Biological and Health Sciences
Mandakh Bekhbat, PhD
ASSISTANT PROFESSOR, SCHOOL OF MEDICINE, PSYCHIATRY AND BEHAVIORAL SCIENCES
The role of monocyte immunometabolism in brain-immune communication and symptoms of anhedonia in depression
Approximately 30-50% of patients with major depression (MD) have increased inflammation, which promotes anhedonia – a core and disabling symptom that is often treatment-resistant. While rodent studies have demonstrated a key role for monocytes, immune cells that traffic to reward-related brain regions to lead to depressive and anhedonic behavior, how these cells communicate with the brain to contribute to anhedonia symptoms is not fully known. A better understanding of these mechanisms is required to develop more nuanced and specific immune-based treatment strategies in MD. When activated by inflammatory stimuli, monocytes are metabolically rewired to favor the glycolysis pathway, thus providing the energy and nutrients required for pro-inflammatory functions. My preliminary findings in MD patients with high inflammation revealed an increase in circulating monocytes with glycolytic reprogramming in association with the severity of anhedonia. These glycolytically activated monocytes also expressed gene signatures of inflammation and trafficking to the brain, suggesting that monocyte glycolysis may promote inflammation, brain-immune communication, and anhedonia. Combining clinical studies, metabolic assays, and an innovative “human blood-brain barrier (BBB)-on-a-chip” in vitro platform, in this pilot I will test the hypothesis that monocyte glycolytic reprogramming will be associated with inflammation, BBB transmigration in vitro, and anhedonia severity. I will also explore existing immunometabolic modulators for their potential to reverse monocyte phenotypes in vitro. This work will provide pilot data and conceptual and technical platforms for subsequent NIH grants to test clinically-relevant strategies targeting monocyte immunometabolic and migratory pathways to reverse the effects of inflammation on the brain and behavior.
Candace Floyd, PhD
PROFESSOR, SCHOOL OF MEDICINE, EMERGENCY MEDICINE
Optimization of Ommaya intraventricular cannulation in pig models for CNS drug discovery
The overarching goal of this project is to develop and optimize a new tool that will increase the armamentarium of translational research and fill a critical technological gap in the development of drugs to treat diseases, disorders, and injury of the central nervous system (CNS). We propose to develop and optimize the use of an Ommaya reservoir intraventricular catheter system that can be used for safe, longitudinal (i.e., repetitive) sampling of cerebrospinal fluid (CSF) or intracerebroventricular (ICV) drug delivery in pigs. There are three goals to the research. The first is to compare the "classical" trajectory to a novel trajectory for intrventricular cannulation with the Ommaya reservoir in adult pigs using MRI image-guide neuronavagation. The second goal is to assess the ability to obtain longitudinal CSF draws in unanesthetized pigs using humane methods. The third goal is to assess the CSF cytology and expression of inflammatory markers from longitudinal CSF samples. This new method will be used as a translational research tool in drug development settings that will facilitate our ability to transcend the boundaries and undertake transformative research that leads to development and translation of new drugs for treatment of CNS injury and disease.
Masayuki Hirano, PhD
ASSISTANT PROFESSOR, SCHOOL OF MEDICINE, PATHOLOGY AND LABORATORY MEDICINE
Max Cooper, MD
PROFESSOR, SCHOOL OF MEDICINE, PATHOLOGY AND LABORATORY MEDICINE
Identification and characterization of innate lymphoid cells in jawless vertebrates
We have shown that the jawless vertebrates, a lineage that diverged from jawed vertebrates approximately 500 million years ago, possess a system of somatically diversified antigen receptors, the Variable Lymphocyte Receptors (VLRs), that are structurally unlike the Ig/TCR of jawed vertebrates. Nonetheless, they are expressed on cells with features of B and T cells, suggesting that the vertebrate common ancestor had a complex, lymphocyte-based adaptive immune system. Innate Lymphoid Cells (ILCs), recently identified as non-T and non-B lymphocytes in mammals, are divided into five groups, including natural killer (NK) cells, that play vital roles in immunity and mucosal homeostasis. This prompts questions about the evolution and function of ILCs, and of the origins of lymphocytes in general. This proposal outlines a research project aimed at elucidating the characteristics and function of ILCs in lampreys. Specifically, the research will focus on transcriptome analysis and scRNA-seq studies of lymphocytes from gut mucosal and hematopoietic tissues, and CRISPR/Cas9 gene knockout of key ILC genes in lamprey embryos. The significance of this research lies in its potential to transform our understanding of vertebrate immunity, offering insights into the early forms of immune mechanisms and their evolution. This work is fundamental for the broader fields of evolutionary biology and immunology, as it seeks to reconstruct the evolutionary lineage of vertebrate immune cells.
