OBJECTIVES/SPECIFIC AIMS: Children born with a single ventricle congenital heart defect requires three invasive open-heart surgeries in the first three years of life. The third operation, the Fontan procedure, includes connection of the vena cava (VC) to the pulmonary artery (PA) using a bio-inert conduit to reduce work required by the right ventricle (RV). While this operation greatly extends the lives of HLHS patients, the Fontan circuit eventually fails, and the only solution is a scarcely available donor heart. This failed circuit is explained by the “Fontan paradox” where central venous pressures build up over time, causing increased systemic resistance and congestion. The absence of the sub-pulmonary ventricle leads to abnormal hemodynamics associated with life-threatening complications. We believe that decreasing central venous pressures through the use of a tissue engineered contractile, patient specific conduit will decrease the amount and severity of complications caused by the “Fontan paradox.” We will use amniotic fluid derived induced pluripotent stem cells (AF-iPSCs) differentiated into cardiomyocytes (CMs) to generate flow within a biodegradable conduit. Additionally, AF-iPSC will be differentiated into structural support cells (SSCs), including cardiac fibroblasts and epicardium. Several studies suggest advanced contraction and structure of CMs in specific ratios with SSCs, particularly mouse and human fetal fibroblasts. In combination, these cells have shown advanced tissue organization and function through mechanically and electrically aligned junctions. This allows them to have a magnitude higher contractile force than CMs alone, making them ideal for increasing pressure within a tissue engineered construct. This poster focuses on the differentiation and selection of SSCs. METHODS/STUDY POPULATION: AF-iPSCs differentiation began at roughly 80% confluency. Mesoderm formation occurred via WNT pathway modulation by supplementing RPMI+insulin media with 0.5 ng/mL BMP4 at day 0, followed by 3 ng/mL BMP4, 2 ng/mL Activin A, and 5 ng/mL BFGF for four days. Then, RPMI+insulin media was supplemented with 10 ng/mL of BMP4 until day fifteen for epicardial formation. Cells were lifted to induce epithelial-to-mesenchymal transition (EMT) and RPMI-insulin media was supplemented with 10 ng/mL BFGF for cardiac fibroblasts. They were then harvested and characterized using immunofluorescence. Planned experiments include RT-qPCR for further characterization of cardiac fibroblasts. Additionally, a fibroblast isolation plating technique will be utilized to obtain cardiac fibroblast from AF-iPSC CMs and AF-iPSC epicardium. Commercially obtained human cardiac fibroblasts will be utilized as a control for all studies. RESULTS/ANTICIPATED RESULTS: Immunofluorescence (IF) revealed positive expression of vimentin and α-SMA indicating a fibroblast and vascular smooth muscle phenotype after supplementation with 10 ng/mL of BMP4 after EMT induction. It is expected that IF of epicardial formation at day 15 will show positive expression of WT1, a well-known epicardial marker. We also suspect RT-qPCR will reveal high expression of cardiac fibroblast specific markers COL1A1, PDGFA, TCF21, and THSB1. We expect to yield a higher number of cardiac fibroblast from the small molecule AF-iPSC differentiation compared to a timed plating technique of AF-iPSC CMs and AF-iPSC epicardium (separately plated). Results will be quantified and compared using the aforementioned techniques. DISCUSSION/SIGNIFICANCE OF IMPACT: Discussion/significance of impact: Although fibroblasts make up a large portion of cells in the heart and greatly enhance CM function, they are poorly characterized in the literature and not easily obtained. This study will provide an efficiency comparison on the best method for acquiring cardiac fibroblast for cardiac tissue engineering applications as we move forward with translational cardiac pediatric research.

OBJECTIVES/SPECIFIC AIMS: The goals of this study were (1) to evaluate the effect of proarrhythmic drugs on calcium transient and (2) to use three-dimensional human engineered cardiac tissue (hECT) technology to evaluate cardiac contractile properties in response to pharmacological challenge with proarrhythmic drugs. METHODS/STUDY POPULATION: Calcium transient was measured in subject-specific iPSC-CMs by using the IonOptix system in Sotalol treated vs. untreated conditions. We fabricated human engineered cardiac tissues (hECT) in a custom designed bioreactor using low- and high-sentitive subject-specific iPSC-CMs. Contractile function of the hECT was evaluated at baseline and after Sotalol [300 µM] administration. The change in beat rate was recorded under spontaneous beating conditions; changes in other twitch parameters, including time to relaxation, were recorded under electrical stimulation. Time to relaxation served as an indicator of action potential duration (APD), which has a temporal correlation with the QT interval. RESULTS/ANTICIPATED RESULTS: The low-sensitive iPSC-CM showed a considerable drop in overall peak height of the calcium transient, in the presence of 100 µM Sotalol. The high-sensitive line, however, showed a more pronounced drop in peak height. Sotalol treatment also induced a more pronounced increase in the exponential decay time constant (tau) in the high-sensitive line compared to the low-sensitive line. The hECT fabricated with high sensitive hiPSC-CM showed a larger decrease in spontaneous beat rate in response to Sotalol (0.41 vs 0.23 fold decrease), with a higher increase in time to relaxation (1.8 vs 1.3 fold increase), compared to hECT from low sensitive hiPSC-CM. Moreover, while the low-sensitive hECT showed a positive correlation between time to relaxation and developed force, as expected after Sotalol stimulation; the high-sensitive hECT failed to show a positive inotropic response. DISCUSSION/SIGNIFICANCE OF IMPACT: Our findings suggest subject-specific iPSC-CMs and hECT, can be used to model functional abnormalities observed in diLQTS in response to Sotalol, and offer novel insights into human-based screening assays for toxic drug reactions. Success of this study may help identify key components underlying diLQT susceptibility to ultimately develop novel therapeutic agents.

OBJECTIVES/SPECIFIC AIMS: The cellular mechanisms that underlie the IFNβ/α ratio that predicts response are not known. Effects of IFN on single immune cells may be masked in whole blood or mixed cell populations. By studying the effect of IFNβ/α activity ratio on individual monocytes, we can determine the functional impact of the IFN ratio and suggest the cellular mechanisms that underlie response/non-response to TNFi therapy in RA. METHODS/STUDY POPULATION: We used single cell analysis to investigate whether monocyte gene expression differs significantly between RA patients according to their pre-TNFi serum IFN-β/α ratio. Single classical (CL) and non-classical (NC) blood-derived monocytes were isolated from 15 seropositive RA subjects prior to biologic therapy. Subjects were grouped by pre-TNFi serum IFN-β/α ratio into two groups, those with a high IFN-β/α ratio (≥1.3, n = 6) and those with a low IFN-β/α ratio (<1.3, n = 9). 87 target genes were analyzed. Genes that varied significantly between the groups by categorical analyses were tested in multivariate logistic regression models. RESULTS/ANTICIPATED RESULTS: Every participant was seropositive for rheumatoid factor and antibodies to cyclic citrullinated peptide. Among the participants in the groups, there were no significant differences in age or DAS scores (P>0.05). The treatments were comparable and none were being treated with biologic therapy. There were striking differences in monocyte gene expression between patients with pre-treatment blood IFNβ/α activity <1.3 and ≥1.3. Expression of (1) key type I IFN pathway genes (JAK1, STAT2, IFIT2, IFIH1, PRDM1); (2) IL12; (3) CD36; and (4) CTLA4 were the strongest differentiators between groups (p<0.0001 for each, corrected for multiple comparisons). DISCUSSION/SIGNIFICANCE OF IMPACT: In this study we were able to measure gene expression in single monocytes from seropositive RA patients prior to biologic treatment. Within-cell co-expression patterns demonstrate biological differences in monocytes of RA patients with an IFNβ/α ≥1.3, the ratio of type I IFNs which predicts non-response to TNFi. The data suggest that there may be differential IFN production and pathway activation in patients who do not respond to TNFi. The increased expression of CD36 in monocytes from RA patients with high IFN β/α activity may be a reflection of increased “foam cells” in the inflamed tissue of patients who do not respond to TNFi. Enrichment of CTLA4 in those with high serum IFNβ/α suggests that CTLA4-Ig may be less likely to be an effective alternative for someone who is not likely to respond to TNFi. Current work includes determining whether the peripheral blood findings reflect altered cellular composition, type I IFN production and signaling in the synovium. Significance: This work will help to develop a more individualized approach to therapy in RA and determine an immunological basis of response/non-response to TNFi.

