University Of Florida

NIH Research Projects · FY 2025 · 2021-08

PROJECT SUMMARY: Older adults are the fastest-growing group of cannabis users in the US. Older adults use cannabis for a variety of reasons, including pain, insomnia, anxiety, and for recreation. Cannabis can, however, also exert robust effects on cognition. Almost all research on cannabis/cannabinoids and cognition has been conducted in young adults, and largely shows that acute administration impairs mnemonic and executive functions mediated by the medial temporal lobe and prefrontal cortex (which are also those most vulnerable to decline in aging and age- related neurodegenerative disease). In contrast, a few studies suggest that cannabinoids can exert distinct effects on the aged compared to the young brain, and preliminary data from our labs show that cannabis can actually enhance cognition selectively in aged rats. Indeed, cannabinoids have been proposed as potential treatments for the age-related neurodegenerative condition Alzheimer's disease (AD), and some preclinical research shows that cannabinoids can attenuate markers linked to AD pathology (e.g., neuroinflammation). Aging studies evaluating cannabis to date, however, are very limited and have not employed either cannabis itself or routes of administration that model those used most frequently by people (smoking and oral consumption). As such, it is unclear how cannabis, as it is actually used, affects cognitive decline and the synaptic dysfunction and AD-like pathology that contribute to cognitive impairments in older subjects. The long-term goal of our program is to determine how cannabis affects cognitive decline in aging and AD, and to determine the mechanisms of such effects. The objective of the current proposal is to model the two most common routes of human cannabis use (smoking and oral consumption) in well-characterized rat models of age-related cognitive decline, and to use these models to begin to elucidate effects of cannabis on behavioral and neurobiological dysfunction associated with aging and AD. Our overarching hypothesis is that cannabis can benefit cognition in aging by attenuating age-associated synaptic dysfunction, neuroinflammation, and tau pathology. Aim 1 will determine how acute cannabis affects performance in young adult and aged rats, as well as the synaptic mechanisms supporting effects of cannabis on cognition in aged subjects. Aim 2 will assess effects of chronic cannabis on cognition in young adult and aged rats, as well as on excitatory/inhibitory signaling and inflammatory markers linked to age-related cognitive impairments. Aim 3 will assess effects of chronic cannabis on AD-like tau pathology and cognition using a novel, targeted AAV-based approach in aged rats. The proposed experiments will be significant because they will provide foundational data concerning whether and how cannabis administration relevant for human consumption yields benefits for age-related cognitive decline and neuropathology.

NIH Research Projects · FY 2025 · 2021-08

Santa Fe College (SF) and the University of Florida (UF) propose to continue the SF2UF program, a partnership strategically designed to expand the pool of students who transfer from SF to UF, earn baccalaureate degrees, and pursue advanced careers in biomedical and behavioral sciences. The program will target high-performing students who demonstrate the greatest potential for innovation, excellence, and persistence in biomedical and behavioral research. Recruiting and mentoring these individuals not only sustains the nation’s global leadership in biomedical science but also strengthens our capacity to address pressing health challenges that impact the US population. The SF2UF program is grounded in evidence that the first two years of college are pivotal for attracting and retaining top science students, that early and sustained mentored research engagement supports achievement and persistence, and that addressing mental health and wellness is essential for undergraduate transfer student success. As of 2025, the program has recruited 41 trainees since its start in 2016, of whom 40 (98%) transferred to UF (37), another research university (1), an applied BAS program at SFC (1), or are still enrolled at SF (1). 35 SF2UF trainees (85%) completed a bachelor’s degree (27) or are still enrolled in a BS program (8). Of those who graduated, 20 (74%) have continued to graduate or professional programs or to biomedical careers: 7 to PhD programs, 4 to professional doctoral programs (2 DO, 1 DVM, 1 JD), 4 to other graduate programs (1 MPH, 3 MS), and 6 directly to the biomedical/behavioral workforce. The continuing SF2UF program’s goals include: increase by 25% the number of SF freshmen considering research careers; maintain support for continuing program trainees and recruit two additional trainees; achieve a 100% transfer rate to four-year institutions; retain at least 90% of trainees for the entire program, graduating at least 90% with a BS within four years; and ensure at least 75% pursue post-baccalaureate training, with at least 60% entering PhD programs within two years of graduation. Through innovative curricula, research mentoring, and tailored career development, SF2UF prepares resilient, high-performing students to become leaders in the biomedical sciences and contribute to improved health outcomes for the US population.

NIH Research Projects · FY 2026 · 2021-08

Program Summary This Maximizing Investigators’ Research Award (MIRA) proposal is directly relevant to the long-range plans of the National Institute of General Medical Sciences (NIGMS). Our laboratory received continuous NIGMS funding since 2004 that allowed us to make substantial advances in our understanding of the mechanisms of the dynamic contacts between neighboring cells (adherens junctions), as well as between cells and the extracellular matrix (focal adhesions structures). These cell junctions, in addition of holding animal cells together, communicate signals and control the stress placed upon cells. Over the past 16 years, we contributed important mechanistic discoveries towards an understanding of · how the cell-cell junctions connect cells in tissues to regulate tissue homeostasis that are crucial to provide the tissue barrier of epithelia, as well as cell migration and proliferation; and · how cell junctions initiate and maintain cell adhesion while regulating the organization of the underlying actin cytoskeleton by establishing a center for cell signaling and gene transcript regulation. Such processes are highly dynamic and tightly regulated. Our laboratory focused on defining the activation mechanisms of key regulators of these cell junctions that we studied biochemically and in live cells. Our discoveries were accelerated by our development of new techniques that overcame significant structural biology hurdles that stalled the field and that are applicable to many other structural biology studies. We discovered how talin activates vinculin, two ubiquitously expressed, actin-binding proteins, to stabilizes focal adhesions and thereby suppressing cell migration. Our high-resolution vinculin crystal structures, that we confirmed biochemically and in live cells, showed the auto-inhibitory intramolecular interactions that inactivate vinculin and thereby prevent vinculin from binding to the actin cytoskeleton. On the other hand, our high-resolution crystal structures of a-catenin, a crucial mediator of intercellular adhesions, revealed the mechanistic roles that its quaternary structures play in cell-cell adhesion and in the formation of the dynamic link to the actin cytoskeleton. Significantly, our discoveries led to mechano- transduction studies of cell-cell and cell-matrix junctions on how cells sense and transmit forces. More recently, we discovered how lipid binding to vinculin, to its cardiac isoform metavinculin, and to talin regulates focal adhesion turnover. This knowledge and expertise are the foundation for further discoveries that will additionally focus on the understudied role that the plasma membrane plays in cell adhesion. In the long run, we hope to gain a complete understanding of cell adhesion by attaining a near atomic structure of a “synthetic” cell junction. The regulation and dysregulation of cell junctions are fundamental to many biological processes such as development and cancer, and our proposed studies have therefore both basic and potentially translational significance.

