OBJECTIVES/GOALS: The management of head and neck cancers is complicated and allows for a variety of disparate approaches from providers. However, data from several hundred or thousands of patients is necessary to decipher the optimal decisions for populations of patients. And prospective trials would take years to accrue and often are financially not possible. METHODS/STUDY POPULATION: Instead, we collated the entire electronic medical record for all patients at our institution treated for head and neck cancers. We employed a variety of clinical informatics and natural language processing to gather text data into large data frames. We found key conclusions in the diagnostic, treatment, and surveillance of our patients. RESULTS/ANTICIPATED RESULTS: First, obtaining post-operative PET/CT changes in management in over one-third of patients, highlighting the utility of optimizing diagnostic imaging. Second, using a newer silicone-based cream instead of just a moisturizer decreased the absolute risk of grade 2+ radiation dermatitis by almost 15%. Lastly, we are deploying novel autosegmentation frameworks to better understand tissue decomposition in the head and neck to identify patients in need of further nutritional support while undergoing radiation therapy. DISCUSSION/SIGNIFICANCE: Collectively, we showcase the value and opportunity of mining oncological data for the improvement of patient care.

OBJECTIVES/GOALS: The goal of the study is to provide insights into the use of machine learning methods as a means to predict heterogeneity of treatment effect (HTE) in participants of randomized clinical trials. METHODS/STUDY POPULATION: Using data from 2,441 participants enrolled in the ASPirin in Reducing Events in the Elderly (ASPREE) randomized controlled trial of daily low-dose aspirin vs placebo in the United States, we developed multivariable risk prediction models for the composite outcome of dementia, disability, or death. We used two machine learning techniques, decision trees and random forests, to develop novel non-parametric outcomes classifiers and generate risk-based subgroups. The comparator method was an extant semi-parametric proportional hazards predictive risk model. We then assessed HTE by examining the 5-year absolute risk reduction (ARR) of aspirin vs placebo in each risk subgroup. RESULTS/ANTICIPATED RESULTS: In the random forest classifier, the ARR at 5 years in the highest risk quintile was 13.7% (95% CI 3.1% to 24.4%). For the semi-parametric proportional hazards model, the ARR in the highest risk quintile was 15.1% (95% CI 4.0% to 26.3%). These results were comparable and provide evidence of the viability of internally developed parsimonious non-parametric machine learning models for HTE analysis. The decision tree model results (5-year ARR = 17.0%, 95% CI= -5.4% to 39.4% in the highest risk subgroup) exhibited more uncertainty in the results. DISCUSSION/SIGNIFICANCE: None of the models detected significant HTE on the relative scale; there was substantial HTE on the absolute scale in three of the models. Treatment benefit on the absolute scale may be regarded as bearing greater clinical importance and may be present even in the absence of benefit on the relative scale.

OBJECTIVES/GOALS: The correction of spinopelvic parameters is associated with better outcomes in patients with adult spinal deformity (ASD). This study presents a novel artificial intelligence (AI) tool that automatically predicts spinopelvic parameters from spine x-rays with high accuracy and without need for any manual entry. METHODS/STUDY POPULATION: The AI model was trained/validated on 761 sagittal whole-spine x-rays to predict the following parameters: Sagittal Vertical Axis (SVA), Pelvic Tilt (PT), Pelvic Incidence (PI), Sacral Slope (SS), Lumbar Lordosis (LL), T1-Pelvic Angle (T1PA), and L1-Pelvic Angle (L1PA). A separate test set of 40 x-rays was labeled by 4 reviewers including fellowship-trained spine surgeons and a neuroradiologist. Median errors relative to the most senior reviewer were calculated to determine model accuracy on test and cropped-test (i.e. lumbosacral) images. Intraclass correlation coefficients (ICC) were used to assess inter-rater reliability RESULTS/ANTICIPATED RESULTS: The AI model exhibited the following median (IQR) parameter errors: SVA[2.1mm (8.5mm), p=0.97], PT [1.5° (1.4°), p=0.52], PI[2.3° (2.4°), p=0.27], SS[1.7° (2.2°), p=0.64], LL [2.6° (4.0°), p=0.89], T1PA [1.3° (1.1°), p=0.41], and L1PA [1.3° (1.2°), p=0.51]. The parameter errors on cropped lumbosacral images were: LL[2.9° (2.6°), p=0.80] and SS[1.9° (2.2°), p=0.78]. The AI model exhibited excellent reliability at all parameters in both whole-spine (ICC: 0.92-1.0) and lumbosacral x-rays: (ICC: 0.92-0.93). DISCUSSION/SIGNIFICANCE: Our AI model accurately predicts spinopelvic parameters with excellent reliability comparable to fellowship-trained spine surgeons and neuroradiologists. Utilization of predictive AI tools in spine-imaging can substantially aid in patient selection and surgical planning.