OBJECTIVES/SPECIFIC AIMS: This project aims to determine the key molecular pathways that link increased myocardial wall stress to cardiomyocyte hypertrophy and subsequent heart failure. We will use a cardiac microtissue (CMT) model with dynamically tunable cantilever stiffness to examine changes in CMT hypertrophy and electro-mechanical properties in response to increased afterload (cantilever stiffness). Subsequently, we will determine if inhibition of pro-hypertrophic or anti-hypertrophic pathways alter the hypertrophic response to increased afterload. Primary outcomes for this study are static/dynamic force, minimum electric field strength (VT), maximum capture rate (MCR), average cell area, and tissue cross-sectional thickness, and secondary outcomes are degree of myoblast activation and apoptosis. METHODS/STUDY POPULATION: CMT platforms will be fabricated using iron-doped polydimethylsiloxane (PDMS) to create magnetically tunable cantilevers. Cantilever stiffness will be increased with the application of an external magnetic field. Cantilever stiffness will be measured using a capacitance probe, where the force required to deflect both the cantilever and calibration probe is in accordance with Hooke’s Law. Human induced pluripotent stem cell cardiomyocyte (hiPSC-CMs) will be cultured and matured as 3D CMTs. In-vitro static/dynamic force generation will also be calculated by measuring the deflection of the cantilevers and applying Hooke’s law. CMTs will be paced using carbon electrodes to obtain VT and MCR. Structural data will be obtained using immunostaining and confocal microscopy. Finally, we will use pharmacologic inhibitors to inhibit molecular pathways that we identified in prior genetic screens such as ABCC8 (anti-hypertrophic mediator) and C1QTNF9 (pro-hypertrophic mediator). We will examine each of these pathways in low- and high-stiffness conditions. RESULTS/ANTICIPATED RESULTS: We believe increased afterload will cause significant hypertrophy, measured by increases in CMT cross-sectional thickness, cardiac myocyte area, myofibroblast activation, and myocyte apoptosis. In addition, we expect to see increases in static/dynamic force, increased voltage threshold, and decreased maximum capture rate. Preliminary results show a 64.3% increase in force generation when stiffness is increased by approximately 30%, and a 44.4% decrease in force generation when stiffness is decreased by approximately 30%. Finally, we expect that inhibiting a pro- or anti-hypertrophic molecular pathway will weaken or strengthen the hypertrophic response to increased afterload, respectively. DISCUSSION/SIGNIFICANCE OF IMPACT: To our knowledge, our lab is the first to create a dynamically tunable afterload system in the cantilever CMT model. This advance provides us with a robust platform to determine the molecular pathways that cause increased myocardial wall stress to result in cardiomyocyte hypertrophy and heart failure, which remain a critical knowledge gap in our understanding of cardiovascular disease. With more precise understanding of these pathways, we will equip ourselves with the knowledge to develop novel therapeutic agents to prevent the development or progression of heart failure.

OBJECTIVES/SPECIFIC AIMS: Early life stress is known to greatly impact neurodevelopment during critical periods, conferring risk for various psychopathologies, including the onset and exacerbation of schizophrenia and anxiety disorders. The endocannabinoid system is highly integrated into the stress response and may be one means by which early life stress produces such deleterious effects. Using a naturalistic, ecologically valid animal model, this study explored interactions between the stress response and endocannabinoid systems within the cerebellum, a region dense with the CB1 endocannabinoid receptors and shown to be susceptible to stress. METHODS/STUDY POPULATION: This study explored behavioral and neural impacts of early life stress in Long-Evans rats reared with or without limited access to bedding material during postnatal day (PND) 2-9. Corticosterone (CORT) levels were measured at PND8 and 70. During PND50-70, rats were assessed on Novel Object Recognition to test memory, Rotarod to evaluate cerebellar integrity, Elevated Plus Maze to assay anxiety, Social Preference, and Eyeblink Conditioning, a cerebellar-dependent and endocannabinoid-mediated task. Lipid analysis was performed on PND70 tissue samples of cerebellar interpositus (IP) nucleus via high-performance liquid chromatography and tandem mass spectrometry. RESULTS/ANTICIPATED RESULTS: Both male and female rats experiencing early life stress exhibited significantly impaired recognition memory (N = 16-20/group). Female rats having undergone stress exhibited decreased social preference compared to normally reared females (N = 11/group). Stressed males showed facilitated eyblink conditioning compared to normally reared males (N = 7-9/group). There were no group differences in rotarod or elevated plus maze performance or CORT levels at PND8 or 70 across rearing groups. At PND70, male rats experiencing early life stress exhibited a significant decrease in 2-arachidonoyl glycerol (2-AG) and arachidonic acid levels in the IP nucleus compared to normally reared males (N = 8-9/group). Compared to normally reared females, those experiencing early life stress exhibited a significant increase in prostaglandin E2 levels in the IP nucleus (N = 6-7/group). DISCUSSION/SIGNIFICANCE OF IMPACT: Early life stress, induced by limited bedding, resulted in sex-specific behavioral and lipid impairments. Results suggest that stress causes long-term alterations in endocannabinoid dynamics in males in the cerebellar IP nucleus and sex-related lipids in female cerebellum. These changes may contribute to observed long-term behavioral aberrations. Moreover, findings suggest these behavioral changes may be the result of negative-feedback dysfunction (as evidenced by decreased endocannabinoids in males) or increased neural inflammation or proliferation (as evidenced by increased prostaglandins in females). Future analysis will quantify mRNA and protein for cannabinoid receptors to better characterize aberrations to this system. Moreover, other neural regions dense with cannabinoid receptors (i.e., PFC, hippocampus) will be investigated. This work provides a basis for understanding stress impacts on the development of cognitive deficits observed in psychotic and anxiety disorders. Specifically, facilitation of eyblink conditioning complements research in humans with anxiety disorders. Broadly, understanding stress-related endocannabinoid dysregulation may provide insights into risks for, and the development of, psychopathology and uncover novel therapeutic targets with high translational power.