NIH Research Projects · FY 2025 · 2021-08

PROJECT SUMMARY/ABSTRACT The long-term objectives of our research program are to (i) discover novel bacterial natural products (NPs), (ii) elucidate the biosynthetic pathways and regulatory mechanisms of these NPs, and (iii) characterize and utilize the discovered NPs and their biosynthetic enzymes for biomedical and biotechnological applications. NPs are highly functionalized and evolutionarily optimized small molecules that possess unrivaled chemical and structural diversities, resulting in a wide range of biological activities. Terpenoids, the largest and most structurally diverse family of NPs, are considered rare in bacteria; only ~1.2% of known terpenoids are of bacterial origin. However, genomics studies revealed that the biosynthetic enzymes responsible for terpenoid biosynthesis are widely distributed in bacteria, particularly actinobacteria. We hypothesize that (i) bacterial terpenoids are considerably underestimated among current NP libraries and the discovery and characterization of novel terpenoids will lead to new drug leads and (ii) understanding the sequence-structure-function relationships of terpenoid biosynthetic enzymes will lead to new opportunities in genome mining, combinatorial biosynthesis, and oxidative biocatalysis. Our initial efforts follow two research directions that address immediate needs and will set the stage for continued success in the field of terpenoid discovery and biosynthesis. In the first direction, we will use an integrated genomics–metabolomics approach to discovery novel bacterial terpenoids from bacteria. This will include the development of new and innovative methodologies for targeted identification of complex bacterial terpenoids and the activation or upregulation of terpenoid biosynthetic gene clusters. In the second direction, we will elucidate the biosynthetic pathways of both new and known bacterial terpenoids and functionally, mechanistically, and structurally characterize terpene synthases and their associated oxidative enzymes, particularly cytochrome P450s. We will use a rigorous multidisciplinary approach involving genome mining, bioinformatics analysis, in vivo pathway engineering, (un)natural product isolation and structural determination, in vitro enzymology, and protein X-ray crystallography. Our experience in terpenoid biosynthesis and enzymology and our significant progress in both research directions supports the feasibility of the proposed research and that we are well-suited to establish and sustain a successful independent program in this field. In addition, we have established several key collaborations with leaders in the fields of synthetic biology, NP drug discovery, and X-ray crystallography that further strengthen this research program. Expected outcomes of this research program include the revelation of the bacterial terpenome, understanding the underlying principles of how terpene synthases dictate terpene cyclization, and the exploitation of naturally evolved oxidative enzymes to create a toolbox of biocatalysts.

NIH Research Projects · FY 2025 · 2021-08

Project Summary/Abstract: ILC3s, gdT17 and Th17 cells share common features, e.g., expressing the master transcription factor RORgt and the effector cytokines IL-17A, IL-17F and IL-22, and perform distinct immune functions under different environment context. Our preliminary data suggest that RORgt+ cell-intrinsic deletion of Tfam in Tfamfl/flRorc- cre mice affected RORgt+ gdT17 cells and ILC3s in vivo maintenance and led to small intestinal tissue remodeling via a tuft cell–ILC2 circuit. An emerging concept of mitochondrial control of immunity beyond ATP generation has recently been proposed. Based on the premise and our preliminary data, we hypothesize that that Tfam-mediated mitochondrial respiration in gdT17 cells and ILC3s is pivotal for gdT17/ILC3 cell homeostasis and regulation of small intestine tissue remodeling/metabolic changes and immunity/inflammation. Specifically, we will investigate 1) the role of Tfam in gdT17 and ILC3 lymphocyte maintenance, 2) the role of Tfam in gdT17 cells and/or ILC3s in regulating tuft cell-ILC2 circuit and small intestine tissue remodeling, and 3) the role of Tfam in gdT17 cells and/or ILC3s in regulation of microbiome and small intestinal immunity and inflammation. These experiments will offer an opportunity to elucidate Tfam- mediated mitochondrial respiration in RORgt+ lymphocytes in the small intestine under the steady state and during infection/immunity. Our study will provide novel cellular and molecular insights into the maintenance and function of gdT17 cells and ILC3s regulated by Tfam. Understanding the mechanisms underlying the requirement of Tfam for RORgt+ cells in regulation of small intestine tissue remodeling and immunity may represent a new paradigm for human disease treatment and/or prevention.

NIH Research Projects · FY 2025 · 2021-08

Project Summary Classical aversive conditioning is a well-established laboratory model for studying acquisition and extinction of defensive responses. In experimental animals, as well as in humans, research to date has been mainly focused on the role of limbic structures (e.g., the amygdala) in these responses. Recent evidence has begun to stress the important contribution by the brain’s sensory and attention control systems in maintaining the neural representations of conditioned responses and in facilitating their extinction. The proposed research breaks new ground by combining novel neuroimaging techniques with advanced computational methods to examine the brain’s visual and attention processes underlying fear acquisition and extinction in humans. Major advances will be made along three specific aims. In Aim 1, we characterize the brain network dynamics of visuocortical threat bias formation, extinction, and recall in a two-day learning paradigm. In Aim 2, we establish and test a computational model of threat bias generalization. In Aim 3, we examine the relation between individual differences in generalization and recall of conditioned visuocortical threat biases and individual differences in heightened autonomic reactivity to conditioned threat, a potential biomarker for assessing the predisposition to developing the disorders of fear and anxiety. It is expected that accomplishing these research aims will address two NIMH strategic priorities: defining the circuitry and brain networks underlying complex behaviors (Objective 1) and identifying and validating new targets for treatment that are derived from the understanding of disease mechanisms (Objective 3). It is further expected that this project will enable a paradigm shift in research on dysfunctional attention to threat from one that focuses primarily on limbic-prefrontal circuits to one that emphasizes the interactions among sensory, attention, executive control and limbic systems.

NIH Research Projects · FY 2025 · 2021-08

Computational modeling of genetic variations by multi-omics integration to decipher personal genome A person’s genome typically contains millions of genetic variants. Understanding these variants by assessing their functional impact on a person’s phenotype, is currently of great interest in human genetics and precision medicine. Though Genome-Wide Association Studies (GWAS) or Quantitative Trait Locus (QTL) studies have successfully identified variants associated with traits or molecular phenotypes, most of them are in noncoding regions and hampered by linkage disequilibrium, making the identification and interpretation of casual variants difficult. Moreover, most of these discoveries are common variants, however, rare and individual-specific variants in personal genome are underexplored. Understanding these variants will not only explain the missing heritability from GWAS but also improve the precision medicine. Recently, the advent and popularity of whole genome sequencing (WGS) and paired multi-omics functional assays provide an unprecedented opportunity to identify rare and individual-specific casual variants. However, the sample sizes of most WGS studies are modest compared to GWAS, making the WGS analysis particularly challenging. Nevertheless, statistical and computational methods for analyzing WGS are underdeveloped. Given these challenges and my unique multi- disciplinary training, the overall goals of my research program are to develop a novel class of machine learning, statistical and system biology approaches for the identification, prioritization and interpretation of noncoding variants by integrating GWAS, WGS and multi-omics functional assays, which will empower precision medicine by identifying individualized biomarkers for disease prevention, diagnosis and treatment. Specifically, in the next five years, my lab will (i) develop a novel transfer learning approach to improve the prediction of noncoding casual variants using multi-dimensional omics features (ii) develop a multi-omics integrated omnibus scan test to improve the identification of rare casual variants from whole-genome sequencing data (iii) develop an integrative computational framework for scoring impact of noncoding variants in personal genome (iv) develop a novel class of multi-trait methods to improve phenotype prediction using whole-genome genetic variations. In the meantime, supported by Indiana University Precision Health Initiative, we will apply the methodologies to different studies from Indiana Alzheimer’s Disease Center and Indiana Multiple Myeloma Biobank for novel scientific findings. We will work close with collaborated geneticists and clinician-scientists to interpret the discoveries. Importantly, we will work with experimental labs to validate the findings. In line with our previous work, we will continue to make all developed methods into open-source software tools that are accessible and useful to the biomedical research community.

