Yale University

NIH Research Projects · FY 2025 · 2025-09

Project Summary Immunologic and Imaging studies with TNF Therapy in Prodromal Synucleinopathies is a pioneering, prospective, randomized, double-blind parallel group study designed to assess the potential of anti- TNF (adalimumab) to slow or prevent the emergence of motor and cognitive symptoms of synucleinopathy. The trial is based on data from our ASAP grant where we integrated single-cell genomics analysis and observed T-cell pleocytosis in the CSF of RBD patients and an increase in circulating inflammatory central memory Th17 cells in RBD similar to other autoimmune diseases. In CSF of RBD and PD patients, we observed increases in activated non-classical monocytes with upregulated TNFR2 and TNF-mediated signaling pathways indicating increased CNS inflammation. Core funding for PRISMS was provided by a grant from the Marcus Foundation, AbbVie is providing drug, and the study is being carried out with the Parkinson Study Group. 100 subjects with polysomnographically-proven RBD who have not been diagnosed with either PD or DLB will be randomized 1:1 to receive anti-TNF or placebo for two years. In addition to clinical assessments, subjects will undergo multimodal neuroimaging studies and will be given a body-attached wearable biosensor. The core trial funding for PRISMS is sufficient to support conduct of site activities, including clinical outcome measures, MRI and dopamine transporter (DaT) scans, collection of biological samples, trial operations, oversight and regulatory reporting. In this proposal, we are requesting funding to support novel interrogation of the immune cell populations (in vivo perturb seq) and clinical imaging. Specifically, we propose to perform: Aim 1) immunophenotyping with single-cell RNA-Seq, characterization of FoxP3 regulatory CD4 T cells, and evaluation of the soluble markers of inflammation and neurodegeneration in CSF of a subset of 30 subjects and in blood of the entire study population; Aim 2) FDG-PET scans for assessment of brain metabolic activity using the statistical parametric methods, structural integrity of brain dopaminergic systems using Dopamine Transporter SPECT imaging to evaluate dopamine nerve cell terminals, and neuromelanin-MRI to assess catecholaminergic cell bodies. While the clinical trial will test the hypothesis that prodromal PD as manifest with RBD is inflammatory mediated by TNF whether the treatment approach is successful, the proposal will provide deep mechanistic insight into the role of the TNF pathway in the progression of synucleinopathies.

NIH Research Projects · FY 2025 · 2025-09

PROJECT SUMMARY An increase in human life expectancy without a proportional extension of time spent in good health, or “healthspan,” has led to expansion of the global population of aged and frail individuals with multiple morbidities. Chronic exercise improves healthspan in multiple model organisms, and physical activity level is inversely associated with all-cause mortality risk in humans. There is a preponderance of evidence for the benefits of physical activity and exercise in youth and during aging, yet the cellular and molecular mechanisms underpinning these benefits remain ill-defined. Previously, I demonstrated that appropriate inflammatory tone in muscles is required for normal tissue- and organism-level metabolic adaptations and improved performance in response to exercise. The current research plan will advance our understanding of exercise-induced immunomodulation and its effects on muscle physiology and age-related muscular decline. My preliminary data show that muscle stromal cells potentiate exercise-induced muscle inflammation in response to mechanical stress; this is exacerbated in aged muscles. In Aim 1, I will test the hypothesis that an appropriate level of mechanical-stress-mediated stromal activation is critical for the immunological, metabolic, and functional adaptations to exercise observed in young mice; in aged mice, excessive mechanical stress augments muscle inflammation, which limits these adaptations. In Aim 2, I will determine the contributions of muscle stromal cells and macrophages to the opposing effects of inflammation, in particular IFN, and exercise training on age-related decline in muscle function. I postulate that aging skews muscle stromal-cell and macrophage phenotypes toward states that contribute to muscular decline and that training is sufficient to counter these changes. Furthermore, I hypothesize that increased IFN signaling into stromal cells and macrophages is a basis of age-related decline in muscle function. In addition to conceptual advancements, the present proposal will generate rich transcriptomics datasets and multiple mouse strains of utility in my future independent studies. I have completed most of the Aim 1 experiments involving young mice and will continue Aim 1 in both the approval and award phases. The approval phase will be completed at Harvard Medical School in the joint-lab of Drs. Diane Mathis and Christophe Benoist, leaders in immunological tolerance and systems immunology. In the approval phase, I will work with my advisory committee to polish my skills in mentorship, grant writing, communication, and lab management. This training will be complemented with formal instruction in the form of courses and workshops designed to promote professional development and independence. I have an unwavering passion for immunometabolism, and I have structured my scientific training to afford me with a diverse skillset suitable for establishing a productive niche in which I can lead a successful laboratory. The datasets generated by this plan, in particular the transcriptomic and metabolic profiles of muscle- resident cells from the proposed experimental conditions, will inform my laboratory’s future work aimed toward understanding metabolic regulation of skeletal muscle inflammation and adaptation during exercise and aging.

NIH Research Projects · FY 2025 · 2025-09

Project Summary Collective cell motion is involved in diverse physiological and pathological processes, from the separation of tissues during early development, to tissue repair and cancer invasion in the adult. To date, collective motion is predominantly associated with the mechanisms and driving forces that underlie single cell migration. During migration, the cell undergoes a cyclic process of cell polarization and protrusion, adhesion to the extracellular matrix (ECM) and the generation of traction forces. Though the transmission of mechanical stresses at cell-cell junctions, the motion of a cell population becomes correlated over long distances and long times. However, cell- cell interactions can also accumulate large mechanical stresses in the form of tissue pressures and surface tensions. By force balance, gradients in these stresses can drive convection – mass transport due to bulk motion, as occurs in fluids. Further, as the forces that arise from gradients in tissue-scale surface tensions and pressure can be larger than those associated with single cell traction forces, ‘convective’ motions may be faster and more correlated that what can be achieved by migration alone. However, despite the potential generality of this phenomenon, how surface tension and pressure gradients are accumulated and transmitted within tissues is unclear. Further, how convection and migration coordinate their diverse timescales and lengthscales to yield complex cellular motions within is also unknown. This proposal seeks to identify the principles that underly convection, its coordination with migration, and its role in physiological processes. Identification of these principles will yield fundamental insights in biological mechanism, but also suggest novel targets for intervention in motility-associated diseases.

