University Of Iowa

NIH Research Projects · FY 2024 · 2022-07

ABSTRACT Smoking is the largest risk factor for both lung cancer and obstructive lung disease. The National Lung Screening Trial (NLST) enrolled subjects who reported a cigarette smoking history of at least 30 pack years and showed that annual low-dose computed tomography (LDCT) screening could reduce mortality from lung cancer by approximately 16%, compared to conventional chest x-ray. However, it remains clinically challenging to efficiently distinguish the small number of malignant nodules from the many benign lung nodules detected with screening. In addition, the chest LDCT data captured during screening also has untapped utility in quantitatively evaluating obstructive lung disease. LDCT captures a wealth of information that can be automatically and objectively quantified and extracted from the image data using computer algorithms. We have methods for automated segmentation of structures of interest from the image data and will extract hundreds of radiological biomarkers focused on pulmonary nodules, peri-nodular lung parenchyma, the whole lung, and capture lobar heterogeneity. This study will also incorporate an objective epigenetic biomarker of smoking history via measurement of DNA methylation at cg05575921. Our epigenetic biomarker has been shown to strongly predict smoking intensity by several studies. We will use the objective radiological and epigenetic biomarkers and machine learning approaches to predict both (1) the risk of lung cancer and (2) rapid obstructive lung disease progression in the NLST screening population. We hypothesize that incorporating DNA methylation at cg05575921 will be a valuable addition to both prediction models. Determining the outcome of the hypothesis will guide if this epigenetic biomarker should be incorporated in prospective lung cancer screening studies. This project will have impact as it will result in an improved automatic risk prediction algorithm to guide management in subjects with a lung nodule detected by LDCT screening. This approach can facilitate rapid treatment for those with cancer and prevent complications from invasive diagnostic testing as well as unnecessary radiation exposure from diagnostic imaging in those with benign lesions. Predicting rapid obstructive lung disease progression may be beneficial for clinician/subject shared decision-making discussions and targeted smoking cessation interventions in addition to improving lung cancer prediction.

NIH Research Projects · FY 2025 · 2022-07

Project Summary Campylobacter jejuni is the leading cause of bacterial-derived gastroenteritis in the world. Human infection often occurs through the ingestion of contaminated food, especially poultry, which leads to the bacterium colonizing the colon and causing severe inflammation and diarrhea. While infection and disease is often self-limiting, persistent colonization and chronic diseases do occur. Despite the significant impacts of C. jejuni on human health, very little is known about the interactions that occur at the host-pathogen interface during infection, including how C. jejuni senses and adapts to the host intestinal environment to promote infection. This is primarily due to the evolutionary divergence of this organism from other gastrointestinal pathogens, which limits the relevance of findings from those organisms and necessitates specific study of the Campylobacter genus. To that end, our group previously identified a unique regulator in C. jejuni, which we call HeuR, that promotes maximum colonization of a natural avian host and was subsequently found to positively or negatively regulate several genetic determinants, including those involved in the acquisition of iron from host heme and the biosynthesis of methionine. In addition, HeuR and its downstream targets are required for efficient invasion or persistence in human colonocytes, which suggests these mechanisms need to be better understood as they are clearly involved in infection of animals. We preliminarily determined that this novel regulator binds several TCA intermediates and may sense TCA cycle activity to control expression of colonization determinants. First, we will define all direct targets of HeuR and examine whether TCA intermediates impact the ability of HeuR to bind those DNA targets and impact gene expression. Additionally, we will identify the ligand binding motif of this novel regulator and how it facilitates HeuR activity. Second, because we have determined that C. jejuni TCA intermediate abundance is affected by iron-restriction, we will use mass isotopomer analysis to identify the points along the C. jejuni TCA cycle that are affected by iron-limitation and determine whether altering TCA cycle activity affects HeuR-dependent colonization determinant expression. In addition, we will directly determine the levels at which each TCA enzyme indicated by mass isotopomer analysis is affected by iron-limitation. Lastly, one of the direct targets of HeuR we identified that may be impacted by TCA intermediate-dependent binding is the heme utilization system of C. jejuni. This system is poorly characterized in C. jejuni and we will examine whether this system facilitates iron acquisition during animal infection and will work to fully characterize the process of heme utilization so that it can be leveraged in future studies to inhibit the infection potential of C. jejuni.