OBJECTIVES/SPECIFIC AIMS: In the context of skeletal muscle, IL-6 plays a major role in muscle quality. The goal of this project was to study the influence of systemic IL-6 on skeletal muscle mitochondrial physiology, most notably mitochondrial function (respiration and ROS production) and mitochondrial content. METHODS/STUDY POPULATION: To determine the influence of interleukin-6 (IL-6) on skeletal muscle mitochondria, high-resolution respirometry was performed to simultaneously measure oxygen consumption (JO2) and ROS production in differentiated myotubes incubated with increasing IL-6 (0, 10, 50, 100 ng/mL) for 18 hours in serum free conditions. To evaluate the impact of IL-6 on mitochondrial content we performed western blots on cell lysates from treated cells, measuring proteins of the mitochondrial electron transport chain (ETC) using a cocktail antibody and PGC-1α/PGC-1ß for mitochondrial biogenesis. To determine the role of mitochondrial ROS production on JO2 and mitochondrial content, we co-treated differentiated myotubes for 18 hours with 50 and 100ng/mL IL-6 and the mitochondrial specific antioxidant, MitoQ and performed respirometry for mitochondrial functional measurements and western blots for mitochondrial content.Statistical significance was evaluated by using a 2-tailed Student’s t-test and two-way ANOVA. Post hoc all-group analyses were conducted to determine which groups were different when the model was significant. RESULTS/ANTICIPATED RESULTS: Mitochondrial functional measurements show increased JO2 and increased ROS production in an IL-6 dose-dependent manner. Targeting mitochondrial ROS production with 0.5µm MitoQ attenuated IL-6 induced increases in JO2 and ROS production. Complexes I and II (CI, CII) of the ETC increased significantly in an IL-6 dose-wise fashion, and co-treatment with MitoQ normalized increases at 100ng/mL Il-6. 100ng/mL IL-6 significantly increased protein expression of PGC-1α and PGC-1ß. Co-treatment with MitoQ normalized IL-6 induced increase in PGC-1α. DISCUSSION/SIGNIFICANCE OF IMPACT: Our data suggest that when treated chronically at a high dose, IL-6 increases mitochondrial respiration, ROS production, and content. Targeting mitochondrial ROS production normalizes these mitochondrial adaptations. The present study provides new insights into mitochondrial physiology in the context of inflammation. Therapeutically targeting mitochondrial ROS production may impact skeletal muscle quality in certain populations.

OBJECTIVES/SPECIFIC AIMS: Consequently, we have decided to evaluate the presence of single nucleotide polymorphism (SNP) previously associated with AF on a European-descent population in an attempt to first identify the most common loci present in the PRH population and then search for specific PRH SNP associated with AF. METHODS/STUDY POPULATION: A secondary analysis of a Puerto Rican population sample (n = 120) from The Pharmacogenetics of Warfarin in Puerto Ricans Study will be performed. We will implement data from the 1000 genome project to establish a control group of healthy PRH population. Will evaluate the presence of 111 known single nucleotide polymorphisms associated with AF in Europeans and determine the frequency in PRH population sample, and validate predictability of such SNPs. Using admixture informatic markers (AIM) analysis will determine the percentage of admixture by Yoruba, Native American and Iberic-European. Statistical analysis will include the use of the Pearson Product-Moment Coefficient correlation analysis and multivariate linear regression. For admixture will use Maximum Likelihood Estimation and Markov Chain Monte Carlo models. RESULTS/ANTICIPATED RESULTS: A higher frequency of AF associated European single nucleotide polymorphisms, and an overall higher percentage of European admixture will be associated with atrial fibrillation in Puerto Rican Hispanic patients. DISCUSSION/SIGNIFICANCE OF IMPACT: Our contributions here are expected to be the elucidation of European ancestry as a risk factor for AF. These contributions will be significant because it can provide a robust scientific basis for larger GWAS studies in the Puerto Rican community and further narrow down the mechanism specific to this population. Research in this subject could lead to early identification of patients with high risk of developing atrial fibrillation and further decrease incidence and disease burden in the PRH population. Puerto Rican Hispanics have an exclusive genetic admixture that makes for an appealing research subject that could deliver unique results.

OBJECTIVES/SPECIFIC AIMS: Although two Ribeye protein isoforms have been identified in zebrafish, information about the identities of their variants is incomplete. This study aims to identify and characterize both of the Ribeye isoforms and their splice variants. METHODS/STUDY POPULATION: Immunohistochemistry was performed on the retina and neuromasts of zebrafish larva and adults.Ribeye expression was analyzed by western blot. Ribeye proteins will be separated, isolated and identified by mass spectrophotometry. RESULTS/ANTICIPATED RESULTS: Immunohistochemistry performed on larval and adult zebrafish retinas revealed the expression of Ribeye A in the inner and outer plexiform layers. Ribeye B was likewise expressed in both plexiform layers in larval zebrafish, but more pronounced expression in the outer plexiform layer in the adult zebrafish retina. Immunohistochemical experiments also demonstrated the co-expression of both Ribeye isoforms in the hair cells of both larval and adult neuromasts. Analysis of Ribeye expression by western blot showed the presence of more than the three previously identified variants. Current experiments are being conducted to characterize the additional Ribeye variants. We expect to identify the residual Ribeye protein as a result of this analysis. DISCUSSION/SIGNIFICANCE OF IMPACT: This study is necessary in order to gain a clear understanding of Ribeye expression in zebrafish tissues. Doing so will enable us to target this protein for gene editing to address outstanding questions about the mechanisms that govern ribbon synapse function. Synapse and synapse-associated proteins are involved in a wide-array of diseases that arise as a result of their dysfunction (e.g. blindness, deafness, bradycardia, autism spectrum disorders, and schizophrenia). Thus, it is important for us to identify the shared and distinct mechanisms that give rise to diseases associated with synaptic dysregulation. Such information could provide the basis for novel therapeutic interventions for synaptic disorders.

