Theses and Dissertations at Montana State University (MSU)
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/733
Browse
2 results
Search Results
Item Honey bee host-virus interactions at the individual and cellular level(Montana State University - Bozeman, College of Agriculture, 2021) McMenamin, Alexander James; Chairperson, Graduate Committee: Michelle Flenniken; This is a manuscript style paper that includes co-authored chapters.Honey bees are important pollinators of the fruits, nuts and vegetable crops that feed our growing population. Unfortunately, honey bee colony losses have averaged 38% from 2008-2018. These losses are due to a variety of factors, including reduced quality forage, pesticide exposure in agricultural fields, parasites like the Varroa destructor mite, and pathogens. The most diverse group of pathogens effecting honey bees are small RNA viruses. Honey bees have evolved numerous strategies to restrict virus infection, including the RNA interference (RNAi) pathway. Bees infected with a model virus, Sindbis-GFP (SINV) have differential expression of hundreds of genes, including RNAi genes and several heat shock protein (HSP) encoding genes. Therefore, we hypothesized that heat shock proteins are antiviral in honey bees. To induce the heat shock response (HSR), SINV-infected bees were heat shocked at 42°C for 4 hours. Heat shock resulted in a 74-90% reduction in SINV RNA copies as compared to bees maintained at 32°C. Heat shocked and/or virus-infected bees had increased expression of several core HSR protein-encoding genes, but heat shock did not consistently result in the increased expression of RNAi genes (argonaute-2 and dcr-like). This indicates that heat shock proteins are contributing to an antiviral response. SINV-infected bees also had higher expression of a recently identified antiviral gene - bee antiviral protein-1 (bap1). Therefore, we further characterized bap1 using computation approaches including phylogenetic analysis, which determined that this gene is taxonomically restricted to Hymenoptera and Blatella germanica (the German cockroach). Structural predication programs indicated that bap1 is a highly disordered protein. Intriguingly, transcriptome and correlation analyses determined that bap1 was coexpressed with several genes implicated in antiviral immunity (i.e., ago2, tudor-sn and TEP7). Although the precise antiviral function of bap1 remains to be elucidated, we further developed experimental tools that will enable more incisive investigation of bap1 and other antiviral genes. Primary cultures of larval hemocytes (immune cells) and mixed-cell pupal tissue cultures supported productive replication of sacbrood virus, deformed wing virus, and Flock House virus. Infected pupal cell cultures exhibited virus-specific transcriptional responses in bap1, ago2, and dcr-like expression. Together, these data further elucidate honey bee antiviral immunity and provide new tools for studying honey bee host-virus interactions.Item Monitoring protien cage nanopaticle morphology for applications in medicines and materials(Montana State University - Bozeman, College of Letters & Science, 2011) Johnson, Benjamin Lawrence; Chairperson, Graduate Committee: Trevor DouglasProtein cage nanoparticles are naturally occurring proteins found in all domains of life. The breadth of structural knowledge and the ability to modify protein cage nanoparticles both chemically and genetically set them apart for use as platforms for biomedical templates and materials synthesis. The work described herein focuses on the use of protein cage nanoparticles as a protective agent from a suite of viral pathogens. Protein cage nanoparticles exist in many different morphological forms both within a specific particle and between particles. It is essential to characterize these different states in order to engineer a protein cage nano particle for biomedical and materials synthesis. Described here is an expanded protocol for determining the morphological state with the bacteriophage P22 capsid. Using multiple techniques including multi angle light scattering, analytical ultra centrifugation, agarose gel electrophoresis and transmission electron microscopy these states are described and characterized. P22 exits in four different morphological states: the procapsid, empty shell, expanded shell and so-called "wiffleball". Also characterized in the work is the small heat shock protein from Methanococcus jannaschii, which exists in two morphological states. One of the states being the assembled 12 nm cage structure and the other state being a disassembled cage structure that is most commonly described at elevated temperatures. The characterization of these structures can aid in the understanding the mechanism of formation for the immunological phenomena induced bronchial associated lymphoid tissue.