NIH Research Projects · FY 2025 · 2025-09

This project seeks to develop a culturally adapted Contingency Management (CM) intervention for adults with stimulant use disorder (StUD) in the New Haven community. CM is grounded in behavioral economics, involving the use of tangible positive reinforcements to incentivize verifiable pro-health behaviors. There has been a persistent increase in fatal drug overdoses in New Haven despite four years of consistent reduction in other Connecticut counties. A resurgence in stimulant use, contamination of community drug supplies with high potency synthetic opioids (HPSO) and a range of structural and social issues have been noted as major drivers of this mortality trend. CM has been shown to be the most effective intervention for StUD as there are no FDA approved medications for this indication. Further, emerging evidence shows that adults who entered treatment with cocaine-positive urines did not show any gains in treatment retention or other clinical outcomes. This observation of disparate health outcomes informs the urgency to culturally adapt CM for New Haven, a city with culturally rich population, but with heightened risk of overdose given the prevalence of opioids/stimulant polysubstance co-use. The objective of this research is to develop components of a culturally adapted CM for New Haven using theoretically and empirically driven approaches. Specific research aims include: 1) Assessment of the target population’s behavioral risks, perceived need for prevention, barriers, preferences for intervention and development of components of CM adaptation; 2) production of iterative drafts of the adapted CM and 3.) Pilot RCT to examine the short-term efficacy of the adapted CM with the primary outcomes of percent negative urines and longest duration of abstinence during treatment. Completing this K23 proposal will provide the PI with critical new training in several key areas to achieve his long-term career goal of becoming an independent investigator capable of developing, testing, and implementing effective, accessible, and culturally informed substance use interventions for adults in community. Dr. Jegede and his mentors have compiled a comprehensive training plan in the following areas: conducting community-engaged and community based participatory research; developing mastery in culturally salient interventions for StUD, obtaining knowledge and skills in Dissemination Implementation Science methods; and developing skills in conducting randomized controlled trials, responsible conduct of research, and grant writing. This proposal addresses a vexing public health problem of escalating drug related mortality in New Haven by developing a robust and culturally informed adaptation of CM to treat StUD. The vital support from this K23 award will allow Dr. Jegede’s scientific development as he develops into an independent investigator and develop a highly integrated community-engaged research program addressing stimulant use and improving wellbeing among adults in the New Haven community.

NIH Research Projects · FY 2025 · 2025-09

Project Summary The flexible ability to work together for mutual benefits while competing against others for limited resources is a hallmark of advanced social cognition. Cooperative and competitive interactions are highly dynamic and complex. However, studying the precise behavioral mechanisms of these interactions has been challenging. This is partly due to the fact that the standard animal models in lab studies do not reliably cooperate. Moreover, typical studies do not include multidimensional behavioral measurements that are essential to understand such complex interactions. Therefore, there is a need to investigate complex social interactions in a species whose social structure strongly depends on both cooperation and competition, while tracking multiple action-based and internal state-related variables to obtain a comprehensive understanding of social behavior. The marmoset is an excellent species for studying complex social interactions grounded in context-dependent cooperative and competitive tendencies within their natural ethology. The first major goal of this proposal is to simultaneously and continuously collect multidimensional biobehavioral measurements, both action-based and internal state-based, during naturalistic cooperative and competitive interactions between freely moving marmosets. We aim to understand the functional and directionally causal dependencies of these biobehavioral variables in cooperative and competitive behaviors. The second major goal is to build comprehensive and empirically testable generative models of primate social interaction and to validate our understanding iteratively between the models and the experiments. We will use multiple modeling approaches to exploit their strengths: multi-agent reinforcement learning with recurrent neural networks will be used to learn complex patterns for prediction, and the structure and inputs to these models will be informed by dynamic Bayesian networks to increase the interpretability of the models. We will use an embodied agent-based framework, with the recurrent neural networks driving musculoskeletal models of marmosets, to better model cooperative and competitive interactions of nonhuman primates. With the comprehensive biobehavioral data and the musculoskeletal model, we will build generalizable models of primate social interaction via a multi-level constraints-based framework. Finally, we will validate the generative models of primate social interaction by inducing multiple types of in silico environmental and task manipulations that are designed to predictably alter social strategies and carrying out those experiments in vivo that significantly alter the resulting social strategy. Overall, we aim to provide the most comprehensive understanding of primate social interactions to date, along with novel generative models of such behavior.

NIH Research Projects · FY 2025 · 2025-08

PROJECT SUMMARY Reproduction is a systemic decision that relies on nutrient availability to support the high energetic cost of gamete production and reproductive behaviors. Disorders that correlate with insufficient or excess body fat mass like anorexia nervosa or polycystic ovarian syndrome are associated with decreased ovulation and infer- tility. In humans and the model organism Drosophila melanogaster, steroid hormones are essential for reproduc- tion, though the molecular cues that relay nutrient information to direct hormonal function are not well understood. In Drosophila, activation of Ecdysone receptor (EcR) by the steroid hormone 20-hydroxyecdysone (20E) is re- quired for oocyte maturation in the ovary. Interestingly, the transcription factor Cryptocephal (Crc), which is in- duced by starvation via the Integrated Stress Response (ISR) pathway, interacts physically with EcR. This study will examine how nutrient sensing alters reproductive capacity via ISR signaling and steroid hormones. I recently found that loss of crc in the fat body (FB), a liver-like and adipose-rich tissue in Drosophila, caused follicle death and decreased lipid/yolk protein composition, defects associated with 20E dysregulation. Additionally, loss of ISR factors caused excess retention of mature oocytes in the ovary. Together, my data suggest that ISR signaling co-regulates oocyte maturation and egg laying behavior. During the training (K99) phase of this award, I will uncover how Crc and EcR link metabolic status to gametogenesis and egg- laying behavior. To this end, I am collaborating with Dr. Kafui Dzirasa at Duke University to adapt a novel neural editing tool for use in Drosophila, creating artificial synapses to characterize regulation of egg laying by the ISR. Starvation, which activates the ISR, attenuates post-mating increases in intestinal function and courtship behavior. During the independent (R00) phase, I will apply the insights and tools acquired during the training phase to identify molecular cues downstream of ISR signaling that control nervous system and gut functions to alter reproductive potential. First, I will determine how the ISR regulates female courtship behavior, which requires inputs from central and peripheral neurons. Next, I will leverage the collaborations forged during the K99 phase to characterize organism-wide expression of EcR- and Crc-responsive reporters under different feeding conditions to interrogate the roles of Crc and EcR in the intestine, where both regulate stem cell dynamics. This will open multiple lines of inquiry into how nutrient sensing controls multiple reproductive events via ISR signaling and inter-organ crosstalk. My proposed studies will develop novel tools and insights that will lay a strong foundation for my independent research program, wherein I will characterize diverse phys- iological consequences of ISR and steroid hormone signaling in metabolic tissues and decipher how this impacts behavior and whole-organism physiology. Ultimately, my work will reveal important insights into how metabolism controls reproduction across organisms, which may lead to novel therapeutics for treating human metabolic disorders that cause sex hormone dysregulation and infertility.

