The COVID-19 pandemic, caused by Severe Acute Respiratory Syndrome Coronavirus 2, or SARS-CoV-2, has been ongoing for over two years. The virus spreads easily and is more unpredictable than well-known viruses like the flu, making it important to have reliable combative measures before we fully drop non-vaccine preventive actions, like mask-wearing.Therefore, we used computational protein modeling to investigate the interactions of three nonstructural proteins (abbreviated Nsp) encoded in the viral RNA genome– Nsp3, Nsp5, and Nsp6 – which are involved in the viral life cycle, with human P-type polyamine transporting ATPases ATP13A2 and ATP13A3, whose disease symptoms when mutated mimic certain COVID-19 complications. Understanding these interactions can help shed light on the mechanism of unexpected symptoms seen in COVID-19 and provide an avenue through which to treat infections. Additionally, papain-like protease (PLpro) and 3-chymotrypsin-like protease (3CLpro), which correspond to Nsp3 and Nsp5, respectively, are highly conserved between SARS-CoV and SARS-CoV-2 and thus make good potential drug targets due to their active sites and presumable lower ability to tolerate mutations (reducing the likelihood of treatments becoming ineffective), although the potential effects on the human proteasome would need to be further investigated. In addition, Nsp6 may help the virus evade host defenses by limiting the ability of autophagosomes to deliver viral particles to lysosomes, so limiting its interactions may increase the ability of the host cell to target its viral invader. One compound in particular, Haloperidol, showed promising results; predicted docking (via computational molecular docking software) to Nsp6 alone, as well as to Nsp6-heteroprotein complexes suggested strong binding, indicating a potential strong interaction that could impact the viral protein function and thus the viral life cycle.

The purpose of this study was to focus on whether solely obesity (measured by BMI) leads to an increased risk of COVID-19 mortality in terms of excess in-hospital deaths. As the grim milestone of one million deaths in the United States from COVID-19 was reached, one could assume the disease would continue to coexist with humanity in the long term. While vaccination continued to limit the spread of COVID-19, it was essential to investigate risk factors that may exacerbate the severity of the illness in humans. Obesity is already a global pandemic affecting 40% of Americans and over 650 million people worldwide. Obesity is connected to an entire range of clinical conditions including some of the leading causes of death worldwide making it a more generalizable statistic. Furthermore, the purpose of this study was to conduct a systemic review of major risk factors between obesity and COVID-19, and this analysis shall ascertain which factors have the most predictive value in determining mortality and severity of the condition. Ten research studies of 3,780,926 COVID-19 patient cases were included. Meta-analysis results indicate a pooled OR of 0.93 (0.71-1.23, p = 0.627) for in-hospital mortality of obese patients relative to non-obese patients when adjusted for confounders. All comorbidities associated with the development of severe disease were found to have an equal chance of leading to mortality. In other words, obesity did not lead to a statistically significant risk of dying from COVID-19.

I december 2019 i Wuhan, Kina, blev en grupp personer infekterade av det nya viruset SARS-CoV-2 som inducerade sjukdomen COVID-19. Sjukdomen påverkar lungfunktionen och studier har visat att långvarig påverkan på lungfunktionen kan förekomma. Syftet med den aktuella studien var att undersöka långvariga effekter av COVID-19 på diffusionskapaciteten i lungorna. Studier som undersökte diffusionskapaciteten, mätt med kolmonoxid (DLCO), hos patienter minst 30 dagar efter insjuknande i COVID-19 samlades in och analyserades. Resultatet visade att en stor del av deltagarna hade DLCO <80% av det förväntade värdet. Det visade även att diffusionskapaciteten kan vara nedsatt upp till sex månader efter utskrivning från sjukhus. Då COVID-19 är en ny sjukdom var den aktuella studien begränsad av antalet studier inom området. Framtida studier bör undersöka effekterna av COVID-19 på lungfunktionen under ett längre tidsspann. Slutsatsen i den här litteraturstudien var att COVID-19 påverkar diffusionskapaciteten i lungorna. Långvariga nedsättningar i diffusionskapaciteten har, än så länge, kunnat påvisas upp till sex månader efter sjukdom. Allvarligt insjuknande i COVID-19 ökar risken för långvariga DLCO -nedsättningar.

