The Students Participating as Ambassadors for Research in Kentucky (SPARK) program provides novel health equity research training and targeted mentorship for undergraduates, particularly those from groups underrepresented in the biomedical and behavioral research and workforce. SPARK aims to address inadequate diversity in the medical and scientific research fields by providing comprehensive research mentorship and skill-building. Unlike most existing research training programs that are brief, focus on laboratory research, or are limited to graduate students and junior faculty, SPARK delivers a 16-month intensive behavioral and population health science training, equipping students with needed tools to conceptualize, plan, execute, and analyze their own health equity research study. Trainees complete didactic coursework on health equity, study design and proposal development, data analysis, and ethics. Students receive a stipend and research expenses, and multiple mentors guide them in creating original research projects for which they serve as Principal Investigator. Students disseminate their findings annually at an academic research conference as a capstone. Evaluation data from the first three cohorts suggest SPARK has been pivotal in preparing students for graduate studies and research careers in health equity and behavioral and population health sciences, providing strong support for further investments in similar undergraduate research training models.

The COVID-19 global pandemic required the rapid development of vaccines with a quick start up of phase 1–3 studies with large enrollment targets. The University of California San Diego was identified as a site for the phase 3 trial of the mRNA-1273-SARS-CoV-2 vaccine. There were many challenges with scaling up a large-scale clinical trial in such a short time. This report describes the processes and procedures that were implemented to successfully complete the enrollment target in under 10 weeks. This required the team to identify existing tools that could rapidly be accessed to develop a database, scheduling system, effective communication, document management, staff time tracking/efficiency, subject scheduling/tracking, project management, and accrual/study performance. The outcome of these efforts resulted in rapid enrollment and study completion in a short time. The lessons learned from this experience can be used by other clinical trial sites faced with similar challenges.

OBJECTIVES/GOALS: Although there is ample evidence that environmental contaminants impact reproductive health, the exact mechanisms of action, for the most part, remains unclear. We sought to determine whether known contaminants in Puerto Rico can contribute to the selection of a bioassay to add granularity to geospatial contamination data at the cellular level. METHODS/STUDY POPULATION: A PubMed literature search was conducted: Puerto Rico AND Vieques AND Environmental Contaminants AND Heavy Metals OR Phthalates OR Metals OR PCB OR Air Pollution OR CVOC . Additional inclusion criteria were free full text, English language and year of publication between 2000 to 2022 (n = 244 studies). References that were not related to Puerto Rico and environmental contaminants in air, soil, water, or vegetation were excluded. A second PubMed literature search was conducted to determine whether a clinical link has been established between contaminant exposure and the male reproductive system. Search terms were: heavy metals AND hypospadias OR cryptorchidism NOT female NOT animal NOT review , heavy metals AND male infertility NOT female NOT animal NOT review . The same strategy was used for phthalates. RESULTS/ANTICIPATED RESULTS: We found that 12 out of 15 studies that were conducted in the Archipelago of Puerto Rico between 2000-2022 reported heavy metals- and/or phthalates- contamination in soil and water. We also found that there is a paucity of clinical studies that consider plausible relationships between a given contaminant and congenital conditions or male reproductive function. Specifically, we found that heavy metal exposure has been linked to hypospadias (n=1 study), comorbidity of hypospadias plus cryptorchidism (n= 1 study) or male infertility (n=14 studies). Phthalates exposure has been linked to comorbidity of hypospadias and cryptorchidism (n=1 study) or male infertility (n=1 study). Male subfertility has been overlooked so far. We noted that Sertoli cell dysfunction has been linked to all of these conditions. DISCUSSION/SIGNIFICANCE: The geography of Puerto Rico provides an opportunity to close the gap in knowledge between environmental contamination and male reproductive health. Based on our findings, we propose that the use of a bioassay with an immortalized Sertoli cell line can uncover the cellular processes that may be affected in male reproduction upon contaminant exposure.