NIH Research Projects · FY 2025 · 2021-08

Summary The transforming human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi’s sarcoma- associated herpesvirus (KSHV) are linked to the development of multiple types of malignancies, including a wide range of germinal center (GC)-derived B cell lymphomas. These viruses establish lifelong latent infections in B cells by infecting naïve B cells and driving those cells, independent of antigen, to utilize GC reactions to proliferate and differentiate into resting memory B cells. Thus, the transit of infected B cells through the GC is critical to gammaherpesvirus biology. Despite this, the specific mechanisms by which gammaherpesviruses manipulate GC reactions and contribute to GC-derived B cell lymphomas are not fully understood. Virus-encoded microRNAs (miRNAs) are employed by gammaherpesviruses to manipulate infected cells. Importantly though, the specific in vivo functions and biological relevance of these miRNAs are almost completely unknown due to the strict species specificity of the human viruses. Murine gammaherpesvirus 68 (MHV68, MuHV-4) is genetically and pathogenically related to EBV and KSHV, and causes B cell lymphomas with features of human gammaherpesvirus malignancies. We have recently demonstrated that MHV68 miRNA miR-7-5p repression of the multifunctional host protein EWSR1 (Ewing sarcoma breakpoint protein 1) promotes latent infection of GC B cells. Notably though, the roles of EWSR1 in both gammaherpesvirus infection and GC B cell biology are completely unknown. In work here, we will test the hypothesis that EWSR1 repression is critical for proliferative expansion of germinal center B cells, define the molecular mechanism by which EWSR1 repression contributes to germinal center B cell expansion, and define the contribution of miR-7-5p-mediated EWSR1 repression to B cell lymphomagenesis.

NIH Research Projects · FY 2025 · 2021-08

SUMMARY We have known for some time that α-synuclein aggregates to form insoluble fibrils in pathological conditions characterized by Lewy bodies, such as Parkinson’s disease (PD), multiple system atrophy, and dementia with Lewy bodies. People with synucleinopathies desperately need disease modifying therapies, that either slow or stop neurodegeneration. In order to facilitate the development of new therapies, the fields of neurology, motor control, neuroimaging, and α-synuclein biomarkers need to join forces to identify disease far earlier, well before a neurologist currently makes a diagnosis. In Alzheimer’s disease, investigators have defined Mild Cognitive Impairment (MCI) before dementia and this has unleashed a series of preclinical behavioral, imaging, and pathologically-relevant markers that have revolutionized how clinical trials are conducted for dementia. This same type of revolution in early identification is sorely missing, but clearly needed, in the area of Parkinsonism. In this proposal, we will define a Mild Parkinson Impairment (MPI) using innovative markers that cut across imaging and physiology. We will study a preclinical model of Parkinsonism, known as rapid eye movement (REM) behavior disorder (RBD). The reason RBD is a preclinical model of Parkinsonism, is that 50-60% of patients with RBD go on to develop PD, and the remainder develop either dementia with Lewy bodies or multiple system atrophy. Individuals with RBD will eventually exhibit clinical Parkinsonism with varying degrees of severity. Here, we test the central hypothesis that we can identify early cross-sectional and longitudinal markers of Mild Parkinson Impairment in patients with RBD. Our goal in this proposal is to study patients with RBD prior to other diagnoses to identify early cross-sectional and longitudinal markers of preclinical Parkinsonism. Based on our strong preliminary data and our prior work we will: 1) evaluate innovative measures of brainstem functional magnetic resonance imaging and task-based striatal-cortical functional connectivity; 2) test our robust marker free-water in the substantia nigra in RBD for the first time; 3) measure a newly developed α-synuclein skin biomarker called real-time quaking-induced conversion (RT-QuIC) assay; 4) evaluate motor control assays to define a preclinical mild motor impairment; and 5) follow patients longitudinally after 24 months to determine if these imaging and physiology markers progress over time in people with RBD.

NIH Research Projects · FY 2024 · 2021-08

Cardiotoxicity related to cancer therapies is such a significant clinical problem that NCI and NHLBI have jointly issued PA-19-112 to stimulate applications with the intent to mitigate cardiovascular dysfunction while optimizing cancer outcomes. Cardiotoxicity, such as heart failure (HF), related to the proteasome inhibitor carfilzomib has been an increasingly recognized adverse event that contributes to the symptom burden and poor outcomes of multiple myeloma (MM) patients. Given the knowledge gap in the understanding of carfilzomib-related cardiotoxicity, a pharmacogenomic approach may identify pharmacogenomic/metabolomic biomarkers of such adverse effect and provide an opportunity to improve cardiovascular outcome of cancer patients in a personalized manner. Our long-term goal is to identify and institute preventive strategies for cancer patients at high risk for carfilzomib-related cardiotoxicity, prior to administration of this cardiotoxic treatment, in order to prevent or minimize such risk. Our central hypothesis is that characteristic biomarkers for carfilzomib-related cardiotoxicity can be discerned through interrogation of multi-omics data. Our preliminary results demonstrate the feasibility of such an approach and suggest that the metabolomic and proteomic profiles of carfilzomib-related HF are similar to those of HF in non-cancer patients. More importantly, our findings support the hypothesis that there are overlapping pathways in the development of cardiotoxicity induced by carfilzomib and anthracyclines. The overall objectives of this application are to identify and validate metabolomic and pharmacogenomic biomarkers for carfilzomib-related HF in MM patients using a multi-omics approach and existing whole exome sequencing (WES) data from the Oncology Research Information Exchange Network (ORIEN), and in large electronic health record (EHR) systems, namely the UK Biobank and biobank at Vanderbilt University (BioVU). We have assembled a multidisciplinary team to carry out the following three specific aims: 1). Identify and validate metabolomic biomarkers at baseline that differentiate MM patients who develop versus do not develop carfilzomib-related HF. 2). Identify and replicate germline genetic variants associated with carfilzomib-related HF among MM patients. 3). Build and validate a predictive model for carfilzomib-related HF among MM patients. The proposed work is expected to provide tools to enable stratification of MM patients for cardiotoxicity risk based on pharmacogenomic and metabolomic biomarkers and provide the basis for clinical translation of these biomarkers. In addition, this work will also provide important insight as to what extent the genetic variants associated with anthracycline-related cardiotoxicities are also associated with carfilzomib-related HF. Ultimately, our research will potentially lead to a paradigm shift in current clinical practice to better prevent cardiotoxicity, and improve outcomes in the MM patient population.