As obligatory intracellular parasites, viruses are in a constant battle with their host to establish infection. They can facilitate their propagation by modulating host immune or metabolic pathways. This modulation involves targeting various molecular factors such as microRNAs (miRNA), enzymes, or small molecules. Understanding how viruses alter the chemical makeup of a cell is crucial to identifying what pathways are being targeted, furthering our understanding of the virus life cycle, and may aid in identifying biomarkers of disease. Here, we examine host-virus interactions in the context of two viruses, hepatitis c virus (HCV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). First, the modulation of serine hydrolases by a pro-viral microRNA, miRNA-122, is investigated using activity-based protein profiling (ABPP). This study identifies a downstream target of miRNA-122 that is differentially activated during HCV infection which can be targeted pharmacologically to reduce HCV infectivity. Second, we apply similar techniques to identify serine hydrolase changes associated with SARS-CoV-2 infection. Results point towards enrichment of endocannabinoid metabolism which may offer an alternative therapeutic avenue for combating SARS-CoV-2 infection. Together, the work presented in this thesis provides avenues for further investigation into miRNA-122 interactions during HCV infection and endocannabinoid metabolism in SARS-CoV-2 infection.

Unexpected high mutations detected in new emerging variants of concern (VOCs) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), especially in the case of omicron, raises concerns and efforts to understand their evolutionary trajectory. Several hypotheses have been discussed in literature to conceptualize the source of their emergence, including intra-host viral evolution in immunocompromised patients. These patients grant opportunities for the emergence of new variants through a persisting virus winning against host immunity, and selection for viral mutations driven by treatment interventions. VOCs have in common high mutation rate exceeding the average rate of 1-2 mutations per month. Not many studies have investigated the evolutionary rate of SARS-CoV-2 in immunocompromised candidates. Therefore, the purpose of this study is to reveal potential mechanisms underlying the emergence of VOCs by exploring substitution rate of SARS-CoV-2 genomes from surveyed COVID-19 immunocompromised patient’s studies. First, SARS-CoV-2 genome sequences were collected at sequential time series throughout host infection, which were reported in the previous studies. Filtration criteria was applied to reanalyze patients with prolonged infection documented for ≥ 2 months, and comprehensive sequenced samples for ≥ 6 time points. Then, phylogenetic analysis was conducted using Nextclade (https://clades.nextstrain.org/), followed by mutation rate analysis using two substantial similar approaches to calculate the rate in i) substitutions per month and ii) substitutions per site (per year). The mutation tendency of SARS-CoV-2 in immunocompromised hosts was compared to reported VOCs, particularly to omicron. The highest observed mutation rate accounted for approximately 2.2 mutations per month, which is higher than the average rate. High mutation rate was due to prolonged infection and selection pressure by treatment interventions (i.e., convalescent plasma and antibodies). Here, higher rate of intra-host viral evolution in immunocompromised patients is detected, potentially leading to the emergence of VOC. Hence, this research highlights the need for sequencing efforts in high-risk individuals, updating treatment strategies along with further analysis on adaptive mutants pronounced due to intra-host evolution. Together, such findings provide an ultimate synergy for future public health guidelines and infection control measures.

