Despite the development of effective COVID-19 vaccines, countries with high rates of HIV infection still have limited vaccine access and inadequate access to antiretroviral medications essential for controlling HIV. Studying COVID-19 vaccination in people living with HIV (PLWH) is needed to improve vaccination strategies in immunosuppressed populations. Previously, in pigtail macaques (PTM) we showed that COVID-19 repRNA vaccination elicits durable and protective immunity against SARS-CoV-2 infection. Here we utilized the simian immunodeficiency virus (SIV)-infected PTM model of HIV/AIDS to test the hypothesis that COVID-19 repRNA vaccination is less durable during immunosuppression. Nine PTM were enrolled into the SIV naive (n=4) and experimental SIV-infected (n=5) cohorts. SIV-infected PTM were infected with 10,000 units of SIVmac293M seven weeks prior to the first vaccination. All PTM were given 2-4 COVID-19 repRNA immunizations, encoding the SARS-CoV-2 WA.1 Spike protein, to reach maximal immunogenicity and monitored for 26 weeks for vaccine durability. Vaccine recall was evaluated by administering a booster immunization after immunity responses waned. Blood and bronchoalveolar lavage samples were collected every 2-4 weeks. SIV-infected animals were monitored for SIV disease progression, including measuring CD4 counts in peripheral blood. Enzyme-linked immunosorbent assays (ELISAs) were used to quantify longitudinal Spike-specific binding IgG antibodies. Preliminary data shows that COVID-19 repRNA vaccination elicited robust anti-Spike IgG antibodies in both PTM groups, with diminished responses in some animals within the SIV-infected group.  Anti-SARS-CoV-2 neutralizing antibodies were also generated in both groups and interestingly, more durable in SIV-infected animals. Ongoing analysis includes evaluation of IgM and IgA binding antibodies. Collectively, this study suggests SIV-associated immunosuppression impacts vaccine-induced humoral memory, which could, in turn, impact long-term protection from COVID-19. These findings are crucial for improving vaccine regimens for PLWH and other immunosuppressed individuals.

The King County Brightwater Treatment Plant includes a marine outfall pipe anchored to the seafloor that discharges highly treated effluent from the Seattle metropolitan area into Puget Sound, Washington. Since 2009, as part of an eelgrass survey study, King County biologists have collected annual video footage of the outfall pipes from which they witnessed the abundance of organisms colonizing the pipe at all depths. Consequently, in 2012, King County biologists launched a ten-year project assessing the effectiveness of the high-density polyethylene (HDPE) outfall pipe at providing habitat for marine organisms and the composition of organisms it houses. Using a  remotely operated vehicle (ROV), they placed thirty plates of HDPE material adjacent to the outfall pipe at 100ft, 300ft and 600ft depths. Sets of replicate plates were then retrieved after 2, 5, and 10 years of deployment, at which time King County staff immediately took photos of each plate for analytical assessment. In this study, we analyzed the photos for percent live cover and composition of marine organisms inhabiting the pipe material, all across depths and time intervals. We hypothesized that the wastewater outfall pipe can function as a habitat; and the extent to which different organisms, their identifications and abundance, likely vary by depths due to the environmental conditions at different levels of depths. We found that percent live cover increased over time but did not vary across depths, and that certain phyla consistently dominated cover on the plates but dominant groups varied across depths. These findings allow experts in the field to consider using outfall pipes to provide additional habitats for marine organisms, and to assess communities of organisms at depths that are less accessible. 

Seattle’s housing crisis has been a central issue in local politics as it has intensified over the past decade. Stringent zoning restrictions, rising construction costs, and a rapidly growing, high-income workforce have worsened the housing crisis, making challenges evident to many Seattle residents. A key player is Amazon, whose presence and expansion in the heart of Seattle have spurred opportunities while simultaneously worsening challenges. Although Amazon initially maintained a distance from political involvement, its opposition to the 2018 Head Tax—designed to fund affordable housing—marked a pivotal shift in its civic engagement. After successfully lobbying to repeal the tax and attempting to influence City Council elections, Amazon faced public backlash, prompting a strategic pivot toward philanthropy. My research question is: How has Amazon’s response to political and regulatory pressures influenced its philanthropic approach through the Housing Equity Fund? This paper examines Amazon’s Housing Equity Fund, a $2 billion initiative to finance affordable housing in Seattle, Washington D.C., and Nashville. I analyzed local and national media coverage and interviewed community stakeholders—including academics, housing nonprofit professionals, and developers connected to Amazon. The findings suggest that while Amazon’s Housing Equity Fund offers essential capital for housing development, its structure excludes the lowest-income populations most affected by Seattle’s affordability crisis—those who would have benefited from the 2018 Head Tax Amazon opposed. Moreover, the initiative allows Amazon to represent itself as a responsible neighbor while continuing to resist direct taxation and government-led housing solutions. Ultimately, I highlight the implications of private sector influence in public affairs, raising questions about accountability and the repercussions of corporate involvement in societal issues.

