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/SPECIFIC AIMS: Virtual communities are an untested method to enhance community engagement in biomedical research. Our CTSA Hubs collaborated to assess receptivity to engage in a statewide Facebook (FB) group. METHODS/STUDY POPULATION: Cross-sectional online survey administered via iPads at the MN State Fair in 2018 to adults aged 18+ years residing in MN assessed demographics, social media use, interest in participating in a FB group for biomedical research; and open-ended questions on health topics of interest, and what would keep people engaged in this group. RESULTS/ANTICIPATED RESULTS: Respondents (N=487) were 21% racial minorities and 65% female sex. Most (87%, n=422) had created a personal FB profile. Of these, the proportion who agreed/strongly agreed was: 57% that the FB group sounded interesting, 45% were interested in being part of it, 41% were willing to share it with others, 62% that it would allow the community’s thoughts/ideas to be heard and 59% wanted to learn about opportunities to participate in research on health topics they care about. Using content analysis, the top 3 health topics people wanted to learn about were chronic disease and prevention, wellness, and mental health. Top ways to keep people engaged were providing personable, relevant health information; and interactive bi-directional discussions. DISCUSSION/SIGNIFICANCE OF IMPACT: Findings will inform development of a FB group to engage diverse populations in biomedical research.

OBJECTIVES/GOALS: The goal of this study is to highlight the unique characteristics of Miami CTSIs Master of Science in Clinical and Translational Investigation (MSCTI) as part of CTSIs overall translational workforce development program and to describe program outcomes. METHODS/STUDY POPULATION: The MSCTI at the University of Miami offers a structured, individualized, and mentored educational program that trains students in the principles and practice of translational science and clinical research. Based on student feedback and needs assessment, three courses were specifically created for the program to include additional scientific cognates and promote essential skills for the translational research workforce – team science and entrepreneurship, research ethics, and writing for clinical and translational science. A fourth course on applied statistics is currently under development that provides training in practical statistical knowledge required for clinician-researchers. Career trajectory of graduates and academic output were tracked through surveys and secondary data collection. RESULTS/ANTICIPATED RESULTS: The MSCTI Program has enrolled 76 students over its lifetime, including KL2 scholars, NIH K scholars and T32 trainees; with 25% of students holding foreign degrees. In addition to traditional outcomes such as funding and publications, qualitative case studies will highlight scientific impact and career progress of students. The program has performed exceptionally well in recruiting underrepresented persons in research, with 41% of the students identifying as Hispanic, and 52% of the students as female. Of the graduates, 84% have gone on to achieve leadership positions in NIH and pursue research careers in academic institutions, while 16% have moved to industry, government, or non-profit careers. Overall, 92% of graduates were engaged in research after two years of graduating from the program. DISCUSSION/SIGNIFICANCE: Miami CTSIs MSCTI Program has trained students with a wide range of incoming experience to establish successful careers in clinical and translational research and is a critical component of CTSIs translational workforce development program.

ABSTRACT IMPACT: This work sheds diagnostic insight on patients with idiopathic rare disease and has the potential to further their care and treatment as a result. OBJECTIVES/GOALS: Correct diagnosis is imperative to treating patients with idiopathic, suspected genetic conditions, yet sequencing approaches leave up to 70% of these patients undiagnosed. We sought to improve diagnosis rates for a cohort patients referred for sequencing by characterizing deleterious variants within the 5’UTR. METHODS/STUDY POPULATION: We retrospectively analyzed whole exome sequencing (WES) data from 472 unsolved rare disease patients within the Mayo Clinic Center for Individualized Medicine to identify variants within the 5’UTR that affect the presence of upstream open reading frames (uORFs). uORFs are short regions (typically 30bp - 600bp) that typically influence downstream gene translation by sequestering ribosomes. We specifically searched for variants with the potential to disrupt existing uORFs or introduce new uORFs within the 5’UTR, and developed a pipeline to annotate these variants with information including GnomAD allele frequency and gene loss of function intolerance (pLI) score. To aid in variant interpretation, we applied two deep learning tools to predict variant impacts on transcript ribosome load (TITER and FramePool). RESULTS/ANTICIPATED RESULTS: Our pipeline identified a median of 21 variants per patient that were predicted to have a deleterious impact on the translational efficiency of protein coding transcripts, primarily by introducing new start codons within the 5’UTR or by altering the Kozak consensus of existing start codons. A median of 10 of these variants occur upstream of haploinsufficient genes with an existing disease association. We also identified a subset of variants that are predicted to introduce translationally active N-terminal extensions to protein coding transcripts, with the potential to disrupt protein localization and processing. DISCUSSION/SIGNIFICANCE OF FINDINGS: This work demonstrates that analysis of 5’UTR variants can be incorporated into existing WES pipelines, and identifies a group of variants with potential significance to patient disease. Further experimental evidence is necessary to ascertain the pathogenicity of these variants.