OBJECTIVES/SPECIFIC AIMS: Abnormalities in sensorimotor behavior are present in the majority of individuals with ASD and associated with core symptoms. Cortico-cerebellar networks that control sensorimotor behavior have been implicated in ASD, but little is known about their function during sensorimotor actions. The purpose of this functional magnetic resonance imaging (fMRI) study was to examine cortical-cerebellar function during feedback-guided motor behavior in ASD. METHODS/STUDY POPULATION: Individuals with ASD (11-30 years; N = 18) and age-matched controls (N = 15) completed a visuomotor task of feedback-guided precision gripping during fMRI. Participants pressed with their right thumb and forefinger on a force transducer while viewing a green FORCE bar on a screen that moved upwards with increased force toward a fixed white TARGET bar. Individuals were instructed to maintain the FORCE bar at the level of the TARGET bar for 24 seconds. Target force levels were set at 20% and 60% of each participant’s maximum voluntary contraction (MVC). Force variability was characterized as the coefficient of variation (i.e., standard deviation of the force time series / mean force output; CoV). RESULTS/ANTICIPATED RESULTS: Mean force did not differ between groups indicating participants were able to follow task demands. Participants with ASD showed increased force variability (F(1,30) = 5.214, p = 0.03) at both 20% (d = .45) and 60% (d = .77) MVC compared to controls. Compared to controls, individuals with ASD showed decreased activation in left angular gyrus during the visuomotor task compared to rest (AG; maximum t = 4.31). Individuals with ASD also showed greater visuomotor activation compared to controls in ipsilateral ventral M1, extending anteriorly into posterior ventral pre-motor cortex (PMv; maximum t = −4.06, cluster size = 38 voxels). This difference reflected the finding that control participants showed a selective deactivation of ipsilateral M1/PMv during visuomotor behavior, whereas individuals with ASD did not show this pattern. A significant group x force interaction was observed for contralateral Crus I activation (maximum t = −2.42) that was driven by an increase in activity during 60% compared to 20% MVC in control participants, while individuals with ASD showed no change in Crus I activation between force levels. DISCUSSION/SIGNIFICANCE OF IMPACT: Increased force variability in individuals with ASD suggests impaired processing of sensory feedback to guide precision motor behaviors. Individuals with ASD did not show deactivation of right motor cortex during visuomotor behavior relative to rest, suggesting reduced ability to selectively modulate motor cortical output. Reduced activation in left AG may reflect an inability to integrate visual, haptic, and proprioceptive inputs to reactively adjust ongoing motor output. Failure to show force-dependent scaling of Crus I in ASD suggests lateral cerebellar circuits do not adapt sensory prediction and error processes to maintain precision motor output during more demanding conditions. Together, our results demonstrate multiple cortical-cerebellar mechanisms associated with sensorimotor imprecision in ASD.

OBJECTIVES/SPECIFIC AIMS: 1) Determine the mutational landscape, including translocation, mutations and mutational signatures as well as copy number variations of pPCL and identify significant differences to non pPCL MM. 2) Determine whether genetic changes pertinent to pPCL could be explored as therapeutic targets to improve the dismal prognosis of this patient population. METHODS/STUDY POPULATION: Samples from overall 19 pPCL patients that presented to the Myeloma Center, UAMS between 2000-2018 were used for this study. We performed gene expression profiling (GEP; Affymetrix U133 Plus 2.0) of matched circulating peripheral PCs and bone marrow (BM) PCs from 13 patients. Whole exome sequencing (WES) was performed on purified CD138+ PCs from BM aspirates from 19 pPCL patients with a median depth of 61x. CD34+ sorted cells, taken at the time of stem cell harvest from the same 19 patients, were used as controls. Translocations and mutations were called using Manta and Strelka and annotated as previously reported. Copy number was determined by Sequenza. RESULTS/ANTICIPATED RESULTS: 1) GEP from the BM and circulating peripheral PCs showed that the expression patterns of the two samples from each individual clustered together, indicating that circulating PCs and BM PCs in pPCL result from the same clone and are biologically clearly related. 2) The clinical characteristics from the patient cohort used for WES analysis were as follows: median age was 58 years (range 36–77), females accounted for 74% (14/19), an elevated creatinine level was found in 78% (14/18) and an elevated LDH level in 71% (10/14). All patients presented with an ISS stage of III. Median OS of the whole dataset was poor at 22 months, which is consistent with OS from previously reported pPCL cohorts. 3) Primary Immunoglobulin translocations were common and identified in 63% (12/19) of patients, including MAF translocations, which are known to carry high risk in 42% (8/19) of patients [t(14;16), 32% and t(14;20), 10%] followed by t(11;14) (16%) and t(4;14) (10%). Furthermore, 32% (6/19) of patients had at least one MYC translocation, which are known to play a crucial role in disease progression. 4) The mutational burden of pPCL consisted of a median of 98 non-silent mutations per sample, suggesting that the mutational landscape of pPCL is highly complex and harbors more coding mutations than non-pPCL MM. 5) Driver mutations, that previously have been described in non-pPCL MM showed a different prevalence and distribution in pPCL, including KRAS and TP53 with 47% (9/19) and 37% (7/19) affected patients respectively compared to 21% and 5% in non-PCL MM. PIK3CA (5%), PRDM1 (10%), EP300 (10%) and NF1 (10%) were also enriched in the pPCL group compared to previously reported cases in non-pPCL MM. 6) Biallelic inactivation of TP53 – a feature of Double Hit myeloma - was found in 6/19 (32%) samples, indicating a predominance of high risk genomic features compared to non-pPCL MM. Furthermore, analysis of mutational signatures in pPCL showed that aberrant APOBEC activity was highly prevalent only in patients with a MAF translocation, but not in other translocation groups. DISCUSSION/SIGNIFICANCE OF IMPACT: In conclusion we present one of the first WES datasets on pPCL with the largest patient cohort reported to date and show that pPCL is a highly complex disease. The aggressive disease behavior can, at least in part, be explained by a high prevalence of MAF and MYC translocations, TP53 and KRAS mutations as well as bi-allelic inactivation of TP53. It is of interest that only KRAS but not NRAS mutations are highly enriched in pPCL. From all highly prevalent genomic alterations in pPCL, only KRAS mutations offer a potential for already available therapeutically targeting with MEK inhibitors, which should be further explored.

OBJECTIVES/SPECIFIC AIMS: While Hb-induced toxicity has been assumed to cause PT dysfunction, the development of tubular proteinuria from this dysfunction in SCD patients is not well understood. We previously found that free Hb, at concentrations predicted to be present chronically and during hemolytic crisis in the tubular filtrate of SCD patients, impairs uptake of albumin by PT cells via direct competition for binding to megalin and cubilin receptors. The purpose of this study is to further evaluate the consequences of increased filtered Hb concentrations on vitamin D reabsorption and activation. METHODS/STUDY POPULATION: We have developed a PT cell culture model that closely mimics in vivo PT cell structure, morphology, and endocytic capacity. Using this model, we treated cells with physiologic levels of cell-free Hb estimated in SCD and measured protein endocytosis and toxicity/oxidative stress. Endocytosis of fluorescently-tagged DBP and RBP were evaluated and quantified by confocal imaging and spectrofluorometry. Cellular toxicity and oxidative stress were assessed by measuring aconitase activity and accumulation of mitochondrial reactive oxygen species. RESULTS/ANTICIPATED RESULTS: PT cell uptake of DBP was significantly inhibited by both concentrations of Hb estimated to be filtered into the tubule lumen under chronic conditions (0.6μM Hb; 39% inhibition) and hemolytic crisis (≤20μM Hb; up to 92% inhibition) in SCD patients. ****p<0.0001 by one-way ANOVA, Dunnett’s multiple comparisons test. PT cell uptake of RBP was minimally affected by the same concentrations of Hb that profoundly inhibited internalization of DBP. RBP uptake was not significantly inhibited by all concentrations of Hb tested except the estimated hemolytic crisis maximum concentration (20μM; 27% inhibition). RBP uptake inhibition at 20μM Hb treatment was dramatically less than DBP uptake inhibition under the same treatment condition (27% RBP inhibition vs 92% DBP inhibition). *p<0.05 by one-way ANOVA, Dunnett’s multiple comparisons test. Mitochondrial oxidative stress, measured as a decrease in aconitase activity, was significantly increased in cells exposed to Hb (~43% aconitase activity reduction after 72h 20μM Hb treatment, and ~11% aconitase activity reduction after 72h 1μM Hb treatment). *p<0.05, **p<0.01 by one-sample t-test of the differences between treatment and untreated control conditions. We are currently assessing changes in PT cell vitamin D hydroxylase expression levels and vitamin D metabolism after exposure to chronic and hemolytic concentrations of Hb. Because oxidative stress has been previously reported to affect hydroxylase expression and activity, we expect to find a decrease in vitamin D hydroxylase expression and/or activity, resulting in decreased vitamin D activation. DISCUSSION/SIGNIFICANCE OF IMPACT: Our results suggest that competition for megalin/cubilin binding between Hb and normally-filtered proteins, including DBP, may be the primary cause of tubular proteinuria in SCD patients. This inhibition appears to be selective for proteins that are largely α-helical in structure, such as albumin and DBP. Understanding the structural basis for Hb competition with filtered proteins for PT uptake could identify biomarkers to detect tubular proteinuria in SCD patients prior to the onset of kidney disease. This may also help develop therapeutic compounds that would selectively inhibit Hb binding to megalin/cubilin receptors. We have developed a highly sensitive fluorescence-based assay to test for such compounds. Inhibition of DBP uptake and vitamin D metabolism in the PT could lead or contribute to vitamin D deficiency. To our knowledge, our study is the first to suggest a mechanism for vitamin D deficiency commonly observed in SCD patients. Ongoing studies focus on measuring vitamin D metabolism in both cell and mouse models of SCD.