Objectives/Goals: Patients with multiple chronic conditions (MCCs) face care coordination challenges and poorer health outcomes. Outpatient telehealth may be an effective way to enhance MCC patient care given the need for multiple visits and specialists. This study seeks to describe telehealth utilization between 2013 and 2023 in Arkansas. Methods/Study Population: We utilized the Arkansas All-Payer Claims Database (APCD) to identify patients diagnosed with high-prevalence MCCs comprising diabetes with comorbid hypertension, hyperlipidemia, or asthma. We then measured telehealth utilization defined as any claim associated with a telehealth modifier code, a place of service code defining the service as occurring in the patient’s home, or remote patient monitoring. Finally, we created payer-specific (e.g., commercial or Medicaid) yearly measures of the number of any telehealth claims among MCC patients divided by the number of MCC patients for that year. Linear regression was used to measure the difference in utilization during the COVID-19 pandemic (i.e., 2020–2023) versus prior to the pandemic (i.e., 2013–2019). Results/Anticipated Results: Overall, the COVID-19 pandemic era was associated with an increase of telehealth utilization among commercial patients by 1.01 telehealth claims per MCC patient (95% CI: 0.39 to 1.62, p Discussion/Significance of Impact: Variations in telehealth uptake among MCC patients suggest heterogeneity in its suitability and necessity. We will later evaluate whether telehealth use is associated with different levels of inpatient and emergency department utilization. We expect the findings to provide clarity on the suitability of telehealth use by MCC disease status.

OBJECTIVES/GOALS: The present study investigated contextual factors linking rural Black American mens experiences of racial discrimination to their COVID vaccine hesitancy. Specifically, we investigated two potential mediators of the link between racial discrimination and COVID vaccine hesitancy: (1) medical mistrust, and (2) COVID conspiratorial beliefs. METHODS/STUDY POPULATION: Hypotheses were tested using structural equation modeling with 7 waves of data from 504 Black American men participating in a longitudinal study of risk behavior and substance use during young adulthood. At baseline, mens mean age was ~20. Data were collected before and during the COVID pandemic. The COVID pandemic began after Wave 4 data had been collected. A series of 3 online surveys, at 3-month intervals, were conducted to examine acute COVID-related stressors and impacts. RESULTS/ANTICIPATED RESULTS: The dual mediation model fit the data as follows: χ2(7) = 19.00, p < .008; χ2/ df = 2.71; RMSEA = 0.06; CFI = 0.95; SRMR= 0.04. Results indicated that racial discrimination was directly associated with increases in COVID conspiratorial beliefs (B = .14, p<.05) and medical mistrust (B = .22, p<.001). COVID conspiratorial beliefs was directly associated with increases in COVID vaccine hesitancy (B = .11, p<.05). Indirect effects were detected whereby racial discrimination was associated with increases COVID vaccine hesitancy indirectly via increases in COVID conspiratorial beliefs (B = 0.016; 95% CI [0.001, 0.048]). DISCUSSION/SIGNIFICANCE: Investigating race-related factors in the context of vaccine hesitancy is a novel area of inquiry that could facilitate the development of targeted interventions for Black Americans to increase their vaccine uptake. Future research is needed to more thoroughly examine the relationship between racial discrimination and conspiratorial beliefs.

OBJECTIVES/SPECIFIC AIMS: To understand the role of PGF2a and to characterize a novel cyclooxyrgenase (COX)-independent prostaglandin synthesis pathway in epithelial ovarian cancer. METHODS/STUDY POPULATION: We used high grade epithelial ovarian cancer cell line (OVCAR3) as a model to study our pathway. Our main mode of PGF2a detection is through mass spectrometry. RESULTS/ANTICIPATED RESULTS: Our current results suggest the OVCAR3 cells may synthesize PGF2a independently of COX enzymes. We anticipate this novel pathway may be dependent on the TGFb pathway. DISCUSSION/SIGNIFICANCE OF IMPACT: Understanding the role and synthesis pathway of PGF2a may allow us to uncover a novel therapeutic pathway for high grade ovarian cancer.