OBJECTIVES/GOALS: A TIA is a transient episode of symptoms attributed to a cerebrovascular cause, and associated with an increased risk of stroke. Care of these patients often requires substantial resources in the Emergency Department (ED). We therefore described neuroimaging and hospitalization use for TIA within a nationally representative sample of US ED visits. METHODS/STUDY POPULATION: Retrospective cross-sectional analysis using TIA encounters in the 2018 National Emergency Department Sample (NEDS), an AHRQ dataset consisting of a weighted sample of 20% of all US ED encounters. Non-contrast Head CT, CTA Head, Carotid Ultrasound, MRI and CT Perfusion imaging utilization was determined based on Common Procedural Terminology (CPT) codes in the non-admitted encounters. The study population includes all adult patients with a discharge diagnosis of TIA as determined by ICD-10 codes (H34.0, G45.0-3, G45.8 G45.9) in any diagnosis position. The percentage of patients receiving each neuroimaging test was reported with the corresponding 95% confidence interval (CI). We utilized survey sample weights to generate reliable national estimates. RESULTS/ANTICIPATED RESULTS: The study population consisted of 80,803 ED encounters with a discharge diagnosis of TIA, representing 326,802 weighted ED visits nationally. Among this group, 46.8% of patients were discharged and 41.8% were admitted to the same hospital, 7% of patients were transferred to another facility, and the remaining 5% left AMA, were dispositioned to home health, died in the ED, or had an unknown disposition. Because discharged encounters retain their more precise CPT coding of procedural information, imaging analysis was conducted in discharged TIA encounters only. Of these encounters, 73% (95% CI, 70.7-76.5) received a noncontrast head CT, 20.9% (95% CI, 19.1-22.7) a CTA Head, 22.5% (95% CI, 20.6-24.4) a carotid ultrasound, and 31.5% (95% CI, 29.3-33.7) an MRI brain without contrast. DISCUSSION/SIGNIFICANCE: The discharge rate of just under 50% of patients is consistent with other published data, and represents a gradual trend over the past decade of decreased admissions for TIA. The fact that for many of these patients, the entire episode of care occurs in the ED setting suggests that the ED may be a rich target for future innovations in care for TIA.

OBJECTIVES/GOALS: With a growing intеrеst in tailoring disеasе diagnosis to еach individual as opposеd to a “onе-sizе-fits-all” approach, our aim is to еnhancе thе robustnеss of thе Itеrativе Clustеring for Subtypе Discovеry (iKCAT) algorithm in charactеrizing lung cancеr subtypеs for individualizеd trеatmеnt. METHODS/STUDY POPULATION: Our mеthod еxplorеs thе robustnеss of thе prеviously dеvеlopеd iKCAT algorithm. This itеrativе clustеring mеthod finds robust—homogеnеous and diffеrеntiablе—subtypеs of lung nodulеs through itеrativе K-mеans clustеring that hеlps classify thеm and lеavеs somе data unclustеrеd. This sеt of unclustеrеd or “hard” data rеprеsеnts imagеs that cannot confidеntly bе assignеd to any subtypеs and may rеquirе morе rеsourcеs (е.g., timе or radiologists) to diagnosе. Wе еxplorе thе robustnеss of iKCAT across multiplе fеaturе spacеs, including dеsignеd imagе fеaturеs (which arе еnginееrеd to capturе somе propеrtiеs such as lеvеl of еlongation, еccеntricity and circularity), rеducеd dеsignеd imagе fеaturеs using Principal Componеnt Analysis (PCA) and Uniform Manifold Approximation and Projеction (UMAP). RESULTS/ANTICIPATED RESULTS: Whеn running our еxpеrimеnt on thе 64 imagе fеaturеs, our rеsults consistеntly carvеd out a singlе purе, homogеnеous clustеr ovеr thе coursе of 30 iKCAT runs. From an initial datasеt of 1490 data points, 1430 points wеrе lеft unclustеrеd in this fеaturе spacе. Whеn conducting thе 30 iKCAT runs on thе PCA fеaturе spacе with 10 componеnts, wе found it did not producе any distinct clustеr abovе thе dеfinеd homogеnеity thrеshold. Thе 2D UMAP fеaturе spacе consistеntly gеnеratеd 8 clustеrs with an avеragе homogеnеity of 87. 22% ovеr 30 runs, and only lеft 9 points unclustеrеd. Ovеr 30 iKCAT runs, wе idеntifiеd 8 pеrsistеnt clustеrs or subtypеs, 3 mostly malignant and 5 mostly bеnign clustеrs. DISCUSSION/SIGNIFICANCE: Through our еxpеrimеnt using thе iKCAT algorithm, wе found that iKCAT’s clustеring functionality producеd thе most pеrsistеnt rеsults on thе 2D UMAP fеaturе spacе duе to its high avеragе homogеnеity scorеs and consistеncy in idеntifying clustеrs/subtypеs, hеlping improvе tailorеd disеasе diagnosis.

