Immunology and Infectious Disease Commons^™

Insights To Protein Pathogenicity From The Lens Of Protein Evolution, Janelle Nunez-Castilla

FIU Electronic Theses and Dissertations

As protein sequences evolve, differences in selective constraints may lead to outcomes ranging from sequence conservation to structural and functional divergence. Evolutionary protein family analysis can illuminate which protein regions are likely to diverge or remain conserved in sequence, structure, and function. Moreover, nonsynonymous mutations in pathogens may result in the emergence of protein regions that affect the behavior of pathogenic proteins within a host and host response. I aimed to gain insight on pathogenic proteins from cancer and viruses using an evolutionary perspective. First, I examined p53, a conformationally flexible, multifunctional protein mutated in ~50% of human cancers. Multifunctional …

Serpin-Derived Novel Peptide For The Treatment Against Hiv-Induced Inflammation In The Central Nervous System, Yemmy Soler

FIU Electronic Theses and Dissertations

In the brain, HIV predominantly infects microglia/macrophages and astrocytes to a lesser extent. These cells form virus reservoirs with low levels of infection that are very hard to eradicate. Even though the use of cART increases survival rate in HIV patients, the virus persists as a chronic condition. cART is not able to effectively cross the BBB, control HIV replication, or attenuate inflammation in brain reservoirs. Therefore, the virus still causes neuronal dysfunction, pain-related pathology, and ultimately HAND. In this study, we decided to test the hypothesis that a serpin-derived small peptide, SP16, can serve as an anti-viral, anti-inflammatory, pro-survival, …

Understanding Exosomal Extracellular Vesicles And Morphine In The Neuropathology Of Human Immunodeficiency Virus And Differential Zika Virus Strain-Associated Pathology, Allen Caobi

FIU Electronic Theses and Dissertations

Exosomal Extracellular Vesicles (xEVs), integral to intercellular communication and regulation of immune responses, have functional effects based on their contents, which they transport to neighboring cells. However, in the context of infection, EV cargo can be modulated, by either infected or uninfected cells. We hypothesize that CNS-associated neuropathology, is partially, due to the cargo transported by the exosomes. We theorize that the cargo released from infected cell-derived xEVs may either facilitate or inhibit viral neuropathogenicity. Here we investigated xEVs in the case of two neurotropic viruses, Zika virus (ZIKV) and Human Immunodeficiency Virus (HIV). The hallmark characteristic of ZIKV-infection is …

Energetic Cost And Physiological Trade-Offs, Heba A. Ali

FIU Electronic Theses and Dissertations

Understanding how organisms allocate limited resources across physiological systems is a major challenge in biology. This study revealed that high energetic demand of electric signals of male electric fish (Brachyhypopomus gauderio) is matched by a metabolic trade-off with other cellular functions. We used thyroxine (T4) to modulate the fish’s signal metabolism, partitioned the energy budget pharmacologically, and measured energy consumption using oxygen respirometry. In males, total energy consumption was unchanged pre- and post-T4 treatment, while signal metabolism rose and the standard metabolic rate fell in an even trade-off. Total metabolism in females did the opposite. Under T4, the …

Food Insecurity Is Associated With Nonalcoholic Fatty Liver Disease, Cognitive Impairment, And Immune Activation In People Living With Hiv, Javier A. Tamargo

FIU Electronic Theses and Dissertations

Food insecurity (FI) is a socioeconomic condition characterized by inadequate access to enough food and nutrition to sustain health and wellbeing. Food insecurity is a risk factor for chronic and age-related conditions, raising concerns for the aging population of people living with HIV (PLWH), in whom food insecurity is disproportionately prevalent. PLWH are at increased risk of nutrition-related complications and chronic co-morbidities, thus food insecurity may exacerbate adverse health outcomes in this population. This study investigated whether food insecurity was associated with nonalcoholic fatty liver disease (NAFLD), cognitive impairment, and immune activation among socioeconomically disadvantaged adults living with and without …

Deciphering The Micrornaome In Hiv Associated Lung Comorbidities, Rajib Kumar Dutta

FIU Electronic Theses and Dissertations

Chronic Respiratory diseases like chronic obstructive pulmonary disease (COPD), pulmonary hypertension, asthma, and pneumonia are emerging as significant comorbidities in people living with HIV in the combination antiretroviral therapy (cART) era. HIV is an independent risk factor for these diseases independent of tobacco smoke, and cigarette smoking exacerbates outcomes in HIV patients. Both tobacco smoke and HIV infection suppress nasal mucociliary clearance (MCC) as well as bronchial MCC, a primary innate defense mechanism in the airway. Optimal MCC depends on airway surface liquid (ASL) lining the airway epithelium that facilitates ciliary beating to clear the mucus. Attenuation of any component …