NIH Research Projects · FY 2024 · 2021-07

INTERPRETABLE GRAPHICAL MODELS FOR LARGE MULTI-MODAL COPD DATA ABSTRACT One of the most important tasks in today’s era of precision medicine is to understand the mechanisms and the factors affecting the development of clinical outcomes. Another important task is to develop interpretable, predictive models for outcomes. In the last years, many machine learning methods have dominated the task of predictive modeling, including deep learning, random forests and others. They are fueled by the unprecedent volume of data that have been generated in some research areas. However, the interpretability of these methods is not straight forward and their accuracy decreases when only small to medium size training datasets are available. Furthermore, their predictive models do not uncover the complex web of interactions between other variables in the dataset, which is essential for fully understanding disease mechanisms. Also, most such methods are not well suited to accommodate mixed data types (e.g., continuous, discrete) in the same dataset. Probabilistic graphical models (PGMs) offer a promising alternative to classical machine learning methods, because they are flexible and versatile. They can identify both the direct (causal) relations between variables, pointing to disease mechanisms, and build predictive models over diverse data, with good results even with smaller training datasets. They have been used for classification, biomarker selection, identification of modifiable risk factors of an outcome, or for mechanistic studies of perturbations of disease networks. In the previous years we extended the PGM theoretical framework to the analysis of mixed continuous and discrete variables, with or without unmeasured confounders; and we can now evaluate and incorporate prior information in mixed data graph learning. We successfully applied those methods to diverse clinically important problems, including malignancy prediction of undetermined lung nodules, identification of microbiome and other factors affecting pneumonia, selection of SNP biomarkers for combination treatment of cancer patients. Our objective is to develop novel interpretable methods for analysis of any-type data and use them to address clinically relevant questions in COPD, an important chronic lung disease. Method evaluation will be done on synthetic and real data, including parallel datasets with genomic, genetic, imaging and clinical COPD data. Our central aim is to identify factors of disease mechanisms of progression using different modalities of patient data. The deliverables will be (1) new PGM approaches for integrative analysis of any-type data; (2) a new, fully documented software package (in R, Python) that can be incorporated in other pipelines; (3) a new web portal to disseminate our methodologies to non-computer-savvy COPD researchers; (4) results on the pathogenesis and predictive features of chronic obstructive pulmonary disease (COPD). This cross-disciplinary team project is expected to have a positive impact beyond the above deliverables, since the generality of our approaches makes them suitable for studying any disease; and they can be easily integrated into personalized medicine strategies when high-throughput data collection will become a routine diagnostic procedure in all hospitals.

NIH Research Projects · FY 2025 · 2021-07

Project Summary Since we discovered repeat associated non-ATG (RAN) RAN translation in 2011, we and others have shown that RAN proteins accumulate in nine different expansion disorders. These proteins, which can be expressed from both sense and antisense expansion transcripts, accumulate in disease-relevant human tissues including spinocerebellar ataxia type 8 (SCA8) and Huntington disease (HD). We now have evidence that polySer and polyLeu RAN proteins accumulate in a group of spinocebellar ataxias (SCA1, 2, 3, 6 and 7) in which the CAG·CTG expansion mutations are located in polyGln open reading frames. Additionally, we have developed AAV and small molecule approaches to inhibit RAN translation. We will use these tools and genetic approaches to test our central hypotheses that RAN protein pathology is a common feature shared across polyglutamine encoding CAG·CTG expansion disorders and that inhibiting the PKR pathway will reduce RAN protein levels and mitigate disease. We will address our central hypothesis in three specific aims (1) To test the hypothesis that RAN proteins contribute to spinocerebellar ataxias (SCAs) caused by polyglutamine encoding CAG·CTG repeat expansion mutations. (2) To test the hypothesis that SCA and HD RAN proteins are toxic and PKR inhibition will decrease RAN protein levels and improve cellular phenotypes in HD and SCA3 iPSC derived cells (3) : To test the hypothesis that RAN proteins contribute to HD and SCA3 phenotypes in mice independent of polyGln effects using genetic and pharmacological approaches. Taken together these specific aims will determine the contribution of RAN proteins to HD,SCA3 and CAG·CTG repeat expansion disorders and characterize PKR inhibition as a potential therapeutic approach for this large class of devastating repeat expansion diseases.

NIH Research Projects · FY 2025 · 2021-07

PROJECT SUMMARY/ABSTRACT Type 1 diabetes (T1D) is caused by T cell-mediated destruction of pancreatic β-cells. A combination of genetic and environmental factors contributes to this complex autoimmune disease. T1D is without any durable disease- altering therapies though several clinical trials in recent-onset T1D have demonstrated transient β-cell preservation. Anti-thymocyte globulin (ATG), which at low doses can modulate T cells and other adaptive/innate immune cells, is one such immunomodulatory therapy. Compared to placebo, ATG, given in a low dose over 2 days, demonstrated more than 40% higher preservation of C-peptide and nearly 1% lower HbA1c 2 years after therapy in recent-onset T1D subjects. However, within successful T1D immunotherapy trials like low dose ATG, there are clinical “responders” (those who produce significantly more C-peptide in response to therapy) and “nonresponders.” The field of T1D lacks an ability to determine these clinical responders prior to clinical trial enrollment and drug administration, thus exposing some individuals to ineffective interventions with considerable side effect profiles. Utilizing samples from the NIH-funded TrialNet Low-dose ATG in Recent-Onset T1D clinical trial (TN19), the objective of this proposal is to develop a response signature to ATG for use in future clinical trial enrollment criteria and eventual clinical care. The objective that transcriptome, methylome and immunophenotyping differences can identify a responder signature to ATG in T1D will be tested. Specifically, Aim 1 will develop a biomarker of response using a unique in vitro model of ATG stimulation in TN19 baseline clinical trial samples. The hypothesis being that innate and adaptive-specific genes will demonstrate differential expression and methylation profiles with distinct immune phenotypes in clinical responders compared to nonresponders following in vitro ATG stimulation. This is assessing the methodology of performing in vitro pre- enrollment testing of a subject’s peripheral blood to determine their likelihood of response. Aim 2 will identify the mechanisms of clinical efficacy through innovative single cell RNA sequencing, T cell receptor (TCR) α/β pairing, TCR immunosequencing, and surface marker expression. In addition, the function of immune subpopulations known to play a key role in immune tolerance (regulatory T cells and exhausted T cells) will add to the mechanistic determination of ATG efficacy. This work may facilitate prospective personalized therapeutic planning for individual patients or precision medicine-directed clinical trial enrollment criteria. These biomarkers would improve responder rates and reduce exposure of nonresponders to side effects. My career goal of developing predictive biomarkers for T1D immunotherapy clinical trials will be advanced by this proposal. Highly valued skills set forth in the career development plan aim to promote further independence as an investigator and include training in 1) immunological assays, 2) big data analytics, 3) responsible conduct of research, and 4) clinical trial design. The collaborative rapport and mission of training the next generation of investigators across all institutes and departments of the University of Florida provide an ideal environment for career success.