OBJECTIVES/GOALS: The aim of this study was to quantify balance impairments in stance in individuals with degenerative cervical myelopathy (IwDCM) in response to external perturbations. IwDCM have damage to their spinal cord due to degeneration of the cervical vertebral column, but little is known about balance. METHODS/STUDY POPULATION: Recovery time following a perturbation may be an important measure of balance. Changes in recovery time were measured in 7 IwDCM (2m, 58.59±15.00y) and 6 controls without DCM (2m, 56.91±11.04y) as they stood on an instrumented treadmill and received cued (predictable) and uncued (unpredictable) lateral pulls to the waist at 12% (high) and 6% (low) pull magnitudes. Individuals stood with feet together, shoulder width, and wide. Recovery time was defined as the time following pull onset when the absolute value of the center of pressure velocity returned to <1x baseline standard deviation. Repeated measures ANOVA was performed on recovery time. RESULTS/ANTICIPATED RESULTS: We anticipate that feet together standing, unpredictable, higher magnitude perturbations will be most challenging evidenced by longer recovery times. For waist pull recovery time, there was a trend for a Group x Predictability x Magnitude x Stance Width interaction (p = 0.1) which we anticipate being greater with additional participants. There were significant Group x Predictability x Stance Width (p = 0.01) and Group x Magnitude x Predictability (p = 0.01) interactions. IwDCM had exaggerated recovery times in narrow and wide stances with unpredictable pulls. IwDCM recovered more slowly in response to unpredictable higher magnitude pulls. DISCUSSION/SIGNIFICANCE OF IMPACT: Balance responses in IwDCM are most impaired in narrow stances and when perturbations are unpredictable. Rehabilitation should focus on shortening latency of response timing and increasing power utilization during balance response to promote quicker recovery.

OBJECTIVES/GOALS: A growing number of older adults in the United States have multiple social determinants of health (SDoH) that are barriers to effective medical care. We used generalizable machine learning methods to identify and visualize subtypes based on participant-reported SDoH profiles, and their association with delayed medical care (self-reported yes/no). METHODS/STUDY POPULATION: Data. All participants aged >=65 in All of Us with complete data on 18 SDoH self-reported variables, selected through consensus by 2 experienced health services researchers, and guided by Andersen’s behavioral model. Covariates included demographics, and the outcome was delayed medical care . Cases (n=4090) consisted of participants with at least one of the 18 SDoH variables, and controls (n=7414) consisted of participants with none of them. Method. (1) Used bipartite network analysis and modularity maximization to identify participant-SDoH biclusters, and visualize them through ExplodeLayout. (2) Used multivariable logistic regression (adjusted for demographics and corrected through Bonferroni) to measure the odds ratio (OR) of each participant bicluster to the outcome, compared with the controls. RESULTS/ANTICIPATED RESULTS: The analysis identified 7 SDoH subtypes (https://postimg.cc/Vd7Pg4xZ) with statistically significant modularity compared with 100 random permutations of the data (All of Us=.51, Random Mean=.38, z=20, P DISCUSSION/SIGNIFICANCE: The results identified 7 distinct subtypes based on SDoH profiles and their risk for delayed medical care, highlighting the importance of addressing specific combinations of barriers, with affordability having the highest risk. Furthermore, the analytical methods used are generalizable and have been made publicly available on CRAN and All of Us.