OBJECTIVES/GOALS: We report an automated manufacturing system, and a series of cylindrical multi-layer microfluidic artificial lungs manufactured with the system and tested for fluidic fidelity and function. METHODS/STUDY POPULATION: A Roll-to-Roll (R2R) system to engrave multiple-layer devices was assembled. A 100 um-thick silicone sheet passes through an embedded CO2 laser engraver, which creates patterns of any geometry on the surface. The sheet is plasma-activated to create an irreversible bond, and rerolled into a processed device. Unlike typical applications of R2R, this process is synchronized to achieve consistent radial positioning. This allows the fluidics in the device to be accessed without being unwrapped. The result is a cylindrical core surrounded by many layers of microfluidic channels that can be accessed through the side of the device or through fluidic vias. This core is cut to expose the microfluidic layers, and then installed into a housing which routes the fluids into their respective microfluidic flow paths. RESULTS/ANTICIPATED RESULTS: To demonstrate the capabilities of the R2R manufacturing system, this method was used to manufacture multi-layer microfluidic artificial lungs (µALs). Gas and blood flow channels are engraved in alternating layers and routed orthogonally. The close proximity of gas and blood separated by gas-permeable PDMS permits CO2 and O2 exchange. Three µALs were successfully manufactured. Their flow paths were visualized using dyed water and checked for leaks. Then they were evaluated using water for pressure drop and CO2 gas-exchange. The top performing device had 15 alternating blood and gas layers. Test with whole blood demonstrated oxygenation from venous (70%) saturation levels to arterial (95%) saturation levels at a flow rate of 3 ml/min. DISCUSSION/SIGNIFICANCE: The ability to cost-effectively produce high surface area microfluidic devices would bring many small-scale technologies from the realm of research to clinical and commercial applications. In particular, most microfluidic artificial lungs only have small rated flows due to a lack of manufacturing processes able to create high surface area devices.

OBJECTIVES/SPECIFIC AIMS: Traditional hospice focuses on symptoms and quality of life (QOL) at the very end of life. Clinical symptoms and QOL in the last 1–2 years of life are also important and may be affected by dementia. Our objective was to characterize how symptoms differ between people with and without dementia in the last years before death and whether symptoms impact social dimensions of QOL. METHODS/STUDY POPULATION: We studied 1270 community-dwelling participants who died between 2011 and 2015 in the National Health and Aging Trends Study, a nationally representative cohort of older adults. From the last interview before death, we examined sensory (vision; hearing), physical (pain; problems with breathing, chewing/swallowing, speaking, upper or lower extremity strength/movement, and balance/coordination), and psychiatric (depression; anxiety; insomnia) symptoms by dementia status. We examined associations between symptoms and participation restrictions (visiting family/friends, attending religious services, participating in clubs/activities, going out for enjoyment, and engaging in favorite activity). RESULTS/ANTICIPATED RESULTS: Low energy (69%), pain (59%), and lower extremity strength/movement problems (56%) were most common. People with dementia (37.3% of decedents) had higher prevalence of all symptoms (p≤0.01), except pain, breathing problems, and insomnia. Dementia and greater symptom burden were independently associated with greater odds of participation restrictions (p<0.05). Problems speaking were significantly associated with limitations in all activities except for attending religious services. Balance/coordination, energy, and strength/movement problems were associated with limitations in 3 activities. DISCUSSION/SIGNIFICANCE OF IMPACT: Sensory, physical, and psychiatric symptoms are common in the year before death, with greater symptom prevalence in people with dementia. Both dementia and symptoms are associated with restrictions in participation. Older patients may benefit not only from earlier emphasis on palliative care but also programs and assistive devices that accommodate physical impairments.

Objectives/Goals: Investigating the B-cell acute lymphoblastic leukemia (B-ALL)-associated germline SNP rs7090445, located in intron 3 of ARID5B, which is more frequently observed in individuals of Hispanic/Latino descent. Investigating the mechanisms behind this inherited single nucleotide polymorphisms (SNP) that may contribute to the higher incidence of B-ALL in this population. Methods/Study Population: Specific Aim 1: We hypothesize ARID5B SNP rs7090445 disrupts intrinsic enhancer function. Identification of critical DNA looping events impacted by ARID5B variants using Capture C. Affinity purification-mass spectrometry to identify potential ARID5B transcription mediators. Specific Aim 2: We hypothesize the B-ALL-associated SNP leads to a partial human B-cell differentiation block. Utilize Cas9-mediated homology-directed repair to create ARID5B SNP in primary human hematopoietic stem cells. Gene-edited HSCs will be differentiated into B cells using an ex vivo system. Fluorescence-activated cell sorting to sort our pool of cells into stages of B-cell development spectrum. Amplicon sequencing and variant allele frequency of rs7090445 SNP to evaluate its impact on B-cell development. Results/Anticipated Results: This proposal is conceptually innovative as it seeks to understand the mechanism by which the B-ALL-associated SNP rs7090445 in intron 3 of ARID5B disrupts enhancer function and investigates its impact on human B-cell development. Future research will investigate a tumor-suppressive role of ARID5B and whether it constitutes a “first-hit” of leukemogenesis. Discussion/Significance of Impact: Successful completion of this research will elucidate the critical role of the B-ALL-associated ARID5B SNP rs7090445 in human B-cell development and leukemogenesis. As this SNP is more prevalent in Hispanic/Latino populations, it will also provide crucial insights into the genetic factors behind the elevated incidence of B-ALL.