Judith Fridovich-Keil, PhD
PROFESSOR, SCHOOL OF MEDICINE, HUMAN GENETICS
Rabindra Tirouvanziam, PhD
ASSOCIATE PROFESSOR, SCHOOL OF MEDICINE, PEDIATRICS
Extending the reach and efficacy of gene therapy
The long-term goal of the proposed work is to extend the reach and efficacy of gene therapy by enabling transduced cells to share their expressed transgene product with other cells. This could make gene therapy, already FDA-approved for a small number of disorders, more viable for others, and effective at lower viral doses for most. The short-term goal of this pilot study is to test the ability of small tags, added individually to a transgene encoding human galactose-1P uridylyltransferase (GALT), to drive the encoded GALT mRNA or protein product into extracellular vesicles (EVs) for distribution both locally to neighboring cells and distally via transport through the blood stream. If successful, this approach could dramatically increase the percentage of cells rendered GALT+ for a given dose of virus. This approach could also extend the duration of gene therapy efficacy by enabling low mitotic tissues, such as muscle, to serve as endogenous “factories” producing EVs that enter the blood stream and distribute virus-encoded transgene product to high mitotic tissues, such as liver, that have lost their viral genomes due to tissue expansion and turn-over. The results of the proposed work will serve as preliminary data for extramural grant applications and inform the design of more extensive future studies testing the potential of EV-targeting of viral transgene products to improve efficacy and duration of gene therapy.
Cynthia Giver, PhD
ASSOCIATE PROFESSOR, SCHOOL OF MEDICINE, HEMATOLOGY AND MEDICAL ONCOLOGY
Joshua Chandler, PhD
ASSISTANT PROFESSOR, SCHOOL OF MEDICINE, PEDIATRICS
Identifying indoles that limit graft vs host disease and promote survival in allogeneic BMT/HSCT patient
Allogeneic bone marrow transplantation [allo-BMT] is a curative therapeutic option for patients with hematologic diseases. However, in ~40% of transplant recipients, allogeneic donor T cells in the transplanted bone marrow induce a progressive and deleterious hyper-inflammatory response called Graft vs. Host Disease [GvHD], which may be fatal. GvHD pathophysiology starts with damage to the intestinal epithelium caused by pre-transplant irradiation or chemotherapy. This leads to allogeneic inflammatory responses resulting in colitis and enteritis, and leakage of bacteria and microbial metabolites across the epithelium into the lymph and blood. We have shown that one class of microbial metabolites, indoles, derived from tryptophan, provide protection against GvHD, while preserving anti-tumor immune responses (Graft vs. Leukemia, [GvL]) in murine MHC mismatched allograft transplantation models. Limited clinical data in the literature show that human BMT patients with diminished levels of indoles (from fecal and urinary measurements) exhibit increased susceptibility to intestinal GvHD and higher mortality. An important knowledge gap is whether directly measured indole levels in circulating blood are correlated with GvHD risk and progression in allo-BMT/HSCT patients. This question forms the basis of the current URC proposal. Using clinical plasma samples previously collected by our team, and carefully executed targeted mass spectrometry measurements, we will correlate plasma levels of indole metabolites in BMT patients with the incidence of severe GvHD to identify potentially beneficial indole metabolites. These studies will contribute support to the rationale for developing indoles as a therapeutic option for BMT patients at risk for developing GvHD.
