Lung-resident type 1 conventional dendritic cells (cDC1s) are critical for initiating immune responses against foreign respiratory viruses and endogenous assaults like cancer cells. Importantly, the cDCs of each tissue display unique phenotypes and functions dictated by the environment they populate. However, our understanding of the factors that regulate cDC1 development and function in the lung is minimal. The cytokines, FMS-like tyrosine kinase 3 ligand (FLT3L), and granulocyte-macrophage stimulating factor (GM-CSF) are essential for the development of tissue-resident cDC1, but in in vitro systems, these factors are insufficient to generate cDC1s with a lung-specific phenotype. RNAseq analysis of lung cDC1 identified a clear enrichment in genes associated with transforming growth factor beta (TGF-β) signaling, a factor also known to be enriched in the airspaces of the lung. TGF-β has been previously reported to maintain DC quiescence in the lung, however, our data suggested it may also play a role in differentiation and lung specification of these cells. Based on this, I hypothesized that adding TGF-β to in vitro bone marrow (BM) cultures alongside established cytokines FLT3L and GM-CSF would generate cDC1s phenotypically and functionally similar to in vivo lung cDC1s. The addition of TGF-β, but not GM-CSF, to optimized FLT3L-BMDC cultures resulted in development of cDC1 which highly resemble lung cDC1. The development of a high throughput in vitro system that differentiates functional lung cDC1s will not only inform the in vivo factors required for development of these cells but also provides a useful platform for interrogation of lung cDC1 function and a stepping-off point to begin models for human lung cDC1 production and study.

With increasing temperatures and changing ocean conditions, it is important to measure the effects felt on both a species specific and ecosystem level, to better understand the consequences of this change. To investigate this issue specifically off of the Northeast US Atlantic Coast, I worked collaboratively with the National Oceanic and Atmospheric Administration, using both bottom temperature and sea surface temperature as oceanographic variables to examine whether the changes observed have influenced fish consumption over time across seventeen prominent fish species. We calculated average annual fish consumption per species from 1993-2018, where I then compared this to both sea surface temperature and bottom temperature using generalized additive models. Additionally, we plotted the above variables independently using generalized linear models and linear models to analyze their respective trends. I also created a sea surface temperature model to compare the extreme temperature changes the ecosystem was experiencing. Overall, increasing trends in both sea surface temperature and bottom temperature were detected, and within species’ consumption trends, four species showed significant increases in consumption (buckler dory (Zenopsis conchifer), fourspot flounder (Hippoglossina oblonga), longhorn sculpin (Myoxocephalus octodecemspinosus), striped searobin (Prionotus evolans)) whereas two indicated significant decreases in consumption (Atlantic cod (Gadus morhua), thorny skate (Amblyraja radiata)). When compared to sea surface and bottom temperature, three species' consumption rates were found to be significantly influenced by these variables (longhorn sculpin, thorny skate, spiny dogfish (Squalus acanthias)). Given these results, it is likely that the adaptability of species and their respective mobility will influence the degree of impact by changing ocean conditions, constituting both winners and losers in this changing time period. Therefore, we recommend further analysis to better understand how various related biological factors influenced by climate change will be impacted in the future to develop a more thorough understanding of the consequences of this change.

Colorectal cancer (CRC) is a prevalent and often lethal form of cancer, with complex underlying biology and a wide range of associated risk factors. CRC is a significant global public health challenge, it is the second leading cause of cancer-related deaths in the United States. A growing body of research suggests that activin can stimulate the MAPK pathway which plays a critical role in the development and progression of CRC. In the context of colorectal tumors, innate immune cells such as macrophages, dendritic cells, and natural killer (NK) cells can both promote and suppress tumor progression. Macrophages, for example, can either promote tumor growth by secreting growth factors that stimulate angiogenesis and immune suppression, or they can suppress tumor growth by producing cytokines that activate T cells and other immune cells. In this study, our aim is to examine the relationship between activin and the MAPK signaling pathway in macrophages and to determine the role of macrophages in producing and responding to activin. We will be using RAW264.7 macrophage cell line to study the role of macrophages in cancer and Western blot to detect changes in specific proteins in macrophages stimulated with activin. We predict to see an increase in MAPK activation in activin-stimulated macrophages which will enhance tumor elimination. Our findings will also improve the understanding of the innate immune response to colorectal tumors and how it can be modulated by targeting activin signaling. This research will provide new insights into the complex interplay between the immune system and colorectal tumors and may inform the development of new diagnostic methods and more effective treatments.

