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Open Access Publications from the University of California

Scholarly Works (4 results)

  • Thesis
  • Peer Reviewed
UC Santa Cruz Electronic Theses and Dissertations (2024)

Respiratory syncytial virus (RSV) is a leading cause of bronchiolitis and pneumonia worldwide especially in infants, young children, immunocompromised individuals, and the elderly. In the United States alone, the economic burden to treat or prevent severe respiratory disease caused by RSV estimated 6.6 billion dollars in a study conducted with financial reports from 2021. Since its discovery in the late 1950’s, the question of how to elicit a protective immunogenic response against RSV remained unclear, that is, until 2023 when the first FDA approved vaccines became commercially available. These vaccines serve to prevent severe RSV-associated respiratory disease with endpoints involving major economic and quality of life burdens like hospital visits. However, studies have shown that correlates of protection involve antibody responses against two major surface glycoproteins that are required for efficient viral entry: RSV F and RSV G. Currently, all commercially available vaccines and prophylactic monoclonal antibodies use RSV F as their antigenic target. To investigate RSV G as an antigenic target for protective immune responses, commercially unavailable correlates of protection, I develop structure guided RSV G based vaccine designs and determine novel RSV G conformational epitopes recognized by broadly reactive monoclonal antibodies. I begin by discussing our work to address the issue of RSV G’s poor immunogenicity and its association to the apparent immune modulating activity seen in natural infection and vaccination using a nanoparticle vaccine platform where my role was the design, production, and characterization of the vaccine constructs. Following this, I describe a synthetically produced microparticle vaccine design based on layer-by-layer technology where my role was to determine its reactivity with an antibody that relies heavily on correct CX3C folding to recognize the CCD. Finally, I present our structural studies involving five broadly reactive antibodies in complex with the CCD where we characterize three novel conformational epitopes and reveal two non-competing antigenic sites. This work serves as a blueprint for the generation of structure guided mutagenesis, structure guided vaccine design, and antibody therapeutic or prophylactic strategies to protect from and prevent RSV-associated respiratory disease.

    Cover page: Structural and Immunogenic Studies on the Respiratory Syncyital Virus G Glycoprotein
    • Article
    • Peer Reviewed
    LBL Publications (2013)

    Background

    Agaves are succulent monocotyledonous plants native to xeric environments of North America. Because of their adaptations to their environment, including crassulacean acid metabolism (CAM, a water-efficient form of photosynthesis), and existing technologies for ethanol production, agaves have gained attention both as potential lignocellulosic bioenergy feedstocks and models for exploring plant responses to abiotic stress. However, the lack of comprehensive Agave sequence datasets limits the scope of investigations into the molecular-genetic basis of Agave traits.

    Results

    Here, we present comprehensive, high quality de novo transcriptome assemblies of two Agave species, A. tequilana and A. deserti, built from short-read RNA-seq data. Our analyses support completeness and accuracy of the de novo transcriptome assemblies, with each species having a minimum of approximately 35,000 protein-coding genes. Comparison of agave proteomes to those of additional plant species identifies biological functions of gene families displaying sequence divergence in agave species. Additionally, a focus on the transcriptomics of the A. deserti juvenile leaf confirms evolutionary conservation of monocotyledonous leaf physiology and development along the proximal-distal axis.

    Conclusions

    Our work presents a comprehensive transcriptome resource for two Agave species and provides insight into their biology and physiology. These resources are a foundation for further investigation of agave biology and their improvement for bioenergy development.
      Cover page: De novo transcriptome assembly of drought tolerant CAM plants, Agave deserti and Agave tequilana
      • Article
      • Peer Reviewed
      UC Santa Cruz Previously Published Works (2023)

      Introduction

      Respiratory syncytial virus (RSV) can cause lower respiratory tract disease in infants and elderly populations. Despite decades of research, there remains no safe and approved RSV vaccine. Previously, we showed that an RSV G glycoprotein subunit vaccine candidate with a single point mutation within the central conserved domain (CCD), i.e. S177Q, considerably improved immunogenicity.

      Methods

      Here, we examine the development of nanoparticle (NP) vaccines having either an RSV G protein CCD with wild-type sequence (NPWT) or an S177Q mutation (NP-S177Q). The NP vaccine immunogens were adjuvanted with monophosphoryl lipid A (MPLA), a TLR4 agonist to improve Th1- type responses. BALB/c mice were primed with 10 μg of NP-WT vaccine, NPS177Q, or vehicle, rested, and then boosted with a high (25 μg) or low (10 μg) dose of the NP-WT or NP-S177Q homologous candidate and subsequently challenged with RSV A2.

      Results

      The results showed that mice boosted with NP-S177Q developed superior immunogenicity and neutralizing antibodies compared to NP-WT boosting. IgG from either NP-S177Q or NP-WT vaccinated mice did not interfere with fractalkine (CX3CL1) binding to CX3CR1 and effectively blocked G protein CX3C-CX3CR1 binding. Both NP-WT and NP-S177Q vaccination induced similar neutralizing antibodies to RSV in challenged mice compared to vehicle control. NP-S177Q boosting improved correlates of protection including reduced BAL cell infiltration following RSV challenge. However, the NP vaccine platform will require improvement due to the poor solubility and the unexpectedly weaker Th1-type IgG2a response.

      Discussion

      The results from this study support further NP-S177Q vaccine candidate development.
        Creative Commons 'BY-ND' version 4.0 license
        • Article
        • Peer Reviewed
        UCLA Previously Published Works (2012)

        Objective

        Tissue glucocorticoid (GC) levels are regulated by the GC-activating enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). This enzyme is expressed in cells and tissues arising from mesenchymal stromal cells. Proinflammatory cytokines dramatically increase expression of 11β-HSD1 in stromal cells, an effect that has been implicated in inflammatory arthritis, osteoporosis, obesity, and myopathy. Additionally, GCs act synergistically with proinflammatory cytokines to further increase enzyme expression. The present study was undertaken to investigate the mechanisms underlying this regulation.

        Methods

        Gene reporter analysis, rapid amplification of complementary DNA ends (RACE), chemical inhibition experiments, and genetic disruption of intracellular signaling pathways in mouse embryonic fibroblasts (MEFs) were used to define the molecular mechanisms underlying the regulation of 11β-HSD1 expression.

        Results

        Gene reporter, RACE, and chemical inhibitor studies demonstrated that the increase in 11β-HSD1 expression with tumor necrosis factor α (TNFα)/interleukin-1β (IL-1β) occurred via the proximal HSD11B1 gene promoter and depended on NF-κB signaling. These findings were confirmed using MEFs with targeted disruption of NF-κB signaling, in which RelA (p65) deletion prevented TNFα/IL-1β induction of 11β-HSD1. GC treatment did not prevent TNFα-induced NF-κB nuclear translocation. The synergistic enhancement of TNFα-induced 11β-HSD1 expression with GCs was reproduced by specific inhibitors of p38 MAPK. Inhibitor and gene deletion studies indicated that the effects of GCs on p38 MAPK activity occurred primarily through induction of dual-specificity phosphatase 1 expression.

        Conclusion

        The mechanism by which stromal cell expression of 11β-HSD1 is regulated is novel and distinct from that in other tissues. These findings open new opportunities for development of therapeutic interventions aimed at inhibiting or stimulating local GC levels in cells of mesenchymal stromal lineage during inflammation.
          Cover page: Inflammatory regulation of glucocorticoid metabolism in mesenchymal stromal cells
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