<p>  </p> <p>Seven-membered ring structures are one of the most important structural motifs found widely in natural products and bioactive molecules. Although several [5+2]-cycloaddition reactions have been developed to construct these seven membered cores, asymmetric cycloaddition reactions are less explored. Described in Chapter-1 is a base mediated intramolecular diastereoselective [5+2]-cycloaddition reaction that afforded highly functionalized seven membered rings in good yields and excellent diastereoselectivities. The high diastereoselectivity is controlled by the alkyl stereocenter and the chain length of the alkene tether. The existing chirality of the substrate can direct the stereochemical outcome of the [5+2]-cycloaddition reaction. Furthermore, this methodology has been applied to synthesize various potent HIV-1 protease inhibitors. </p> <p>COVID-19 pandemic has profoundly affected life around the globe and costed us 6 million lives. Therefore, there is an urgent need for rational design of new drug candidates to specifically target different SARS-CoV-2 proteins. Recently, Pfizer developed an FDA-approved antiviral therapeutic agent, Paxlovid, targeting SARS-CoV-2 3CLpro. Chapter-2 discusses a concise synthetic route to synthesize active component of Paxlovid, Nirmatrelvir, in 6-steps without any epimerization. We have also developed a series of potent covalent inhibitors targeting SARS-CoV-2 3CLprotease and compared the antiviral activities of these inhibitors with that of Nirmatrelvir. </p> <p>In the final chapter, a concise partial synthesis of the segment A of (-)-Rafonin is discussed. (-)-Rasfonin is an antitumor agent that induces apoptosis in <em>ras</em>-dependent cells. We have proposed an asymmetric chiron approach to install the α-pyranone ring of rasfonin. Our goal is to perform SAR studies on this natural product by designing various analogues. </p>

All cells depend on properly folded proteins for survival and function. Misfolding of proteins results in loss of critical functions and may trigger the misfolding of other nearby proteins leading to toxic aggregation. While many proteins can fold on their own, others with complicated domain structures require assistance from protein folding machines called chaperones. The most complex and highly specialized of all chaperones is the eukaryotic chaperonin complex CCT which is necessary for the folding of a wide variety of essential proteins. These include the cytoskeletal proteins actin and tubulin as well as the Gβ subunit of the G protein heterotrimer. However, CCT activity can also drive diseases such as cancer and viral infections and could represent a high value therapeutic target if the mechanisms by which it folds its different client proteins were better understood. To this end, we identified and characterized an interaction between CCT and the RNA-dependent RNA polymerase of SARS-CoV-2, the virus responsible for the deadly global pandemic that began in 2019. We showed that SARS-CoV-2 replication is impaired by loss of CCT and that the polymerase, designated Nsp12, interacts with CCT upon synthesis and quickly releases - the hallmark pattern of a CCT substrate. Furthermore, we solved a 3.3 Å cryo-EM structure of Nsp12 bound to open CCT showing Nsp12 binding between the two rings of CCT and extending up through of the folding chambers and out of CCT. At 107 kD, Nsp12 is the largest substrate ever visualized inside of CCT and answers a long-standing question in the field of how CCT could accommodate substrates larger than its 70 kD folding chamber. Given that CCT is known to fold proteins with WD40-repeat domains, we also investigated a potential relationship between CCT and RPE65. RPE65, which contains a WD40 domain, is the retinyl ester isomerase that converts all-trans retinyl esters into 11-cis retinol, a key step in the visual cycle, and its mutation is a common cause of hereditary retinal dystrophies. We showed that CCT interacts with RPE65 and that nascent RPE65 binds and releases from CCT albeit with relatively slow kinetics. However, RPE65 is not dependent on CCT for expression or activity. This suggests that the relationship between RPE65 and CCT may represent a novel CCT function distinct from the canonical obligate substrate dynamic.