OBJECTIVES/GOALS: Artificial Intelligence (AI) is gaining popularity in a variety of disciplines. While clinical applications for AI have increased in recent years, the use of AI in pediatric congenital heart disease (CHD) is limited. The goal of this systematic review was to assess how AI is currently used in this patient population and to describe knowledge gaps. METHODS/STUDY POPULATION: A systematic search was performed up to July 2023 using PubMed and Scopus databases and revealed 814 articles. Upon initial screening, 161 duplicates, 76 non-AI articles, and an additional 318 irrelevant articles were removed. A total of 259 full-text articles were reviewed for relevance. Articles that did not include a retrospective or prospective review of human subject data were excluded. Articles that had only results in the adult, prenatal, or non-CHD population were excluded. The remaining 68 articles were included in this review. RESULTS/ANTICIPATED RESULTS: Of the 68 articles in this review, 19 were performed within cardiac surgery, 41 were within cardiology, and the remaining 8 included articles were combined cardiac surgery and cardiology. Upon initial review, 24 used AI for diagnostic purposes, 40 for predicting survival or adverse outcomes, 2 for developing training tools, and 2 for surveillance of CHD trends. We anticipate that upon further review of these 68 articles, there will be a wide variety in the types of AI models that were used. The results will reveal a multitude of challenges and limitations that future studies will need to further address. DISCUSSION/SIGNIFICANCE: While technical innovations in pediatric CHD have dramatically improved survival rates, we have hit a plateau in improving the complications of these patients. AI has created an opportunity to build new diagnostic, predictive, teaching, and surveillance tools for advancing CHD care, but it seems we still have a long way to go.

OBJECTIVES/GOALS: Characterizing and analyzing research studies presents several challenges given the various ways studies may be labeled or organized. The Medical Subject Headings (MeSH) thesaurus is a hierarchical vocabulary that can index and organize research foci using common business intelligence tools to enable rapid exploration of research portfolios. METHODS/STUDY POPULATION: Metadata from ClinicalTrials.gov on 455,437 trials were downloaded and all MeSH terms associated with trials in the condition_browse section were loaded into a database. The corresponding MeSH trees for each term were then identified and mapped to their ancestor terms within the tree. Trials were then indexed based on top four hierarchical levels for each associated MeSH term. Trials performed at the University of Miami (UM) were identified based on locations associated with the trial as well as matching National Clinical Trial (NCT) numbers identified from internal research administration systems. Business intelligence software (Microsoft PowerBI) was applied to the corresponding dataset to enable end user exploration and analysis of the trials within ClinicalTrials.gov. RESULTS/ANTICIPATED RESULTS: A total of 3,271 studies associated with UM were identified, of which, 3,054 (93.3%) had at least one condition MeSH term linked. A total of 7,711 MeSH terms were associated with the trials overall, representing 1,112 unique MeSH terms; the most common terms were carcinoma (164), lymphoma (155), HIV Infections (139), neoplasms (136), and leukemia (122). Utilizing MeSH hierarchy, trials were characterized were categorized into 36 different trees. The most common top tree nodes were neoplasms (1,181), followed by pathological conditions/signs and symptoms (913), immune system diseases (574), nervous system diseases (513), and digestive system diseases (483). Within trees, a total of 184, 681, and 1057 different MeSH terms were specified at the second, third, and fourth nodes in the hierarchy respectively. DISCUSSION/SIGNIFICANCE: Utilizing existing metadata from trials posted on ClinicalTrials.gov and MeSH tree structures can enable organizations to readily explore the foci of clinical trials research. High rates of MeSH term association to research study conditions are necessary to ensure adequate representation of research foci.