The Immunosuppressive Role Of Edn3/Ednrb Signaling In The Melanoma Microenvironment, Juliano Tiburcio De Freitas

FIU Electronic Theses and Dissertations

Endothelins are cytokines ubiquitously expressed in the microenvironment of several tumors. In melanoma is not clear whether stromal cells respond to the endothelin present in the microenvironment. To address this question, I generated tumors derived from different murine melanoma cell lines (B16F10, YUMM1.7, YUMMER1.7) in a transgenic mouse that overexpresses endothelin 3 (Edn3) by keratinocytes in the skin (K5-Edn3). Tumors from all the cell lines grew larger and were more aggressive when Edn3 was overexpressed in the skin. In tumors derived from YUMM1.7-GFP cells, very few tumorigenic cells expressed the Edn3 receptor, Endothelin receptor b (Ednrb) suggesting an …

Hiv Tat And Morphine-Induced Neurodegeneration In A Beclin 1 Hemizygous Mouse Model, Jessica A. Lapierre

FIU Electronic Theses and Dissertations

Early in infection, HIV crosses the blood-brain barrier and induces neuropathology. Viral presence in the CNS coupled with secretion of neurotoxic proteins causes neuroinflammation, glial dysfunction, excitotoxicity, and neuronal death. Despite advances in combined antiretroviral therapy, HIV-infected patients present with a spectrum of cognitive and psychomotor deficits collectively referred to as HIV-associated neurological disorders (HAND). A subset of HAND patients abuses drugs such as opiates like heroin and morphine show an exacerbation and rapid progression of HIV neuropathology; however, the mechanisms of this synergy are not well understood. Autophagy is a lysosomal degradative process which eliminates and recycles cytosolic components …

Phenomenological And Molecular Basis Of The Cnidarian Immune System, Tanya Brown

FIU Electronic Theses and Dissertations

Coral reefs are one of the most diverse ecosystems on the planet due partially to the habitat structure provided by corals. Corals are long lived organisms that can live for hundreds of years and as a result growth of many species is very slow. As a result of this, recovery of corals from disease outbreaks is very slow and difficult and therefore the ecosystem is deteriorating rapidly. Due to this increase in disease and its detrimental effect on coral reefs, it has become imperative to study how corals respond to disease outbreaks. The response of the coral to pathogens is …

Profiling Populations Using Neutral Markers, Major Histocompatibility Complex Genes And Volatile Organic Compounds As Modeled In Equus Caballus Linnaeus, Ketaki Deshpande

FIU Electronic Theses and Dissertations

Assessing the genetics of wild animal populations aims to understand selective pressures, and factors whether it be inbreeding or adaptation, that affect the genome. Although numerous techniques are available for assessing population structure, a major obstacle in studying wild populations is obtaining samples from the animals without having to capture them, which can lead to undue distress and injury. Therefore, biologists often use non-invasive sampling methods (i.e., collection of feces, hair) to extract host DNA. In this study, new DNA extraction protocols were developed that improved the quality and quantity of DNA obtained from fecal matter. Fecal samples aged up …

Regulatory Mechanisms Of Leishmania Aquaglyceroporin Aqp1, Mansi Sharma

FIU Electronic Theses and Dissertations

Pentavalent antimonials [Sb(V)] are the primary drug of choice against all forms of leishmaniasis. Emergence of antimony unresponsiveness is a major issue. There is a dire need of understanding antimony resistance mechanisms in Leishmania. One important mechanism is the down regulation of the trivalent antimony [Sb(III)] (the active form of Sb(V)) uptake system. To date, Leishmania aquaglyceroporin AQP1 is the only reported facilitator of Sb(III). Leishmania do not have promoters. They primarily regulate their genes at post-transcriptional and/or post-translational levels. We reported that mitogen activated protein kinase 2 (MPK2) positively regulated AQP1 stability through the phosphorylation of the threonine …

In Search Of Safety, Negotiating Everyday Forms Of Risk: Sex Work, Criminalization, And Hiv/Aids In The Slums Of Kampala, Serena Cruz