NIH Research Projects · FY 2025 · 2021-07

Marie Nancy Seraphin, PhD, is a Research Assistant Professor at the University of Florida (UF), Department of Medicine, and a trainee affiliated with both the UF Emerging Pathogens Institute (UF-EPI) and Clinical and Translational Science Institute (UF-CTSI). Dr. Seraphin has spent the last seven years, including two as a postdoc, acquiring tuberculosis (TB) molecular epidemiology skills. She has experience linking genotyping and whole genome sequence (YVGS) with patient clinical data to investigate TB outbreaks. She has nine TB publications, six as the lead author. In the short-term, this K01 award will provide training and professional development opportunities in genomics and bioinformatics. Dr. Seraphin's long-term goal is to become a leader in infectious diseases molecular epidemiology, focusing on TB. Environment: Dr. Seraphin will perform her K01 research with guidance from a multidisciplinary mentoring committee. Each mentor is a leader in their respective field. The lead mentors are Dr. Marco Salemi, an expert in phylogenetic, computational, evolutionary biology, and Dr. Kyle Rohde, an expert in TB genetics, pathogenesis, and diagnostics. Dr. Seraphin will also receive formal training in genomics and bioinformatics and acquire research leadership and grantsmanship skills. Research: Mycobacterium tuberculosis (Mtb) is an incredibly successful pathogen, with an estimated 10 million people newly diagnosed with TB annually. Rapid diagnosis, effective treatment, and contact tracing are public health interventions that decrease TB morbidity and mortality. Routine strain surveillance by WGS of cultureconfirmed TB cases facilitates the rapid detection and control of outbreaks to prevent further transmission in communities. More importantly, the rapid detection of outbreaks assures the timely identification of recently infected contacts that can benefit from prophylaxis. Unfortunately, contact tracing activities are currently highly inefficient as TB programs struggle to identify and target efforts towards the 20% of TB cases that generate secondary cases (i.e., super spreaders). This critical public health function could be improved if we capitalize on the extensive Mtb within-host genetic diversity (YVHD) that can be profiled with deep WGS. Thus, we propose to assess the utility of Mtb deep WGS as a higher resolution marker of person-to-person transmission and super spreading. Specifically, we propose first assessing variation in WHO transmission (i.e., bottleneck size) under diverse epi scenarios (Aim 1). WHO measurement is likely to be confounded by laboratory processing of specimens and single genome/sample analysis. Thus, we will assess WHO measure bias by sputum decontamination, subculturing, and sputum sampling (Aim 2). Finally, we will test in a pilot study the feasibility of tracking WHO transmission to detect de novo Mtb transmission and superspreaders (Aim 3). The proposed research and the training activities will successfully position Dr. Seraphin for her first R01 and an independent career as a research scientist.

NIH Research Projects · FY 2025 · 2021-07

PROJECT SUMMARY Eukaryotic SLs are the basic building blocks of cell membranes and serve as key signaling molecules. Bacterial synthesis of SLs is poorly understood, and almost entirely restricted to the phylum Bacteroidetes. These microbes are generally considered symbionts of mammalian hosts. Although microbe-elicited chronic dysregulated inflammation is central feature of soft and hard tissue destruction and periodontal disease pathogenesis, this inflammation is, paradoxically, insufficient to clear the source of infection. Thus, subversion of host immunity is central to the chronic nature of this disease. Research has shown that Porphyromonas gingivalis, a member of the Bacteroidetes is uniquely capable of targeted and dynamic immune suppression, yet little is known of the underlying mechanisms. Remarkably, our studies have illuminated the importance of P. gingivalis SL in regulating the elicited host immune response to this organism and we have shown that these SLs are transferred from this organism and incorporated into host cells – putatively understood as an interkingdom communication system. The overarching hypothesis of the research we propose is that synthesis of SLs affords P. gingivalis and possibly other oral Bacteroidetes a mechanism of immune regulation. Specifically, our published and preliminary studies have determined that P. gingivalis secretes SL-containing outer membrane vesicles (OMVs) that elicit only mild inflammation compared to OMVs from a P. gingivalis mutant incapable of synthesizing SLs, and that the phosphoglycerol-dihydrocerimides (a subset of SLs) containing OMVs are particularly adept at immune suppression. We are proposing that SL-OMVs are an exquisite delivery system that forms the basis of a mechanism of P. gingivalis-host communication to control inflammation. The goal of our proposed studies is to determine how P. gingivalis SLs contribute to OMV cargo loading and subsequently how these SL-OMVs modulate the host innate inflammatory response. We will interrogate host sensing of P. gingivalis SL-OMVs both in vitro and in vivo. As early innate immune responses control host responses at mucosal surfaces such as the oral cavity, we will employ unique genetically modified P. gingivalis strains, and OMVs isolated from these strains to determine which OMV-components are involved in suppression. Molecular, immunologic, imaging, and transcriptomic, and biochemical techniques will be deployed to elucidate the underlying functions of SL-OMVs and mechanisms of host innate signaling. Lastly, we will use oral bone loss modelling to examine the virulence of P. gingivalis strains that are altered in the synthesis of SLs. The rationale for these studies is that identifying immunoregulatory mechanisms used by oral pathogens will provide prime targets for the development of therapeutic strategies. Thus, the long-term goal of this research program is to elucidate the mechanisms underlying SL-mediated OMV delivered immune suppression and to determine if bacterial SL-synthesis can be targeted for treatment and prevention of periodontal disease.

