Cell Biology Commons^™

Dicer Represses Antiviral Innate Immunity Pathways In Mouse Embryonic Stem Cells, Chandan Gurung

Dissertations

Recent studies have demonstrated that embryonic stem cells (ESCs) are deficient in expressing type I interferons (IFN), the cytokines that play key roles in antiviral responses. However, the underlying molecular mechanisms and biological implications of this finding are poorly understood. In this study, I used a synthetic RNA-based assay that can simultaneously assess multiple forms of antiviral responses in ESCs. Dicer is an enzyme essential for RNA interference (RNAi), which is used as a major antiviral mechanism in invertebrates but not clear in vertebrates. RNAi activity is detected in wild-type ESCs but is abolished in Dicer knockout ESCs (D−/−ESCs) as …

Comprehensive Study Of Human Pathogenic Trypanosomatids: From Chemotherapies To Disease Ecology, Felipe Rodriguez

Open Access Theses & Dissertations

The vector-borne diseases Leishmaniasis and Chagas disease, caused by the kinetoplastid parasites Leishmania spp. and Trypanosoma cruzi respectively, are among the most important parasitic diseases in the group of neglected tropical diseases. Even though the two diseases are endemic to the Americas, they affect millions of people worldwide. Leishmaniasis and Chagas disease cause a great array of symptoms and some of them can be fatal if left undiagnosed and untreated. Current treatment regimens are becoming less effective, vaccines are still not available, and diagnosis needs to be improved. Vector control has been responsible for a decrease of diseases in endemic …

Osmr Signaling Induces Tamp-Specific Bbb Dysfunction Following Autoimmune-Mediated Neutrophil Recruitment, Travis Scott Wertz

Boise State University Theses and Dissertations

Integrity of the brain microvessels that form the blood-brain barrier (BBB) is maintained through fine-tuned regulation of endothelial tight junction proteins, chiefly represented by claudin 5 and the tight junction-associated MARVEL protein (TAMP) occludin. Under proinflammatory conditions in autoimmune-mediated multiple sclerosis (MS), autoreactive effector T cells are activated in white matter regions of the brain and spinal cord and release cytokines to recruit circulating neutrophils that, in turn, release neurotoxic substances. Lack of tight junctions in peripheral blood vessels allows neutrophils to exit blood vessels unhindered, but BBB tight junctions must first be downregulated before neutrophils can transmigrate into the …

Uncovering A Myc-Driven Tumor-Suppressive Program In Proliferating Lymphocytes, Elena Tonc

Arts & Sciences Electronic Theses and Dissertations

Rapid cell proliferation is a hallmark feature of adaptive immune cells lymphocytes. It is essential for the establishment of diverse antigen receptor repertoires and amplification of antigen-specific immune responses. While such proliferation is beneficial for host protection from infections and cancers, it inevitably elevates the risk of oncogenic transformation. In developing and germinal center B lymphocytes, the risk is further increased by endogenous, genomic insults due to antigen receptor rearrangements and somatic mutations, with which expression of the proto-oncogene c-MYC is closely associated. Nonetheless, frequencies of cancers originated from B lymphocytes are relatively low, suggesting that they are protected from …

Characterization Of Metabolic Gene Expression In The Raw 264.7 Monocyte Cell Line, Lauren Macaisa

PANDION: The Osprey Journal of Research and Ideas

Immune cells undergo changes in gene expression and metabolism when activated by a foreign molecule. Although the changes are short-lived in response to an acute infection, they persist in disorders with underlying chronic inflammation. To understand how changes in gene expression relate to changes in metabolism, the expression of metabolic transporter proteins, was analyzed in response to chronic inflammation in a mouse monocyte cell line. Specifically, Glucose Transporter-1 (GLUT1), Monocarboxylate Transporter-1 (MCT1), Monocarboxylate Transporter-4 (MCT4), and Glutamate Aspartate Transporter (GLAST) were analyzed, and it was hypothesized that all the transporters would increase in expression in response to a prolonged inflammatory …

The Regulation Of Pannexin1 And Pannexin2 In The Skin In Health And Disease, Rafael E. Sanchez Pupo

Electronic Thesis and Dissertation Repository

Pannexins (PANX1, 2, 3) are a family of channel-forming glycoproteins that mediate intracellular and paracrine signaling. In contrast to PANX2, PANX1 has been extensively investigated in the skin, modulating cell differentiation, wound healing, and melanoma development. PANX1 and PANX2 can co-exist in the same cell and form mixed channels where their glycosylation seems to regulate their intermixing. N-glycosylation and caspase cleavage have been proposed as modulators of the function of PANX1, but their effects on PANX2 are unknown. We explored the PANX2 expression in mouse skin and showed that a Panx2 splice variant (PANX2-202) is continuously expressed throughout aging skin. …