ABSTRACT IMPACT: This proof-of-concept study demonstrates that systematically altering limb dynamics with two exoskeleton devices alters ingrained, bilateral upper-limb coordination with the potential to rehabilitate functional reaching in chronic stroke survivors OBJECTIVES/GOALS: Advances in virtual reality and exoskeleton technologies have allowed researchers to alter upper limb coordination with more precision than ever before. The goal of this study was to systematically enhance the use of the nondominant limb during a bimanual reaching task, with an eye towards improving rehabilitative strategies post stroke. METHODS/STUDY POPULATION: Healthy, right-handed volunteers performed a bimanual reaching task in virtual reality (VR) space while simultaneously moving under the influence of two exoskeleton devices. The VR task had participants move a shared cursor, displayed at the midpoint between the hands, to targets arranged at shoulder and eye levels and located at 70% of full arm extension. Two exoskeleton devices applied either resistive torque to the dominant limb or assistive torque to the non-dominant limb. Three-dimensional hand position data were recorded at 50 Hz and analyzed offline. The primary outcome measure was relative contribution, calculated as the ratio of dominant/non-dominant displacement. RESULTS/ANTICIPATED RESULTS: Preliminary results from 3 participants showed that during baseline trials, when no torque was applied by the exoskeletons, relative contribution was 50.6% in favor of the dominant hand, with the dominant hand reaching on average 1.1cm farther than the left. When the exoskeletons resisted movement in the dominant limb while simultaneously assisting movement in the non-dominant limb, relative contribution was 49.7% indicating an increase in non-dominant limb usage. Further analysis showed that this effect was driven by one participant who reached 3.7cm farther with her non-dominant hand compared to baseline. DISCUSSION/SIGNIFICANCE OF FINDINGS: These pilot data suggest our testing platform is capable of altering normal coordination patterns and is likely the result of participants adopting an optimal control strategy imposed by the shared cursor. These findings will form the basis for a rehabilitation intervention to promote the use of the paretic limb in chronic stroke survivors.

OBJECTIVES/SPECIFIC AIMS: Background: Children with autism spectrum disorder (ASD) show a broad range of unusual responses to sensory stimuli and experiences. It has been hypothesized that early differences in sensory responsiveness arise from atypical neural function and produce “cascading effects” on development across a number of domains, impacting social and communication skill, as well as broader development in children affected by ASD. A primary challenge to confirming these hypotheses is that ASD cannot be definitely diagnosed in the earliest stages of development (i.e., infancy). A potential solution is to prospectively follow infants at heightened risk for ASD based on their status as infant siblings of children who are diagnosed. We examined the developmental sequelae and possible neurophysiological substrates of three different patterns of sensory responsiveness—hyporesponsiveness (reduced or absent responding to sensory stimuli) and hyperresponsiveness (exaggerated responding to sensory stimuli), as well as sensory seeking (craving of or fascination with certain sensory experiences). Infants at high risk (HR) for ASD were compared with a control group of infants at relatively lower risk for ASD (LR; siblings of children with typical developmental histories). Objectives: Research questions included: (a) Do HR infants differ from LR infants in early sensory responsiveness?, (b) Does sensory responsiveness predict future ASD and related symptomatology? and (c) Is sensory responsiveness predicted by resting brain states? METHODS/STUDY POPULATION: Methods: To answer these questions, we carried out a longitudinal correlational investigation in which 20 HR infants and 20 LR controls matched on sex and chronological age were followed over 18 months. At entry to the study, when infants were 18 months old, sensory responsiveness was measured using the Sensory Processing Assessment and the Sensory Experiences Questionnaire, and a number of putative neural signatures of early sensory differences were measured via resting state EEG. When infants were 24 and 36 months of age, ASD and related symptomatology was evaluated in a comprehensive diagnostic evaluation. RESULTS/ANTICIPATED RESULTS: Results: HR infants trended towards increased hyporesponsiveness and hyperresponsiveness and showed significantly elevated levels of sensory seeking relative to LR controls at 18 months of age. Both groups, furthermore, displayed a high degree of heterogeneity in sensory responsiveness. Atypical sensory responsiveness (increased hyperresponsiveness and/or hyporesponsiveness, as well as sensory seeking behavior) predicted several aspects of ASD and related symptomatology, including social, communication, and play skill, and was associated with differences in resting brain state, including metrics of oscillatory power, complexity, and connectivity, as well as hemispheric asymmetry. Moderation analyses revealed that several relations varied according to risk group, such that associations were stronger in magnitude in the HR Versus LR group. DISCUSSION/SIGNIFICANCE OF IMPACT: Conclusion: Findings provide empirical support for the notion that early sensory responsiveness may produce cascading effects on development in infants at heightened risk for ASD. Differences in resting brain states may underlie atypical behavioral patterns of sensory responsiveness. From a clinical standpoint, results suggest that early sensory differences may be useful for predicting developmental trajectories, and be potentially important targets for early preventive intervention, in infants at risk for autism.