NIH Research Projects · FY 2026 · 2025-08

PROJECT SUMMARY Multiple organ dysfunction syndrome (MODS), most commonly caused by sepsis, is a hyperinflammatory condition in which ≥2 organ systems are dysfunctional. Disseminated microvascular thrombosis is a hallmark of MODS. When MODS presents with thrombocytopenia, pediatric mortality is as high as 80%. The combination of inflammation, thrombosis and thrombocytopenia suggests that platelet dysfunction plays a central role in pediatric MODS. Our highly promising preliminary data supports a role for endoplasmic reticulum (ER) stress and unfolded protein response (UPR) in producing a heterogeneous dysfunctional platelet response, including apoptosis. Due to inflammation and other stressors, ER stress with accumulating protein aggregates triggers the UPR to restore protein folding homeostasis. When ER stress is severe, the pro-survival protective UPR may be overwhelmed and divert some platelets to dysfunction, specifically apoptosis, contributing to thrombosis, thrombocytopenia, then MODS. We have shown that the UPR may be a master regulator of these pathological pro-thrombotic and pro-bleeding responses. UPR in platelets remains unexplored in children whose platelets are functionally different from adults, and in response to ER stress in MODS. Our central hypothesis states that hyperinflammation causes severe ER stress and overwhelms the UPR leading to platelet dysfunction in children. This platelet dysfunction contributes to thrombosis, thrombocytopenia, then MODS. But the UPR can be modulated to prevent these complications. We propose to determine the effects of ER stress due to inflammation on platelet UPR activation and dysfunction in pediatric MODS (Specific Aim 1), to determine the molecular mechanisms of ER stress-induced platelet dysfunction and its complications in in vivo model of pediatric MODS (Specific Aim 2), and to determine the diagnostic and therapeutic implications of platelet UPR activation in pediatric MODS (Specific Aim 3). We will use innovative concepts, cutting-edge techniques, and ex vivo pediatric and in vivo murine models to investigate the role of UPR in platelet dysfunction in MODS in children. At the completion of this research, we expect to define a novel, pediatric-specific role of platelet UPR in platelet dysfunction, thrombosis, thrombocytopenia and MODS. These results are expected to provide a strong foundation for the development of therapies specific to MODS in children that are based on the UPR in platelets.

NIH Research Projects · FY 2025 · 2025-08

Abstract The majority of small molecule therapeutics function by inhibiting the target protein. Recent research has shown that, in many cases, achieving the degradation of the target protein is more effective than merely pharmacologically inhibiting it. This proposal focuses on the development of "Modular degradation of extracellular proteins" (MoDEs) designed to enable the removal of extracellular proteins from circulation. Through the proposed research program, we will (1) develop improved MoDEs with more favorable, druglike properties, (2) establish a high-throughput assay and rigorous mathematical framework for evaluating MoDE candidates to accelerate development cycles, and (3) demonstrate MoDE efficacy in an autoantibody-driven animal model of autoimmune disease. This research will pave the way for the future clinical development of MoDEs to treat antibody-driven autoimmune disorders and heart failure. To accomplish this, we have created and tested bifunctional molecules with the capability to selectively deplete antibodies based on their epitope specificity, while preserving the remainder of the immunoglobulin repertoire. This technology relies on bifunctional small molecules, composed of a target-binding portion linked to a ligand for the asialoglycoprotein receptor (ASGPR) on hepatocytes via a spacer. Upon the administration of these compounds, a ternary complex is formed among the target protein, the bifunctional molecule, and the ASGPR on the surface of liver cells. This complex is subsequently internalized into endosomes, leading to the trafficking of the target protein to lysosomes for degradation. To develop improved MoDEs, we will use computer-assisted molecular modeling and medicinal chemistry to adapt these novel ASGPR ligands into wholly small-molecule MoDEs. We expect that MoDEs incorporating the small molecule ASGPR ligands discovered in our laboratory will exhibit improved affinity, oral bioavailability, ease of large-scale production and profound improvements in PK/PD properties. To accelerate the future development cycles of MoDEs, we will develop a bioluminescence-based high-throughput assay for target protein endocytosis and lysosomal trafficking, as well as a mathematical model of the kinetics of the intracellular process underpinning MoDE-dependent degradation. Finally, we will develop and test MoDEs that incorporate antigen mimics to selectively eliminate pathogenic autoantibodies associated with heart failure while preserving the healthy antibody repertoire.

NIH Research Projects · FY 2025 · 2025-08

PROJECT SUMMARY In the United States (US), glioma accounts for 53% of tumors in the brain and central nervous system among children (0-14 years), causing more deaths than any other types of childhood cancer. The incidence of glioma is higher in younger children (0-5 years) than in older children (6-14 years), and it has been increasing in the US despite a decrease in overall cancer incidence during 2000-2018. The brain undergoes the fastest development during pregnancy and is susceptible to environmental exposures that may impact cancer risk, either on their own or jointly with genetic factors. The objective of this study is to investigate the etiology of glioma in young children, with a focus on prenatal exposure to per- and poly-fluoroalkyl substances (PFAS), while accounting for other putative risk factors for glioma, including genetic susceptibility. PFAS are a family of more than 10,000 fluorinated compounds. These chemicals are widely present and extremely persistent in clothing, furnishings, paper products, food packing, and kitchenware. There is strong evidence that PFAS can induce oxidative stress, are immunosuppressive, and modulate receptor-mediated effects. As PFAS are known to cross the placenta during pregnancy and blood brain barriers and have been demonstrated to be neurotoxic, it is biologically plausible that prenatal PFAS exposure can interfere with multiple maternal-fetal systems at critical time windows and impact brain development. PFAS have been detected in surgically resected glioma tissue samples. In the proposed study, we will select 350 cases who were diagnosed with astrocytoma (the most common subtype of glioma in young children) in California at the age of 0-5 years from a population- based statewide linkage of birth records and cancer registry data, as well as 350 cancer-free controls from the same linkage, forming a nested case-control study within the California birth cohort. Using state-of-the-art technology to measure PFAS in the archived newborn blood specimens, we will pursue two aims: (1) conduct a targeted analysis of 13 PFAS and examine whether prenatal exposure to these legacy and alternative PFAS is associated with the risk of glioma in young children; and (2) conduct a non-targeted analysis to identify novel, previously unknown or unexpected PFAS and evaluate whether prenatal exposure to these PFAS is associated with glioma risk in young children. This study is distinguished by its rigorous study design, innovative focus on prenatal PFAS exposure using a unique resource from the California Biobank Program, application of novel exposure methods to comprehensive characterize PFAS beyond the several compounds that have been traditionally assessed, and the ability to account for other putative environmental and genetic risk factors. Responding to the urgent need to assess cancer risk related to PFAS, which are largely unregulated, our study will not only help elucidate the etiology of glioma in children but may also have policy implications.