ABSTRACT IMPACT: Preliminary results will inform the formal evaluation of the reliability of point-of-care ultrasound (POCUS) done by the gastroenterologist compared to standard of care methods such as MR-Enterography. OBJECTIVES/GOALS: Evaluation of mucosal healing is standard for pediatric patients with inflammatory bowel disease (IBD). Point-of-care ultrasound is a non-invasive, cost-efficient tool for assessing intestinal inflammation. We aim to evaluate the agreement between POCUS and typical cross-sectional imaging, such as MR-Enterography (MRE). METHODS/STUDY POPULATION: In this cross-sectional study, we recruited consecutive patients newly diagnosed with IBD, presenting to the specialty outpatient clinic or hospitalized in a pediatric tertiary care center between August to November 2020. They underwent POCUS performed by a single gastroenterologist, in addition to MRE. The sonographer was blinded to MRE results. Bowel wall thickness (BWT) was measured across different bowel segments and recorded twice in longitudinal view and twice in axial view. An average segmental BWT of the four measurements of more than 3 mm was considered inflamed. Agreement between sections of the bowel measured as inflamed were compared to inflamed bowel segments seen by MRE, using Cohen’s kappa. RESULTS/ANTICIPATED RESULTS: Eight of 12 patients completed both MRE and POCUS.A total of 40 bowel segments were assessed, namely the terminal ileum, ascending, transverse, descending and sigmoid colon. There were 4 girls with a median age of 15 years (IQR 14.25-16 years), and 6 patients were diagnosed with Crohn’s disease. Median PCDAI was 32.5 (IQR 30.6-40), and median PUCAI was 75 (72.5-77.5). Agreement between MRE and point-of-care ultrasound was substantial to perfect for the terminal ileum *(κ= 0.75, 95%CI 0.31-1), transverse colon (κ= 1, 95%CI 1-1) and sigmoid colon (κ= 1, 95%CI 1-1). The agreement was poor for the ascending (κ= 0, 95%CI 0-0) and moderate for the descending colon. (κ= 0.6, 95%CI -0.07-1) DISCUSSION/SIGNIFICANCE OF FINDINGS: In pediatric patients with IBD, we found a high agreement between POCUS and MRE for imaging of the terminal ileum, transverse and sigmoid colon, areas commonly involved in IBD. This reinforces adult data, outlining the potential of POCUS as an evaluation tool of disease activity in clinical practice.

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/SPECIFIC AIMS: The overall objective of this study is to develop a novel, clinically-relevant, image-guided mouse model for radiation-induced cardiotoxicity, which can be used to gain insight into clinically-targetable, pathophysiologic mechanisms of cardiac injury in thoracic radiotherapy patients. METHODS/STUDY POPULATION: Photon or sham radiation will be administered at differential doses to a defined portion of the heart and/or lungs of C57BL/6 female mice using micro-CT visualization of the heart with Xstrahl’s MuriSlice Software applied to the Small Animal Radiation Research Platform (SARRP). Cardiac and lung segments from a subset of mice will be harvested at specific time points for confirmation of radiation targeting, local apoptosis assessment, and evaluation of fibrosis and vascular tissue morphology. Quantitative echocardiography, myocardial 18F-fluorodeoxyglucose positron emission tomography computed tomography (18F-FDG PET/CT), and myocardial perfusion imaging (MPI) with Technicium-99 (Tc-99) sestamibi will be implemented to identify sensitive imaging measures of cardiac injury and asses myocardial mechanics, inflammation, and perfusion deficits, respectively. Concurrently, a multiparametric analysis will be conducted to identify novel, circulating biomarkers of cardiotoxicity. RESULTS/ANTICIPATED RESULTS: We hypothesize that a clinically-relevant mouse model can be generated by the in situ, focal irradiation of a portion of heart and/or lung tissue segments, and can be used to elucidate molecular mechanisms of radiation-induced cardiac damage. We anticipate time-dependent and dose-dependent, focal histopathologic changes in the mouse heart, with cardiac fibrosis development, vascular damage, and cellular apoptosis in irradiated mice. Additionally, we anticipate that our mouse model of focal heart irradiation will reveal radiologic and biochemical changes that can be used to characterize and predict radiation-induced cardiac injury. Specifically, we expect our quantitative echocardiography, FDG-PET, and MPI parameters to identify and characterize cardiac damage that topographically matches histopathological analysis, and expect levels of select biochemical markers to differentially vary with time. DISCUSSION/SIGNIFICANCE OF IMPACT: Our mouse model of radiation-induced cardiotoxicity has the potential to shift current preclinical research paradigms to more closely mimic the radiation plans most commonly administered in clinical practice. The primary technologic innovation to be developed here is the use of the SARRP to deliver image-guided, in situ, focal radiation to a defined portion of the mouse heart. From a conceptual perspective, we propose a novel approach for phenotyping radiation-induced cardiac damage in patients undergoing chest radiation therapy, integrating sensitive radiomic and biochemical markers into a predictive model of cardiotoxicity.