NIH Research Projects · FY 2025 · 2022-07

Enter the text here that is the new abstract information for your application. This section must be no longer than 30 lines of text. The Interdisciplinary Graduate Program in Genetics at the University of Iowa has a 45-year history of training PhD students in Genetics, with 174 graduates in that time. The program currently serves 74 faculty and 42 students in four colleges and 17 academic departments across our campus. Students receive training in rigor and reproducibility and research conduct throughout the span of their educational training. Students align with either the standard curriculum in foundational genetics or elect to pursue the Computational Genetics (CG) subtrack, which trains students in the biological aspects of Genetics and sophisticated computational approaches for the analysis of large sets of genomic and genetic data. Research opportunities in both tracks span the spectrum of Genetics, from bacterial to model organism to human genetics, from developmental genetics to evolution, and from epigenetics and genomics to cell biology and disease mechanisms. Students complete the program equipped for a broad range of careers in contemporary science. Our mission is to develop well-trained Geneticists and Bioinformaticists with the technical, operational, and professional skills necessary to conduct rigorous and reproducible research safely and responsibly, and transition into careers in the biomedical research workforce. We recognize the power of wide perspectives of faculty and students across the breadth of the discipline of genetics. Specifically, we propose to 1) develop and sharpen the skills of our trainees in scientific logic and communication, 2) provide broad technical and operational training across the multiple facets of the genetics discipline, interfacing with many areas of biology, medicine and data science, 3) enhance the program and the field through broad recruitment, retention and training for excellence, and 4) establish a culture of mentorship through mentor training education and activity. The training program will accomplish these goals through a solid core curriculum with additional flexibility to enhance training in specific areas. Trainees will receive integrated training in writing skills, data analysis, rigorous experimental design and critical thinking. They will also develop individual career plans guided by mentors and informed by opportunities to interact with alumni and other experts from a variety of career paths. Through teaching assistantships and opportunities to present their work at the program retreat, regional and national conferences, they will enhance their communication skills, supplemented by formal instruction in these areas. The program will emphasize mentor training for trainers, with mentor training opportunities for trainees. Support is requested for 7 trainees per year, each trainee for 1 or 2 years in years 2 or 3 of their training.

NIH Research Projects · FY 2026 · 2022-07

PROJECT SUMMARY/ABSTRACT Neurodegenerative disorders represent a significant challenge to human health. Many therapeutic strategies revolve around suppressing death of the neuronal cell body. However, neuronal connectivity depends on long projections called axons that use specialized mechanisms to survive in isolation from the soma. The degeneration of axons is a common, sometimes initiating event in a variety of neurodegenerative disorders including Alzheimer’s disease, Parkinson’s disease, and peripheral neuropathies. Protecting axon health is necessary for sustaining functional connectivity and will have broad relevance to many diseases. In the aging nervous system there is a well-documented decline in protein homeostasis and accumulation of protein aggregates that threaten neuronal function. Protein homeostasis is predominantly studied in context of the neuronal cell body. However, axons are also susceptible because protein aggregates interfere with transport and disrupt synaptic function. Polypeptides are most vulnerable to misfolding and aggregation as they exit the ribosome. Axons locally synthesize many proteins needed for survival however there is a gap in knowledge regarding basic mechanisms that protect axons from protein misfolding. This project will determine the capacity of axon segments to resist protein misfolding and aggregation. We will also determine the preferred mechanisms used within axon segments for degrading non-native polypeptides and disposing of aggregates. NAD+ levels decline as we age and this project will identify the consequences local NAD+ depletion on protein homeostasis within the axon compartment. Altogether, this project will generate new insight on local mechanisms controlling axon health and reveal treatment opportunities in neurodegenerative disorders.