NIH Research Projects · FY 2025 · 2025-08

MODIFIED PROJECT SUMMARY/ABSTRACT SECTION Although effective prevention and treatment tools are available to end the HIV epidemic, their impact on reducing HIV incidence, morbidity, and mortality in the US has been limited by challenges identifying and deploying these tools in a feasible, acceptable, and sustainable way. Implementation science (IS) is a vital tool to overcome these challenges. Thus, increasing IS capacity to engage the community and rigorously plan, evaluate, and monitor implementation is critical to achieving EHE goals. To provide the resources outlined in the NOSI and support the Coordination, Consultation, and Data Management Center (CCDMC), the R3EDI (Rigorous, Rapid, & Relevant Evidence aDaptation & Implementation) IS consultation hub to EHE will provide advanced expertise in IS methods and community-engaged research (CEnR) using an innovative cross-cutting approach. We will draw on significant experience from our prior successful R3EDI Hub EHE Supplements and continually adapt to the evolving needs of end-users and the EHE initiative. Specifically, the R3EDI Hub will (1) provide technical assistance and coaching to assigned EHE project teams, (2) develop targeted technical resources and mentoring for HIV researchers and implementers, (3) collaborate with the CCDMC on cross-hub activities and evaluation, and (4) create opportunities to translate local knowledge into generalizable knowledge. We will leverage the outstanding environment and investigators at Yale’s Center for Methods in Implementation and Prevention Science (CMIPS) and Center for Interdisciplinary Research on AIDS (CIRA) to create a resource & consultation hub accountable to the community, the CCDMC, and EHE goals. Activities to support these aims include: (1) providing consultations on IS methods and CnER; (2) developing and delivering innovative webinars, resource materials such as IS dissemination templates, workshops on key topics such as Community-based Participatory Research for IS (CBPR-IS), and mentoring (early stage investigators, implementing partners, students); (3) documenting and synthesizing cross-hub learnings, (4) conducting systematic reviews, developing a contextual variables database covering all 57 EHE jurisdictions, and continuously evaluating and improving our services. The R3EDI Hub has assembled an exceptional team of principal investigators, co-investigators, and community consultants to contribute expertise in IS methods, frameworks, strategies, measures, and outcomes in HIV/AIDS research; quantitative, qualitative, and mixed-methods analytic approaches; partnership formation, and CBPR. The R3EDI Hub’s activities will maximize the rigor, rapidity, and relevance of IS in EHE projects, build capacity in CEnR and IS methods, support implementing partners, increase the rigor of contextual variables research as applied to the EHE initiative, strengthen dissemination of research results to community, policy, and academic audiences throughout the research process; facilitate effective coordination and collaboration with the CCDMC; and produce generalizable knowledge leading to future grants, high impact, peer-reviewed publications, and better evidence for policy.

NIH Research Projects · FY 2026 · 2025-08

PROJECT SUMMARY Career Goal: My career goal is to become an independent academic researcher conducting high-impact scientific studies that aim to improve HIV treatment outcomes in the United States (U.S.). This NIH Pathway to Independence Award (K99/R00) will provide the training and resources that I need to be able to conduct a hybrid efficacy-implementation trial of a multi-level, multi-component theory-driven intervention to optimize HIV treatment outcomes among men with the highest incidence of HIV (MHIH) in the U.S. Career Development: The training plan outlined in this proposal will increase my understanding of the landscape of emerging HIV treatment products and prepare me to transition from my original training in HIV prevention research to HIV treatment research. During the mentored phase, my learning goals will be to 1) develop an understanding of the lived sociocultural and healthcare experiences of MHIH who are living with HIV, 2) improve my knowledge on clinical advances in HIV treatment, 3) gain skills in multi-level intervention design and implementation, 4) learn hybrid efficacy-implementation science approaches that use randomized controlled trial designs, and 5) improve my grant writing and teaching skills. Research Project: HIV care retention is a consistently strong predictor of viral load suppression; however, some men, are less likely to be retained in HIV care and reach viral suppression. This is because of multi-level individual, health system and structural factors. I propose the use of the client-centered care coordination (C4) intervention to help improve treatment adherence and retention in HIV care among MHIH in the U.S. and ultimately their state of viral suppression. I will gain knowledge and skills learned in the K99 mentored training phase to: 1) conduct a qualitative study that aims to understand implementation strategies and adaptations relevant for C4 use within HIV treatment practice in the U.S., and 2) conduct a hybrid efficacy-implementation trial that aims to assess the effect of C4 on treatment adherence, HIV care retention and viral suppression among MHIH who are living with HIV as well as assess intervention implementation using the Implementation Research Logic Model. Mentorship: A multidisciplinary team will mentor me through the K99 phase including Drs. LaRon E. Nelson, Zhao Ni, Leo Wilton, Onyema Ogbuagu, and Sangchoon Jeon whose complementary expertise and experience will support my transition to research independence.

NIH Research Projects · FY 2026 · 2025-08

SUMMARY Upon fertilization, the zygotic genome is dramatically remodeled to achieve a transient totipotent state that is necessary to lay the foundation for embryonic development and differentiation. Activation of the genome requires choreographed contacts between enhancers and promoters. Mutations in the genes that encode the machinery required to orchestrate this remodeling and contact are causative of numerous developmental syndromes or embryonic lethality. Despite its unequivocal importance for child development, reproduction and fertility, the relationship between chromatin structure and enhancer-promoter communication that underpins correct developmental programming remains poorly understood, particularly in vertebrates. In addition, the factors and motifs that mediate these structures and gene regulatory communication, including their specific functions, have not been extensively studied. A major barrier to understanding these relationships in the dynamic system of a developing vertebrate has been a dearth of suitable approaches that can achieve genome-wide and high-resolution information given the limitations in input material. To overcome these limitations, in our preliminary studies we have optimized techniques to detect novel regulatory factors and chromatin structures with unprecedented resolution in zebrafish embryos. In addition, our recently developed expansion microscopy technique now allows us to address fundamental questions about how enhancers and promoters interact and transmit information at nucleosome resolution. The confluence of development of these techniques now allows us to investigate the molecular mechanisms that regulate genome activation and gene expression in a dynamic vertebrate system. Using these approaches, we aim to understand how specific factors contribute to the establishment of the 3D genome architecture as well as investigate a mechanism for explaining how transient genomic contacts can propagate longer-term regulatory information (Aim 1), and identify the repertoire of regulatory elements that mediate enhancer-promoter interactions as well as the factors and their motifs that regulate gene expression (Aim 2). By defining the regulatory grammar and mechanisms guiding genome activation in the zebrafish embryo, this work will fill critical gaps in our knowledge of gene regulation in a dynamic developing system, and provide valuable insights with broad implications for developmental biology, epigenetics, and reproductive medicine.

NSF Awards · FY 2025 · 2025-08

Empirical analysts now routinely generate new data by deploying artificial intelligence (AI) or machine learning (ML) algorithms on large, unstructured data sets. Examples include quantifying sentiment or uncertainty in news text using large language models or natural language processing methods; measuring product characteristics from review text and product images on online platforms; or imputing missing variables from demographic information. In standard practice, AI- or ML-generated data are treated as if they were regular numerical data for the purposes of data analysis. However, this standard approach can introduce bias in parameter estimates and lead to invalid conclusions. This project develops new econometric methods and statistical theory to inform best practice for empirical researchers using these data. This research project improves the quality of data analysis performed by businesses, non-profits, and government organizations. The interdisciplinary nature of the research helps to forge connections between academia, policy makers, and industry. The research improves the validity of empirical research using AI- and ML-generated data. The projects contribute novel econometric methods for working with data generated by AI and ML algorithms that correct the bias and inference problems present in current empirical practice. The methods are rigorously justified with new statistical theory for AI- and ML generated data. A key contribution is the development of novel asymptotic frameworks that are appropriate for modern use cases where AI and ML algorithms are deployed on massive data sets. Additionally, the projects develop an effciency theory for working with AI- and ML-generated data. General methods and frameworks are developed, along with specialized approaches for important business and economic contexts. These include demand estimation using text and image data (relevant for pricing decisions on online platforms) and vector autoregressions with AI- and ML-generated components (relevant for fiscal and monetary policy analysis). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NSF Awards · FY 2025 · 2025-08