OBJECTIVES/GOALS: The goal of this study is to describe the implementation of a formal research mentoring training program at Miami CTSI in collaboration with University of Colorado CTSI, to build effective mentor-mentee relationships that help build successful research careers for junior faculty. METHODS/STUDY POPULATION: The Miami CTSI Research Mentoring Training is a three-part series for early stage faculty and their mentors to strengthen mentoring skills and build successful relationships. The curriculum uses evidence-based strategies and is modeled after University of Colorado CTSIs CO-Mentor Training Program. The pilot training was conducted as a train-the-trainer program with subsequent workshops led by Miami CTSI faculty. The program has mentee-only, mentor-only, and joint sessions covering topics such as networking skills, managing financial aspects of an academic career, and career mapping. To assess program effectiveness, pre/post surveys were conducted and follow up surveys are planned. Data collected will assess participant diversity, research productivity, and mentoring relationship status. RESULTS/ANTICIPATED RESULTS: A total of 49 mentor-mentee teams from 18 departments participated in the training over two cohorts. An upcoming third cohort will be included in the analysis. Overall, 100% mentors and 86% mentees reported the overall value of the program as positive. Post-training, mentees reported an increase in confidence in creating career development plans and articulating career goals. Mentors reported an increase in confidence in providing guidance tailored to mentees needs. Mentees reported improvement in their knowledge of developing personal narratives and handling financial aspects of research; both mentors and mentees reported improvement in insights into achieving work-life balance. Follow up survey results will provide insight into the evolution of the mentoring relationships. DISCUSSION/SIGNIFICANCE: Miami CTSIs mentoring training demonstrated successful participation and positive feedback from mentors and mentees and is poised to become a critical component of the Miami CTSIs research career development pipeline.

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: Nearly all thoracic aortic aneurysm patients suffer from hypertension leading to elevated wall tension and abnormal extracellular matrix remodeling. PTSD patients have higher blood pressure both at rest and in response to stimuli. Although stress is associated with cardiovascular disease, the exact mechanism linking the two is still unknown. METHODS/STUDY POPULATION: Adult C57BL/6 mice underwent a PTSD induction protocol consisting of inescapable foot shock followed by single prolonged stress. The mice were assessed incrementally for their PTSD-like phenotype using specific behavioral tests chosen to assess for each of the human criteria of PTSD according to the DSM-V. Tail cuff blood pressure measurements were taken serially throughout the 16-week protocol. At terminal study, thoracic aortic diameter measurements were obtained through digital microscopy and plasma was harvested for cytokine analysis. Thoracic aortic aneurysms (TAA) were induced through periadventitial application of a calcium chloride solution on the descending thoracic aorta in BPH/2J and BPN/3J adult mice. The thoracic aortic diameter was measured at terminal study through digital microscopy. RESULTS/ANTICIPATED RESULTS: Using our PTSD-like mouse model we have demonstrated that PTSD-like mice have significantly higher systolic blood pressure following a reminder of the traumatic event than control mice recapitulating the human phenotype. They also had increased plasma proinflammatory cytokines and larger thoracic aortic diameters than control mice. Although the increased thoracic aortic diameter is not an aneurysm, it suggests ECM remodeling is occurring predisposing the aorta to aneurysm formation. Finally, we have shown that in neurogenic hypertensive mice, TAA formation was accelerated by 12 weeks with roughly 70% dilation at 4 weeks post-TAA induction surgery as compared to roughly a 20% dilation in control mice. DISCUSSION/SIGNIFICANCE: Altogether, these studies reinforce the link between stress and TAA development, and our mouse model will allow for the underlying mechanism to be elucidated. Better understanding of the mechanism linking PTSD and TAA will allow for the creation of novel therapeutics to treat PTSD symptoms while also delaying TAA progression.

