of Cells., Robin S. Quartin, Charles N. Cole, James M. Pipas, Arnold J. Levine

Dartmouth Scholarship

High levels of the p53 tumor suppressor protein can block progression through the cell cycle. A model system for the study of the mechanism of action of wild-type p53 is a cell line (T64-7B) derived from rat embryo fibroblasts transformed by activated ras and a temperature-sensitive murine p53 gene. At 37 to 39 degrees C, the murine p53 protein is in a mutant conformation and the cells actively divide, whereas at 32 degrees C, the protein has a wild-type conformation and the cells arrest in the G1 phase of the cell cycle. Wild-type simian virus 40 large T antigen and …

Efficient Transcriptional Activation Of Many Simple Modular Promoters By Simian Virus 40 Large T Antigen., Philip W. Rice, Charles N. Cole

Dartmouth Scholarship

Simian virus 40 (SV40) large T antigen is a multifunctional protein which plays central roles during both lytic and transforming infections by SV40. It is a potent transcriptional activator and increases expression from the SV40 late promoter and from several cellular promoters. To understand better the transcriptional activation activity of large T antigen, we examined its ability to transactivate a set of simple modular promoters containing one of four upstream activation sequences coupled with one of three different TATA box sequences originally constructed and studied by Taylor and Kingston (Mol. Cell. Biol. 10:165-175, 1990). Large T antigen activated transcription from …

Molecular Cloning Of Infectious Ecotropic Murine Leukemia Virus Ak7 From An Emv-14-Positive Akxl-5 Mouse And The Resistance Of Ak7 To Recognition By Cytotoxic T Lymphocytes., Hillary D. White, William R. Green, Nuria R. Giné

Dartmouth Scholarship

The AKXL-5 recombinant inbred mouse strain is positive for the endogenous ecotropic murine leukemia virus emv-14, the only emv present in its germ line. emv-14 is of particular interest because spleen cells expressing emv-14 virus escape recognition by anti-AKR/Gross virus-specific cytotoxic T lymphocytes. We report here the isolation and characterization of a replication-competent emv clone, pAK7, derived from an AKXL-5 mouse. This clone is novel in that it encodes a variant ecotropic murine leukemia virus that, when expressed in SC.Kb target cells, fails to be recognized efficiently by anti-AKR/Gross virus cytotoxic T lymphocytes. The pAK7 clone can therefore be used …

Two Factors That Bind To Highly Conserved Sequences In Mammalian Type C Retroviral Enhancers., Nancy R. Manley, Mary M. O'Connell, Wanwen Sun, Nancy A. Speck, Nancy Hopkins

Dartmouth Scholarship

The transcriptional enhancers of the Moloney and Friend murine leukemia viruses (MLV) are important determinants of viral pathogenicity. We used electrophoretic mobility shift and methylation interference assays to study nuclear factors which bind to a region of these enhancers whose sequence is identical between Moloney and Friend viruses and particularly highly conserved among 35 mammalian type C retroviruses whose enhancer sequences have been aligned (E. Golemis, N. A. Speck, and N. Hopkins, J. Virol. 64:534-542, 1990). Previous studies identified sites for the leukemia virus factor b (LVb) and core proteins in this region (N. A. Speck and D. Baltimore, Mol. …

Characterization Of A Protein That Binds Multiple Sequences In Mammalian Type C Retrovirus Enhancers., Wanwen Sun, Mary M. O'Connell, Nancy A. Speck

Dartmouth Scholarship

Mammalian type C retrovirus enhancer factor 1 (MCREF-1) is a nuclear protein that binds several directly repeated sequences (CNGGN6CNGG) in the Moloney and Friend murine leukemia virus (MLV) enhancers (N. R. Manley, M. O'Connell, W. Sun, N. A. Speck, and N. Hopkins, J. Virol. 67:1967-1975, 1993). In this paper, we describe the partial purification of MCREF-1 from calf thymus nuclei and further characterize the binding properties of MCREF-1. MCREF-1 binds four sites in the Moloney MLV enhancer and three sites in the Friend MLV enhancer. Ethylation interference analysis suggests that the MCREF-1 binding site spans two adjacent minor grooves of …