In Escherichia coli, the Cpx system is understood to be a two-component cell envelope stress response system. In Pseudomonas aeruginosa however, the Cpx system is largely unstudied. Based on predictive modeling, the Cpx two-component system in P. aeruginosa is thought to involve interactions with two novel accessory proteins, PA3203 and PA3207. Previous genetic analysis in our lab has indicated that PA3207 acts as a negative regulator of Cpx signaling, while PA3203 promotes activity of the system. I evaluated biochemical interactions between these two proteins using the Bacterial Two-Hybrid assay. I generated N- and C-terminal fusions to two functional domains (T18 and T25) of an adenylate cyclase enzymatic reporter. Adenylate cyclase activity, occurring when T18 and T25 were brought into proximity by fusion protein interactions, was measured by a qualitative color assay on MacConkey agar. By this method, I confirmed functional interactions between PA3207 and cytoplasmic signaling domains of both CpxS and CpxR. Interactions between PA3203 and CpxSR were also detected, but were more dependent on the orientation of protein fusions. These findings indicate that CpxSR signaling is regulated through protein-protein interactions with multiple accessory proteins, a unique mechanism among bacterial two-component systems.

Diabetes is characterized by hyperglycemia, which is exacerbated by the inappropriate storage and mobilization of hepatic glycogen. Incretin drugs, specifically GIP and GLP1 agonists, have been clinically successful. In the islet, GIP stimulates insulin and glucagon, while GLP1 stimulates insulin and inhibits glucagon production. Incretin receptors are not in the liver, suggesting that any effect of incretins on liver metabolism is through indirect islet hormone effects. Preclinical studies show the benefits of increasing hepatic glycogen storage in diabetes models, yet no drugs currently target this important source of carbohydrate metabolism. Therefore, my study aims to investigate how incretin drugs interact with hepatic glycogen stores to modulate islet hormone action. I hypothesized that increased hepatic glycogen will amplify islet hormone action and GIPR agonism will increase glycogen metabolism, while GLP1R agonism will have little effect on hepatic glycogen. I used hepatocyte-specific AAVs to overexpress the PPP1r3b protein in mice (PPP1r3bOE), resulting in a significant increase in hepatic glycogen compared to the control. Post-incretin injection (GIPR agonist, D-Ala2-GIP or GLP1R agonist, Ex4), I measured blood glucose and collected plasma to quantify circulating insulin and glucagon by ELISA. I collected liver to measure glycogen by glucose oxidase reaction and glycogen signaling intermediates by western blot. My results have indicated that GIP is less effective at glucose lowering in PPP1r3bOE compared to controls, while there is no effect on GLP1R-mediated glucose-lowering. This supports that elevated hepatic glycogen is likely altering glucagon action in response to GIP, with no effect on GLP1 action. I am currently analyzing plasma insulin and glucagon and will be assessing post-receptor insulin and glucagon signaling in the liver in response to GIP. This study will provide a better understanding of hepatic glycogen regulation, and offer an opportunity to investigate how incretin action can be optimized as a diabetes treatment.

The lung microbiome plays an important role in immunity where any shifts within the microbial community can affect the immune response. Tropheryma whipplei, a bacterium that causes Whipple’s disease primarily in the human gastrointestinal tract, can also reside in the human lung microbiome of both healthy and immunocompromised individuals. Tropheryma is more commonly found in lungs of individuals with pneumonia, those who smoke, or in people living with HIV. Tropheryma is also found in the lung microbiome of certain non-human primate species, where the dominance of Tropheryma is associated with shifts in pulmonary immune cells. Similarly, we found that Tropheryma is highly prevalent and dominant in the pigtail macaque (PTM) lung. However, little is known regarding the factors contributing to the establishment and dominance of Tropheryma in the non-human primate lung. Here, we test the hypothesis that Tropheryma dominance and microbial diversity (beta diversity indexes) in the PTM lung are similar in co-housed animals. Bronchoalveolar lavage (BAL) and housing metadata were collected from PTM (n = 50). Genomic DNA was extracted using the QIAgen PowerFecal Pro DNA kit and the V3-V4 region of the 16S rRNA subunit was amplified and sequenced. The QIIME2 bioinformatics platform was used to evaluate the composition of the lung microbiome and to determine the dominance index and the beta diversity of the sample set. Expected findings will show similar lung microbial compositions across co-housed animals. Results from this study will help us determine the specific environmental factors contributing to the emergence and colonization of Tropheryma in the lung microbiome of PTM. This will lay the groundwork for further research into the role of Tropheryma in the immune response against respiratory diseases, ultimately guiding the development of targeted therapies for lung infection.