OBJECTIVES/SPECIFIC AIMS: Objective: apply checkpoint inhibitors that are specific to the exhaustive markers expressed on tumor CD8+ T-cells ex vivo in order to improve cytokine release and cytotoxic function in comparison to two control groups: (1.) T-cells that receive no antibodies; (2.) T-cells that receive standard inhibition with PD-1 and CTLA-4 antibodies only. Long-term objective: provide personalized medicine in the treatment of HCC by using checkpoint inhibitors that are specific to the receptors expressed by an individual tumor. METHODS/STUDY POPULATION: The study population includes patients undergoing liver transplantation or surgical resection for HCC. Two grams of tumor, two grams of healthy liver tissue at least one centimeter from the tumor margin, and 50 milliliters of blood will be obtained. Solid tissue will be mechanically and enzymatically disrupted and CD8+ T-cells will be isolated from all sites. Using flow cytometry, the expression of surface receptors PD-1, CTLA-4, LAG-3, TIM-3, BTLA, CD244, and CD160 will be categorized in each tissue to identify which receptors are upregulated in the tumor microenvironment. Up to three antibodies specific to the upregulated receptor(s) on the tumor T-cells will be applied per specimen. The experimental arm will receive these antibodies and co-stimulation with CD3/CD28 and will be compared to two controls. One control will receive only CD3/CD28, and the other will receive CD3/CD28 in addition to the standard combination of PD-1 and CTLA-4 inhibitors. From each condition, flow cytometry will be used to assess the mean production of interleukin-2, tumor necrosis factor-α, interferon-γ, granzyme B, and perforin expression as an assessment of T-cell function. RESULTS/ANTICIPATED RESULTS: Preliminary data from the peripheral blood of healthy controls confirms that the developed flow cytometry panels effectively identify the surface receptors and cytokine production of CD8+ T-cells. Two patients have successfully been enrolled in this study. It is predicted that T-cells extracted from the tumor will express more inhibitory receptors than normal liver or peripheral blood and will have increased function after they are targeted with checkpoint inhibitors that are specific to the inhibitory surface receptors they express. DISCUSSION/SIGNIFICANCE OF IMPACT: HCC is the second leading cause of cancer-related death worldwide and therapeutic options are limited for patients who are not surgical candidates. T-cells are a critical component of the anti-tumor response to HCC. However, T-cells can develop an exhausted phenotype characterized by up-regulated inhibitory receptors (PD-1, CTLA-4, LAG-3, TIM-3, CD-244, CD-160, BTLA) and decreased function, allowing for immune escape. Clinical trials using combined checkpoint inhibition with PD-L1 and CTLA-4 antibodies have been considered a breakthrough for patients with advanced HCC, as up to 25% show an objective tumor response. The explanation for the varied susceptibility to checkpoint inhibition remains unknown and is hypothesized to be secondary to inconsistencies in the expression of surface inhibitory receptors. Although inhibitory receptor expression has been shown to be upregulated under conditions of hepatitis and/or HCC, there has been no single study to effectively investigate the expression of all known inhibitors in order to better explore the interplay between them. It will be of great academic interest and clinical purpose to evaluate individual receptor expression and engage the correlating antibodies given the possibility of synergism between receptors and the need for a more profound anti-tumor T-cell response in HCC.

OBJECTIVES/SPECIFIC AIMS: The central goal of this proposal is to characterize the mechanisms that mediate success or failure of immature intestinal barrier in necrotizing enterocilitis. METHODS/STUDY POPULATION: To do this, I will utilize stem cell derived human intestinal organoids (HIOs), an innovative model of the immature intestine, and a cohort of bacterial isolates collected from premature infants who developed NEC to interrogate the cause-effect relationship of these strains on maintenance of the intestinal barrier. I hypothesize that the epithelial response to bacterial colonization is strain-dependent and results in differences in inflammatory signaling that shape epithelial barrier function in the immature intestine. RESULTS/ANTICIPATED RESULTS: Preliminary data shows that colonization of HIOs with different bacteria leads to species-specific changes in barrier function, and some species selectively damage the epithelial barrier while others enhance epithelial barrier function. I have identified key inflammatory signals that serve as central drivers of intestinal barrier function. DISCUSSION/SIGNIFICANCE OF IMPACT: Characterization of this process is expected to substantially advance scientific understanding of early events in NEC pathogenesis and lead to new opportunities for targeted therapeutic intervention to accelerate barrier maturation or prevent hyperinflammatory reactivity in the neonatal intestine. The research proposed in this application represents an entirely novel approach to studying host-microbial interactions in the immature. Conceptually, this novel translational approach will help to define the pivotal role of colonizing bacteria in initiating epithelial inflammation in NEC patients.