NIH Research Projects · FY 2026 · 2021-07

Project Summary Chronic pain conditions place significant burdens on patients, their families, and society by reducing quality of life and creating enormous financial consequences that total more than 630 billion USD annually for the United States of America alone. Neuropathic pain is a debilitating type of chronic pain that arises from a lesion or disease affecting the somatosensory system. Neuropathic pain affects 7-8% of the general population yet is poorly responsive to analgesic drugs, including opioids, thus, alternative therapeutics for treatment are desperately needed. However, the underlying mechanisms of the development and maintenance of neuropathic pain are poorly understood. It is hypothesized that neuropathic pain results from a loss of spinal cord dorsal horn inhibition and/or a gain in dorsal horn excitation that allows the propagation of low threshold innocuous inputs to be perceived as painful. Exactly how nerve injury disrupts this balance to generate a net pronociceptive tone, however, remains unclear. Specific Aim 1 describes promising preliminary data within our laboratory that implicates glutamatergic dorsal horn interneurons expressing the neuropeptide Y (NPY) Y1 receptor in both the development and maintenance of neuropathic pain. First, selective ablation of neuropeptide Y1 receptor- expressing interneurons (Y1-INs) with intrathecal NPY-saporin reduced the development of behavioral signs of neuropathic pain. Second, intrathecal pharmacology and intraspinal chemogenetic techniques indicate that Y1- INs are both necessary and sufficient for the behavioral manifestations of neuropathic pain. Lastly, both single cell RNA-sequencing and fluorescence in situ hybridization data indicate that Y1-INs segregate into three distinct dorsal horn interneuron subpopulations. Together, these observations form the premise for my central hypothesis that nerve injury increases the excitability of Y1-INs, and this makes one or more subpopulations of Y1-INs necessary for the behavioral symptoms of neuropathic pain. Specific Aim 2 will explore this hypothesis via intraspinal pharmacology, behavioral testing, in vivo wireless optogenetics, intersectional Cre-lox transgenics, and patch clamp electrophysiology. Together these methods will test which Y1-IN subpopulation(s) is/are necessary for the behavioral signs of neuropathic pain. Further, these methods will assess changes in pre- or postsynaptic excitatory and inhibitory activity to Y1-INs following nerve injury to uncover mechanistic changes in the circuit that might lead to the development of neuropathic pain. Specific Aim 3 details a plan to identify and pursue a neuroscience focused postdoctoral fellowship following the completion of the dissertation work described in Specific Aim 2. The overarching goals of this study are to increase our understanding of how nerve injury increases the excitability of Y1-IN subpopulations, and provide rationale for targeting spinal Y1-INs as a novel approach to treat neuropathic pain.

NIH Research Projects · FY 2025 · 2021-07

Project Summary More than half of traumatic spinal cord injuries (SCI) occur at the cervical level, leading to paralysis and respiratory compromise or failure. Approximately 20% of cSCI patients will require ventilator support for which there are very few therapeutic options for recovery. Epidural stimulation has emerged as a strategy to restore a variety of motor, sensory, and autonomic functions in both experimental and clinical conditions after SCI. Though limited underlying mechanisms have been proposed, to date little is known how epidural stimulation elicits motor function at the neuronal level. Even less is known about the capacity for epidural stimulation to promote long-lasting spinal plasticity for true device-independence and to date no studies have explored the potential for eliciting respiratory plasticity. The fundamental hypothesis guiding this proposal is that long-term, closed-loop epidural stimulation elicits functional improvement in diaphragm activity that outlasts the period of stimulation via activity-dependent mechanisms involving BDNF/TrkB signaling in phrenic motor neurons. Preliminary data are promising and indicate at least some short-term plasticity with longer periods of stimulation (4d). We envision that more chronic and targeted stimulation parameters will result in longer persistence of motor recovery. This is the first study to propose chronic epidural stimulation in awake, freely-behaving animals in a defined respiratory neural circuit. Ultimately, data from this project will serve to inform development of future investigations of the mechanistic basis of epidural stimulation efficacy essential for advancing the therapeutic applications to many motor systems but especially to the neural system controlling breathing.

NIH Research Projects · FY 2025 · 2021-07

Abstract Porphyromonas gingivalis is a major pathogen of severe adult periodontitis, a polymicrobial disease caused by the coordinated action of a complex microbial community that leads to inflammation of tissues supporting the teeth. A central hurdle limiting progress in periodontal disease research is the paucity of information detailing microbial signals that correlate with clinical progression at a site from health to disease. Filling this void, we recently reported metatranscriptome findings of the microbial community from human clinical samples during periodontal disease progression and discovered that CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-associated proteins in the periodontopathogen P. gingivalis were highly up-regulated only at those sites that progressed. CRISPRs-Cas systems are used by bacteria to prevent foreign DNA incorporation, as occurs with a viral attack. The goal of this research program is to understand the role that CRISPR-Cas systems have on virulence determinants of important periodontopathogens during disease progression. A comprehensive analysis of the mutants will provide information required to increase our understanding of not only CRISPR gene function, but also the contribution of these novel genes to virulence. To this end we propose the following Specific Aims: Aim 1. Identify targeted endogenous genes comparing transcriptome profiles of the wild-type and the mutants growing intracellularly. Aim 2. Determine the impact of CRISPR-associated genes on the innate immune host responses to P. gingivalis. Aim 3. Aim 3. Determine the role of CRISPR-Cas genes in the pathogenicity of P. gingivalis. We expect that this knowledge will facilitate the development of targeted approaches to prevent and treat periodontitis by inhibiting specific Cas proteins essential for virulence. Such results will fundamentally advance our understanding that such systems have in the metabolism of periodontal pathogens besides their traditional role assigned as a mechanism of protection against foreign DNA. We believe that the team we have assembled for this project has all the qualifications to accomplish successfully the goals proposed in the present application.

NIH Research Projects · FY 2024 · 2021-07

PROJECT SUMMARY Clinical implementation of Precision Medicine faces major challenges in precision disease stratification and staging, determining optimal treatment, monitoring therapy response, and overcoming drug resistance and relapse. To address these challenges, there is a critical unmet need for better biomarkers and tests that complement current methods for accurate diagnosis, prognosis and monitoring of response to treatments. Liquid biopsy presents an innovative non-invasive modality for precision oncology as it promises to provide a global view of tumor dynamics. Extracellular vesicles (EVs), including exosomes, are emerging as a new paradigm of liquid biopsy for non-invasive cancer diagnosis and monitoring. Exosomes are 40-150 nm membrane vesicles secreted by most cells and have been identified as essential mediators of cell interactions and signaling that promote tumor metastasis, drug resistance, and relapse. Despite the potential clinical impact of these findings, precise biological functions of exosomes, including matrix metalloproteinases (MMPs)-mediated modulation of tumor microenvironments, and their potential clinical value remain yet to be determined. This is due in part to the daunting challenges in isolation and analysis of these nanovesicles with diverse molecular and functional properties. Here we hypothesize that functional phenotypes of circulating exosomes can provide potent biomarkers for detecting early malignancy, monitoring tumor progression and metastasis, and assessing therapy response in breast cancer. To test this hypothesis, we propose the advanced development and validation of a nano-engineered microfluidic biosensing system capable of integrative analysis of both molecular and functional phenotypes of exosomes in one streamlined workflow. The research will be performed by three specific aims: 1) Expand the MINDS strategy to develop an optimal 3D nano-engineered integrative EV molecular and activity profiling (EV-MAP) nanochip platform; 2) Adapt and optimize the EV-MAP technology for monitoring tumor burden and therapy response using mouse models; and 3) Evaluate and validate the EV-MAP technology for potential applications to clinical diagnosis and classification of breast cancer patients. The new technology will confer superior analytical capabilities to substantially accelerate the functional studies of circulating exosomes. Harnessing exosome activities for diagnostic, prognostic or therapeutic benefit presents a paradigm-shifting mechanism for precision medicine. While focused on breast cancer in this project, our research will ultimately create a transformative tool for studies of a wide range of bioactive exosomes in various malignancies to develop reliable non-invasive liquid biopsy of cancer.