OBJECTIVES/SPECIFIC AIMS: Research on cancer difference is of significant scientific and practical value. For leukemia, the survival disadvantage of the Blacks has been suggested in multiple studies. However, the existing epidemiologic analysis has multiple technical limitations. The goal of this study is to more accurately quantify so as to better understand different sources of racial differences in leukemia survival. METHODS/STUDY POPULATION: A new statistical method, which is based on robust regression and resampling, is developed. Data are obtained from the SEER (Surveillance, Epidemiology, and End Results) database. Using the “classic” epidemiologic methods as well as the new method, analysis is conducted on the prognosis of 4 leukemia subtypes (ALL, CLL, AML, and CML) for 4 major racial groups (White, non-Hispanic White, Black, and Asian and Pacific Islander). RESULTS/ANTICIPATED RESULTS: After effectively removing differences caused by the observed clinicopathological and demographic factors, the survival disadvantage of the Blacks persists for the following patient groups: ALL and age>14, CLL and age>14, and ALL and age≤14. The quantitative results are significantly different from those from classic epidemiologic analysis. Such observed racial differences are more attributable to the unobserved risk factors and cancer disparity. DISCUSSION/SIGNIFICANCE OF IMPACT: This study provides a more effective and more direct quantification of racial difference in leukemia prognosis. The survival disadvantage of the Blacks which is observed for certain subtypes/age groups deserves further attention but should not be overstated. More data collection and analysis are needed to more accurately decipher racial differences in leukemia and other cancer types.

OBJECTIVES/SPECIFIC AIMS: Approximately 1.6 million Americans suffer from inflammatory bowel diseases (IBD), ulcerative colitis, and Crohn’s disease. It is a challenge for both physicians and patients alike to manage the disease, primarily due to lack of disease specific biomarkers. Endoscopy remains the gold standard to diagnose and evaluate IBD activity. Current biomarkers or their combinations cannot adequately predict IBD progression or relapse, and response to therapy. METHODS/STUDY POPULATION: In total, 97 IBD patients recruited at University of Kentucky undergoing endoscopy. Patients medical information was collected from electronic database including C-reactive protein (CRP), fecal calprotectin (FC), endoscopy/pathology report. RESULTS/ANTICIPATED RESULTS: The mean CRP and FC levels were 1.3 (normal <1) and 679 (normal <162), respectively. FC (sensitivity 74%) was more reliable to predict mucosal inflammation compare to CRP (sensitivity 36%). However, 52% of patients did not have FC performed (vs. CRP only 4%), and 45% of these patients failed to submit stool sample for analysis. DISCUSSION/SIGNIFICANCE OF IMPACT: Our data suggests FC is the most promising noninvasive marker for disease monitoring in IBD. It correlates well with endoscopic activity and mucosal inflammation. However, further analysis must be done to evaluate barriers to testing and issues with compliance from patients. We feel strongly that a blood biomarker for disease activity is vital for disease monitoring and response to therapy in IBD.