OBJECTIVES/SPECIFIC AIMS: Inflammatory Bowel Disease (IBD) is a chronic, life-long condition characterized by inflammation of the intestine that greatly affects an individual’s quality of life. While biologic therapy directed against TNFα (anti-TNFα, Infliximab) and α4β7 integrin (anti-α4β7; Vedolizumab) is used to treat IBD, a substantial number of patients remain non-responsive. Using a comprehensive bioinformatics approach, the aim of this study was to characterize immune cell profiles and altered molecular pathways in IBD patient non-responders to anti-TNFα and anti-α4β7 therapy to determine potential mechanisms and/or indicators of treatment non-response. METHODS/STUDY POPULATION: Publicly available whole transcriptomes from 65 healthy control and IBD endoscopic biopsies were assessed (NCBI GEO GSE73661). Specifically, transcript profiles from responders or non-responders to anti-TNFα and anti-α4β7 therapy were utilized. Differentially expressed transcript profiles were obtained by comparing responders or non-responders prior to receiving therapy versus healthy controls using NCBI’s GEO2R after adjustment with Benjamini and Hochberg testing (p<0.05). Immune profiling of DEgs were analyzed by the core LM22 immune signature for subsets of B-, T-, dendritic-, mast-cells, macrophages, and neutrophils (CIBERSORT, cibersort.stanford.edu) (p<0.05). Networks, functional analysis, and interpretation of transcriptomic data were performed using Ingenuity Pathway Analysis (IPA) (Qiagen) (p<0.05). RESULTS/ANTICIPATED RESULTS: Initially, we determined colonic immune profiles in responders and non-responders to anti-TNFα and anti-α4β7 therapy. Compared to responders, in both anti-TNFα and anti-α4β7 non-responders we found elevated neutrophil levels (p<0.05). Specific to anti-TNFα treatment, non-responders demonstrated substantially reduced Treg cells (p<0.05); whereas, exclusive to anti-α4β7 treatment, non-responders showed elevated dendritic cells, activated CD4 T cells, and reduced M2 macrophages (p<0.05). Next we profiled differentially expressed transcripts to determine molecular pathways associated with therapy non-response. In both anti-TNFα and anti-α4β7 non-responders, we observed alterations in pathways specific to cellular growth and metabolism. Among cell growth pathways we found activated growth hormone, Wnt, ErB, and IGF-1 signaling; whereas, among metabolic regulation we found altered triglyceride, tryptophan, and leptin signaling. Moreover, unique to anti-TNFα non-responders, we found activated sphinogosine-1-phosphate and paxillin pathways. While non-response to anti-α4β7 indicated activation of SAPK/JNK and IL-9 signaling. DISCUSSION/SIGNIFICANCE OF IMPACT: Together these data define specific immune profiles and molecular pathways observed in non-responders to anti-TNFα and anti-α4β7 therapy. Our analysis identified substantial alterations in pathways specific to cellular growth and metabolism, identifying a link between non-response to biologic therapy and specific cell functions. These data suggest particular alterations in immune profiles and molecular pathways could play a role in non-response to biologic therapy, highlighting a future direction for personalized treatment regimens that could lead to more targeted use of existing therapies and more favorable patient health outcomes.

OBJECTIVES/SPECIFIC AIMS: While the role of antiphospholipid antibodies in activating endothelial cells has been extensively studied, the impact of these antibodies on the adhesive potential of leukocytes has received considerably less attention. Mac-1 is a heterodimeric beta-2 integrin primarily expressed by myeloid-lineage cells. In its activated state, Mac-1 mediates cell-cell interactions by engaging a variety of surface molecules, including the endothelium-expressed glycoprotein ICAM-1. Here, our goals were (1) to determine the extent to which APS neutrophils adhere to healthy, resting endothelial cells under physiologic flow conditions, and (2) to identify potential therapeutic targets by elucidating the molecules required for that adhesion. METHODS/STUDY POPULATION: Primary APS patients (meeting Sydney criteria) and non-autoimmune controls were matched for age and gender. Freshly isolated human umbilical vein endothelial cells (HUVECs) were utilized within five passages. Samples were introduced into a flow channel via a programmable syringe pump, and perfused across a resting HUVEC monolayer. After 15 minutes of perfusion, the chamber was flushed, and the remaining adherent cells were quantified. Flow cytometry was used to identify differentially-expressed molecules on the surface of APS neutrophils. Neutrophil extracellular trap (NET) release was assessed in static neutrophil-HUVEC cultures. RESULTS/ANTICIPATED RESULTS: Pre-treating control neutrophils with APS plasma resulted in increased adhesion as compared with control plasma (>2.5-fold for n = 12 plasma samples; p < 0.05). This was true under both venous conditions (low shear) and conditions representative of the microvasculature (pulsatile flow and higher shear). Control neutrophils treated with APS plasma demonstrated upregulation of CD64, CEACAM-1, beta-2 glycoprotein I, and activated Mac-1 on the neutrophil surface, as well as shedding of L-selectin. Upregulation of activated Mac-1 and shedding of L-selectin were also triggered by IgG purified from APS plasma. For these changes to be meaningful clinically, we reasoned that they should be present on neutrophils in the peripheral blood of APS patients. Indeed, perfusion of anticoagulated blood through the flow chamber resulted in increased adhesion of patient neutrophils as compared with controls (>5-fold for n = 18 patients; p < 0.05). Similarly, patient neutrophils demonstrated upregulation of CD64, CEACAM-1, beta-2 glycoprotein I, and activated Mac-1 on the neutrophil surface. A monoclonal antibody specific for activated Mac-1 reduced the adhesion of APS neutrophils to HUVECs in the flow-chamber assay (>2-fold reduction for n = 5 patients; p < 0.05). Importantly, the same monoclonal antibody reduced NET release in neutrophil-HUVEC co-cultures. DISCUSSION/SIGNIFICANCE OF IMPACT: APS neutrophils have an increased adhesive potential, which is dependent upon the activated form of Mac-1. This may lower the threshold for both neutrophil-endothelium engagement and NET release in patients, and thereby have implications for events such as venous thrombosis. Studies are underway to determine the extent to which Mac-1 is a viable therapeutic target in preclinical models of APS.

OBJECTIVES/SPECIFIC AIMS: Determine PTL’s mechanism(s) of action in a panel of canine hematopoietic cell lines; this will enable us to 1) verify that PTL is working as expected and 2) rationally select combination therapeutics. Characterize the in vitro sensitivity of canine hematopoietic cell lines to PTL in combination with other chemotherapeutic agents. Determine immunohistochemical NFκB expression in tissue microarrays of spontaneous canine neoplasms and correlate with outcome-linked data. Characterize the in vivo sensitivity of canine hematopoietic cell lines to PTL using a murine xenograft model. METHODS/STUDY POPULATION: Growth inhibition assays were performed using a panel of canine mast cell, histiocytic sarcoma, lymphoma, and leukemia cell lines, with PTL alone or in combination with redox-perturbing standard-of-care therapeutics. Cell death was assessed using flow cytometry. Immunofluorescence and immunoblotting were used to assess NFκB localization and phosphorylation of NFκB p65 (transcriptional activation), respectively. Intracellular glutathione with and without PTL and combination chemotherapeutics will be assessed spectrophotometrically. Archived spontaneous canine tumors will be evaluated immunohistochemically (IHC) for increased NFκB pathway activation relative to normal control tissues. Nude mice will receive intravenous, intraperitoneal, or subcutaneous injections of canine HS cells and will be treated with PTL or with PTL in combination with standard-of-care chemotherapeutics. RESULTS/ANTICIPATED RESULTS: Results: All immortalized canine cell lines evaluated are sensitive to PTL therapy and undergo dose-dependent apoptosis following exposure to drug. PTL exposure leads to inhibition of NFκB, as evidenced by immunofluorescent nuclear exclusion and decreased p65 phosphorylation. Some chemotherapeutics appear to synergize with PTL in vitro. Anticipated results: We expect to find increased IHC NFκB pathway activation in malignantly transformed tissues relative to controls. We expect standard-of-care therapeutics to synergize with PTL in vivo based on preliminary in vitro data. DISCUSSION/SIGNIFICANCE OF IMPACT: These studies will determine whether PTL therapy may be beneficial in dogs with a variety of hematopoietic neoplasms, either alone or in combination with other therapeutics that are currently in clinical use. Dogs with mast cell or histiocytic neoplasia are an excellent model for rare and deadly human diseases, which may also benefit from PTL therapy.