The King County Brightwater Treatment Plant includes two twin outfall pipes that were installed in 2012, and discharge approximately 36 million gallons of highly treated effluent into Puget Sound daily. After observing colonization of the pipes by marine organisms, King County biologists launched a ten-year study examining the impact of effluent discharge on motile and sessile species on and near the outfall over time. They placed plates of the pipe material, high-density polyethylene (HDPE), on the seafloor, with replicates near the effluent discharge diffusers and approximately 300 ft away. King County retrieved the replicate plates after 2, 5, and 10 years and, photographed each plate for subsequent image analysis. In this study, we analyzed the photos to investigate whether there was a measurable effect of effluent discharge on the abundance, identity, and size of organisms colonizing the plates. We concluded that effluent discharge likely does not affect percent live cover, number of taxa, or the identities of taxa present. However, some motile species may be more abundant in the absence of effluent discharge, and there may be some effect of effluent on the size of some species. These abundance and size differences are worth further investigation as they may indicate that, although highly treated, effluent discharge from the Brightwater Treatment Plant impacts some species' demographic rates, like survival and growth rates, and the water quality of the Puget Sound. Our results indicate that even highly treated effluent impacts the surrounding water and the species that depend on it and that further research is needed to fully investigate the impacts of wastewater discharge in the Puget Sound ecosystem.

In the face of global climate change, there is growing interest in growing seaweed and sinking it to depths to remove carbon dioxide. However, quantifying the carbon sequestration potential of such ventures is challenging. One key consideration is that rising seawater temperatures may increase the rate of kelp decomposition, thereby reducing the export of carbon-containing tissue to the seafloor. To assess whether blades of the bull kelp Nereocystis luetkeana decompose more rapidly in warmer water, twelve 35 mm-diameter tissue disks were allowed to decay at 10-12 °C (ambient temperature treatment) and another 12 tissue disks were allowed to decay at 17-19 °C (elevated temperature treatment). After 7 days, the mean change in disk mass for the ambient temperature treatment was compared to the mean change in mass for the elevated temperature treatment. Samples at elevated temperatures were visibly flimsier and more diaphanous, which was correlated with a significantly greater decrease in weight. In tandem with other studies, this finding suggests that brown algae may decompose more rapidly at elevated temperatures, which has important implications for how to maximize future macroalgal carbon sequestration as ocean temperatures rise.

Individuals with diabetes experience a unique set of challenges as metabolic disease impairs the proper regulation of glucose homeostasis. Glycogen stores in the liver are mobilized in response to islet hormones, insulin and glucagon, to address changes in circulating blood glucose levels. Individuals with diabetes are known to have lower hepatic glycogen levels and repairing these levels in preclinical mouse models of metabolic disease improves the diabetic state, suggesting hepatic glycogen storage may be a rational therapeutic target. With the use of a mouse model of increased hepatic glycogen by overexpression of a protein called Ppp1r3b ( Ppp1r3bhepOE), I explored the hypothesis that increasing hepatic glycogen levels affects the hormonal response and hepatic post-receptor signaling in response to nutrient feeding. Using oral gavage mixed-nutrient meals (consisting of varying glucose and/or alanine), I monitored plasma glucose and hormone levels from mice under different feeding conditions. I collected blood glucose and plasma samples from the tail vein and used ELISA to quantify circulating insulin and glucagon levels. In comparison to a control AAV group, the Ppp1r3b OE mice showed significantly elevated glycogen levels and following an overnight fast increased blood glucose levels. Furthermore, after conducting a 5 hour fast, the Ppp1r3b OE group had lower insulin levels without changes in glucose, signifying increased insulin sensitivity.  Yet, after an insulin tolerance test, Ppp1r3bhepOE mice did not decrease blood glucose to the same extent as controls, perhaps due to increased liver-derived glucose output. Lastly, to measure post-receptor signaling I administered either insulin or glucagon to control and Ppp1r3bhepOE mice and measured the glycemic response and activation of relevant hepatic signaling intermediates. My preliminary evidence reveals the importance of hepatic glycogen in energy metabolism and lays the foundation for future studies investigating how the alteration of glycogen storage could optimize energy expenditure in metabolic disease.