OBJECTIVES/SPECIFIC AIMS: Clinical guidelines recommend using predicted atherosclerotic cardiovascular disease (ASCVD) risk to inform treatment decisions. The objective was to compare the contribution of changes in modifiable risk factors Versus aging to the development of high 10-year predicted ASCVD risk. METHODS/STUDY POPULATION: Prospective follow-up of the Jackson Heart Study, an exclusively African-American cohort, at visit 1 (2000–2004) and visit 3 (2009–2012). Analyses included 1115 African-American participants without a high 10-year predicted ASCVD risk (<7.5%), hypertension, diabetes, or ASCVD at visit 1. We used the Pooled Cohort equations to calculate the incidence of high (≥7.5%) 10-year predicted ASCVD risk at visit 3. We recalculated the percentage with a high 10-year predicted ASCVD risk at visit 3 assuming each risk factor [age, systolic blood pressure (SBP), antihypertensive medication use, diabetes, smoking, total and high-density lipoprotein cholesterol], one at a time, did not change from visit 1. RESULTS/ANTICIPATED RESULTS: The mean age at visit 1 was 45.2±9.5 years. Overall, 30.9% (95% CI 28.3%–33.4%) of participants developed high 10-year predicted ASCVD risk. Aging accounted for 59.7% (95% CI 54.2%–65.1%) of the development of high 10-year predicted ASCVD risk compared with 32.8% (95% CI 27.0%–38.2%) for increases in SBP or antihypertensive medication initiation and 12.8% (95% CI 9.6%–16.5%) for incident diabetes. Among participants <50 years, the contribution of increases in SBP or antihypertensive medication initiation was similar to aging. DISCUSSION/SIGNIFICANCE OF IMPACT: Increases in SBP and antihypertensive medication initiation are major contributors to the development of high 10-year predicted ASCVD risk in African Americans, particularly among younger adults.

OBJECTIVES/GOALS: Patients with nsCL/P are prone to infections due to their open like wound cleft and immune system susceptibility. COVID-19 affected nsCL/P patients access to care and treatment delays. This study will determine COVID-19 infection risk between children with nsCL/P compared to those unaffected. METHODS/STUDY POPULATION: Retrospective cohort of children 5 years old and under with nsCL/P (exposed group) and children without nsCL/P (unaffected group); matched by age and gender. Participants will be selected from ongoing case-control study (n=500), School of Dental Medicine, and Pediatric University Hospital. Power analysis will calculate minimum sample size (power=0.80 alpha=0.05). Exclusion criteria: syndromic clefts, patients without diagnosis information and with history of co-morbidity. Other bacterial and viral infections present at the time of COVID-19 diagnosis, sex, age, geographic location, COVID-19 vaccination status and others will be considered as possible cofounders. Descriptive statistics, Chi-square, Odds Ratios at 95% confidence intervals and multiple logistic regression will be estimated. RESULTS/ANTICIPATED RESULTS: We hypothesize that we will identify an increased risk of COVID-19 infection in children with nsCL/P than in those unaffected or children without nsCL/P. Children with nsCL/P will also have an increased risk of symptoms and complications of COVID-19 infection than those unaffected. DISCUSSION/SIGNIFICANCE: Knowing the increased risk of COVID-19 infection in children with nsCL/P will aid to prioritize treatment. If a higher risk of COVID-19 infection is found, it will generate a need to modify elective surgery status to semi-elective; minimizing delayed treatments, unnecessary hospitalizations, complications and increased cost of treatment.

ABSTRACT IMPACT: We describe a novel methodology that combines CRISPR/Cas9-induced double stranded DNA breaks with homology dependent repair from an adeno associated virus (AAV) encoded template to generate single-allele edited isogenic cell line models of cancer-associated mutations with high efficiency. OBJECTIVES/GOALS: Conventional approaches to creating isogenic knock-ins, to model disease-associated mutations, are limited by poor efficiency and loss of the mutant allele on extended culture. We present an optimized editing approach combining CRISPR/Cas9 with Adeno-associated virus, using mutant SF3B1 as a prototype. METHODS/STUDY POPULATION: Left and right homology arms for SF3B1 were PCR amplified and cloned into pAAV-SEPT-Acceptor plasmid (containing a chimeric intron, neomycin resistance cassette and polyA tail). The disease-associated K700E mutation was introduced by site-directed mutagenesis. Single guide RNA (sgRNA) complexed with recombinant Cas9 along with the AAV donor were delivered into K562 cells, G418 resistant clones selected, and screened for integration by PCR. Confirmed clones were then transduced with a doxycycline-inducible Cre-recombinase containing lentiviral vector. Inducible expression of Cre-recombinase and expression of the mutant allele were confirmed by Western blot and Sanger sequencing respectively. RESULTS/ANTICIPATED RESULTS: Targeted-integration efficiencies among the Neo-resistant clones, generated by AAV-alone and AAV+CRISPR/Cas9, were 16% and 94%, respectively. Single cell cloning after Cre-mediated excision of loxp was unsuccessful presumably due to toxicity of the K700E mutation. To overcome this limitation, clones were transduced with doxycycline-inducible Cre-recombinase lentiviral vector. Doxycycline induction of Cre-recombinase resulted in reliable excision of the loxp cassette and expression of mutant allele at about 50% variable allele frequency (as determined by Sanger sequencing). The approach was validated in additional cell lines and for introduction of N-terminal FLAG tag for SF3B1. DISCUSSION/SIGNIFICANCE OF FINDINGS: Combining AAV and CRISPR/Cas9 can generate scalable single-dominant allele mutants with high precision and efficiency compared to AAV or CRISPR alone. Together with inducible Cre-recombinase, our approach can generate isogenic models where the mutation confers a growth disadvantage.

