ABSTRACT IMPACT: This project aims to investigate the impact of spermine oxidase inhibition on amelioration of neuronal injury. OBJECTIVES/GOALS: Our group has recently described a series of triazole-based reversible inhibitors of spermine oxidase (SMOX) (Holshouser et al. 2019). The purpose of the current project is to optimize our most promising inhibitors by structural modification, and to determine whether they can reduce oxidative damage in models of neuronal injury. METHODS/STUDY POPULATION: A small number of SMOX inhibitors have been described in the literature, however, currently available inhibitors lack selectivity for the enzyme and are associated with dose-limiting toxicity. For this project we used multiple medicinal chemistry techniques to synthesize novel triazole-based analogs of our most potent inhibitors as potential SMOX inhibitors. In addition, we plan to utilize virtual and physical screening methods to identify new potential scaffolds. Compounds with demonstrated activity against SMOX via enzymatic assay will then be evaluated in a cell-based model of neuronal injury. In a preliminary study, we investigated the ability of hydrogen peroxide to induce SMOX expression in an SH-SY5Y neuroblastoma cell line using western blot. RESULTS/ANTICIPATED RESULTS: We found that cellular SMOX protein increases in response to hydrogen peroxide exposure in a dose-dependent manner, indicating that this may be a viable cellular model for testing the efficacy of our experimental compounds. To extend these studies, we have developed a SMOX enzymatic assay that will be used for high-throughput screening of commercial libraries, as well as the South Carolina Compound Collection (SC3), which contains 100,000 proprietary, fully annotated analogs. As hits are identified, they will be synthesized and evaluated for potency and selectivity as SMOX inhibitors. The most potent and selective compounds will then be evaluated in our cellular model of neuronal injury. DISCUSSION/SIGNIFICANCE OF FINDINGS: Studies have linked the overexpression of SMOX and the production of associated toxic byproducts with increased susceptibility to excitotoxic stress and neuronal injury. Our objective is to develop potent and selective inhibitors for this enzyme that can serve as chemical probes for elucidating the role of this enzymatic pathway in neuronal injury.

ABSTRACT IMPACT: Racial differences in the prevalence of hypertension and endothelial (dys)function are well established, yet research investigating the mechanism(s) underlying this disparity is still lacking. OBJECTIVES/GOALS: Investigate the influence of race and the effect of serum collected from hypertensive donors on Protein Phosphatase 2A (PP2A) and endothelial nitric oxide synthase (eNOS) expression and activity in human umbilical vein endothelial cells (HUVECs) from Caucasian (CA) and African American (AA) donors. METHODS/STUDY POPULATION: HUVECs from 3 CA & 3 AA donors were cultured in parallel. Experiments were conducted between passages 5-7. At ?90% confluency, cells were serum starved ˜12hrs prior to incubating for 24 or 48 hours in one of the following conditions: 1) Control (Fetal Bovine Serum), 2) serum from normotensives (NT; 5 CA & 5 AA donors), or 3) serum from hypertensives (HT; 5 CA & 5 AA donors). NT and HT serum was pooled from donors with the following characteristics: Male, 30-50 years, nonsmokers, no comorbidities, and non-obese (BMI < 30 kg/m2). Western blotting was used to measure protein expression of total eNOS, p-eNOSS1177, total PP2A, and p-PP2AY307. For activity p-eNOSS1177/total eNOS and p-PP2AY307/ total PP2A ratio was used. A two-way ANOVA was used for statistical analysis. RESULTS/ANTICIPATED RESULTS: Irrespective of the donors’ race, there was no influence of serum treatment or interaction effect in any of the measured proteins of interest. Moreover, compared to CA, HUVECs from AA had lower expression of eNOS irrespective of condition (race p=0.01). Compared to CA, HUVECs from AA tended to have lower expression of p-eNOSS1177 irrespective of condition (race p=0.07). However, there was no racial differences in eNOS activity (p=0.68). There was no racial difference in the expression of PP2A (p=0.35), p-PP2AY307 (p=0.30), or PP2A activity (p=0.97) in all conditions. DISCUSSION/SIGNIFICANCE OF FINDINGS: Our preliminary results suggest no influence serum constituents from hypertensive donors or race on PP2A or eNOS expression and activity in HUVECS. Future research should consider conducting proteomics profiling to compare NT and HT serum.