OBJECTIVES/SPECIFIC AIMS: Objective: To summarize the diagnosis and management of two acute rejection (AR) episodes in the first penis transplant patient in the U.S. Background: Vascularized composite allotransplantation (VCA) has been utilized for state-of-the-art reconstruction of devastating craniofacial defects, limb loss, and recently, severe genitourinary defects. To date, more than 200 VCA’s have been performed, of which four successful penis transplants have been achieved worldwide (Two in the U.S.). However, despite the technical success of VCAs in general, acute rejection episodes remain a significant postoperative management problem, with 80-85% experiencing at least one episode in the first-year post-transplantation. The incorporation of skin in VCAs, which is highly immunogenic, allows early visible recognition of rejection but requires prompt management to prevent allograft failure as well as the progression of chronic rejection, which has been associated with the frequency of acute rejection episodes in preclinical models. We present the first report of acute rejection in a penile allograft. AR episodes in VCA typically manifest with erythema of the allograft skin and/or maculopapular lesions that can be either patchy, focal or diffuse. Histopathologic assessment is essential for diagnosis and management. The Banff classification of histopathologic criteria for degree of AR is most commonly utilized to direct clinical management. METHODS/STUDY POPULATION: We reviewed the clinical course of the first American patient who underwent penis transplantation at Massachusetts General Hospital in 2016. Postoperatively, routine clinical and chemical assessment (immunosuppression levels, routine blood work) was performed, with increased frequency during AR episodes. Skin punch biopsies were obtained during (suspected) AR episodes, analyzed and graded according to the Banff 2007 classification of rejection of skin-containing composite allografts. Histopathologic tissue assessment included CD3, C4d, CD4/8, CD20 FOXP3 and cellular infiltration (hyper keratinization, lymphocytic infiltrate, dermal erosion, macrophage, eosinophilia, T-cell infiltration) and epidermal or perivascular fibrosis. RESULTS/ANTICIPATED RESULTS: The patient is a 65-year-old male with history of penile carcinoma requiring subtotal penectomy in 2012. He is currently 30-months post penile transplantation (as of 11/15/2018). First Rejection Episode: At 28 days post-transplantation, the patient noted induration, swelling and erythema of the allograft, which was diagnosed as AR clinically (Image 1A). Biopsy showed a Banff Grade III AR, with focal keratinocyte apoptosis with lymphocytic infiltration in epidermis and arteriolar endothelialitis with perivascular inflammation. Initially this episode was treated for 2 days with 2 pulse doses of methylprednisolone (500mg/d IV) with clinical improvement. However, recurrent allograft erythema was observed on postoperative day 32 and an acute rejection grade III according the Banff classification was confirmed by a second biopsy that demonstrated epidermal perivascular lymphocytic infiltrates, spongiosis and dyskeratosis, deep dermis focal lymphocytic infiltrates and focal infiltrates in arterioles as well as endothelialitis in venules. Donor specific antibodies and C4d were negative. CD3+ T cells were present in the epidermis and perivascular space. This was treated with anti-thymocyte globulin (thymoglobulin) course for 4 days (1.5mg/kg/day IV) and 3 more pulse doses of methylprednisolone (500mg/d IV.), followed by a prednisone (250mg/d) taper to baseline. This resulted in complete resolution of AR. Second Rejection Episode: At 10.8 months post VCA the patient presented with penile erythema and scrotal swelling suggestive of AR and received three doses of methylprednisolone (day 1: 500mg/d IV, day 2: 1000mg/d IV and day 3: 500mg/d IV respectively) followed by increased baseline prednisone (10mg PO daily; increased dose compared to previous AR episode). A skin biopsy confirmed Banff Grade III AR. Compared to the previous biopsy, this biopsy demonstrated an increased density of lymphocytic inflammation of the dermis with endarteritis. Prominent involvement of epidermis and adnexal structures corresponding to acute T-cell mediated rejection was also observed (Figure 1). Donor specific antibodies and C4d were again negative. Three doses of ATG (1.5mg/kg/day IV) were administered. In addition, tacrolimus was increased and local tacrolimus (1% ointment) treatment was begun. Clinical signs of rejection improved and repeat biopsy showed dramatic histopathological improvement. Current maintenance immunosuppressive regimen consists of tacrolimus, sirolimus, prednisone, mycophenolic mofetil acid (MMF), rapamycin, and tacrolimus ointment, with no new clinical or histopathological signs of rejection (Image 1B). DISCUSSION/SIGNIFICANCE OF IMPACT: We report the first described case of acute T-cell mediated rejection in penile transplantation. These rejection episodes demonstrated that, even on stringent immunosuppressive regimens, severe acute rejection episodes in VCA may still occur. Edema and acute induration preceded the development of erythema in our cases, representing a harbinger for the more severe grade of rejection that eventually developed. Our experience was consistent with other VCAs in that donor specific antibodies did not develop, despite a severe Banff Grade. Consistent use of topical calcineurin inhibitor based immunosuppression on the allograft skin may be helpful in warding off future episodes, as our patient has been rejection free now for 18 months. To date, no histologic signs of chronic rejection were present on 2-year protocol surveillance biopsy. We have added rapamycin to the current drug regimen, with concurrent reduction of tacrolimus dosing for renal protection, which has been demonstrated in cardiac transplantation to deter the intimal hyperplasia/vasculopathy associated with chronic rejection.

OBJECTIVES/SPECIFIC AIMS: To better understand host, viral and bacterial responses underlying disparate outcome. METHODS/STUDY POPULATION: We utilized metagenomic analysis of 559 genes, the NanoString nCounter Immunology Panel-Plus kit and FFPE mouse lungs from a published BSI time course. RESULTS/ANTICIPATED RESULTS: Results show an overall increased level of gene expression during BSIs associated with survival when compared to gene expression during peak viral titers. Early viral clearance and the presence of S. pyogenes in the lungs of TX98 infected lungs 24 hours after BSI was confirmed. Host responses tied to differences in early viral detection and clearance consisted of RIG-I, OAS, TLR3, TLR8 and TLR9. Key changes were noted in the expression of type I and II interferons, complement proteins, cytokines, chemokines, Fc receptors, scavenger receptors, the immunoproteasome and genes associated with T, B, Treg and NK cell activation. Interestingly, there was no significant increase in host antimicrobial peptides during BSIs associated with survival while CAMP and Nos2 were significantly increased 24hrs prior to death in lethal BSIs. DISCUSSION/SIGNIFICANCE OF IMPACT: To our knowledge this is the first side by side metagenomics study of influenza BSIs associated with death and survival. Results offer mechanistic insight into clinical outcomes.

