Immunology and Infectious Disease Commons^™

Immunomodulatory Effects Of Resolvin D2 In A Model Of Infection, Prem Yugandhar Kadiyam Sundarasivarao

Graduate School of Biomedical Sciences Theses and Dissertations

Dysregulated hyperinflammatory host immune response to underlying bacterial infections is a characteristic of sepsis. In sepsis, bacteria often trigger abnormal hyperinflammatory responses which can cause multiple organ failure and if sustained can lead to an immunosuppressive phase where the host is susceptible to secondary infections caused by opportunistic bacteria like Pseudomonas aeruginosa (P. aeruginosa). In our studies, we used a 2-hit model of cecal ligation and puncture (CLP) followed by P. aeruginosa secondary lung infection to investigate cellular and molecular mechanisms in the beneficial action of resolvin D2 (RvD2). Resolvins of the D-series are a group of fatty acids known …

The Effects Of Specialized Pro-Resolving Mediator Lipoxin A4 On Pseudomonas Aeruginosa Biofilms And Interactions With Monocytes, Julianne M. Thornton

Graduate School of Biomedical Sciences Theses and Dissertations

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen known as a major cause of hospital-acquired secondary infections, commonly causing chronic respiratory infections in immunocompromised individuals, especially those with cystic fibrosis, and often found in wound infections. P. aeruginosa uses the quorum sensing pathway to readily form protective biofilms, which reduce the efficacy of antibiotics and access by host immune cells to eradicate the pathogen. Specialized pro-resolving mediators (SPMs) are lipids endogenously produced by the host immune response to infection to aid in infection resolution. One SPM, Lipoxin A4 (LxA4), has been shown to be a robust quorum sensing inhibitor.

The …

Investigating The Antibacterial And Immunomodulatory Properties Of Lactobacillus Acidophilus Postbiotics, Rachael M. Wilson

Graduate School of Biomedical Sciences Theses and Dissertations

Probiotics are nonpathogenic microorganisms that have been extensively studied for their ability to prevent various infectious, gastrointestinal, and autoimmune diseases. The mechanisms underlying these probiotic effects have not been elucidated. However, we and other researchers have evidence suggesting that probiotic bacteria secrete metabolites that are antimicrobial and anti-inflammatory. As such, we developed a methodology to collect the secreted metabolites from a probiotic bacterium, Lactobacillus acidophilus, and tested this cell free filtrate (CFF) both in vitro and in vivo. Using this CFF, we have demonstrated that L. acidophilus secretes a molecule(s) that has specific bactericidal activity against the opportunistic pathogen, Pseudomonas …

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 …

The Autoimmune System: The Effect Of Physiological Stressors On Autoantibody Glycosylation And Fidelity Of Autoantibody Profiles, Rahil Kheirkhah

Graduate School of Biomedical Sciences Theses and Dissertations

The presence of thousands of autoantibodies (aABs) in the human sera is typical, and therefore it is possible to identify an aAB profile for each individual. In the first part of this thesis, we will show the cerebrospinal fluid also exhibits an extraordinarily complex immunoglobulin G aAB profile that is composed of thousands of aABs. We show that the pattern of expression of individual aABs in CSF closely mimics that in the blood, indicative of a blood-based origin for CSF aABs. In addition, using longitudinal serum samples obtained over a span of nine years, we show remarkable stability in aAB …

Natural Autoantibodies: Origin, Function And Utility For Diagnosis Of Disease, Abhirup Sarkar

Graduate School of Biomedical Sciences Theses and Dissertations

Autoantibodies (aAbs) by the simplest definitions have been described as antibodies against self-antigens and were exclusively associated with autoimmune diseases. Eventually, studies demonstrated that they are abundant in the blood of all human sera, regardless of age, gender, or the presence or absence of disease, and were thus named as ‘natural autoantibodies’. The underlying reason for their ubiquity has remained elusive, but we have hypothesized that they are responsible for clearing blood-borne cell and tissue debris generated under conditions of health and disease. To test this, we chose to use two widely different disease model systems, namely neurodegenerative diseases and …

A High Throughput Assay For The Detection Of Stimulator Of Interferon Genes (Sting) Agonists, Michael J. Ingling

Graduate School of Biomedical Sciences Theses and Dissertations

The innate immune system includes a menagerie of different cell types, each with a different role in the process of monitoring the body for invaders and presenting gathered debris (antigen) to the adaptive immune system. Somatic cells have intracellular receptors for the same purpose. Cancer cells, however, have avoided these methods of detection despite, in many cases, the tumor’s immunogenic traits. Immuno-oncology is a field dedicated to the immunological traits of tumors, more recently finding ways of instigating an immune response against tumors. In this regard, STING, a receptor of cyclic dinucleotides (CDN), has come to the forefront of immuno-oncology. …

Development Of Cellular Assays To Monitor Enzymatic And Biological Activity Of Cd73: A Key Modulator Of Anti-Tumor Immune Response, Alexandra Fanuka

Graduate School of Biomedical Sciences Theses and Dissertations

Ecto-5’-nucleotidase, known as CD73, is an extracellular enzyme that converts adenosine monophosphate (AMP) to adenosine and has recently been identified as a potential drug target for cancer immunotherapy. Its immunosuppressive effects, mediated by the activity of adenosine, are associated with higher rates of tumor invasion and metastasis, as well as poorer prognoses overall in many cancer types. CD73 is often co-expressed with ectonucleoside triphosphate diphosphohydrolase-1 (CD39), which catalyzes the conversion of adenosine triphosphate (ATP) to adenosine diphosphate (ADP), and ADP to AMP on the surface of tumor cells. Dual expression further propagates immunosuppressive effects of adenosine in the tumor microenvironment. …

Structural And Functional Interactions Between Bro1 Domain Of Human Alix Protein And Nucleocapsid Packaging Rna Complex From Hiv, Scott Gross

Graduate School of Biomedical Sciences Theses and Dissertations

A virus is only as powerful as its ability to spread. Enveloped retroviruses, namely HIV-1, use exocytosis pathways that normal host cells use to release particles from the plasma membrane. The main pathways of interest in this study are the Endosomal Sorting Complex Required for Transport (ESCRT) and adjacent ALIX pathways. The ESCRT pathway is especially important for degradation of receptor/cargo complexes that form Multi-Vesicular Bodies (MVBs). Currently, there is no known therapy that targets this endosomal pathway, which would prevent the spread of the virus to other cells. The virus has adapted to jump from pathway to pathway when …