ABSTRACT IMPACT: If immune checkpoint blockade increases bacterial clearance with or without antibiotics in vitro, clinical application would be almost immediate and dramatic creating a seismic shift in the current therapeutic paradigm of periprosthetic joint infection. OBJECTIVES/GOALS: Periprosthetic joint infection (PJI) is a major cause of failure after joint replacement. Currently, the treatment of PJI relies on removing biofilm contaminated implants. Some of the bacteria within biofilm undergo a phenotypic shift becoming small colony variants (SCVs). SCVs induce local immunosuppression through PD-1/L1 signaling. METHODS/STUDY POPULATION: We will infect cultured human macrophages and bone marrow aspirate with stable Staphylococcus aureus SVCs and treat with anti-PD-1 or anti-PD-L1 monoclonal antibodies with and without antibiotics (e.g., gentamycin, cefazolin, vancomycin, rifampicin) and assess the residual bacterial viability. We will utilize multiplexed ion beam imaging to quantify PD-1/L1 expression in human tissue from patients with a chronic PJI and compare those to patients undergoing an aseptic revision. Patients with a chronic PJI are likely to have increased expression of PD-1/L1 as their tissue samples are prospectively screened. RESULTS/ANTICIPATED RESULTS: SCVs reduce the phagocytic activity of macrophages and can survive intracellularly. SCVs also induce anti-inflammatory M2-macrophage polarization and recruit a heterogeneous group of immature monocytes and granulocytes called myeloid-derived suppressor cells (MDSC) to the periprosthetic microenvironment. M2-macrophages and MDSCs then produce an immunosuppressive cytokine milieu characterized by increased IL-10 and decreased TNF-α. Clinically isolated SCVs up-regulate the expression of PD-L1 and PD-L2 on the surface of macrophages, representing a mechanism by which SCVs induce host immunosuppression and survive immune clearance. Our preliminary data show PD-L1 expression during septic PJI, but not in aseptic revisions. DISCUSSION/SIGNIFICANCE OF FINDINGS: If immune checkpoint blockade is shown to increase bacterial clearance with or without antibiotics, host immunomodulation would represent a novel class of therapeutic adjuvants to assist surgical debridement and antibiotic administration that could be superimposed on existing treatment algorithms to improve PJI related outcomes.

ABSTRACT IMPACT: The knowledge acquired from my research can inform the development of early diagnostic methods for HIV-associated neurocognitive disorders. OBJECTIVES/GOALS: In the era of combination antiretroviral therapy (cART), the prevalence of HIV-associated neurocognitive disorders (HAND) remains high but the neural mechanisms are unclear. We examined whether older people with HIV (PWH) with minimal cognitive impairment have reduced functional connectivity in frontostriatal circuits compared to controls. METHODS/STUDY POPULATION: 99 PWH (mean age 56.6 years, 75% male, 62% Black, mean duration of HIV-infection 26.2 years ±9.3, 90% viral load <50 copies, 98% on stable cART) and 38 demographically-comparable controls (mean age 54.5 years, 71% male, 58% Black) participated in a cross-sectional study. A 7-domain neuropsychological battery and an Activities of Daily Living index were used to determine HAND diagnoses: 32 PWH met criteria for asymptomatic to mild HAND. Motor skill was assessed using the Grooved Pegboard Test by measuring performance speed. Structural MRI and resting-state functional MRI were collected. Seed-to-voxel analyses were conducted using 4 distinct regions in the striatum as seed regions. We used a voxel threshold of p<0.001 and cluster threshold of p<0.05 (FDR-corrected) after controlling for demographic variables. RESULTS/ANTICIPATED RESULTS: Compared to controls, PWH had lower resting state functional connectivity between the default mode region of the striatum (i.e., medial caudate) and bilateral superior frontal gyrus, supplementary motor cortex and paracingulate gyrus (p<0.05; cluster size: 567 voxels). Also, compared to controls, PWH had reduced resting state functional connectivity between the motor division of the striatum (i.e., posterior putamen) and anterior cingulate cortex and left supplementary motor cortex (p<0.05, cluster size: 405 voxels). Performance speed on the Grooved Pegboard motor test negatively correlated with functional connectivity between the motor region of the striatum and supplementary motor frontal regions in all participants (Spearman’s rho=-0.18, p=0.04). DISCUSSION/SIGNIFICANCE OF FINDINGS: Our results support the hypothesis that frontostriatal abnormalities are widely present in PWH and might play a key role in HAND development. Our data suggest that dysfunction within the frontostriatal circuits may be involved in motor impairment in PWH, and ongoing inflammation may contribute to motor impairment and frontostriatal injury.