Claire-Anne, Gutekunst, PhD
ASSOCIATE PROFESSOR, SCHOOL OF MEDICINE, NEUROSURGERY
Exploring the role of neurons of the anterior nucleus of the thalamus in temporal lobe epilepsy
Epilepsy is one of the most common neurological disorders. Approximately one third of patients are drug-resistant, underscoring the need for alternative therapies. One of the biggest challenges to developing disease-modifying therapies is the limited understanding of the underlying mechanisms behind epileptogenesis and propagation of seizures. While electrical stimulation of the anterior nucleus of the thalamus (ANT) has been effective in reducing seizure burden in patients with drug resistant mesial temporal lobe epilepsy (MTLE), few patients become seizure free. Lesions in the ANT may curb seizures in MTLE, but the associated memory risk could be too high.To enhance therapy by better understanding pathogenesis, we aim to investigate intrinsic ANT neurons in the intrahippocampal kainic acid (IHKA) mouse model of MTLE for their role in epileptogenesis and spontaneous seizures. We will use a combination of viral vectors to express an inhibitory DREADDS in specific cell populations in the ANT and determine whether turning off the ANT glutamatergic neurons prevents the progression of epileptogenesis. We will also investigate whether ANT inhibition has therapeutic effects and is able to suppress spontaneously recurrent seizures. We hypothesize that inhibition of glutamatergic neurons in the ANT will delay epileptogenesis and suppress spontaneous seizures in the IHKA model. These studies will shed light on the role of ANT neurons during the epileptogenic period as well as after epilepsy has become established. Our findings will bring a better circuit-level understanding of how seizures develop and propagate and could lead to development of cell specific therapies.
Daniel Kalman, PhD
PROFESSOR, SCHOOL OF MEDICINE, PATHOLOGY AND LABORATORY MEDICINE
Indole limits sarcopenia during aging
Aging is associated with loss of mobility and infirmity. Frailty is associated with dysbiosis2-5, but it is unclear what microbiota products contribute to health or frailty. We identified indole and its derivatives as molecules secreted by commensal bacteria or from food that act in C. elegans, Drosophila and mice to augment healthspan, allowing aging animals to retain mobility for longer1. Indoles promote healthy intestinal homeostasis1,2,6, DNA repair and genome integrity in germ cells7, and limit the loss of muscle proteins during aging concomitant with loss of mobility. Recent metabolomic studies found loss of indole-producing bacteria and reduced plasma indole levels also correlated with decreased mobility in aged humans8,9. Our finding that indole promotes stability of muscle proteins essential for the contractile apparatus in aged animals, led us to hypothesize that indole promotes refolding of damaged proteins, regulates proteasome activity to promote loss of irreparable proteins and limit aggregation of damaged proteins, and/or reduces age-associated oxidative damage to muscle proteins. To determine the mechanistic basis for indole effects, we will use genetic analysis in C. elegans to identify cellular pathways utilized by indole to maintain mobility during aging. C. elegans striated muscle exhibits significant structural conservation with mammals, and, as they age, dysregulation of mobility and proteostasis, resulting in loss of the contractile apparatus and mitochondrial function, characteristics of sarcopenia in mammals. These studies will provide mechanistic information on how indoles counteract sarcopenia during aging and are essential to developing indoles as possible therapeutics to treat sarcopenia in elderly people.
Kosuke Kato, Ph.D
ASSISTANT PROFESSOR, SCHOOL OF MEDICINE, MEDICINE
Targeting MUC1 in Chronic Airway Mucus Hypersecretion
Chronic Obstructive Pulmonary Disease (COPD) is the sixth leading cause of morbidity and mortality in the United States, characterized by persistent respiratory symptoms and airflow limitation. Among these symptoms, mucus hypersecretion is a critical factor contributing to airway obstruction, infection risk, and exacerbation frequency, significantly impairing patients' quality of life. Despite this, therapeutic options to manage mucus hypersecretion in COPD patients are limited and largely ineffective.
This research proposal aims to address the gap in COPD treatment by targeting MUC1, a membrane-associated mucin implicated in the regulation of mucus production. Our preliminary findings indicate that MUC1 plays a pivotal role in airway mucus hypersecretion, suggesting a potential novel therapeutic target for COPD management.
The proposed studies are designed to elucidate the mechanistic role of MUC1 in COPD-associated mucus hypersecretion and to evaluate the pre-clinical efficacy of a novel MUC1 memetic inhibitor to prevent pathological airway remodeling and reduce mucus overproduction. Using state-of-the-art molecular biology techniques and robust in vitro models, we will investigate the MUC1 signaling pathways that mediate these pathological changes in COPD.
By advancing our understanding of MUC1's role in COPD pathogenesis and exploring its inhibition as a therapeutic strategy, this research has the potential to lead to the development of new treatments for mucus hypersecretion, enhancing disease management, and improving the quality of life for COPD patients.