Nontechnical Summary Chirality is a geometric property of a material that lacks mirror image symmetry. For example, the left hand cannot be transformed into its mirror image, the right hand, by any combination of rotation and translation. This project investigates how structural chirality at the molecular level can be harnessed to control the quantum property of electrons known as spin, without relying on the movement of electrical charge. Spin-based electronics, or spintronics, offers compelling advantages by reducing power consumption and heat generation in devices used for data storage, sensing, and computing. This project investigates structural chirality in semiconductors made from organic and inorganic components, called hybrid semiconductors. By tailoring molecular and crystal structures to manipulate spin transport, investigators will enable new mechanisms for spin transport. These findings will offer a path toward compact, reconfigurable spintronic devices that function without containing magnetic elements. The project integrates research with education and outreach efforts. New course modules and research opportunities for undergraduate and graduate students that will provide students with accessible resources in emerging technologies and contribute to the development of the next-generation semiconductor workforce. Technical Summary The research investigates how molecular chirality—specifically, the handedness and orientation of organic cations—modulates spin transport in low-dimensional chiral hybrid organic-inorganic semiconductors composed of alternating molecular cations and metal halide octahedra. The central scientific hypothesis is that anisotropic spin absorption, where spin current is preferentially absorbed in one direction over another, is determined more by the orientation and strength of the molecular chiral axis than by the overall symmetry of the crystal. To test this, the research team will synthesize a library of chiral hybrid organic-inorganic semiconductors with tailored molecular chirality and tunable alignment between the chiral axis and the crystal screw axis. Using spin-pumping and ultrafast magneto-optical Kerr effect techniques, pure spin current will be injected into the hybrid semiconductors, and the anisotropic spin absorption will be characterized as a function of the angle between spin polarization and chiral axis. By systematically varying molecular structure and chirality, the researchers aim to reveal the correlation between the degree and orientation of chirality and spin absorption anisotropy. The project will also develop new chirality descriptors that can be used to correlate structural features with spintronic behavior. This project will not only advance the fundamental understanding of spin transport in non-magnetic materials, but also establish new design principles for functional spintronic components that are tunable, scalable, and energy-efficient. By integrating material synthesis, structural characterization, and spin transport measurements, this work pushes the frontiers of low-dimensional and hybrid materials, enabling tailored quantum functionalities through the control of structural chirality. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2025 · 2025-08

PROJECT SUMMARY Vascular smooth muscle cells (SMCs) do not terminally differentiate, but retain the remarkable ability to assume a new cellular identity in response to extracellular stimuli. The ability of mature, contractile SMCs to transition to fibroblast/myofibroblast (“synthetic”), macrophage-like, or osteochondrocyte-like phenotypes allows for vascular growth and remodeling, but also contributes to cardiovascular pathologies, including atherosclerosis, restenosis, aneurysm, transplant vasculopathy, pulmonary hypertension, and others. Understanding how SMCs profoundly alter their phenotype has important implications for prevention and treatment of cardiovascular diseases. Cell type-specific gene expression is controlled by DNA distribution in accessible euchromatin and silenced heterochromatin, which is governed by epigenetic modifications of DNA and histones. Our prior work reveals that dynamic epigenetic regulation contributes to the unique plasticity of SMC, identifying TET2 and p300 as key pro-differentiation mediators. We now hypothesize that a uniquely dynamic heterochromatin state allows for SMC fate transitions. Epigenetic marks, including H3K9me3, silence unnecessary gene programs, and H3K9me3 heterochromatin helps maintain cellular identity. SUV39H1 is a histone methyltransferase that generates H3K9me3 heterochromatin marks. Our new preliminary data suggest important roles for SUV39H1 and H3K9me3 in SMC plasticity. We observed SUV39H1-dependent changes in H3K9me3 during SMC phenotypic transitions. We find that SUV39H1 expression is regulated during SMC phenotypic switching, with low level expression in healthy arteries, but robust induction of SUV39H1 and H3K9me3 following vascular injury or PDGF treatment in vitro. SUV39H1 knockdown induces SMC differentiation-specific genes while suppressing proliferation and migration, and inhibits expression of KLF4, and SUV39H1 represses KDM4A, an enzyme that removes H3K9me3 marks. Notably, PDGF and SUV39H1 mediate reversible H3K9me3 enrichment at key proximal promoter regions in differentiation-specific contractile genes. We will test the overarching hypothesis that unique SUV39H1-dependent heterochromatin dynamics underlie the phenotypic plasticity of vascular SMCs. In Aim 1, we will use high resolution imaging and genome- wide epigenetic analyses to determine whether SMC phenotypic switching involves extensive heterochromatin remodeling, whether H3K9me3 represents a reversible mark that exists outside of heterochromatin, and whether SMCs contain unique subtypes of heterochromatin that allow for accession of alternate gene programs. In Aim 2, we will identify mechanisms that contribute to SUV39H1 regulation and function. In Aim 3, we will study heterochromatin dynamics and SUV39H1-effects in SMC remodeling in vivo.

NIH Research Projects · FY 2025 · 2025-08

PROJECT SUMMARY / ABSTRACT Alzheimer's Disease (AD) is the most common neurodegenerative disorder and a major cause of dementia among the elderly. Affective symptoms, especially anxiety, manifest during the early stages and may reflect cortico- limbic circuit changes in AD. Notably, healthy aging is associated with a “positivity” effect in affect, including reduction in anxiety, despite age-related cognitive decline. Thus, it is critical to understand how people with AD risks deviate from healthy aging and manifest higher levels of anxiety and whether these neural phenotypes may predict cognitive decline in those at risk. We propose to address these questions by investigating the roles of the cortico- limbic circuit dysfunction in manifesting anxiety in people with mild cognitive impairment (MCI) and subjective cognitive decline (SCD). We will use resting-state functional magnetic resonance imaging (fMRI) data of healthy participants of the HCP-A and both healthy participants and people with MCI of the ADNI (K99 studies) and collect task-based fMRI data on negative emotion processing in people SCD and healthy participants along with follow-up assessments (R00 study) to address three specific aims. Our two K99 aims are to (Aim 1) characterize the functional connectivities of emotion regulation circuit during healthy aging and (Aim 2) characterize the functional connectivities of emotion regulation circuit in MCI and employ machine learning to identify the connectivity markers that distinguish AD and HC. The R00 aim is to (Aim 3) investigate corticolimbic circuit dysfunction in emotion perception, regulation, and memory in SCD vs. HC using task-based fMRI and employ connectome predictive modeling to identify the predictors of cognitive changes during follow-up. Our overall goal is to understand emotion circuit dysfunction and the neural markers of anxiety and how these processes contribute to changes in cognitive function in early AD. The K99/R00 study will prepare the candidate for an independent career in aging and AD neuroscience research. The proposed study will support this goal by providing additional training in systems and clinical neuroscience, machine learning, and statistical modeling for the candidate. The candidate has identified her training needs, assembled a team of expert mentors and formulated a training plan that includes structured mentoring, supervised research, formal coursework, presentations at scientific meetings, and professional development. The study will also allow the candidate to collect critical pilot data for an R01 proposal in career development. Together, the K99/R00 study will allow the candidate to receive ample guidance, broaden her knowledge, learn novel techniques, and gain independence, while pursuing a research program of critical importance to public health.