ABSTRACT IMPACT: Our data demonstrate that VC2 oncolytic virotherapy has significant clinical potential. OBJECTIVES/GOALS: Use our novel oncolytic herpes simplex virus type I (HSV-1), VC2, to understand how oncolytic virotherapy affects the immunosuppressive tumor microenvironment as a mechanism of efficacy. METHODS/STUDY POPULATION: We tested the efficacy of VC2 as an oncolytic virotherapy (OVT) in a syngeneic B16F10-derived mouse model of melanoma. We modified the B16F10 to express nectin-1 (B16F10n-1), the major receptor for HSV-1. Engrafted B16F10n-1 tumors were intratumorally treated with either phosphate-buffered saline (PBS) or 1x10^6 pfu VC2. At indicated time points, treated tumors were excised and processed for immunohistochemistry or flow cytometry analysis. For our experimental metastasis studies, mice were intravenously challenged with B16F10n-1 cells. For our depletion studies, CD4+ and CD8+ T cells were depleted in mice by treatment with mouse anti-CD4 and anti-CD8 monoclonal antibodies respectively, while the control mice were given Rat IgG2b isotype. RESULTS/ANTICIPATED RESULTS: We found that VC2 slowed tumor growth rates and significantly enhanced survival times over control treated mice. VC2-treated mice that survived initial tumor engraftment were able to reject a second tumor challenge and were also resistant to lung colonization (experimental metastasis) of tumor cells. Furthermore, VC2 treatment promoted increased intratumoral T cell infiltration and induced a strong antitumor effect that decreased growth rates of distant, untreated tumors. DISCUSSION/SIGNIFICANCE OF FINDINGS: Our data demonstrate that VC2 OVT has significant clinical potential. Furthermore, due to the increased survival rates and CD8+ T cells dependence, our model will enable study of the immunological correlates of protection for VC2 OVT and OVT in general, as well as to inform the rational design of future OVs with improved therapeutic potentials.

The mission of the National Center for Advancing Translational Science (NCATS) is to speed the development of drugs from discovery to approval to dissemination and implementation. The Medical University of South Carolina and the South Carolina Clinical and Translational Research Institute host a NCATS funded predoctoral T32 training grant (TL1) with a focus on translational research. Doctoral (PhD) trainees working at the bench usually have limited opportunity for clinical interactions to gain a clinical perspective on the diseases that are the focus of their dissertation research. To provide TL1 trainees with an opportunity to see how their research could be translated into improved patient care, we developed a mentored clinical exposure experience named the Translational Sciences Clinic. Trainees spend one-half day a week in a clinic related to their basic science research for one semester interacting with patients and clinical mentors and discuss the most recent literature related to the patient’s clinical problem with their clinical mentor. Trainees deemed the rotation to be one of the most rewarding experiences that they had as a part of their predoctoral training. Participating clinical mentors were also very enthusiastic and agreed that they would be willing to mentor similar trainees again.

ABSTRACT IMPACT: This work will provide a rational approach to improve the efficacy of current immunotherapy approaches in patients that have historically responded poorly to immune checkpoint inhibitors. OBJECTIVES/GOALS: Recent evidence of immunogenic cell death as a predictor of response to therapy has increased the interest in monitoring the presence of damage-associated molecular pattern protein (DAMPs). By regulating DAMP expression, our lab is interested in discovering new ways to improve the patient response rate to immune checkpoint inhibition. METHODS/STUDY POPULATION: Using cultured cell, and a limited number of patient tumors and serum (n=4), we measured intracellular and extracellular levels of DAMP molecule, high mobility group box 1 (HMGB1) using enzyme-linked immunosorbent assays and immunoblots. Immunological assayed were compared to the expression of immune checkpoint molecules PD-1/PDL1 on patient tumors as presented in pathology reports. RESULTS/ANTICIPATED RESULTS: HMGB1 release was associated with increased levels of PD-L1 on tumor cells. Targeted inhibition of HMGB1 altered the expression of programmed death-ligand 1 (PD-L1), a target for immune checkpoint inhibition therapy. Patients with higher levels of PD-L1 possessed increased levels of HMGB1 in serum. DISCUSSION/SIGNIFICANCE OF FINDINGS: This implies that regulating the expression of HMGB1 could have an effect on the response of patients to immunotherapy. The main objective of the work is to determine the potential benefit of targeting HMGB1 to improve the efficacy of current therapeutic approaches to treating lung cancer.