Allison Linden, MD, MPH
ASSISTANT PROFESSOR, SCHOOL OF MEDICINE, SURGERY, DIVISION OF PEDIATRIC SURGERY
Development of a multi-institutional registry for anorectal malformations in Rwanda
Congenital anorectal malformations (ARM) are a significant source of morbidity and mortality in low-income countries due to challenges in access to safe, timely, affordable pediatric surgical care. Current data regarding epidemiology, suggested operative approach, and short- and long-term outcomes originate in well resourced, high-income countries with multidisciplinary care teams. This environment is immensely different than that in low-income countries. Access to appropriate care, cultural differences, equipment availability and cost of care are only a few of the elements which can greatly affect suggested optimal care in a low-income country setting. The effect of these elements on ARM short- and long-term outcomes has not been studied. Better outcomes cannot be achieved without a greater understanding of these elements.
The goal of this proposed research is to establish an ARM patient registry at the three hospitals that perform pediatric surgical care in Rwanda in order to better inform outcomes and provide a platform for quality improvement. This valuable data will provide essential information to develop more effective treatment pathways for ARM care that are culturally relevant and context appropriate.
Maud Mavigner, PhD
ASSISTANT PROFESSOR, SCHOOL OF MEDICINE, PEDIATRICS
Disrupting HIV persistence in memory CD4+ T cells by targeting stemness signaling pathways
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Antiretroviral therapy (ART) inhibits HIV-1 replication but is not curative. Latent HIV-1 persists indefinitely as replication-competent silent proviruses in long-lived memory CD4+ T cells maintained through clonal expansion. Long-lived cells such as central (CM) and stem cell memory (SCM) CD4+ T cells that continually maintain their own pool size through proliferation likely represent this HIV reservoir core. Disrupting this reservoir core may prove essential for an HIV cure. Stemness signaling pathways such as Wnt or Notch regulate the fate of these long-lived memory T cells to self-renew or differentiate. We previously demonstrated that inhibition of proliferation and induction of differentiation of SCM and CM and CD4+ T cells can be achieved in ART-treated SIV-infected rhesus macaques (RMs) through modulation of the Wnt pathway. We also showed that the combined pharmacological modulation of Wnt and Notch stemness pathways during acute SIV infection of RMs impacts viral reservoir seeding by transiently reducing the relative contribution of the CM cells to the peripheral CD4+ T cell compartment and to the pool of the infected CD4+ T cells.
Here, we seek to perform a detailed ex vivo analysis of the effect of pharmacological modulation of stemness signaling pathways on SIV latency and SIV reservoir cells to evaluate the therapeutic potential of this approach for HIV cure an to expand our understanding of the basic biology and dynamics of persistent HIV reservoirs.
Eleftherios Michailidis, PhD
ASSISTANT PROFESSOR, SCHOOL OF MEDICINE, PEDIATRICS
Host-dependency factors of coronaviruses
The emergence of coronaviruses that result in epidemics and pandemics have a serious impact on global health and economy. The COVID-19 pandemic that is caused by SARS-CoV-2 has resulted in more than six million deaths worldwide. Vaccines and antivirals have ameliorated the spread of the virus and the disease outcomes, but new variants continue to emerge. Zoonotic infections like coronaviruses will continue to be a problem in the future as the global population increases and people inhabit areas where coronaviruses are present. Basic biological studies that address virus-host interactions in the context of coronaviruses are necessary for understanding and preparing for the emergence of future epidemics and pandemics. Major components of virus-host interactions are the innate immune defense mechanisms that cells have in place to counteract invading viruses. Type I interferons (IFNs) and the IFN signaling pathway have been studied in the context of multiple viruses and cell types and constitute a continuous source of information about novel antiviral strategies. Towards this direction we have done extensive studies on a subset of genes that are regulated by IFN and are termed interferon-stimulated genes (ISGs). Our work on coronaviruses and the use of innovative CRISPR-based screens identified an ISG that acts as a host-dependency factor in the context of coronaviruses. Here we propose to characterize the mechanism of action of this ISG and determine which cellular pathways affect coronavirus biology. We hope that our proposed work will yield new information about host-virus interactions and will provide insights into coronavirus biology.