FIU Electronic Theses and Dissertations

This dissertation offers an in-depth descriptive account of how women manage daily risks associated with sex work, criminalization, and HIV/AIDS. Primary data collection took place within two slums in Kampala, Uganda over the course of fourteen months. The emphasis was on ethnographic methodologies involving participant observation and informal and unstructured interviewing. Insights then informed document analysis of international and national policies concerning HIV prevention and treatment strategies in the context of Uganda. The dissertation finds social networks and social capital provide the basis for community formation in the sex trade. It holds that these interpersonal processes are necessary components for …

Investigating The Driving Mechanisms Behind Differences In Bleaching And Disease Susceptibility Between Two Scleractinian Corals, Pseudodiploria Strigosa And Diploria Labyrinthiformis, Zoe A. Pratte

FIU Electronic Theses and Dissertations

Disease and bleaching are two conditions which commonly lead to coral death. Among coral species, susceptibility to disease and bleaching is variable, and Pseudodiploria strigosa tends to be diseased more than Diploria labyrinthiformis, while D. labyrinthiformis bleaches more readily. The focus of this dissertation was to investigate and compare multiple components of these two coral species, and identify how they may relate to disease and bleaching resistance. Compenetnts examined included the surface mucopolysacharide layer (SML) thickness, gene expression, microbial associates, and a white plague aquarium study. The SML thickness decresased with increasing temperature regardless of coral species, indicating that SML …

Overweight/Obesity And Hiv Disease Progression In Hiv+ Adults In Botswana, Sabrina Sales Martinez

FIU Electronic Theses and Dissertations

Studies indicate that overweight and obesity protect against HIV-disease progression in antiretroviral therapy (ART)-naïve patients. We examined retrospectively the relationship of overweight/obesity with HIV-disease progression in ART-naïve HIV+ adults in Botswana in a case-control study with 18-month follow-up, which included 217 participants, 139 with BMI 18.0-24.9 kg/m² and 78 with BMI ≥25 kg/m². Archived plasma samples were used to determine inflammatory markers: leptin and bacterial endotoxin lipopolysaccharide (LPS), and genotype single nucleotide polymorphisms (SNPs) of the Fat Mass and Obesity Associated Gene (FTO).

At baseline, BMI was inversely associated with risk for AIDS-defining conditions (HR=0.218; 95%CI=0.068, 0.701, …

Auto-Antigenic Properties Of The Spliceosome As A Molecular Tool For Diagnosing Systemic Lupus Erythematosus And Mixed Connective Tissue Disease Patients, Annia Mesa

FIU Electronic Theses and Dissertations

Systemic Lupus Erythematosus (SLE) and Mixed Connective Tissue Disease (MCTD) are chronic, autoimmune disorders that target overlapping autoantigens and exhibit similar clinical manifestations. Despite 40 years of research, a reliable biomarker capable of diagnosing these syndromes has yet to be identified. Previous studies have confirmed that components of the U1 small nuclear ribonucleoprotein complex (U1 snRNP) such as U1A are 1000 fold more autoantigenic than any other nuclear component in SLE patients. Based on these findings, I hypothesize that models derived from the U1 snRNP autoantigenic properties could distinguish SLE from MCTD patients. To test this hypothesis, 30 peptides corresponding …

Aspects Of The Innate Immune System In The Caribbean Octocoral Swiftia Exserta, Lorenzo P. Menzel

FIU Electronic Theses and Dissertations

The immune systems of cnidaria are important to study for two reasons: to gain a better understanding of the evolution of immune responses, and to provide a basis to partially redress the precipitous world-wide die-offs of reef corals, some of which have been attributed to diseases and stress. Many immune responses share ancient evolutionary origins and are common across many taxa.

Using Swiftia exserta, an azooxanthellate ahermatypic local octocoral, as a proxy model organism to study aspects of innate immunity in corals and cnidaria allows us to address both of the reasons listed above while not using endangered species. …

Regulation Of Rab5 Gtpase Activity During Pseudomonas Aeruginosa-Macrophage Interaction, Sushmita Mustafi

FIU Electronic Theses and Dissertations

Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen. Several antibiotic resistant strains of P. aeruginosa are commonly found as secondary infection in immune-compromised patients leaving significant mortality and healthcare cost. Pseudomonas aeruginosa successfully avoids the process of phagocytosis, the first line of host defense, by secreting several toxic effectors. Effectors produced from P. aeruginosa Type III secretion system are critical molecules required to disrupt mammalian cell signaling and holds particular interest to the scientists studying host-pathogen interaction. Exoenzyme S (ExoS) is a bi-functional Type III effector that ADP-ribosylates several intracellular Ras (Rat sarcoma) and Rab (Response to abscisic acid) small GTPases …