ABSTRACT IMPACT: A mouse model of minimally-invasive chronic sleep deprivation is essential for elucidating the impact of sleep deprivation on various health issues, and it would lead to the possibility of sleep as a therapeutic target. OBJECTIVES/GOALS: The lack of sleep has been associated with various health conditions. In mice, sleep deprivation has been achieved mainly by physical disturbances, which raises concern about confounding effects by stresses. Without physical disturbance, targeted neuron ablation can address this methodological flaw. METHODS/STUDY POPULATION: AdultVgat-IRES-cre mice undergo a stereotaxic injection of adeno-associated virus (AAV) vector containing mCherry-dtA to bilateral parafacial zone (PZ) to perform GABAergic neuron-specific cell ablation. Control mice receive an injection of AAV vector containing hSyn-DIO-mCherry. All mice are implanted with electroencephalogram and electromyogram (EEG/EMG) electrodes for sleep-wake analysis. After 7-10 days of the postoperative recovery period, mice are kept individually in a cage for sleep-wake state recording. EEG/EMG and video recording are used to measure total wake time, total sleep time, percent of rapid eye movement (REM) and non-REM sleep, and detailed characterization with spectral analysis. RESULTS/ANTICIPATED RESULTS: We anticipate that the ablation of GABAergic neurons in bilateral PZ decreases the fraction of sleep state in mice, especially non-REM sleep. In the Vgat-IRES-cre mice that received the injection of AAV vector containing mCherry-dtA, total sleep time is expected to be decreased constantly during the 8-week observation period. Sleep-wake staging by video activity recording is anticipated to be closely correlated with the gold standard staging by EEG/EMG. Possible stresses caused by the restriction of physical activity and handling of mice for EEG/EMG recording can be further minimized by the sleep-wake staging performed with the video activity recording. DISCUSSION/SIGNIFICANCE OF FINDINGS: The lack of sleep has been associated with negatively affecting overall health and is implicated in major health conditions including obesity, diabetes, and cardiovascular diseases. This chronic sleep deprivation mouse model can be used to understand the mechanisms of such detrimental effects on health, and would improve many health conditions.

ABSTRACT IMPACT: We hope to provide a more nuanced understanding of the type-III IFN system, thereby exploring its therapeutic potential in the realm of infectious diseases. OBJECTIVES/GOALS: The role of IFNLR1 receptor dynamics and plasticity in regulating the type-III IFN response is largely unknown. As a specific, powerful component of innate immunity, understanding how the type-III IFN system is regulated could lead to the development of novel therapeutic targets and strategies to face a multitude of viral illnesses. METHODS/STUDY POPULATION: To facilitate our investigation, we will generate doxycycline-inducible FLAG-tagged IFNLR1-expression plasmids representing all known transcriptional variants. These plasmids will allow us to: 1) Evaluate the effect of IFNLR1 surface abundance on the type-III IFN transcriptional profile and 2) Assess the extent of IFNLR1-FLAG co-localization with several notable intracellular structures using immunofluorescence, before and after stimulation with IFNL3. RESULTS/ANTICIPATED RESULTS: We have successfully generated three IFNLR1-FLAG transcriptional variants and confirmed inducible-expression and function in vitro. We are currently assessing the role of surface abundance, internalization, differential isoform expression, and trafficking. DISCUSSION/SIGNIFICANCE OF FINDINGS: By completing this study, we hope to provide a more nuanced understanding of the type-III IFN system, thereby exploring its therapeutic potential in the realm of infectious diseases.

