Virology Commons^™

The Effects Of Nutrient Limitation And Cyanophage On Heterotrophic Microbial Diversity, Claire Elyse Campbell

Masters Theses

Marine viruses are critically important in the regulation of biogeochemical cycles and host microbial communities. In this study, we tested whether the indirect effects of virus predation on a phototroph (i.e., Synechococcus) affected the composition of co-occurring heterotrophic bacteria under nitrogen and phosphorus limitation in long-term chemostat experiments. Using 454 Titanium barcoded pyrosequencing of the 16S rRNA gene, microbial diversity and technical (i.e., sequencing) reproducibility were assessed for nine individual chemostats across five different time points. A total of 325,142 reads were obtained; 194,778 high-quality, non-cyanobacterial sequences were assigned to 110 OTUs. Our results show high reproducibility …

Evidence For Viral Infection In The Copepods Labidocera Aestiva And Acartia Tonsa In Tampa Bay, Florida, Darren Stephenson Dunlap

USF Tampa Graduate Theses and Dissertations

Mesozooplankton are of critical importance to marine food webs by transferring energy from the microbial food web to higher trophic levels and depositing energy to the deeper ocean layers through fecal deposition. While decades of research have shown that viruses have significant impacts in the oceans, and infect a wide range of organisms from bacteria to whales, there is still little known about the impacts of viruses on the mesozooplankton community. As copepods are the most abundant mesozooplankton group, this study sought to characterize the viruses present in natural populations of the calanoid copepods Acartia tonsa and Labidocera aestiva in …

Restriction Of Hiv-1 Replication By Unique Trim22 Isoforms., Clayton Hattlmann

Electronic Thesis and Dissertation Repository

Understanding how the immune system reacts to HIV infection and why normal antiviral defenses are insufficient to fight infection is a key step towards creating better therapies. Several interferon-induced proteins, such as the tripartite motif protein TRIM22, are capable of restricting HIV-1 replication; however single nucleotide polymorphisms (SNPs) can dramatically impact the actions of these proteins. While the trim22 gene contains numerous SNPs, no study has addressed how these may affect TRIM22 functions. Here we provide the first direct comparison of two TRIM22 unique isoforms. Through confocal microscopy we observed these isoforms exhibit different patterns of localization. In vitro studies …

Further Characterization Of The Nodamura Virus Rna2 3'-Terminal Stem Loop Structure And Its Role In Viral Rna Replication, Joshua Frederick

Open Access Theses & Dissertations

Nodamura virus (NoV) is an excellent model system for studying many aspects of the life cycle of positive-strand RNA viruses. NoV's simple genome organization and ability to replicate its genome to high levels in a wide variety of host cells, including plants, yeast, insects and mammals (Ball et al., 1992; Garzon et al., 1978, 1990; Murphy et al., 1970; Price et al., 2005; Scherer & Hurlbut, 1967; Selling et al., 1990; reviewed by Ball & Johnson, 1998), make it a prime model system for studying the basic mechanisms of viral RNA replication. Other positive-strand RNA viruses, including those that are …

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 …

Purification And Applications Of A Bacteriophage-Derived Enzyme Chapk Against Problematic Staphylococci., Niamh Marie O'Shea

Theses

The bacteriophage K-derived peptidase CHAPk (Cysteine/Histidine-dependant amidohydrolase peptidase) can be produced from E. coli XL 1-Blue. Standard operating procedures for the production, purification and quality assessment of the peptidase were developed and set out in detail in this thesis. CHAPk exhibits strong antistaphylococcal properties and the purified enzyme was evaluated for its potential to eliminate S. aureus from the bovine udder and from human skin. As a teat dip CHAPk reduced the levels of S. aureus by three to five log cycles on both animal and human surfaces. CHAPk activity in milk was evaluated using challenge assays against the bovine …

Phylogenetic Analysis Of Rotavirus Strains Gl, G3 5g9 5p[8] And P[4] Using Both Neighbour-Joining And Maximum Parsimony, Jenny Cotter

Theses

Globally rotavirus is one of the most important causes of gastroenteritis in children and affects nearly all children by the age of 5 years. It also infects adults with most severe symptoms in the elderly or immune compromised. The most common strains associated with human rotavirus gastroenteritis are G1-G4 and G9 along with P[8],[6]and [4].All previous studies used only neighbour-joining method in the phylogenetic analysis of rotavirus genes. In this study rotavirus genes VP7 and VP4 for rotavirus strains G1 .G3 ,G9 , P[8] and P[4] were analysed in MEGA4.0 using both neighbour-joining and maximum parsimony. The main difference in …

Intra And Interhost Dynamics Shaping Arbovirus Adaptation And Evolution, Alexander T. Ciota

Legacy Theses & Dissertations (2009 - 2024)

Arthropod-borne viruses (arboviruses), which are predominately mosquito-borne and almost exclusively RNA viruses, are maintained in nature in complex transmission cycles involving blood sucking invertebrates and vertebrate hosts. Although over 120 arboviruses are human pathogens responsible for causing a significant and expanding global health burden, a detailed understanding of the complex interactions between these pathogens and their hosts, particularly invertebrate hosts, is lacking. Defining these interactions is necessary if we are to understand the selective pressures and, therefore, evolutionary, adaptive, and epidemiological potential of arboviruses. This requires experimental infection and evolution studies, particularly in vivo, with natural hosts. The results presented …

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 …

Membrane-Bound Immunomodulators As Adjuvants In A Cell Culture-Based Avian Influenza Vaccine, David Daniel Fischer

Wayne State University Dissertations

Inactivated viral vaccines often generate suboptimal immune responses. Adjuvants are incorporated into vaccines to increase their immunogenicity, however currently available adjuvants have shortcomings which have limited their use in human and veterinary medicine. This necessitates the development of new adjuvants and delivery systems. Cytokines have been extensively tested as adjuvants in vaccines but challenges such as diffusion from antigen, short half-lives and production costs have been encountered. To address this, we developed a technology that efficiently produces inactivated, whole-virus influenza vaccine bearing membrane-bound cytokines. Tethering the cytokine to the antigen of interest keeps the immunomodulator in close contact with the …