NIH Research Projects · FY 2025 · 2025-08

ABSTRACT Dr. James T. Nugent is an Instructor of Pediatrics in the Sections of Pediatric Nephrology and General Pediatrics at Yale School of Medicine. The goal of this K23 Career Development Award is to provide mentored training in applying clinical research methods to support Dr. Nugent’s development into an independent physician-scientist studying hypertension in children. Dr. Nugent’s scientific mission is to tailor cardiovascular disease prevention to the needs of disproportionately affected populations. His prior work has leveraged electronic health records and historical data to improve the care of children with hypertension in the inpatient and outpatient settings. To become an independent physician-scientist, Dr. Nugent requires the support of this K23 award to achieve the following training objectives: (1) methodologic expertise in implementation science, mixed methods, clinical decision support, trial design, and cost-effectiveness analysis; (2) direct experience in prospective human subjects research; and (3) structured professional development to lead a clinical research team. The scientific objective of the planned research is to develop and test a multilevel implementation strategy to improve the guideline-recommended use of ambulatory blood pressure monitoring (ABPM) in children and adolescents with hypertension. Screening for hypertension in childhood is recommended to prevent long-term cardiovascular morbidity and mortality. However, the diagnosis of hypertension in children is challenging due to the unreliability of office BP measurement. Therefore, current pediatric guidelines recommend performing ABPM to diagnose hypertension in children. Despite its superior accuracy, ABPM is not widely available in pediatric primary care, and we have found that only 8% of US children with hypertension have ever completed this guideline- recommended test. Practical and sustainable approaches are needed to implement guideline-based ABPM outside the subspecialty setting. In Aim 1, we will characterize the barriers to and facilitators of ABPM utilization among patients, primary care clinicians, hypertension specialists, and nurses. The results of the pre- implementation assessment in Aim 1 will inform the design and evaluation of an implementation strategy in Aim 2 to promote the completion of guideline-recommended ABPM in pediatric primary care. This multifaceted implementation strategy will have several key components, including electronic clinical decision support, the use of a centralized ABPM service, and closed-loop communication of ABPM results and recommendations from the hypertension specialist to the primary care clinician. In Aim 3, we will determine the costs associated with ABPM implementation and compare the cost-effectiveness of different ABPM screening strategies in the general pediatric population. Completion of these aims will inform an R01 to conduct a multicenter, cluster randomized trial to further optimize and test the efficacy of a multilevel implementation strategy to increase guideline-based utilization of ABPM across a national network of pediatric hypertension centers and referring primary care clinics.

NIH Research Projects · FY 2026 · 2025-08

PROJECT SUMMARY Transcription factors Klf2 and 4 are strongly induced in vascular endothelial cells (ECs) by fluid shear stress from blood flow, where they confer vascular stability and suppress the inflammatory pathways and genes responsible for atherosclerosis and other diseases that involve vascular inflammation. This application is based on our recent discovery that gamma protocadherins (Pcdhg) block Notch-dependent transcription and thus suppress expression Klf2/4 in ECs, which facilitates vascular inflammation and disease. Pcdhg knockout in endothelial cells limits atherosclerosis in mice and alters vascular morphogenesis in the postnatal retina. Based on our findings, we hypothesize that Pcdhg is a key regulator of vascular stability and resilience that contributes to vascular morphogenesis but whose inhibition provides a novel means of treating vascular inflammation without compromising host defense against pathogens. To test these hypotheses, we propose to: 1) Determine the effects in mice of knocking out the Pcdhg cluster in ECs or inhibiting the key isoform Pcdhga9, examining multiple models of vascular inflammation. 2) Elucidate the mechanism by which Pcdhg controls Klf2/4 expression, focusing on interactions with the Notch pathway. 3) Characterize the effects of EC Pcdhg knockout on angiogenesis and arteriogenesis in the postnatal retina and determine the molecular mechanisms of observed effects.

NIH Research Projects · FY 2025 · 2025-08

With 9,500 inmates and a 10.3% HIV prevalence, 75% of whom have a history of injecting drug use (IDU), including up to 1/3 within-prison, Kyrgyzstan's prisons are crucial for HIV control efforts. Previous interventions failed to increase OAT uptake, encountering significant barriers, including stigma and drug use stigma in prison. During the K01 study, our multidisciplinary Kyrgyz team co-developed HOPE (Help OAT Prison Engagement), a 6-week intervention tailored to the prison HIV high-risk environment. HOPE incorporates several evidence-informed elements, including a) HIV screening followed by HIV literacy session, b) assessing depressive and anxiety symptoms and positive mental health elements (e.g., quality of life, social support, and self-reported resilience), followed by mindfulness enhancement sessions, and c) addiction literacy and self-management. HOPE also increases self-efficacy through empowerment-based skills-building, including managing OAT stigma and conflict in a high-risk prison environment and resource utilization. Each of HOPE’s 12 thematic components comprises a mini-lecture, a group discussion, and group exercises practicing targeted skills. We plan to compare HOPE to an information-only control using a type 1, hybrid implementation trial to evaluate the effectiveness of HOPE for HIV prevention in prison, including uptake of OAT/SSP services, combined with exploration of implementation factors that may contribute to intervention effects and a future scale-up. We aim (1) to conduct a cluster randomized controlled trial of the HOPE intervention to determine its effectiveness for HIV prevention (i.e., OAT and SSP use) over 12 months. We will enroll 360 participants who have over 1 year remaining before release across 20 housing units (each HU has ~100 PIP) from four male prisons in Kyrgyzstan. Assessments will occur at baseline, 3, 6, 9, and 12 months. The primary outcome is OAT start; secondary outcomes include other HIV risk-reduction strategies like SSP use and engagement in HIV risk behaviors. Aim 2 is to conduct a combination of qualitative interviews and focus group discussions to examine implementation factors associated with the effectiveness of HOPE, its uptake and scale-up from the perspective of multi-level stakeholders. Aim 3: Use results from Aim 1 to conduct a cost-effectiveness analysis (CEA) of HOPE relative to the control for reducing HIV transmission and improving quality of life among PIP. This study is relevant to the US (and global) public health as findings will provide effectiveness, implementation and cost-effectiveness data for low-resource settings where PWID are concentrated in prison settings.