NIH Research Projects · FY 2025 · 2021-07

Project Summary/Abstract Programmed cell death 1 (PD-1) and its ligands, PD-L1 and PD-L2, are highly expressed in human and murine thymus. Despite this knowledge, the function of the PD-1 signaling pathway during T cell development has been severely understudied. In the past decade, immunotherapies inhibiting the PD-1:PD-L1 axis have produced remarkable improvements in the clinical management of several malignancies, at least in part by restoring T cell receptor (TCR) signaling within the immunosuppressive tumor microenvironment. However, because TCR signaling is essential for thymocyte development, we postulate PD-1/PD-L1 inhibitors may have profound effects on the function and specificity of newly generated T cells. These thymus-specific actions may highlight a key unexplored mechanism by which PD-1 blockade elicits anti-tumor immune responses. Leveraging this pathway for pediatric cancer patients may be particularly beneficial considering their high rate of thymic T cell production. Our preliminary data illustrate that hematopoietic stem cells (HSCs) administered in conjunction with anti-PD-1 therapy expands the T cell pool and helps overcome treatment-resistance in murine glioblastoma. This may suggest anti-PD-1 therapy acts within the thymus to promote the proliferation and maturation of HSC-derived thymocytes. Importantly, pediatric high-grade glioma (HGG) is the prevailing cause of cancer-related death in children which emphasizes the need for new therapies. Thus it is our priority to investigate this novel pathway with the goal of improving the standard of care for pediatric HGG and other childhood tumors. Our objective is to characterize how inhibiting PD-1 signaling modifies thymocyte development in health and HGG. The central hypothesis of this proposal is that PD-1 inhibition increases thymic T cell production and promotes the positive selection, or survival, of tumor-specific TCRs. Aim 1 will determine the impact of PD-1 blockade on the proliferation, selection, and output of developing thymocytes in healthy and glioma-bearing mice. Aim 2 will assess the thymic contribution towards the therapeutic response in the context of PD-1 inhibiton and HSC transfer. This work is significant because no prior study has investigated how thymus-specific PD-1 blockade impacts anti-tumor immune responses. The results from this study have the potential to substantially influence clinical decision making and treatment regimens for pediatric HGG patients. This project is innovative because it will utilize nontransgenic mouse models to more accurately define how PD-1 inhibition affects thymus physiology in health and disease. In summary this proposal will comprehensively characterize how the PD-1 pathway modulates T cell development and will investigate a novel thymic mechanism that may revolutionize our understanding of anti-PD-1 therapy in cancer.

NIH Research Projects · FY 2025 · 2021-06

This K99/R00 research and training plan will catalyze my efforts to acquire the advanced training necessary to develop and test a tailored behavioral intervention addressing the intersection of stimulant use and HIV risk in men at high risk for HIV in the United States of America. During the K99 phase, my training goals consisted of (1) developing advanced competencies in designing tailored evidence-based behavioral interventions;(2) pursuing advanced training in Randomized Control Trial methods necessary to examine the feasibility, acceptability, and preliminary efficacy of a tailored behavioral intervention and (3) acquire knowledge in the application of Social Network Analysis methods to assess the effects of a tailored behavioral intervention on participant's social network composition. Men at high risk for HIV are disproportionately affected by HIV and other sexually transmitted diseases. The K99/R00 proposal will focus on this underserved population of stimulant-using men who are in desperate need of tailored behavioral interventions to mitigate co-occurring stimulant use and HIV risk in the era of pre-exposure prophylaxis (PrEP). Developing a behavioral intervention that addresses socio-behavioral factors and personal networks as key determinants of stimulant use and HIV risk in men at high risk for HIV in the US represents a viable strategy to reduce stimulant use, decrease engagement in condomless sex (CS), and support PrEP uptake in at-risk men in the USA. The following aims guide the R00 phase: (1) Conduct formative research through mixed methods to develop a tailored behavioral intervention targeting co-occurring stimulant use and HIV risk in men at high risk for HIV who are not on PrEP and (2) Conduct a pilot Randomize Control Trial to test the feasibility, acceptability and preliminary efficacy of a tailored behavioral intervention for optimizing PrEP uptake as the primary outcome with 60 stimulant-using men at high risk for HIV. In aim 1, formative qualitative data is going to be collected through in-depth interviews with stimulant-using men at high risk for HIV (n=20) and with PrEP healthcare providers (n=10) to inform the behavioral intervention protocol development. Aim 2 consists of testing the tailored behavioral intervention protocol developed for stimulant-using men at high risk for HIV who are not currently taking PrEP. A parallel-group pilot RCT will test the feasibility, acceptability, and preliminary efficacy of the tailored behavioral intervention with Contingency Management (CM) for PrEP uptake versus an attention-control condition with CM for PrEP uptake in a sample of 60 stimulant-using men at high risk for HIV who are not taking PrEP, living in the United States of America.

NIH Research Projects · FY 2025 · 2021-06

ABSTRACT Sepsis and severe trauma are linked with challenging clinical trajectories as well as dismal long-term outcomes following hospital discharge. In surgical intensive care units (SICUs), an alarming percentage of sepsis and trauma patients can develop chronic critical illness (CCI; prolonged acute-care and chronic-care hospitalization with unresolved organ dysfunction). CCI frequently manifests as a persistent inflammation, immunosuppression and catabolism syndrome (PICS). SICU survivors suffering from PICS have repeat infections, poor cognitive performance, physical dysfunction and self-reported poor quality of life. These conditions, at least in part, are due to an unresolving pathologic myelopoiesis and ensuing prevalence of distinct myeloid-derived suppressor cells (MDSCs). The principal investigator (PI) and his collaborators have demonstrated significant productivity over the last decade, especially in the last five years, in this research field. The PI’s laboratory has conducted human and murine research to establish that enhanced production of these distinct MDSCs is associated with poor outcomes in sepsis and trauma. The laboratory has also discovered key distinctions in these MDSCs’ accompanying pathologic myeloid activation; for example, they are potently immunosuppressive towards macrophages, CD4+ and CD8+ T cells; while concurrently, they produce inflammatory cytokines, reactive nitric oxide (NO), oxidation and peroxidation products that damage parenchymal cells and promote inflammation. We hypothesize that microRNAs and immunometabolism affect each other in relation to the development and suppressive activity of these MDSCs. Our overarching goal for this application is to build upon this foundation and expand our understanding of the patient immune response to trauma and sepsis, including rationally designing prophylactic and/or therapeutic interventions aimed at treating or preventing grim clinical trajectories and long-term outcomes following sepsis or trauma. This includes identifying sepsis and trauma patient populations at risk of dying or having long-term morbidity. We intend: (1) to examine specific mechanisms, including epigenetic and metabolic changes, to MDSC pathophysiology that engender or maintain pathologic myeloid activation. MDSC and hematopoietic stem and progenitor cell (HSPC) studies will be both descriptive and interventional (ex vivo). For example, MDSCs will undergo phenotypic analysis as well as CITE-seq using 10X Genomics, and HSPCs isolated from bone marrow and blood will undergo phenotypic and functional analysis. With these studies, we will (2) explore the unique biology of pathologic myeloid cell activation in different cohorts of sepsis and trauma patients (such as different patient age and sex groups); and (3) consider possible immunomodulative therapies that affect MDSCs and/or pathologic myeloid activation to mitigate or prevent CCI/PICS. This MIRA would support and enable the PI and his laboratory to determine why sepsis and trauma patients enter pathologic myeloid activation, and how to work towards resolving this to improve patient outcomes.