NIH Research Projects · FY 2025 · 2022-07

The Pharmacological Sciences Training Program (PSTP) at the University of Iowa seeks to achieve interdisciplinary and integrated training of graduate students in Pharmacological Sciences. The result will be successful PhDs who are well prepared for career and leadership positions in pharmacology in academia, government (e.g. regulatory agencies), pharmaceutical companies, biotechs, research institutes, and science-related fields. In addition to training PhDs well-positioned for career success, our outcomes include publication of first-author and collaborative papers, success in obtaining individual, nationally- competitive fellowships, at or below-average time to degree, and establishing a supportive environment conducive to intellectual growth and scientific development. This program is built upon a foundation of an existing Interdisciplinary T32 in Pharmacological Sciences established in 2004, and we build on elements of this program with new programmatic, evaluation, and curricular plans, which bring greater focus on mentorship, team science, rigorous and reproducible research, and career development. The pool of trainees eligible for this program at the University of Iowa is talented and deep. Drawing from 53 mentor laboratories in 13 degree-granting programs across 3 colleges (Medicine, Pharmacy, Liberal Arts & Sciences), we aim for 6 trainees per year to join our program, each appointed for two years (their 2nd and 3rd years of graduate study) for a total of 12 trainee positions. We request funding of only 9 positions, however, because the three participating colleges have pledged support of one matching position each. Our 6 proposed trainees are selected annually from a large pool of strong applicants (5-year average: 19). This PSTP aims to be a highly effective mechanism for interdisciplinary training in the Pharmacological Sciences regardless of departmental affiliation. Even after financial support ends, trainees remain actively engaged in the PSTP through and past graduation. Our core course sequence, Principles of Pharmacology and Pharmacogenetics & Pharmacogenomics, provides trainees a deep understanding of classical and modern pharmacology. Additional courses are required, such as Advanced Problem Solving in Pharmacological Sciences, in which trainees work as a team to design collaborative research plans, while Basic Biostatistics and Experimental Design, and Mastering Reproducible Science focus on rigor and reproducibility, a theme threaded throughout all activities of the PSTP. Science Communication in the Digital Age and PSTP-organized career workshops are offerings that broaden the development of career skills to better prepare our trainees for the job market. These courses lead to cohort-building for our trainees from different programs, as they progress through classes and program activities together including research retreats, summer brown bag discussion luncheons, as well as semi- weekly interactions during Pharmacology Seminar.

NIH Research Projects · FY 2026 · 2022-06

Individuals with Alzheimer’s disease or related dementias (ADRD) and their families are especially vulnerable during a disaster. Disasters it limit caregivers’ ability to continue with care due to disaster related stress and reduced access to resources and support. The COVID-19 pandemic showed the extreme vulnerability of persons with ADRD and their caregivers as they struggled to access support and resources due to fear associated with COVID-19 infection; such impact was exacerbated in rural areas where caregivers are geographically isolated and disaster management resources are scarce. With the number of federally declared disasters increased dramatically over the past 50 years, active public health efforts are needed to support caregivers develop emergency caregiving plans usable in disasters such pandemics and extreme weather emergencies. The long-term goal of this project is to enhance emergency preparedness and support networks of caregivers of individuals with ADRD to increase their resilience and minimize distress by implementing an intervention program, Disaster PrepWise (DPW). In the DPW program, a trained Medical Reserve Corp (MRC) volunteer will provide step-by-step guidance to caregivers to jointly develop emergency preparedness plans and personal support networks. The objectives for this proposed study are to 1) test the impact of DPW on caregiver outcomes (i.e., resilience, stress) and perceptions that may mediate the association between DPW and outcomes (caregiver self-efficacy, preparedness, social support); and 2) evaluate implementation strategies in a real-world setting to optimize future dissemination. We will conduct a randomized control trial of 200 caregivers of persons with ADRD involving two arms: DPW intervention group and information-only control group (print information on disaster preparedness). Assessments will occur before randomization (baseline), and 3- and 6-month after the baseline. This study is innovative in its use of highly personalized disaster preparedness program with built-in assistance to support caregivers; the support will be provided through an existing national-level public health infrastructure (MRC) that has a great potential to reach older adults and caregivers in rural areas. The knowledge and data obtained through this study will lay the foundation for a future larger-scale multi-state pragmatic trial to assess dissemination potentials.