OBJECTIVES/GOALS: Alzheimer’s Disease (AD) displays numerous pathological features, including amyloid-beta deposition, extensive neuroinflammation, and vascular fibrosis. However, putative therapeutic options for alleviating these features remain limited, emphasizing the need to develop comprehensive treatments for patients with AD. METHODS/STUDY POPULATION: CSF from human AD patients treated with nilotinib (n=12), a tyrosine kinase inhibitor, or placebo (n=11) was collected and sequenced, and significantly altered miRNAs were identified and analyzed for alterations to disease-associated genes via gene ontology analysis. TgAPP mice were injected intraperitoneally with one of two novel tyrosine kinase inhibitors, BK40143 or BK40197, or DMSO (n=12 per group) daily for six weeks, during which memory deficits between groups were measured, before brains were harvested for analysis of amyloid-beta load via ELISA, microglial activation via Sholl analysis, and vascular collagen levels via immunohistochemistry. RESULTS/ANTICIPATED RESULTS: CSF obtained from AD subjects treated with nilotinib revealed significantly increased (p<0.05) levels of miRNAs regulating autophagy, neuroinflammation, and collagen production compared to placebo. These results were validated in vivoin TgAPP mice, who displayed improved recall on the novel object recognition test and Morris water maze following treatment with our drugs, correlating with decreased levels of brain amyloid-beta (30% decrease, p=0.002), decreased microglial reactivity and activation (40% decrease, p=0.01), and decreased vascular fibrosis (50% decrease, p=0.005) along small brain blood vessels compared to controls. DISCUSSION/SIGNIFICANCE: These data identify tyrosine kinase inhibition as a valid therapeutic strategy for alleviating various pathological features associated with AD and warrant further investigation as a treatment option for human patients as a means of slowing cognitive decline.

OBJECTIVES/GOALS: To streamline the standards and procedures for operating a research-specific, clinical data warehouse, acheived by defining roles, introducing a common language, and categorizing dataset types to provide transparency regarding data security risks inherent in the use of patient data. METHODS/STUDY POPULATION: We established a Bioethics committee responsible for ensuring clinical data is securely procured, maintained, and extracted in a manner that adheres to all federal, state, and local laws. We created an operational framework in the form of an umbrella IRB protocol and shared it with the bioethics committee for feedback and approval. The protocol was approved first by the bioethics committee and subsequently by the IRB. It was then disseminated across the institution and published online for continuous reference and use by committee members, researchers, and the data warehouse service team. RESULTS/ANTICIPATED RESULTS: The resulting framework defined the roles of researchers, data warehouse service team members, and honest brokers; explains the procedures for accessing and securely delivering data; and lists six categories of datasets according to type and implicit risks: datasets that are preparatory for research/aggregate counts, anonymized datasets, coded datasets, limited datasets, identified datasets for recruitment purposes, and defined identified cohort datasets. The protocol is approved and in use enterprise-wide, has reduced the number of questions from stakeholders, and has given researchers, IRB members, and informatics staff confidence in the use of the clinical research data warehouse. DISCUSSION/SIGNIFICANCE: We offer our framework to CTSAs interested in streamlining their data warehouse operations. We believe the adoption of this framework will establish strong procedures for ensuring compliance with IRB requirements, data privacy, and data security while reducing barriers to clinical research.

OBJECTIVES/GOALS: Preeclampsia, a hypertensive disorder in pregnancy, disrupts immune cell profiles at birth in both mice and humans. In mice, it affects offspring’s memory and behavior. This study aimed to investigate whether preeclampsia induces lasting immune cell changes after birth and its impact on astrocyte and microglia cell counts in offspring. METHODS/STUDY POPULATION: Preeclampsia was induced in C57BL/6 females by infusion of vasopressin (24 ng/hr) or saline throughout gestation via osmotic minipump. Parturition was allowed to occur naturally. Offspring were euthanized at various timepoints post-delivery for experimental measures. Total urine protein was determined via bicinchoninic acid assay. Single cell suspensions were prepared from thymus spleen, and brain tissue and separated via density gradient. Cell suspensions were stained with fluorochrome-conjugated monoclonal antibodies for flow cytometry. Statistical significance was determined using a two-tailed Student t test or one way ANOVA multiple comparisons test. The minimal level of confidence deemed statistically significant was p<0.05. RESULTS/ANTICIPATED RESULTS: Preeclampsia resulted in lower body and heart masses in offspring. Although T cell populations in the thymus were not altered in preeclampsia offspring, total T cells, Thelper, and cytotoxic T cells were elevated. Total B and isotype-switched B cells were increased in offspring of preeclampsia. Total dendritic cell percentages were not changed in offspring of preeclampsia, however, total anti-inflammatory markers on dendritic cells were reduced. Lastly, offspring of preeclampsia had a reduction in microglia and astrocytes within the brain. DISCUSSION/SIGNIFICANCE: Our study could establish including in utero data in predicting future disease risk, addressing gaps in understanding rising rates of cardiovascular and behavioral diseases. It also uncovers the impact of preeclampsia on early immune programming and reduced glial cell populations, potentially affecting cognitive and behavioral development.