NIH Research Projects · FY 2025 · 2025-08

New approaches to understanding the mechanisms of treatments for obstructive sleep apnea (OSA) are desperately needed. OSA affects fifty-four million Americans, leading to significant morbidity and mortality, including hypertension, heart failure, stroke, and neurocognitive impairment. Continuous positive airway pressure (CPAP) is the primary treatment for OSA. However, poor adherence (only 50% use CPAP at one year) and inconsistent impact on neurocognitive and cardiovascular outcomes among users limit CPAP's effectiveness. Traditional measures of OSA severity (apnea-hypopnea index), symptoms, and the psychosocial factors affecting CPAP adherence account for only a fraction of the heterogeneity in response to CPAP. Understanding the mechanisms and biomarkers that predict CPAP success is vital to the health of millions. We hypothesize that arousal threshold (ArTH) in persons with OSA is a key determinant of CPAP adherence and the neurocognitive and cardiovascular responses to CPAP therapy. ArTH reflects a person’s propensity to awaken from a respiratory stimulus. People with low ArTH wake up easily, experience less hypoxia, and are less sleepy than those with high ArTH. Our robust preliminary data indicate that a low ArTH predicts poor CPAP adherence and that individuals with high ArTH show greater improvements in executive and frontal lobe function with CPAP. Knowing whether and how ArTH impacts response to CPAP can identify ArTH as a modifiable biomarker of CPAP success. For example, targeting CPAP to those with a high ArTH or raising ArTH with hypnotic medications or behavioral therapies to improve adherence and neurocognition can create a precision medicine approach to OSA therapy. For this to become a reality, the OSA field must bridge this gap by prospectively validating ArTH’s role in outcomes while accounting for essential confounders of adherence and modifying the ArTH to understand the mechanisms of how ArTH can influence CPAP response. Our overall objective is to bridge this gap by testing whether ArTH is a mechanistic determinant of CPAP success using a prospective, mechanistic clinical trial. We will randomize individuals newly diagnosed with OSA (n=250) to CPAP with a placebo or CPAP with eszopiclone (a medication that raises ArTH). We will measure CPAP adherence and changes in executive function and endothelial function over 12 weeks. Our specific aims include: 1) determining how ArTH affects adherence to CPAP therapy; 2) evaluating the mechanism of ArTH in the neurocognitive response to CPAP; and 3) exploring the link between ArTH and cardiovascular response to CPAP. We hypothesize that a high ArTH will be associated with improved CPAP adherence and neurocognitive and cardiovascular responses to CPAP, with sleep duration and depth, biomarkers of neuro-axonal damage, and oxidative stress mediating these effects. Ultimately, our results can lead to personalized OSA approaches that challenge the “CPAP-for- all” status quo and could improve outcomes for millions suffering from OSA.

NSF Awards · FY 2025 · 2025-08

This award funds a research project that uses existing administrative records to understand the long-term impacts of neighborhood revitalization policies on individual and family economic outcomes. Government interventions that reshape neighborhoods may have profound and lasting effects on residents' economic mobility and well-being. While prior research has studied the effects of these projects on local economies and property values, very little is known about what happened to the families displaced by neighborhood revitalization over decades. By linking historical Census records with modern administrative data, the researchers employ Large Language Models (Artificial Intelligence) to systematically analyze and classify thousands of original source documents, including newspaper articles, project reports, and archival records, enabling systematic extraction of information. The researchers analyze how government policies affected multiple aspects of family well-being including health, labor market outcomes, housing quality, and geographic mobility. Understanding the long- run consequences of economic development policies serves the national interest by providing evidence to guide place-based policies at federal, state, and local levels that affect millions of urban and rural American families. Ultimately, the research findings could help the United States develop infrastructure investment designs and improve citizens’ wellbeing. This award funds a research project providing new evidence on the long-run economic consequences of large-scale displacement and makes three primary contributions to economic science. First, the project develops a comprehensive new database of federal government project boundaries and timing through systematic collection and digitization of archival records, addressing critical measurement gaps in existing data sources. Second, it generates unique longitudinal data by linking public and restricted Census microdata across multiple decades, enabling rigorous analysis of how residential displacement shapes long-term economic trajectories. Third, it leverages historical variation in project implementation and local policy contexts to provide a robust empirical setting for analyzing long-run outcomes. The empirical analysis is divided into three interconnected sub-projects: (1) database construction using federal archives, municipal records, and historical newspapers with Large Language Models used to automate summarizing and classifying diverse textual sources, including newspaper coverage, government project reports, documents from national, state, and local archives; (2) analysis of long-run migration and mortality outcomes for those who lived in or near affected areas, using publicly available data; and (3) examination of long-run outcomes using restricted Census data. This research advances several areas of economic science. In regional economics, it provides the first comprehensive analysis of how federal initiatives transformed neighborhoods and affected families over multiple decades, contributing to debates about neighborhood effects and place-based policies. In labor economics, it demonstrates how housing and neighborhood disruption affect individual economic mobility over the long term. The validated database becomes a public resource enabling future research across multiple disciplines. The findings have potential to inform discussions about urban development, infrastructure investment, and displacement mitigation strategies by providing evidence on whether the effects of neighborhood-level interventions persist across decades. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2025 · 2025-08

Project Summary The tsetse fly transmits trypanosomiasis to humans and animals across 38 countries of Africa. In humans the disease is called African Sleeping Sickness. There is no vaccine to prevent it, and 70 million people are at risk. In animals the disease is called nagana, and it imposes a major economic burden on sub- Saharan Africa. The most effective means of preventing these diseases has been to control the tsetse flies that spread them, and olfactory traps have been particularly useful. Tsetse flies find their human and animal hosts largely through olfactory cues. The flies also depend on olfaction to avoid predators, find mates, and identify sites on which to deposit their offspring. Better understanding of the tsetse olfactory system may lead to better means of control. Parasites use a rich variety of strategies to increase their reproductive success through manipulation of their vectors and hosts. We have recently discovered that infection with trypanosomes leads to the production of 21 volatile compounds in tsetse. This proposal tests hypotheses about the neuronal, receptor, and behavioral responses of tsetse flies to these volatile compounds. The first aim investigates the electrophysiological response of tsetse antennal neurons to trypanosome-induced odorants. This analysis will determine which individual chemical compounds are most effective at low concentrations. These compounds may be useful in controlling tsetse and other insect vectors of mammalian diseases. The second aim measures the response of tsetse odorant receptors to trypanosome-induced odors, taking advantage of an in vivo expression system in Drosophila. The third aim tests hypotheses about behavioral responses to trypanosome- induced odors using a two-port olfactometer. It will also test the impact of trypanosome-induced odors on mating behavior. The proposal should provide new insights into one of the most important themes in vector biology: the biological interactions between the parasites that cause disease and their vectors. The experimental plan is designed to test hypotheses about the trypanosome-induced odors and the responses of tsetse flies to them. The study may also identify odorants that are useful in controlling tsetse in the field and thereby reducing the incidence of the diseases that they spread. The proposal will provide training in electrophysiology and molecular biology to Dr. Shimaa Ebrahim, who has little experience in these topics. The project will benefit from an environment that contains a great deal of expertise in insect olfaction. The study takes unique advantage of resources at Yale, which is one of the world's centers of tsetse research.