ABSTRACT IMPACT: The key to advancing precision medicine is to deepen our understanding of drug modes-of-action (MOA). This project aims to develop a novel method for predicting MOA of potential drug compounds, providing an experimental and computational platform for more efficient drug discovery. OBJECTIVES/GOALS: To develop (1) a targeted CRISPR-Cas9 chemical-genetic screen approach, and (2) a computational method to predict drug mode-of-action from chemical-genetic interaction profiles. METHODS/STUDY POPULATION: Screening drugs against a gene deletion library can identify knockouts that modulate drug sensitivity. These chemical-genetic interaction (CGI) screens can be performed in human cell lines using a pooled lentiviral CRISPR-Cas9 approach to assess drug sensitivity/resistance of single-gene knockouts across the human genome. A targeted, rather than genome-wide, library can enable scaling these screens across many drugs.

CGI profiles can be derived from phenotypic screen readouts. These profiles are analogous to genetic interaction (GI) profiles, which represent sensitivity/resistance of gene knockouts to a second gene knockout rather than a drug. To computationally predict a drug’s genetic target, we leverage the property that a drug’s CGI profile will be similar to its target’s GI profile. RESULTS/ANTICIPATED RESULTS: Five proof-of-principle screens will be conducted with compounds that have existing genome-wide profiles and well-characterized MOA. I will generate CGI profiles for these five compounds and identify genes that are drug-sensitizers or drug-suppressors. I will then evaluate whether targeted library screens can recapitulate the CGIs found in genome-wide screens. Finally, I will develop a computational tool to integrate these CGI profiles with GI profiles (derived from another project) to predict gene-level and bioprocess-level drug targets. These predictions (from both targeted and genome-wide profiles) will be benchmarked against a drug-target and drug-bioprocess standard. DISCUSSION/SIGNIFICANCE OF FINDINGS: This work will develop a scalable, targeted chemical-genetic screen approach to discovering how putative therapeutics work. The targeted screen workflow provides a method for higher-throughput drug screening. The computational pipeline provides a powerful tool for exploring the MOA of uncharacterized drugs or repurposing FDA-approved drugs.