OBJECTIVES/GOALS: To identify novel panel of plasma protein biomarkers to improve prediction and diagnosis of Alzheimer’s disease (AD) for African Americans (AA), who are at greater risk of developing AD compared to non-Hispanic White individuals but are underrepresented in AD research. METHODS/STUDY POPULATION: Pre-existing plasma samples from 460 AA individuals with clinical diagnoses of AD, cognitively unimpaired (CU), mild cognitive impairment (MCI), or dementia with Lewy bodies (DLB) will undergo untargeted proteomics using the SomaScan assay, where modified single stranded DNA aptamers bind to protein targets which are quantified by DNA microarray. Protein expression levels will be compared between diagnostic groups to identify differentially expressed proteins. Additional clinical, genetic, and lifestyle factors will be compared with protein expression when available. Proteins of interest, identified by differential protein expression analysis results, will be included in receiver operating characteristic analyses to identify the optimal set of proteins for diagnostic classification. RESULTS/ANTICIPATED RESULTS: A pilot experiment utilizing plasma from 40 individuals identified multiple differentially expressed proteins (DEPs) between AD and non-AD groups. Eight proteins were nominated from the differential protein analysis into a receiver operating characteristic (ROC) analysis based on pvalue and previous implication in AD genome wide association studies. Proteins involved in microglial activation, neuronal adhesion, cell proliferation, and innate immunity were nominated. The ROC model achieved 100% classification accuracy of AD and CU groups using age, sex, and the eight nominated proteins. It is expected that there will be more significant associations when utilizing the full cohort of 460 AA and that DEPs between AD, CU, MCI, and DLB will be identified. DISCUSSION/SIGNIFICANCE: The nomination of a novel panel of plasma biomarkers developed from an AA cohort will directly serve the AA community by improving access to an early and accurate diagnosis of AD. Access to improved prediction and diagnosis will likely improve disease management, thus improving patient outcomes and decreasing burden on families and caregivers.

OBJECTIVES/GOALS: Determine the exosome mitochondrial DNA (mtDNA) copy number in cerebrospinal fluid (CSF) as a measure of neuronal mitochondrial integrity in patients with subarachnoid hemorrhage (SAH). Determine the patterns of beta amyloid and tau protein biology in CSF of SAH patients and correlate those measures with the clinical status of the SAH patients. METHODS/STUDY POPULATION: The CSF is collected from SAH patients undergoing ventriculostomy-based continuous CSF drainage. Adults from all ethnicities and sex are included in this study. The exosomes are isolated from CSF samples using a precipitation method and particle count and size are measured using NanoSight. The DNA is extracted using an exosomal DNA isolation kit (XCF kit). The CSF mtDNA copy number is measured using digital drop PCR with mitochondrial DNA primers. The levels of beta-amyloid (a-beta-40 and -42) and tau protein in CSF are measured using a sensitive ELISA-based assay. A quantitative evaluation of mitochondrial DNA copy number, clinical status of the SAH patients and beta amyloid, and tau protein levels will be conducted and reported. RESULTS/ANTICIPATED RESULTS: Preliminary results of four CSF samples showed similar patterns in CSF exosome particle number, particle size and exosomal mtDNA copy number in relation to samples from the admission day. Particle number decreased with time while particle size increased. More patient samples will be analyzed to confirm the patterns. We anticipate that mtDNA copy number will correlate with brain beta-amyloid and tau protein levels. Moreover, we anticipate that the clinical status of the SAH patients will associate with the mtDNA copy number. We specifically predict that higher mtDNA copy number levels will correlate with better clinical outcomes. DISCUSSION/SIGNIFICANCE: Mitochondrial function is critical to brain health, but we lack effective ways to monitor this parameter. Here we focus on a CSF based biomarker, exosome-derived mtDNA, which is intended to reflect the integrity of brain mitochondria. As bioenergetic metabolism influences beta amyloid and tau biology, predicting those levels are important.

OBJECTIVES/GOALS: Evaluate the use of IC to improve stroke survivors’ capacity for reactive stepping and adapt their gait cycles in response to a difficult walking environment. We hypothesize that IC will improve stroke survivors’ protective stepping response via improvements in muscle activation and motor learning METHODS/STUDY POPULATION: Stroke survivors have an impaired capacity for protective stepping. Decreased paretic muscle activation results in increased reaction time and reduced force generation. Ischemic conditioning (IC) is a vascular stimulus which improves motor performance in chronic stroke. It is performed by delivering transient, intermittent bouts of ischemia to a limb. It has been demonstrated that IC increases muscle activation post-stroke. 9 chronic stroke survivors completed 3 testing sessions and 7 intervention sessions. Participants walked on an instrumented treadmill and were perturbed unilaterally every step at the waist via a cable pulley system. Kinetic and kinematic data were collected. Step width was measured as the difference in position of the heel markers at the instant of heel strike in the frontal plane. RESULTS/ANTICIPATED RESULTS: After one and seven sessions of IC, controls did not alter their responses from baseline testing, but stroke survivors increased their step width by an average of 15% and 23% respectively. DISCUSSION/SIGNIFICANCE: Ischemic conditioning may be a useful intervention to improve stroke survivors’ ability to adapt their paretic foot placement in response to lateral perturbations during gait. Interventions which optimize muscle activation and neural adaptation could significantly improve balance post-stroke.