During non-REM slow-wave sleep, the thalamus and cortex generate widespread synchronized epochs of action potential firing that repeat at 1 to 7 Hz. This synchronization is thought to be an essential component of healthy sleep. Cortical excitatory synaptic feedback to the thalamus is required to maintain synchronized firing epochs across the thalamus. A major source of cortical to thalamic feedback comes from a subset of layer 5 (L5) pyramidal neurons (PNs) which occur in the largest numbers in the primary motor cortex. There is also evidence that the basal dendrites of those neurons in the motor cortex receive monosynaptic executory inputs from excitatory thalamic neurons but the number and strength of those connections are not known. For our project, we decided to quantify the number of thalamic inputs onto the basal dendrites of those L5 PNs that project back to the thalamus. I used tissue from the motor cortex of thy1 mice which express a yellow florescent protein in the L5 PNs that send axon branches to the thalamus. The tissue was treated with an antibody to the VGLUT2 protein which is selectively expressed in excitatory synaptic terminals from thalamic neurons. The VGLUT2-containing terminals were visualized using florescent immunocytochemical techniques combined with confocal microscopy to count the number of putative thalamic synaptic terminals that were closely opposed to spines (postsynaptic protrusions) on the L5 PN basal dendrites. Preliminary results suggest that between 5-20% of the dendritic spines are closely opposed to VGLUT2-containing presynaptic terminals. The study of this thalamocortical loop will allow for a better understanding of the processes that are necessary for proper sleep and the implications of disrupted neuron synchronization.

Colorectal cancer (CRC) is the third most common cancer globally, and the second leading cause of cancer deaths in the US due to metastasis. The five year mortality rate of Stage IV CRC patients remains around 90%, and most treatments for stage IV CRC are palliative. Activin A, a cytokine that regulates proliferation and apoptosis, is known to induce metastatic phenotypes in CRC cells primarily through the PI3K/ AKT pathway. Glycogen synthase kinase-3 beta (GSK3β) is an enzyme downstream of AKT that regulates energy metabolism and apoptosis. An inactive form, phosphorylated GSK3β (pGSK3β), is unable to inhibit β-catenin activity, which promotes proliferation and epithelial to mesenchymal transition. Very few connections between activin A signaling in colorectal adenocarcinoma cells and GSK3β phosphorylation have been established in scientific literature. Our project aims to study the correlation between activin A signaling and pGSK3β by testing the hypothesis that activin A signaling induces phosphorylation of GSK3β in CRC tumor cells, promoting the attenuation of cell cycle arrest. We will perform Western blot analyses on FET cells treated with a vehicle control, activin A, or TGF-β, a cytokine that is activin-dependent in the context of CRC, to measure the levels of pGSK3β relative to GSK3β. We expect to see the highest levels of pGSK3β relative to GSK3β in FET cells treated with activin A and the lowest relative pGSK3β levels in cells treated with the vehicle control. The findings of this project can contribute to identifying biomarkers useful for risk stratification in metastatic CRC to provide more individualized treatments for patients. 

The health of Sockeye salmon (Oncorhyncus Nerka) stocks are of high importance to the cultural well-being and sovereignty of Coast Salish tribes. There are multiple ecotypes of Sockeye that include anadromous, potamodromous Kokanee, and resident Sockeye that all carry distinct and significant cultural value for Indigenous communities, as well as distinct ecological roles within the ecosystems they inhabit. Sockeye are impacted by anthropogenic stressors such as habitat degradation and pollution, which can cause shifts in food web dynamics, population declines, and impact commercial and traditional fisheries. To more effectively manage these diverse life histories for conservation, it is crucial to understand the distinct ecological functions that may cause ecotypes to differ in their vulnerability to anthropogenic stressors, thus requiring different management strategies. We will analyze carbon and nitrogen isotopic signatures of Sockeye from Lake Washington to differentiate their ecological niches. Muscle samples were collected from 46 frozen sockeye samples, freeze dried, and then analyzed using mass spectrometry. Preliminary results suggest that there are significant differences between the isotopic signatures of anadromous and potamodromous ecotypes. We hypothesize further interpretation of the results coupled with genetic analysis will identify differing ecological roles in accordance with the diverse life history strategies Lake Washington Sockeye display. This study has been conducted as part of ongoing collaborative efforts with partners at the Snoqualmie Tribe, and the Kokanee Work Group, which aims to restore the Kokanee and Sockeye populations of Lake Sammamish. The results of this work will directly inform management actions taken by our partners to conserve the native Sockeye populations of King County, Washington.