The Ability Of Simian Virus 40 Large T Antigen To Immortalize Primary Mouse Embryo Fibroblasts Cosegregates With Its Ability To Bind To P53., Jiyue Y. Zhu, Marina Abate, Philip W. Rice, Charles N. Cole

Dartmouth Scholarship

The large T antigen encoded by simian virus 40 (SV40) plays essential roles in the infection of permissive cells, leading to production of progeny virions, and in the infection of nonpermissive cells, leading to malignant transformation. Primary mouse embryo fibroblasts (MEFs) are nonpermissive for SV40, and infection by wild-type SV40 leads to immortalization and transformation of a small percentage of infected cells. We examined the ability of an extensive set of mutants whose lesions affect SV40 large T antigen to immortalize MEFs. We found that immortalization activity was retained by all mutants whose lesions are located upstream of codon 346. …

Mapping The Transcriptional Transactivation Function Of Simian Virus 40 Large T Antigen., Jiyue Y. Zhu, Philip W. Rice, Michele Chamberlain, Charles N. Cole

Dartmouth Scholarship

T antigen is able to transactivate gene expression from the simian virus 40 (SV40) late promoter and from several other viral and cellular promoters. Neither the mechanisms of transactivation by T antigen nor the regions of T antigen required for this activity have been determined. To address the latter point, we have measured the ability of a set of SV40 large T antigen mutants to stimulate gene expression in CV-1 monkey kidney cells from the SV40 late promoter and Rous sarcoma virus (RSV) long terminal repeat (LTR) promoter. Transactivation, although reduced, was retained by an N-terminal 138-amino-acid fragment of T …

Simian Virus 40 Host Range/Helper Function Mutations Cause Multiple Defects In Viral Late Gene Expression., Terryl Stacy, Michele Chamberlain, Charles N. Cole

Dartmouth Scholarship

Simian virus 40 (SV40) deletion mutants dlA2459 and dlA2475 express T antigens that lack the normal carboxy terminus. These mutants are called host range/helper function (hr/hf) mutants because they form plaques at 37 degrees C on BSC-1 and Vero monkey kidney cell lines but not on CV-1p monkey kidney cells. Wild-type SV40 can provide a helper function to permit growth of human adenoviruses in monkey kidney cells; the hr/hf mutants cannot. Progeny yields of hr/hf mutants are also cold sensitive in all cell lines tested. Patterns of viral macromolecular synthesis in three cell lines (Vero, BSC-1, and CV-1) at three …

Linker Insertion Mutants Of Simian Virus 40 Large T Antigen That Show Trans-Dominant Interference With Wild-Type Large T Antigen Map To Multiple Sites Within The T-Antigen Gene., Jiyue Y. Zhu, Charles N. Cole

Dartmouth Scholarship

Linker insertion mutants affecting the simian virus 40 (SV40) large tumor (T) antigen were constructed by inserting a 12-base-pair oligonucleotide linker into restriction endonuclease cleavage sites located within the early region of SV40. One mutant, with the insertion at amino acid 5, was viable in CV-1p and BSC-1 cells, indicating that sequences very close to the amino terminus of large T could be altered without affecting the lytic infection cycle of SV40. All other mutants affecting large T were not viable. In complementation assays between the linker insertion mutants and either a late-gene mutant, dlBC865, or a host range/helper function …

Improving Potato Seed, James P. Fallon

Journal of the Department of Agriculture, Western Australia, Series 4

SOME of the oldest records of potato cultivation show that throughout the ages it has been generally accepted that periodically, a change of seed is essential, and the only means of maintaining satisfactory yields in crops.

Even today most potato growers are familiar with the term "run out" as applied to any particular line of potatoes which tends to progressively decrease in vigour and productivity when planted from year to year.