OBJECTIVES/GOALS: Donor hearts are transported in cold storage (CS) and undergo ischemia-reperfusion injury (IRI) when transplanted. IRI injures microvascular endothelial cells (EC), heightens the immune response, and has been associated with increased autophagy. We aim to understand the changes in autophagy during CS and IRI and its impact on EC immunogenicity. METHODS/STUDY POPULATION: To study autophagy changes during IRI, immunoblotting for autophagy markers was performed in mouse cardiac ECs (MCECs) lysates. MCECs were in a cold preservation solution in a hypoxic chamber for 6 hours(h) and warm conditions with culture medium for 24 h. MCECs, under standard conditions, served as controls. Secreted interferon-gamma (IFN-γ) levels were quantified via ELISA to study autophagy and EC immunogenicity. MCEC-sensitized CD8+ T-cells were isolated from C57BL/6 spleens and co-cultured with MCECs pre-treated for 16 h with rapamycin or starvation, autophagy inducers, or chloroquine, an autophagy inhibitor under normal or IRI conditions. MCECs without any treatment served as controls. RESULTS/ANTICIPATED RESULTS: To determine autophagy levels in IRI, immunoblotting of MCEC lysates revealed a significant increase (P<0.01) in the established autophagy marker, LC3, at early time points post-reperfusion compared to NT conditions, indicating more autophagosome formation during CS and IRI. To assess the role of autophagy in EC immunogenicity, the co-culture experiment revealed that autophagy induction in MCECs under NT and HCS conditions with rapamycin had a 74.9-fold and 51.5-fold reduction of IFN-γ (pg/mL), resepectively, compared to the non-treated controls. In contrast, autophagy inhibition in MCECs with chloroquine resulted in 1.82-fold increase of IFN-γ compared to untreated controls. This suggests a protective role of autophagy in ECs during IRI. DISCUSSION/SIGNIFICANCE: We observed that autophagy may be protective during IRI by mitigating EC immunogenicity. Thus, pharmacologically modulating microvascular EC autophagy in donor hearts prior to transplantation may mitigate insults incurred during CS and IRI.

OBJECTIVES/GOALS: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system. MS affects more than two million people worldwide, resulting in physical disability, cognitive impairment, and decreased quality of life. We are investigating the role of senescent cells, a hallmark of aging, in inflammation and disease progression in MS. METHODS/STUDY POPULATION: Female mice on a C57BL/6 background were subjected to the Hooke Laboratory EK-2110 experimental autoimmune encephalomyelitis protocol (EAE; n=10) to induce hind limb paralysis, and matching control mice received no injections (naīve; n=10). Immunofluorescent staining was used to visualize senescence cells and their localization in spinal cord tissue sections from naīve and EAE mice based on antibody detection of cell surface or intracellular proteins. Tissue sections from each group were analyzed in duplicates for each antibody (n=3-4/group). Flow cytometry was performed to immunophenotype the senescence cells using conjugated fluorescent antibodies to cell surface or intracellular proteins (n=5/group). RESULTS/ANTICIPATED RESULTS: Immunostaining demonstrated an increase in the cell senescence markers p16 (15-fold; unpaired t-test, p=0.01; n=3) and p21 (15-fold; unpaired t-test, p=0.003; n=3) in the spinal cord of EAE mice compared to naīve mice. Next, we showed that p16+ and p21+ cells increase with disease progression in the meninges adjacent to the ventral demyelinating lesions (one-way ANOVA, p=0.0009; n=3/group). We further found that 30±9.7% of M2 macrophages, a subset of myeloid cells, express p21 in the spinal cord of EAE mice by using flow cytometry analysis compared to only 5±1.6% in naīve mice (unpaired t-test, p=0.002; n=5/group). DISCUSSION/SIGNIFICANCE: Our findings demonstrate that senescent cells accumulate in the meningeal compartment following EAE induction, suggesting that decreasing senescent cell burden is a promising avenue in delaying disease progression and preventing neuroinflammation in MS.