Deep learning has pushed the scope of digital pathology beyond simple digitization and telemedicine. The incorporation of these algorithms in routine workflow is on the horizon and maybe a disruptive technology, reducing processing time, and increasing detection of anomalies. While the newest computational methods enjoy much of the press, incorporating deep learning into standard laboratory workflow requires many more steps than simply training and testing a model. Image analysis using deep learning methods often requires substantial pre- and post-processing order to improve interpretation and prediction. Similar to any data processing pipeline, images must be prepared for modeling and the resultant predictions need further processing for interpretation. Examples include artifact detection, color normalization, image subsampling or tiling, removal of errant predictions, etc. Once processed, predictions are complicated by image file size – typically several gigabytes when unpacked. This forces images to be tiled, meaning that a series of subsamples from the whole-slide image (WSI) are used in modeling. Herein, we review many of these methods as they pertain to the analysis of biopsy slides and discuss the multitude of unique issues that are part of the analysis of very large images.

ABSTRACT IMPACT: Our data reveal a histone modifying enzyme involved in regulating inflammation that may be a novel target for treating non-healing diabetic wounds. OBJECTIVES/GOALS: We investigate molecular mechanisms that regulate the inflammatory phenotype of macrophages in normal and diabetic wound healing. Our goal is to identify novel pathways that may be used to better treat diabetic patients with non-healing wounds. METHODS/STUDY POPULATION: We utilize normal and transgenic murine models on standard chow or high-diet to identify chromatin modifying enzymes involved in regulating macrophage function during wound healing. We validate our murine studies with human blood monocytes or wound macrophages from diabetic patients undergoing limb amputation surgery. RESULTS/ANTICIPATED RESULTS: We have identified the histone methyltransferase SETDB2 as a regulator inflammation in normal and diabetic wound macrophages. We found that SETDB2 was dependent on IFNβ singaling and that both IFNβ and Setdb2 expression were impaired in diabetic wound macrophages. Further, we show that SETDB2 regulates inflammatory response and immune cell trafficking pathways. We also show that SETDB2 genomic localization is dependent on *NFκΒ deposition of the promoter. DISCUSSION/SIGNIFICANCE OF FINDINGS: Our results indicate that SETDB2 is a regulator of macrophage plasticity and that SETDB2 expression is impaired in diabetic wound macrophages leading to hyper-inflammatory response and delayed wound healing. These data provide a novel potential therapeutic pathway for treating non-healing diabetic wounds.

ABSTRACT IMPACT: Identifying an important pathway in treatment resistant TNBC will allow for the future development of clinical therapeutics specific for this disease. OBJECTIVES/GOALS: Triple Negative Breast Cancer (TNBC) is a subtype of breast cancer characterized by negative expression of estrogen receptor, progesterone receptor, and HER2/neu amplification. It resists therapies and has a high recurrence rate after resection. The goal of my research is to identify & characterize a TNBC pathway for future development of therapies. METHODS/STUDY POPULATION: The project uses a combination of cell lines, patient derived xenograft (PDX) models, as well as patient databases. Standard cellular and molecular biology techniques will be used including: Cell culture, qPCR, western blotting, and flow cytometry. RESULTS/ANTICIPATED RESULTS: LKB1 is a master kinase that activates 14 possible downstream kinases. The signaling pathway has been demonstrated to play a role in energy homeostasis and metabolism. Mutation of LKB1 signaling results in Peutz-Jeghers Syndrome and is associated with neoplasias of the lung, pancreas, and breast. Based on preliminary analysis, overexpression of LKB1 by shRNA in TNBC cell lines results in suppression of EMT and reduction of the cancer stem cell population. Additional studies show that LKB1 overexpression has no effect on growth rate in 2D culture while significant reduction in 3D mammosphere formations can be seen. Downstream studies using commercially available SIK1 inhibitor HG-9-91-01 is able to induce a larger fraction of CSC from reduced LKB1 overexpression as well as from baseline levels. DISCUSSION/SIGNIFICANCE OF FINDINGS: Overall, our results suggest that LKB1 acts through SIK1 to suppress EMT and the generation of cancer stem cells. This results in reduced cancer functionality, as evidenced by inhibition of mammosphere formation. These results establishes a foundation for future mechanistic studies on the LKB1 axis and its mechanisms in TNBC.