OBJECTIVES/SPECIFIC AIMS: We are exploring the structure of the interaction between an immunogenic neoantigen and a T cell receptor (TCR) that recognizes the neoantigen while tolerating the counterpart self antigen. No structural example exists to date of how a TCR can discriminate between a neoantigen and the self antigen. We aim to determine the structural and biophysical features that underlie the immunogenicity for this neoantigen, and the features we determine are likely to be present in other immunogenic neoantigens. Algorithms to predict the immunogenicity of neoantigens are available, but do not incorporate structural or biophysical factors. We aim to improve these methods for immunogenic neoantigen prediction by determining structural and biophysical factors that result in recognition by the immune system. METHODS/STUDY POPULATION: Recombinant protein expression, production, and purification. Protein x-ray crystallography. Biophysical protein-protein binding experiments RESULTS/ANTICIPATED RESULTS: The T cell receptor (TCR) bound to the neoantigen with an affinity 15-fold higher than the self antigen. The leucine to phenylalanine mutation occurs at position 8 of a 9-amino acid long peptide antigen. This position is typically in the interface bound by the T cell receptor. The structures of the unbound neoantigen and self antigen showed that the mutated residue was in the TCR interface. Additionally we noted a change in the side chain position of a proximal tryptophan, potentially due to clashes with the larger phenylalanine residue. The structure of the TCR bound to the neoantigen showed that the TCR interacted with the tryptophan in the mutation-induced conformation and with the phenylalanine residue. Thus the mutation may be altering TCR binding affinity by interactions of the residue itself with the TCR, and by locking the proximal tryptophan residue in an optimal position to interact with the TCR. We are testing the contributions of each of these factors to the overall affinity change. Hydrophobicity has been linked to immunogenicity, so mutations that increase hydrophobicity compared to the self antigen are likely to be immunogenic. However, leucine and phenylalanine are similar on hydrophobicity scales. On the other hand, a side chain rotation is unlikely to represent a large energy barrier. Therefore, we hypothesize that another property of the phenylalanine, such as size or aromaticity, is driving the affinity difference. DISCUSSION/SIGNIFICANCE OF IMPACT: Traditional forms of cancer therapy do not specifically target cancer cells, and their toxicity to healthy cells limits their effectiveness. Immunotherapy, which involves orchestrating a specific anti-cancer immune response, is now an established cancer therapy. Several forms of immunotherapy target “neoantigens,” which are derived from mutated proteins in cancer, and are therefore are cancer-specific. Neoantigens represent a foothold that can allow the immune system to distinguish between cancer cells and healthy cells, and thus specifically target cancer cells for destruction while imparting no activity toward healthy cells that lack the neoantigen. Most cancer mutations that result in neoantigens arise from random passenger mutations in cancer and will be different among patients. Neoantigen-based cancer therapies are thus a precision medicine technique. The quality of neoantigens to induce an immune response (immunogenicity), which relates to how likely they are to be presented to the immune system and recognized as foreign, has been shown to be a critical factor in predicting the outcome of immunotherapy treatment. We are investigating, on a structural and biophysical level, features that may increase the likelihood of a neoantigen being recognized as foreign by the immune system. The structural insight we gain can be incorporated into algorithms that predict neoantigens from cancer exome sequencing for patient-specific identification of immunogenic neoantigens for immunotherapeutic intervention.