Jay Patel, PhD
ASSISTANT PROFESSOR, SCHOOL OF MEDICINE, ORTHOPAEDICS
Harnessing Marrow Stimulation for Enhanced Musculoskeletal Regeneration
Articular cartilage lines the ends of joints and is critical to daily movement and function. Unfortunately, it is frequently injured and poor at self-healing. The most common repair procedure is microfracture (MFx), which involves puncturing the bone under cartilage to recruit “regenerative elements” into the defect site. In fact, this concept of marrow stimulation has been widely adapted to augment the surgical management of a variety of musculoskeletal tissues, including meniscus and rotator cuff. However, MFx typically fails long-term, likely due to the formation of inferior fibrous tissue that cannot withstand the loads of the joint. Interestingly, the cellular and molecular makeup of the early MFx environment is relatively unknown, yet it remains the gold standard of cartilage repair. Moreover, while a host of MFx augmentation approaches using scaffolds or growth factors have shown promise, these approaches fail to address the “fibrous” mechanisms that thwart functional repair. In this URC Grant, we will attempt to define the early drivers of MFx fibrosis using a Yucatan minipig model. Particularly, single cell RNA-sequencing will determine the types and transcriptomic profiles of cells within, which can then be correlated with functional outcomes (e.g., mechanical testing, proteomics). The impact of these biophysical stimuli will also be explored further, in vitro in a fibrin clot system. The proposed work will lay the groundwork for specific therapeutic targets to augment not only MFx, but all marrow stimulation techniques. Improving cartilage formation after MFx by limiting fibrosis provides an avenue to improve long-term cartilage repair.
Sarwish Rafiq, PhD
ASSISTANT PROFESSOR, SCHOOL OF MEDICINE, HEMATOLOGY AND MEDICAL ONCOLOGY
Determining the Mechanisms of VIP Receptor Antagonism by CAR T cells
Chimeric Antigen Receptor (CAR) T cell therapies have shown tremendous success in blood cancers but applying these therapies to solid tumors, particularly pancreatic ductal adenocarcinoma (PDAC), faces significant challenges. PDAC, predicted to be the second leading cause of cancer-related deaths by 2030, presents a tough environment for immune response, hindering CAR T cell effectiveness. To address this, a novel approach involves targeting the Vasoactive Intestinal Peptide (VIP) pathway, an immunosuppressive mechanism prevalent in PDAC.
We have engineered CAR T cells that secrete a novel VIP receptor blocking peptide (termed CAR/VIPRa T cells), to counteract the immune evasion strategies of PDAC. Preliminary studies indicate that CAR/VIPRa T cells exhibit enhanced activation and anti-tumor effects. The proposed project has two key objectives. First, using CRISPR/Cas9 gene-editing technology, we aim to confirm that the improved CAR T cell performance we observe is a direct result of VIP pathway antagonism. Second, we intend to evaluate the anti-tumor efficacy of CAR/VIPRa T cells in a mouse model with an intact immune system, exploring potential effects on non-engineered host T cells.
The project's goals include validating the mechanism behind CAR/VIPRa T cell enhancement and assessing their effectiveness in a preclinical setting. By understanding the intricate interactions within the tumor microenvironment, this research holds promise in advancing CAR T cell therapies for solid tumors, with a particular focus on improving outcomes for PDAC patients.
Hongjie Yuan, MD, PhD
ASSOCIATE PROFESSOR, SCHOOL OF MEDICINE, PHARMACOLOGY AND CHEMICAL BIOLOGY
Disease-associated genetic variations in human GRIN3A gene: from molecular mechanisms to rescue pharmacology
Neurodevelopmental disorders are associated with disabilities in brain function that affect a child’s behavior, memory or ability to learn. Such disabilities carry devastating mental, emotional, and economic consequences for individuals, their families, as well as society. The molecular basis for a subset of disabilities involves disease-causing variants in various ion channel families, which recently have been shown to also include GRIN3A/GluN3A receptors. The cation selective GluN3A channels play important roles in normal brain development and cognition. A large number of genetic variations have been identified in the past years, leading to the view that these variants are present in a subset of patients with various neurological disorders, including epilepsy, autism, ADHD, intellectual disability, movement disorders, language problems, sleep disturbance, bipolar, and schizophrenia. Unfortunately, virtually no systemic functional analysis of these variants exists, confounding a meaningful analysis of clinical phenotype. In this grant application for 1 year of funding, I propose 3 lines of experimentation that address the molecular mechanism underlying the neuropathological conditions that arise from ~40 GRIN3A variants and potential rescue pharmacology. Three aims are proposed
Aim 1. How do human GRIN3A variants impact receptor function?
Aim 2. How does the altered GluN3A function influence synaptic connectivity and glial activation?
Aim 3. Can function-altering GluN3A variants serve as therapeutic targets?
The data obtained from these studies will be used to support an application for extramural support (e.g. an MPI R01 from NINDS) to explore in more detail all human disease-causing GRIN3A variants.