Antimicrobial resistance (AMR) threatens our modern standard of living with the potential return to a pre-antibiotic condition where deadly infections are no longer treatable. Wastewater treatment plants (WWTPs) are vital components in water sanitation infrastructure and are now also being recognized as valuable monitoring points for antibiotics, antibiotic resistant bacteria (ARB), and antibiotic resistance genes (ARGs) disposed of or excreted by human populations. Hospital waste water is of special interest as a potential focused monitoring point and in general research is needed to establish the benefits of both on-site and community-scale wastewater treatment as important barriers to the disseminators of ARGs into the environment. The research aims described herein examine these components of wastewater treatment and how they relate to AMR indicators identified through metagenomic sequencing. Through monitoring of local WWTPs, it was found that AMR indicators shifted over time and in relation to human behavior that changed due to the COVID-19 pandemic. Hospital wastewater did not measurably impact the microbiome during simulated activated sludge wastewater treatment according to broad-scale metagenomic ARG profiling; however, some clinically-relevant ARGs escaped treatment. Lastly, a study of a transect of WWTPs indicated impacts on the abundance of certain ARGs in downstream riverine receiving environments. Nonetheless, there appeared to be a number of other factors at play, and upstream and downstream resistomes tended to remain similar, calling for further research to delineate impacts of various wastewaters and treatments on ARGs in affected aquatic environments. / Doctor of Philosophy / Antimicrobial resistance (AMR) occurs when bacteria, viruses, and fungi are able to survive in the presence of antibiotics because they carry antibiotic resistance genes (ARGs) encoded in their DNA. AMR is a major public health concern as it makes it so that antibiotics are no longer effective against potentially deadly infections. Wastewater treatment plants (WWTPs) are being discovered as a hub of opportunity for monitoring potential AMR problems in a community. WWTPs receive sewage from homes and various industries. This sewage contains rich information for researchers to examine in terms of which antibiotics, bacteria, and ARGs are circulating in the community. This makes it possible to find out which antibiotics are being consumed in the community and which ARGs might be prevalent. The purpose of this research was to better understand both how WWTPs can be used as monitoring points for AMR and how they can be improved to help reduce ARGs emitted to rivers and streams where treated water is discharged. It was found that the types of ARGs prevalent in wastewater changed over time, especially during the COVID-19 pandemic as people worked from home and changed habits regarding doctors' visits, which impacted antibiotic use. Hospital sewage was studied as a useful indicator of pathogens and ARGs that are challenging a community and also the antibiotics being used. This research explored what happened to ARGs during the treatment of domestic (i.e., from people's homes) wastewater along with hospital wastewater and found that hospital wastewater introduced some ARGs that are typically found in clinical settings, but did not negatively impact the overall wastewater treatment process. Finally, the impact that WWTPs have on rivers to which treated water is discharged was explored. The results indicated that certain ARGs were elevated downstream of the WWTPs. However, when examining all ARGs together, no major shifts due to the treated wastewater were apparent.

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The COVID-19 pandemic, caused by SARS-CoV-2, has emerged as one of most significant health emergencies in recent history. SARS-CoV-2 has been characterized by the emergence of highly mutated variants that exhibit high transmissibility, virulence, and the capability of immune escape. The constantly evolving nature of the COVID-19 pandemic has underscored the necessity for a thorough comprehension of viral transmission dynamics, the effectiveness of novel monitoring techniques, and the determinants of health inequalities. This study explored several aspects of the pandemic, specifically emphasizing the emergence and dissemination of the Delta variant in Florida, the significance of environmental surveillance, and the factors associated with COVID-19 outcomes. Phylogenetic analysis using SARS-CoV-2 genome revealed that multiple independent introductions of the Delta variant fueled its spread within Florida. Further, we hypothesized that high-touch surface monitoring can be an alternative noninvasive approach to determine infection trend and detect variants. The study found high contamination rate on high-touch surfaces and the viral gene copy was positively correlated to the clinical cases in the university. Moreover, genome sequencing of environmental surface samples detected circulating and emerging variants. Additionally, spatial autocorrelation and regression analysis was conducted to investigate the relationship between county-level demographic, socioeconomic, and health-related factors and variation in COVID-19 cases, mortality, and case fatality rates. This study identified significant variations in COVID-19 outcomes across Florida counties, with factors such as age, obesity, rurality and importantly, vaccination rates playing key roles in explaining these disparities. Overall, this study emphasizes the importance of robust genomic surveillance for monitoring the emergence and spread of viral variants, the potential of environmental surface monitoring as a complementary public health tool, and the urgent need to address the underlying drivers of health disparities. These findings contribute to a more nuanced understanding of pandemic dynamics and inform data-driven strategies to mitigate the impact of future public health emergencies.