OBJECTIVES/SPECIFIC AIMS: Aim 1: To compare frozen MOM to fresh MOM over time as an agent to inoculate DHM and measure the enrichment of commensal microbes and their beneficial bioactive components similar to MOM. Hypothesis: Frozen or fresh MOM inoculated in DHM will produce similar microbial content to MOM over time allowing for the production of beneficial bacterial compounds that may contribute to host immune response. Aim 2: To determine the effect of MOM storage (fresh vs frozen) on the expansion of bioactive components from live microbiota in DHM. Hypothesis: Both fresh and frozen MOM will produce similar results when inoculated into DHM to restore the microbial content (including their bioactive components) similar to each MOM sample. Aim 3: To compare the microbiome found in a mother’s MOM to the microbiome in her infant’s stool. Hypothesis: The mother/infant pair will share a common microbiome between the mother’s MOM and her infant’s stool. METHODS/STUDY POPULATION: Subjects will include 12 pump-dependent mothers of infants born < 34 weeks gestation admitted to the University of Florida Health Shands Hospital, Neonatal Intensive Care Unit (NICU). Inclusion criteria consists of mothers expressing over 100 ml of MOM per day, producing at least 45 ml of MOM at an expression session, at least 18 years of age, and speak English. Mothers are excluded if they have taken antibiotics within 3 days of sample collection, are HIV+, or delivered an infant who has a chromosomal abnormality or is severely ill. An expressed MOM sample will be collected and divided into two fractions: (A) fresh and (B) frozen at -20C for 24 h. The fresh fraction (A) will be processed immediately while the frozen fraction (B) will be processed after 24 h. Each MOM will be inoculated in DHM at dilutions of 10% and 30% and incubated at different time points: 0 h (T0), 2 h (T2), 4 h (T4) at 37°C. At each time point, total viable cell counts as well as microbiome analysis through 16S ribosomal shotgun sequencing will be performed and compared for differences. Bacteria isolated from each MOM will be saved, identified through 16S ribosomal sequencing and grown in culture for future studies. Fecal samples from each corresponding infant will be collected within 48 h after collection of the MOM sample. Stools will be homogenized and subjected to DNA extraction to perform 16S ribosomal shotgun sequencing. Microbiome analysis will be conducted, compared between fecal samples as well as with the microbiome of the MOM. RESULTS/ANTICIPATED RESULTS: Study is ongoing. We anticipate similar results with fresh or frozen MOM to that of a previous pilot study, where enriched microbiota similar to MOM was found when fresh MOM was inoculated and incubated in DHM. The microbiome analysis of the infant fecal samples may illustrate the influence that the microbiome of the MOM may have on the development of the infants’ gastrointestinal microbiota. DISCUSSION/SIGNIFICANCE OF IMPACT: The purpose of this study is to provide evidence on the ability, timing, and efficacy of inoculating DHM with fresh and frozen MOM. Study results will inform future studies to support the implementation of an inoculation procedural protocol to be used in clinical practice and human milk banking. The description of the MOM microbiome, as well as the gastrointestinal microbiome, will expand scientific knowledge on the role breast milk has on the origins of health and disease.

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: Targeting the V-domain immunoglobulin suppressor of T cell activation (VISTA) signaling pathway has been suggested as a promising approach for overcoming resistance to current immune checkpoint therapies in advanced cancer. This review will synthesize the rapidly-expanding literature on VISTA protein expression on prognosis in various cancers. METHODS/STUDY POPULATION: To determine the prognostic significance of high VISTA expression across treatment-naïve malignant tumors, a systematic review and meta-analysis will be performed of published cohort studies which measured VISTA protein expression on solid tumors. Primary and secondary outcome endpoints of overall survival (OS) and disease-specific survival (DSS) will be compared across cohort studies using a random effects model to calculate pooled hazard ratios (HRs) for each time-to-event end point with 95% CIs. For articles that only provide Kaplan-Meier (KM) curves, the Engauge Digitizer software will be used to measure the time and survival probability coordinates on the KM curves to estimate the HRs. Correlations of VISTA expression and clinicopathological characteristics will be evaluated by pooled risk ratios. RESULTS/ANTICIPATED RESULTS: A search of 4 electronic databases including Pubmed, Embase, Web of Science and Cochrane resulted in 5578 publications of which 66 containing a broad spectrum of malignant solid tumors will undergo full-text review for study inclusion. Tumor types most represented with at least 3 articles include lung, pancreas, skin, head & neck, colorectal, mesothelioma, cervix, soft tissue, breast, liver and ovarian. Our working hypothesis is that the pooled HR for high VISTA expression on overall survival will be approaching 1.0 given conflicting reports across the cancer literature. Risk of bias will be assessed across studies. Quantifications of heterogeneity will be assessed by visual exploration of forest plots as well as by multiple statistical metrics including the Q statistic and the I²coefficient. DISCUSSION/SIGNIFICANCE: The results of this systematic review and meta-analysis will provide a more comprehensive understanding of VISTA’s prognostic role both across all malignant tumors and for subgroups of similar tumor types which may impact the types of tumors and tumor microenvironments selected for early trials of anti-VISTA therapy.