OBJECTIVES/SPECIFIC AIMS: Pancreatic ductal adenocarcinoma (PDA) has a dismal 5-year survival rate of 9%, making this disease one of the deadliest human malignancies (https://seer.cancer.gov/). Primary barriers to the treatment of pancreatic cancer include extensive stromal interactions and sustained immune suppression. Aberrant Hedgehog (HH) pathway activity is a hallmark of pancreatic tumorigenesis. Tumor-derived HH ligands signal in a paracrine fashion to the surrounding stroma to influence tumor growth. Expression of HH ligands increases during PDA progression, and previous work has shown that genetic deletion of Sonic HH (Shh) from the epithelium of mice with pancreatic tumors results in increased Indian HH (Ihh) expression. This research aims to investigate the translational impact of changes in immune infiltration following deletion of IHH in a preclinical mouse model of pancreatic cancer. METHODS/STUDY POPULATION: Ihh was deleted in tumor cells lines (IhhKO) derived from a genetically engineered mouse model of pancreatic cancer (LSL-KrasG12D/+;LSL-TrpR270H;P48-Cre), using CRISPR/Cas-9 gene editing to assess the role of Ihh in the tumor microenvironment. The level of HH signaling was determined using tumor cell co-cultures with Gli1lacZ fibroblasts (derived from mice with a lacZ reporter allele knocked into the Gli1 locus), in which Beta Galactosidase activity serves as a readout for HH signaling. WT and IhhKO tumor cells were orthotopically transplanted into the pancreas of syngeneic C57BL/6 mice. Human pancreas samples were obtained from surgical resection of pancreatic adenocarcinoma, or fine needle biopsy procedure (FNB). Immune profiling of mouse and human pancreatic tumors was performed using Cytometry Time-of-Flight analysis (CyTOF), and tumor composition was analyzed by single-cell RNA sequencing (scRNA seq). In vitro cultures with pancreatic fibroblasts treated with either WT or IhhKO tumor cell conditioned media (CM) were cultured with bone-marrow derived macrophages to assess tumor crosstalk. RESULTS/ANTICIPATED RESULTS: Tumor cells lacking Ihh were generated through CRISPR/Cas-9 deletion, and this was confirmed by qRT-PCR. Co-culture of IhhKO tumor cells with Gli1lacZ fibroblasts results in decreased Gli1 expression both in vitro and in vivo. Immune profiling revealed that tumors lacking Ihh have significantly fewer tumor associated macrophages (CD11b+/F4/80+/CD206+), resulting in decreased presence of immunosuppressive factors such as arginase 1 and PDL1. Immune phenotyping of human pancreatic tissues revealed similar populations of immunosuppressive myeloid cells present in tumors. In vitro co-cultures demonstrated that, in the presence of bone-marrow derived macrophages, immunosuppressive IL-6 production was reduced in pancreatic fibroblasts cultured with IhhKO-CM, as compared to fibroblasts cultured with WT-CM, providing mechanistic insight into the in vivo phenotype observed. Further, scRNA seq analysis suggests that modulation of HH signaling in the tumor microenvironment alters chemokine and immunomodulatory signaling pathways driven by fibroblasts in the pancreatic tumor microenvironment. DISCUSSION/SIGNIFICANCE OF IMPACT: HH signaling in pancreatic fibroblasts contributes to the establishment of an immune suppressive environment in pancreatic cancer. Combining methods to target HH signaling and immune checkpoint therapy has translational potential in treating pancreatic cancer patients.

OBJECTIVES/SPECIFIC AIMS: The study aims to track and correlate ocular neuropathic symptoms, corneal sensitivity and dry-eye like pain, after scleral buckle and posterior vitrectomy surgeries. The goal is to identify a population of patients that receive these retinal surgeries that experience ocular neuropathic pain. METHODS/STUDY POPULATION: Methods - Prospective and Retrospective cohort studies were designed with the follow cohorts: scleral buckle, posterior vitrectomy, and control. Typical follow up for SB/PV surgeries are: 1 day, 1 week, 1, 3, 6, 12 months post surgery. CS and DELP metrics are measured at each visit. For study interventions, all subjects (from both arms) will undergo the same series of tests, in the same sequence at each visit. Phase 1 of the visit focuses on CS and phase 2 on DELP. These interventions are as follows: first, subjects will receive Drop A; Drop A will be administered in a randomized, double-blinded manner at each visit to either balanced salt solution (control) or Muro 128 5% hypertonic saline (experimental). Drop A will be administered to both eyes. After receiving the drops, subjects will complete a visual analog scale questionnaire to grade their corneal sensitivity. Next, subjects will undergo a five minute washout. After the washout, subjects will receive Drop B; Drop B will be whichever drop was not administered in the Drop A phase. After Drop B is given, subjects will complete the visual analog scale. To begin phase 2, subjects will be given the Ocular Surface Disease Index to record dry eye signs and symptoms. Finally, tear film parameters will be collected using Schirmer’s tear production test and tear film breakup time. Study Population. - Inclusion criteria: For retrospective cohort studies, subjects who have undergone unilateral SB or PV in the past year. For prospective cohort studies, subjects who will undergo unilateral SB or PV in the near future, and age-matched controls. Exclusion criteria: For both retrospective and prospective arms, the same exclusion criteria apply. They include: a previous diagnosis of dry eye; current use of neuropathic pharmacotherapies (including gabapentin, pregabalin, TCAs, SNRIs, carbamazepine, and opioids). RESULTS/ANTICIPATED RESULTS: As of 11/15/18, only the scleral buckle retrospective study arm had enough subjects for any meaningful preliminary report; the arm currently has 8 subjects. Of these 8 subjects, 5/8 subjects report increased surgical-eye corneal sensitivity and 6/8 show discordant dry eye symptoms and tearfilm parameters. Our power analysis showed that N=16 subjects in a group are required to detect a statistical significant difference in corneal sensitivity response. We expect to see a relapsing and remitting pattern of pain (as measured by corneal sensitivity and dry eye questionnaire), as is typical of neuropathic pain. Regarding dry eye symptoms, we anticipate subjects will have prominent dry eye symptoms (as measured by a validated questionnarie), but show no abnormalities in tearfilm parameters. DISCUSSION/SIGNIFICANCE OF IMPACT: To our knowledge, this is the first observational study of neuropathic pain symptoms of corneal sensitivity and dry-eye like pain, in post retinal surgery patients. We recognize the challenge of diagnosing neuropathic pain; currently the gold standard is clinical. However, symptoms of neuropathic pain are non-specific and subtle. Identification of a population suffering from post-retinal surgery ocular neuropathic pain will provide a foundation to test topical naltrexone as a diagnostic tool. If our hypothesis is correct, topical naltrexone could serve as a cheap, easy, and quick diagnostic test for ocular neuropathic pain. We envision this diagnostic test would allow many misdiagnosed and mistreated post-surgical patients to be treated with appropriate therapies aimed at neuropathic etiologies.