Deciphering The Perpetual Fight Between Virus And Host: Utilizing Bioinformatics To Elucidate The Host's Genetic Mechanisms That Influence Jc Polyomavirus Infection, Michael P. Wilczek

Electronic Theses and Dissertations

JC polyomavirus (JCPyV) is a human-specific pathogen that infects 50-80% of the population, and can cause a deadly, demyelinating disease, known as progressive multifocal leukoencephalopathy (PML). In most of the population, JCPyV persistently infects the kidneys but during immunosuppression, it can reactivate and spread to the central nervous system (CNS), causing PML. In the CNS, JCPyV targets two cell types, astrocytes, and oligodendrocytes. Due to the hallmark pathology of oligodendrocyte lysis observed in disease, oligodendrocytes were thought to be the main cell type involved during JCPyV infection. However, recent evidence suggests that astrocytes are targeted by the virus and act …

Nucleotide P2y₂ Receptor-Dependent Leukocyte-Endothelial Interaction, Spencer E. Thomas

MSU Graduate Theses

Extracellular nucleotides (ATP, UTP) released from cells act on nucleotide receptors to promote vascular inflammation. Increased leukocyte-endothelial interaction is a hallmark of vascular inflammation. The nucleotide P2Y₂ receptor (P2Y₂R), activated by extracellular ATP≈UTP, plays a role in cardiovascular homeostasis and immune regulation. Moreover, accumulating evidence from studies in vitro and in vivo models have implicated the P2Y₂R in the inflammatory response significantly contributing to the progression and pathogenesis of asthma, atherosclerosis, sepsis, and ischemia. I hypothesized that P2Y₂R activation by UTP, an agonist of the receptor, increased leukocyte rolling and adhesion in the microvasculature from baseline. To test the hypothesis, …

Bcr Affinity Influences T-B Interactions And B Cell Development In Secondary Lymphoid Organs, Alec J. Wishnie, Tzippora Chwat-Edelstein, Mary Attaway, Bao Q. Vuong

Publications and Research

B cells produce high-affinity immunoglobulins (Igs), or antibodies, to eliminate foreign pathogens. Mature, naïve B cells expressing an antigen-specific cell surface Ig, or B cell receptor (BCR), are directed toward either an extrafollicular (EF) or germinal center (GC) response upon antigen binding. B cell interactions with CD4+ pre-T follicular helper (pre- Tfh) cells at the T-B border and effector Tfh cells in the B cell follicle and GC control B cell development in response to antigen. Here, we review recent studies demonstrating the role of B cell receptor (BCR) affinity in modulating T-B interactions and the subsequent differentiation of B …

Host-Parasite Interactions Within Food Webs, Adam Zvanut Hasik

Graduate Theses and Dissertations

Parasitism is one of the most common life history strategies employed in nature, yet the effects of parasites are often thought to be minimal, and the vast majority of studies fail to consider parasites and their effects on host organisms. This is likely a problem, as the magnitude of parasite-mediated effects on their hosts can be quite large. Additionally, the effects of parasites are known to extend beyond the host to affect other species interactions. I used a series of approaches to gain a more integral understanding of host-parasite interactions by studying (1) the effects of parasites on biotic interactions …

Immunological And Hematological Outcomes Following Protracted Low Dose/Low Dose Rate Ionizing Radiation And Simulated Microgravity, Amber M. Paul, Eliah G. Overbey, Willian A. Da Silveira, Nathaniel Szewczyk, Nina C. Nishiyama, Michael J. Pecaut, Sulekha Anand, Jonathan M. Galazka, Xiao Wen Mao

Publications

Using a ground-based model to simulate spaceflight [21-days of single-housed, hindlimb unloading (HLU) combined with continuous low-dose gamma irradiation (LDR, total dose of 0.04 Gy)], an in-depth survey of the immune and hematological systems of mice at 7-days post-exposure was performed. Collected blood was profiled with a hematology analyzer and spleens were analyzed by whole transcriptome shotgun sequencing (RNA-sequencing). The results revealed negligible differences in immune differentials. However, hematological system analyses of whole blood indicated large disparities in red blood cell differentials and morphology, suggestive of anemia. Murine Reactome networks indicated majority of spleen cells displayed differentially expressed genes (DEG) …