NIH Research Projects · FY 2025 · 2025-08

SUMMARY Human immunodeficiency virus type 1 (HIV-1) remains a major global public health concern, despite advances in treatment, there is no vaccine and no cure. The challenge in developing a vaccine is primarily due to HIV-1’s high mutation rates, resulting in a diverse viral strains, an effective glycan shield and conformational masking of functional centers on its glycoprotein. The HIV-1 envelope glycoprotein (Env) mediates viral entry into host cells at the beginning of the infection cycle. Although Env exhibits great sequence variation and shield by glycans, some patients developed broadly neutralizing antibodies (bnAbs) that target conserved elements of Env. Among bnAbs, antibodies targeting the membrane-proximal external region (MPER) are highly effective, exhibit good breadth, and immunogens eliciting these antibodies have resulted in encouraging in vivo data. Previous structural studies using purified Env embedded in nanodiscs have provided insights into how bnAbs bind to the MPER. However, much less is known about the interaction of anti-MPER bnAbs with native virus particles. In this study, we will use cryo-electron tomography (cryo-ET) combined with molecular dynamics (MD) simulations to elucidate how anti-MPER bnAbs engage Env in native virus particles, and determine how they interfere with virus-host membrane fusion. Our preliminary study revealed that three DH511 Fab molecules could simultaneously bind to a tilted Env with all three Fabs approaching Env from one side. Thus, MPER regions exhibit great conformational flexibility and can reach the opposite side of the trimer. Upon addition of CD4 and 17b, DH511 binding to Env increased, and an additional mode is observed whereby three DH511 Fab molecules symmetrically bind to an upright Env. In this study, we will characterize the structural basis of how anti-MPER bnAbs bind the unliganded HIV-1 Env on native virions. Additionally, we will define the dynamics of how anti-MPER bnAbs access Env epitopes upon binding of CD4. We will investigate both Fab and IgG forms of the antibodies, in the presence of either soluble CD4 (sCD4) or membrane-bound CD4. MD simulations will provide atomic models corresponding to the cryo-ET density maps. Finally, we will elucidate the mechanism by which MPER antibodies interfere with membrane fusion.

NIH Research Projects · FY 2025 · 2025-08

Summary: In the mouse, multipotent erythro-myeloid progenitors are produced through an endothelial-to- hematopoietic transition (EHT) process, in the vasculature of the yolk sac, between E8-8.5. Starting at E9, a subset of endothelial cells in the intra-embryonic vasculature undergoes EHT, spanning for around 48 hours and resulting in the emergence of the first lympho-myeloid progenitors that enter the circulation and home to the fetal liver (FL). It is in this environment that multipotent progenitors give rise to the hematopoietic stem cell (HSC) compartment starting at E10.5, but it is only after E12 that HSCs can be identified through the acquisition of characteristic surface markers such as SLAMF1 (CD150) and Sca1. For a period of 1.5 days, from E10.5 to E12, HSCs can only be detected indirectly through transplantation experiments, a gap in knowledge we will address in Aim 1. The signals promoting the development of HSCs in the FL remain incompletely defined. Stem cell factor (SCF) and Thrombopoietin (THPO) activate receptor tyrosine kinases (RTK) that play pivotal roles in HSC proliferation and survival, but also orchestrate the intricate process of hematopoietic multipotent progenitor cell differentiation into various cell lineages, including lymphoid, myeloid, and megakaryocyte/erythrocyte cells. We hypothesized that other signals must exist to allow HSC expansion during fetal life while counterbalancing the pro-differentiation effects of RTK signaling induced by SCF and THPO. GPCRs signal through heterotrimeric G proteins composed of alpha, beta and gamma subunits, with the alpha subunit conferring pathway specificity. GPCR signaling via Ga12/13 proteins potently inhibits PI3K activation such that genetic deficiency in Ga12 or Ga13 results in lymphoproliferative disease and lymphomagenesis. In recent and unpublished studies, we uncovered a critical role for the Ga12/13-coupled GPCRs GPR56 and GPR97 in HSCs. Specifically, we demonstrate that deficiency in both receptors is lethal due to a complete loss of HSCs during embryogenesis, while induced deficiency in both receptors in HSCs of adult mice leads to the complete loss of HSCs and adult hematopoiesis. Our findings provide the foundation for a new paradigm in which HSC homeostasis is controlled by a balance between stimulatory (RTKs) and inhibitory (GPCRs) pathways. The central goal of this grant proposal is to precisely define the role of GPR56 and GPR97 in HSCs. In Aim 1 we will test if Gpr56 protein expression marks the birth of the first HSC in early embryonic stages (starting at E9). In Aim 2, we will directly test if GPR56 and GPR97 counter-balance cKit signaling using a combination of in vitro and in vivo experiments that will modulate cKit signaling intensity. We will also study the transcriptional hubs controlled by GPR56 and GPR97 in fetal liver HSCs by bulk and scRNAseq. Together, the experiments described in these aims will reveal novel mechanisms and fundamental new principles of HSC homeostasis and multilineage differentiation.

NIH Research Projects · FY 2026 · 2025-08

PROJECT SUMMARY Male factors contribute to fertility issues for 50% of infertile couples, but women bear most of the burden of in- fertility treatment. Despite a 50% global decline in sperm count and motility over the past 50 years, the molecu- lar pathogenicity of male infertility is incompletely understood, hindering progress toward potential treatments for men. Since ~10% of the genome is involved in the regulation of fertility, most unexplained male infertility is predicted to have a genetic basis. Advances in assisted reproductive technologies have allowed these genetic defects leading to male infertility to be passed on to future generations, emphasizing the urgent need for im- proved ways to diagnose and treat affected individuals. Consanguineous families offer a unique lens for com- paring genetic differences between infertile and fertile men with similar genetic backgrounds. As such, family- based studies combined with advanced genetic tools such as whole exome sequencing can dramatically im- prove the assessment of causal relationships between specific genes and male infertility. Male infertility by reduced sperm motility presents ~80% of the infertile male patients. The overall objec- tive of the proposed studies is to break new ground in understanding the genetic basis and cellular and molec- ular mechanisms underlying reduced sperm motility in male infertility. We seek to capitalize our unique access to sixteen, large consanguineous Pakistani families with abnormal semen parameters and our team’s expertise in mouse genetics, proteogenomics, molecular and cutting-edge imaging tools such as cryo-electron tomogra- phy. Our preliminary analysis has identified three novel genetic mutations, one from each of these families, demonstrating effective gene discovery. These genes encode proteins associated with distinct flagellar appa- ratus that requires high-resolution imaging. To elucidate normal function, molecular pathogenicity, and struc- tural information from intact sperm flagella, we have newly established mouse models that mimic the human mutation or abrogate the gene expression and express a tagged transgene. Our central hypothesis is that mu- tations that lead to subtle abnormalities in the flagellar apparatus can cause obvious motility defects without compromising overall flagellar morphology. To test this hypothesis, we will pursue three specific aims. In Aim 1, we will identify and characterize mutations underlying reduced sperm motility. In Aim 2 and 3, we will eluci- date the normal function and molecular pathogenesis of two causal genes that encode proteins associated with the axonemal radial spokes and the annulus at multiscale levels. Our proposed research will provide novel fun- damental insights into the complex molecular mechanisms that underlie flagella dysfunction and a deeper mechanistic understanding of the intricate regulation of sperm motility at high resolution. The results of our studies will create new opportunities for diagnostic genetic testing and evaluating prognosis in assisted repro- ductive medicine.