OBJECTIVES/GOALS: The objective of this study was to determine whether pet dogs with multicentric lymphoma (ML), a spontaneous, immunocompetent model for human non-Hodgkin lymphoma (NHL), are exposed to higher concentrations of herbicides and volatile organic compounds (VOCs) compared to matched unaffected control dogs. METHODS/STUDY POPULATION: We are prospectively enrolling dogs with ML within a single high-risk breed, the boxer dog, along with age-matched control boxers sampled within the same season. We are measuring urinary concentrations of the herbicides glyphosate (in Roundup®) and 2,4-D, as well as stable urinary metabolites of the VOCs benzene and 1,3-butadiene. To assess the genotoxic potential of herbicide and VOC exposures, we are using reverse dosimetry to estimate plasma exposures, and exposing healthy canine PBMC’s to these concentrations of herbicides and VOCs in vitroto assess double stranded DNA damage using the Comet Chip assay. RESULTS/ANTICIPATED RESULTS: Preliminary data show significantly higher benzene exposures, measured by the stable benzene metabolite PHMA, and significantly higher 2,4-D exposures at the time of diagnosis in cases versus controls. All dogs had measurable exposures to 1,3-butadiene (measured as its stable metabolite DHBM) and glyphosate.In vitro results show significant genotoxicity thresholds of 0.1 uM for both glyphosate and 2,4-D in dog lymphoid cells. To date, these predicted plasma exposures have not been reached in vivo in boxer dogs with ML or unaffected control boxers. DISCUSSION/SIGNIFICANCE: Canine multicentric lymphoma resembles human NHL and is a potentially useful model of non-occupational chemical risk for NHL in people. The goal of this research is to identify potentially preventable non-occupational chemical risk for lymphoma and support evidence-based remediation strategies to decrease lymphoma risk in both humans and dogs.

OBJECTIVES/GOALS: Re-administration of inhaled gene therapies has the potential to overcome low correction efficiencies and limiting immune responses observed in previous trials of gene therapy for Cystic Fibrosis. We therefore tested the hypothesis that pre-treatment with a B-cell depleting α ± CD20 antibody would permit vector re-administration. METHODS/STUDY POPULATION: We first selected Adenoviral (Ad) vectors to study initially due to their well-known ability to elicit potent immune responses. Mice were dosed with a depleting α ± CD20 antibody or isotype control 2 days prior to delivery of Ad-Luc. 4 weeks later, mice were euthanized to assess the development of anti-vector immune responses. Flow cytometry and single-cell RNA sequencing were used to evaluate the development of lung-resident memory cells. Serum and airway antibody responses were assessed by ELISA. After 4 weeks, mice were dosed with Ad-LacZ and euthanized 3 days later to assess efficiency of second-round gene transfer by β-galactosidase activity assay. Similar methods were used in a pilot experiment with Adeno-associated virus vector (AAV), but with euthanasia 3 weeks after secondary gene transfer. RESULTS/ANTICIPATED RESULTS: Delivery of Ad vectors leads to the development of lung-resident memory B and T-cells. The depletion of B-cells prior to first-round vector delivery attenuated airway T-cell infiltration and serum IgG production, abrogated mucosal IgG and IgA production, and completely rescued secondary gene transfer. Genetically modified mouse models suggest secreted antibodies are critical in prevention of vector redosing. AAV vectors were found to be less immunogenic than Ad vectors, with only partial reduction of second-round gene transfer. However, anti-CD20 provided no benefit for AAV redelivery. DISCUSSION/SIGNIFICANCE: Mucosal humoral immunity is critical in preventing re-administration of Adenoviral vectors. Impairment of B-cell responses by α ± CD20 treatment prior to vector delivery allows re-administration and may help overcome low efficiencies of CF gene therapy. AAV vectors may be less susceptible to neutralization by pre-existing immunity.

OBJECTIVES/GOALS: Contrary to current dogma, prior work has suggested that in humans, SNP-determined endothelial cell reduction in CD39 expression associates with a diminished risk for venous thromboembolism. Our objective was to examine the impact of endothelial cell (EC) CD39 expression on arterial thrombosis that replicates human data. METHODS/STUDY POPULATION: We generated a novel CD39 cell-specific conditional knockout mouse line for endothelial cells (EC-cKO: Tie2-Cre+; cd39flox/flox versus WT: Tie2-Cre-; cd39flox/flox). We validated the knockout of expression of CD39 on EC using FACS analysis and measured EC CD39 activity using the Kinase Glo ATP hydrolysis assay on magnetically sorted EC. We then used a standard FeCl3 carotid injury model to evaluate time to arterial thrombosis in vivo by measuring time to occlusion tracked via a Doppler flow probe on the exposed vessel. RESULTS/ANTICIPATED RESULTS: FACS analysis revealed a specific 97% knockout of CD39 expression on EC (p<0.001) but not on other cells within the vasculature. There was also significant reduction in ATP hydrolysis (81%; p=0.019) in EC-cKO mouse EC versus WT. We next examined the time to arterial thrombosis. EC-specific conditional knockout of CD39 exhibited a significant prolongation in time to thrombosis compared to WT (WT: 8.28 minutes +/- 0.82; EC-cKO: 11.92 minutes +/- 1.34; p=0.024). Analysis of carotid blood-flow revealed that EC-cKO and WT mice had similar baseline blood flow velocity (p=0.51), but after vessel injury with FeCl3, EC-cKO mice exhibited a 16% increase maximal flow velocity relative to baseline compared to WT (p<0.001), as well as a 19% increase at 2-minutes post-injury in comparison to EC-WT mice (p<0.001). DISCUSSION/SIGNIFICANCE: Our findings demonstrate that CD39 activity plays a role in modulating arterial thrombosis and blood-flow regulation within the vasculature. These findings exemplify the therapeutic potential of modulating endothelial CD39 activity, as well as the potential for using SNPs within the gene coding for CD39 as a cardiovascular disease marker.