Identifying The Cell Composition And Clonal Diversity Of Supratentorial Ependymoma Using Single Cell Rna-Sequencing, James He

University Scholar Projects

Ependymoma is a primary solid tumor of the central nervous system. Supratentorial ependymoma (ST-EPN), a subtype of ependymomas, is driven by an oncogenic fusion between the ZFTA and RELA genes in 70% of cases. We introduced this fusion into neural progenitor cells of mice embryos via in utero electroporation of a non-viral binary piggyBac transposon system containing ZFTA-RELA. From preliminary data in the LoTurco lab, inducing the expression of ZFTA-RELA into different neural progenitor cells produces tumors of varying lethality and cellular composition. To define the cellular composition and subclonal diversity of ST-EPN tumors, we used single cell RNA-sequencing to …

A High-Throughput Approach To Characterizing Arv1 On The Regulation Of Lipid Homeostasis Uncovers A Novel Interaction With Epidermal Growth Factor Receptor, Nicholas Anthony Wachowski

Graduate School of Biomedical Sciences Theses and Dissertations

Acyl-CoA cholesterol acyl transferase related enzyme-2 required for viability 1 (ARV1) was first recognized in Saccharomyces cerevisiae in a study done in 2000 by Tinkelenberg et al. In yeast, the deletion of ARV1 results in numerous defects including abnormal sterol trafficking [1], the reduction of sphingolipid metabolism [2], synthesis of glycosylphosphatidylinositol (GPI) anchor [3], ER stress [4], and hypersensitivity of fatty acids leading to lipoapoptosis [5]. Arv1 germline deletion in mice displayed a lean phenotype with increased energy [6]. In humans, ARV1 mutations lead to epileptic encephalopathy [7].

Non-alcoholic fatty liver disease (NAFLD) consists of simple steatosis to non-alcoholic steatohepatitis …

Establishing And Validating Methods To Assess The Influence Of Exercise On Circulating Exosome Profiles In Sedentary Older Adults, Heather Quiriarte

LSU Master's Theses

Aging is associated with progressing cellular structural and functional changes, and sedentary behavior can exacerbate these hallmarks of aging. Routine exercise is known to have beneficial effects on physiological systems, but the exact molecular mechanisms behind the health benefits are unclear. Emerging evidence suggests extracellular vesicles called exosomes are involved in the intercommunication between cells and organs following exercise by delivering their cargo such as proteins and miRNAs. miRNA profiles in older adults following acute and chronic exercise need further exploration. Specifically, the effects of regular low-intensity physical activity (LPA) breaks in sedentary time on proteins and miRNA packaged in …

Insights Into Leptopilina Spp. Immune-Suppressive Strategies Using Mixed-Omics And Molecular Approaches, Brian Wey

Dissertations, Theses, and Capstone Projects

Host-parasite interactions influence the biology of each over the course of evolution. Parasite success allows for the passage of potent virulence strategies from generation to generation. Host success passes stronger immunity and resistance strategies to the following generations as well. Only by studying both partners within their natural contexts can we begin to understand the relationship between the two and how immune mechanisms and virulence strategies interact as a molecular arms race.

In this work, we focus on a natural host-parasite pair, the Drosophila-Leptopilina model. Leptopilina species are parasites of several fruit fly species, including Drosophila melanogaster. This model …

Homeostatic T Cell Receptor Interactions With Self-Peptide Tune Cd4+ T Cell Function, Juliet Marie Bartleson

Arts & Sciences Electronic Theses and Dissertations

Homeostatic T Cell Receptor Interactions with Self-Peptide Tune CD4+ T Cell Function

by

Juliet Marie Bartleson

Doctor of Philosophy in Biology and Biomedical Sciences

Immunology

Washington University in St. Louis, 2021

Professor Paul M. Allen, Chair

Mature CD4+ T cells circulate throughout peripheral secondary lymphoid organs using their T cell receptor (TCR) to surveil peptide presented on major histocompatibility complex class II molecules (pMHC) in search of cognate, antigenic peptide. In the absence of an immune challenge, however, the TCR is continuously interacting with self-pMHC, which induces a relatively weak TCR signal known as tonic signaling. These homeostatic TCR:self-pMHC interactions …

An Investigation Of The Role Of Basigin-Variant-1 In The Immune Response Within The Retina, Abigail D. Tompa