OBJECTIVES/GOALS: To explore the severity of posttraumatic stress disorder (PTSD) symptoms in association with hippocampal and amygdala volumes in ICU survivors. We hypothesize that the severity of posttraumatic stress symptoms in ICU survivors is associated with lower volumes of both the hippocampus and amygdala. METHODS/STUDY POPULATION: Secondary analysis of the VISIONS study, a prospective sub-study of the BRAIN-ICU cohort, which included survivors of critical illness. Patients were screened for preexisting PTSD before discharge. The PTSD Checklist Specific (PCL-S) was used at 3 and 12 months to evaluate the ICU as a traumatic experience. A score of >30, indicated significant symptoms of PTSD. A Philips Achieva 3T MRI scanner was used to scan patients at both discharge and 3-month follow-up. To compare median brain volumes at discharge and 3 months for those with and without significant PTSD symptomatology (PCL-S ≥30) at 3 and 12 months, we used a Kruskal-Wallis (KW) equality-of-populations rank test. RESULTS/ANTICIPATED RESULTS: The median age for our sample was 58.5 (52.6, 63.7). One-third of the sample was female, and 90% were Caucasian. Fifty-seven percent of individuals (N = 12) had at least one prior mental health diagnosis, with two having a prior history of PTSD. One third of individuals experienced delirium during their critical illness. At 3-month follow up, there were three patients with PTSD symptomatology and one at 12-month follow up. Median brain volumes (hippocampus or amygdala) did not differ between individuals with or without PTSD symptomatology at either 3 or 12 months (p-values for all tests >0.05). DISCUSSION/SIGNIFICANCE OF IMPACT: Although our study did not reveal significant differences in brain volumes between PTSD patients and non-PTSD patients, sample size is a major limitation and larger scale studies should be undertaken to elucidate possible neurobiological markers of PTSD in ICU survivors. CONFLICT OF INTEREST DESCRIPTION: Dr. Wilson would like to acknowledge salary support from the Vanderbilt Faculty Research Scholars Program (1KL2TR002245), HL111111 and GM120484. Drs. Ely and Jackson as well as Mrs. Kiehl all receive funding for their time working on this investigation from AG035117 and HL111111. Dr. Ely would additionally like to acknowledge salary support from the Tennessee Valley Healthcare System Geriatric Research Education and Clinical Center (GRECC). Dr. Ely will also disclose additional funding for his time from AG027472 and having received honoraria from Orion and Hospira for CME activity; he does not hold stock or consultant relationships with those companies. The authors would like to acknowledge the following: this work was conducted in part using the resources of the Center for Computational Imaging at Vanderbilt University Institute of Imaging Science and the Advanced Computing Center for Research and Education at Vanderbilt University, Nashville, TN, and study data were collected and managed using REDCap electronic data capture tools hosted at Vanderbilt University.

OBJECTIVES/GOALS: The purpose of this small survey-based study was to characterize the current role of neurocritical care physicians in traumatic brain injury (TBI) systems of care and research. In doing so, we aim to highlight potential roles of neurology providers in the medical management and enhancement of translational science in the field of TBI. METHODS/STUDY POPULATION: Between April and June 2021, a web-based survey was disseminated by email to members of the Neurocritical Care Society. The survey was open to all physician providers. A total of 36 surveys were completed. The survey consisted of 18 questions with pre-defined answer choices. Survey questions aimed to determine areas of practice, primary clinical specialty, hospital practice setting, provider involvement in TBI care, provider involvement in TBI research, and current research roles. RESULTS/ANTICIPATED RESULTS: 92% of survey respondents were in the United States (n=33), representing all national regions. 75% of the physicians were neurocritical care trained (n=27). 69% of providers were practicing in academic institutions while 78% were at sites designated as Level I trauma centers. All respondents managed acute TBI, but 50% served as consultants rather than being the primary service provider. At their sites of practice, 31% of patients were on non-neuroscience services, especially those with non-neurologic traumatic injury. Only 36% reported that TBI protocols were written and adhered to at their site. Only 44% reported that TBI research was performed at their site, while 50% had interest in participating in TBI research. TBI was the primary area of research for 17% of physicians. DISCUSSION/SIGNIFICANCE: This small physician survey highlights heterogeneity in TBI systems-based practice and research roles. Areas of potential improvement include greater involvement of neurocritical care physicians in TBI management, protocol-building and implementation, and TBI research. Reasons for current barriers are multifactorial and will be discussed.