NIH Research Projects · FY 2024 · 2021-06

ABSTRACT There is a pressing need for effective interventions to remediate age-related cognitive decline and alter the trajectory toward Alzheimer’s disease. The NIA Alzheimer’s Disease Initiative funded Phase III Augmenting Cognitive Training in Older Adults (ACT) trial aimed to demonstrate that transcranial direct current stimulation (tDCS) paired with cognitive training could achieve this goal. The present study proposes a state of the art secondary data analysis of ACT trial data that will further this aim by 1) elucidate mechanism of action underlying response to tDCS treatment with CT, 2) address heterogeneity of response in tDCS augmented CT by determining how individual variation in the dose of electrical current delivered to the brain interacts with individual brain anatomical characteristics; and 3) refine the intervention strategy of tDCS paired with CT by evaluating methods for precision delivery targeted dosing characteristics to facilitate tDCS augmented outcomes. tDCS intervention to date, including ACT, apply a fixed dosing approach whereby a single stimulation intensity (e.g., 2mA) and set of electrode positions on the scalp (e.g., F3/F4) is applied to all participants/patients. However, our recent work has demonstrated that age-related changes in neuroanatomy as well as individual variability in head/brain structures (e.g., skull thickness) significantly impacts the distribution and intensity of electrical current induced in the brain from tDCS. This project will use person-specific MRI-derived finite element computational models of electric current characteristics (current intensity and direction of current flow) and new methods for enhancing the precision and accuracy of derived models to precisely quantify the heterogeneity of current delivery in older adults. We will leverage these individualized precision models with state-of-the-art support vector machine learning methods to determine the relationship between current characteristics and treatment response to tDCS and CT. We will leverage the inherent heterogeneity of neuroanatomy and fixed current delivery to provide insight in the not only which dosing parameters were associated with treatment response, but also brain region specific information to facilitate targeted delivery of stimulation in future trials. Further still, the current study will also pioneer new methods for calculation of precision dosing parameters for tDCS delivery to potentially optimize treatment response, as well as identify clinical and demographic characteristics that are associated with response to tDCS and CT in older adults. Leveraging a robust and comprehensive behavioral and multimodal neuroimaging data set for ACT with advanced computational methods, the proposed study will provide critical information for mechanism, heterogeneity of treatment response and a pathway to refined precision dosing approaches for remediating age- related cognitive decline and altering the trajectory of older adults toward Alzheimer’s disease.

NIH Research Projects · FY 2025 · 2021-06

Project Summary Noroviruses are a major cause of acute gastroenteritis and the leading cause of severe childhood diarrhea globally. Our discovery of murine norovirus (MNV) in 2003 accelerated progress in the field by providing a small animal model and enabling further understanding of the pathogenesis of these enteric viruses. Yet a major limitation of this model system is that wild-type laboratory mice have not been shown to develop overt disease when infected with MNV, in contrast to human norovirus which is symptomatic in immunocompetent hosts. This limits the field’s ability to elucidate norovirus-induced events responsible for disease. It should be noted, however, that all virulence studies of MNV performed to date have used adult mice. Considering that human norovirus infections are more severe in younger hosts, we hypothesized that young mice would likewise be susceptible to MNV disease. We have generated exciting data confirming that oral MNV infection causes acute self-resolving diarrhea in neonatal pups, a transformative discovery for the norovirus field. Gastrointestinal disease severity is regulated by viral genetic determinants and is associated with pathological changes to the intestinal epithelium although the main targets of infection are intestinal immune cells. We propose to use this novel system to test our working model that infection of intestinal immune cells leads to disruption of the epithelium and consequent diarrhea. Our main objectives are to elucidate the viral determinants of diarrhea, define the key immune cell targets of infection, and probe the interactions of the virus with the intestinal epithelium. The integration of these aims will enable us to map key virus-host interactions responsible for intestinal disease.

NIH Research Projects · FY 2025 · 2021-05

Project Summary-Abstract Metastasis is the major cause of BrCa death. Most women with metastatic BrCa (stage IV) are treated mainly with systemic therapy such as hormone therapy (for estrogen receptor-positive BrCa), chemotherapy, targeted therapy, and some combinations. Current treatments are very unlikely to cure metastatic BrCa, with more than 70% death rate within 5 years of diagnosis. Therapeutic targeting BrCa metastasis is largely lacking. Here we are aiming to develop a single agent with dual targeting capability: 1) to kill metastatic cancer cells directly; 2) to kill cancer specific regulatory T cells (Tregs) hence inducing anti-cancer immunity. With an effort to search the potential molecular target, we decided to inhibit BCL-XL using an emerging novel PROTAC technology. With two lead PROTAC compounds (BCL-XL-Ps) we have recently developed, we found that both compounds can efficiently lead to the degradation of BCL-XL in vitro and in vivo. Interestingly, it appears that the BCL-XL-Ps work in all syngeneic cancer models we have tested with the strongest suppressive efficacy in breast cancer metastasis. Using multidisciplinary techniques, we believe BCL-XL-Ps kill metastatic cancer cells and Tregs simultaneously as we initially expected. The current project will define the lineage-specific role of BCL-XL in cancer cells and in Tregs. Even though the direct cancer cell killing may not be sufficient to eradicate metastatic tumor growth as shown in the preliminary data, a portion of dead cancer cells may provide sufficient auto- or neo-antigens for T cell activation. In addition, BCL-XL depletion in cancer cells sensitizes them to CD8-T cell mediated killing. The BCL-XL-Ps-mediated Treg depletion and direct activation of T cells elicits a strong anti- cancer immunity that can be harvested for cancer therapy. Simultaneous depletion of BCL-XL by BCL-XL-Ps in cancer cells further sensitize them to CD8-T cell mediated killing. Here we will study the lineage-specific roles of BCL-XL in cancer. The translational research is also strongly supported by clinical observations that BCL-XL protein expression predicts shorter patient survival in breast cancer patients. Our long-term goal is to develop the lead compound into clinic for dual targeting of cancer cells and Tregs in treating metastatic breast cancers.