UNF Graduate Theses and Dissertations

The neural retina is considered an immune privileged area, in that the eye attempts to suppress the inflammatory response to preserve vision. If there is damage to the blood-retina barrier, such as in diabetes or macular degeneration, it is possible for monocytes to travel out of the blood vessels and into the retina. While studying retinoblastoma, a research group determined that the protein, Basigin, through its extracellular domain, elicits an immune response by enhancing transcription of the pro-inflammatory cytokine interleukin-6 (IL-6). Basigin is cell adhesion molecule that belongs to the immunoglobulin superfamily. The Basigin gene has two main transcripts, that …

Human Regulatory T Cells Control Inflammation From Effector T Cells In Prediabetes, Rui Liu

Theses and Dissertations--Pharmacy

Type 2 diabetes (T2D) is a chronic low-grade inflammatory disease. A T cell cytokine profile (Th17) from PBMCs can distinguish obese T2D from obese non-diabetes subjects. Individual T cell subsets interact with each other and the diverse subsets jointly determine overall inflammation. Cellular metabolism drives cytokine production of CD4⁺ T cells, and therefore contributes to inflammation in T2D. However, specific changes in metabolism and function of CD4⁺ T cells during the progression from lean healthy to obese and diabetic stages in people have not been clarified.

We hypothesize that human regulatory T cells (Treg) impact metabolism of effector …

Tetraspanins As Potential Therapeutic Candidates For Targeting Flaviviruses, Waqas Ahmed, Girish Neelakanta, Hameeda Sultana

Biological Sciences Faculty Publications

Tetraspanin family of proteins participates in numerous fundamental signaling pathways involved in viral transmission, virus-specific immunity, and virus-mediated vesicular trafficking. Studies in the identification of novel therapeutic candidates and strategies to target West Nile virus, dengue and Zika viruses are highly warranted due to the failure in development of vaccines. Recent evidences have shown that the widely distributed tetraspanin proteins may provide a platform for the development of novel therapeutic approaches. In this review, we discuss the diversified and important functions of tetraspanins in exosome/extracellular vesicle biology, virus-host interactions, virus-mediated vesicular trafficking, modulation of immune mechanism(s), and their possible role(s) …

Investigating The Antitumor Effects Of A Dsrna-Nanoparticle Complex In An In Vitro Ovarian Cancer Model, Aaron Lewis

Theses and Dissertations (Comprehensive)

An estimated 1 in 70 women will be diagnosed with ovarian cancer in their lifetime. Despite advanced detection and treatment methods, it remains a silent killer with an expected survival rate of 50%. A developing method in cancer treatment is the use of compounds that stimulate the immune system to aid in the body's fight against the disease. This project focused on the use of the potent immune stimulant double-stranded RNA (dsRNA), commercially available as polyinosinic:polycytidylic acid, poly(I:C), to induce cytotoxicity in two ovarian cancer cell lines; SKOV-3 and OVCAR-3. Some challenges exist with the delivery of dsRNA due to …

Tick Extracellular Vesicles Enable Arthropod Feeding And Promote Distinct Outcomes Of Bacterial Infection, Adela S. Oliva Chávez, Xiaowei Wang, Liron Marnin, Nathan K. Archer, Holly L. Hammond, Erin E. Mcclure Carroll, Dana K. Shaw, Brenden G. Tully, Amanda D. Buskirk, Shelby L. Ford, L. Rainer Butler, Preeti Shahi, Kateryna Morozova, Cristina C. Clement, Lauren Lawres, Anya J. O'Neal, Choukri Ben Mamoun, Kathleen L. Mason, Brandi E. Hobbs, Glen A. Scoles, Eileen M. Barry, Daniel E. Sonenshine, Utpal Pal, Jesus G. Valenzuela, Marcelo B. Sztein, Marcela F. Pasetti, Michael L. Levin, Michail Kotsyfakis, Steven M. Jay, Jason F. Huntley, Lloyd S. Miller, Laura Santambrogio, Joao H.F. Pedra

Biological Sciences Faculty Publications

Extracellular vesicles are thought to facilitate pathogen transmission from arthropods to humans and other animals. Here, we reveal that pathogen spreading from arthropods to the mammalian host is multifaceted. Extracellular vesicles from Ixodes scapularis enable tick feeding and promote infection of the mildly virulent rickettsial agent Anaplasma phagocytophilum through the SNARE proteins Vamp33 and Synaptobrevin 2 and dendritic epidermal T cells. However, extracellular vesicles from the tick Dermacentor andersoni mitigate microbial spreading caused by the lethal pathogen Francisella tularensis. Collectively, we establish that tick extracellular vesicles foster distinct outcomes of bacterial infection and assist in vector feeding by acting …