OBJECTIVES/GOALS: Ebolavirus disease survivors report persistent, debilitating health concerns dubbed Post-Ebola Syndrome (PES). Attention to PES in young survivors is lacking, we describe PES in pediatric EVD survivors in Eastern Sierra Leone. Additionally, we introduce our proposal investigating differential presentations of PES in pediatric survivors. METHODS/STUDY POPULATION: EVD survivors were enrolled a median of 2.5 years after resolution of disease. Survivors were eligible if listed in a national register maintained by the Sierra Leone Association of Ebola Survivors. Household contacts (HCs) were identified by survivors. Participants were assigned into three comparison groups: pediatric (7-11), adolescent (12-17) and young adult (18-25). A self-reported symptom questionnaire, and a physical exam were conducted. Variables were clustered within organ system and compared across groups. RESULTS/ANTICIPATED RESULTS: Pediatric survivors had lower levels of long-term sequelae compared to adolescents and young adults. Symptoms and abnormal physical exam signs increase with age. Musculoskeletal, psychiatric, ophthalmologic, and GI signs and symptoms were significantly different between groups. Pediatric survivors had significantly more persistent sequelae than age-matched HCs with no history of EVD; particularly within the cardiac/GI (p=.006) and psychiatric/neurological (p=.025) clusters. PES is heterogeneous with respect to age, calling for a deeper understanding of age-based differences. Even the youngest group of survivors experienced significantly more sequelae than HCs, highlighting the elevated symptom burden in these children over their peers. DISCUSSION/SIGNIFICANCE: Understanding mechanistic drivers will ultimately improve targeted treatments for PES. We will characterize symptom groups defining PES in children, determine the relationship between accelerated aging and PES in this population, and test how immune profiles associated with accelerated aging relate to the development of PES in children.

OBJECTIVES/GOALS: The global incidence of calcific aortic valve disease (CAVD) increased 3.5-fold since 1990. No preventative or therapeutic pharmaceutical therapies exist for CAVD. We will establish the therapeutic potential of osteoclast-derived exosomes though characterization of contents and mechanisms of action to protect against mineralization. METHODS/STUDY POPULATION: Exosomes were purified from conditioned media collected from murine myeloid precursor cells, RAW264.7 (control), and osteoclasts induced to differentiate from RAW264.7 cells (OD). Protein content of exosomes was determined using proteomic analyses. Nucleic acid contents will be identified by sequencing mRNA, miRNA, and DNA. The calcification prevention and reabsorption abilities of control and OD exosomes will be tested using human valvular interstitial cells (VIC) and smooth muscle cell calcification assays and acellular osteologic disc assays, respectively. Comparison between cellular and acellular systems will help identify mechanisms of action, and demonstrate potential therapeutic viability of OD exosomes in preventative vs resorptive treatments. RESULTS/ANTICIPATED RESULTS: OD exosomes, but not control exosomes, prevented calcification in VIC in vitro. OD exosomes contained osteoclast-specific proteins including TRAP, MMP6, cathepsin K, and bone reabsorption factors including V type proton pumps, ATPases, and integrins. These genes are also involved in resorptive activities, and were highly upregulated in OD compared to control exosomes. We anticipate miRNA signatures associated with mineral resorption will also be present. Increased knowledge of exosome cargo will illuminate their mechanism of action and allow future work to engineer increased efficacy. We also anticipate a therapeutic response when OD exosomes are applied after calcification has begun, showing exosomes promote calcium reabsorption. DISCUSSION/SIGNIFICANCE: Establishing therapeutic potential and examining mechanisms of action will pave the way for OD exosomes as a CAVD treatment. Analysis of exosome contents will determine active molecules to be enhanced in future studies. This work will lay a foundation for moving into aortic valve organoid models, which are accepted by the FDA for preclinical trials.