NIH Research Projects · FY 2026 · 2022-05

Breast cancer (BC) is the most frequently diagnosed malignancy and the second leading cause of cancer mortality in Western women. As is the case for most other solid tumors, metastasis and drug resistance are the main causes of death. In ~80% of BC cases, the PI3K-AKT pathway is aberrantly activated, due to the alterations in genes encoding the pathway components, such as Ras, Her2, PTEN, PIK3C and AKT. This pathway regulates multiple cellular processes to promote BC development, growth, metastasis, and drug resistance. Consequently, over 100 clinical trials are currently underway worldwide to evaluate the therapeutic efficacy of PI3K and AKT inhibitors in BC; however, initial data revealed that inhibition of this pathway is either not effective or often results in development of resistance and relapse of the disease. Thus, identification of additional targets and therapeutic combinations are urgently needed. We previously mapped TRAF2 phosphorylation sites and reported that TRAF2 Ser-11 phosphorylation enhances NF-κB activation to promote cancer cell survival under conditions of cellular stresses. Recently, we discovered that inhibition of AKT in BC cells leads to increased phosphorylation of TRAF2 by TBK1, and that inhibition of both AKT and TBK1 synergistically induces apoptosis in BC cell lines in vitro and significantly suppresses xenograft BC tumor growth in vivo. TBK1 and its close homologue IKKε are serine/threonine kinases overexpressed in 65-70% of BC and play critical roles in BC cell survival mainly by direct phosphorylation of TRAF2 at Ser-11. In cancer cells, TRAF2 constitutively recruits potent E3 ligases cIAP1 and cIAP2 (cIAPs) to RIP1 to catalyze its noncanonical ubiquitination, which is not only essential for NF-κB activation but also for the suppression of RIP1-dependent apoptosis and necroptosis. Through a series of functional assays, we identified a peptide (Tp-14) that blocks TRAF2 interaction with RIP1 and synergizes with AKT inhibition to induce apoptosis in BC cells that overexpress RIP1. Bioinformatic analyses revealed that TRAF2 and RIP1 are overexpressed in invasive BC, and significantly correlate with poor prognosis. Thus, we hypothesize that combined inhibition of AKT and TRAF2 phosphorylation or interaction with RIP1 synergistically induce apoptosis in BC cells that overexpress TRAF2 and RIP1. To test this hypothesis, we propose the following specific aims. Aim-1. Determine the mechanisms of signaling crosstalks between the PI3K-AKT and TBK1-TRAF2 pathways and identify biomarkers that predict BC cell response to combined AKT and TBK1 inhibition. Aim-2. Evaluate the therapeutic efficacy of combined AKT and TBK1 inhibition in BC xenograft models. Aim-3. Determine how blockade of TRAF2 interaction with RIP1 affects BC cell survival in vitro and xenograft tumor growth in vivo. Our proposals will shed new lights on the mechanisms underlying BC cell resistance to AKT inhibition and identify biomarkers for combined inhibition of AKT and TRAF2 phosphorylation or interaction with RIP1 for BC therapy.

NIH Research Projects · FY 2026 · 2022-05

PROJECT SUMMARY / ABSTRACT Asthma and chronic bronchitis are among the top causes of death and hospitalizations worldwide. Chronic airway inflammation in asthma causes goblet cell metaplasia (GCM), mucus hypersecretion, and airway plugging, resulting in respiratory failure and poor quality of life. The mechanism for acquisition and persistence of chronic inflammation is not known. Current anti-inflammatory treatments for asthma can be ineffective and are not curative; chronic GCM resumes upon treatment discontinuation. Therefore, there is an urgent need to understand the mechanisms of chronic inflammation and GCM in asthma. Host genetics and the environment both contribute to asthma; the environment contributes to asthma by inducing immune and airway epithelial epigenetic memory. Basal stem cells in the airway epithelium may acquire epigenetic changes and act as a memory reservoir; as cellular turnover in the lungs occurs, basal cells replenish the epithelium and may propagate inflammatory memory, causing GCM. The importance of airway epithelial epigenetic memory in chronic lung inflammation is an emerging area of research. The central hypothesis of this proposal is that basal stem cells acquire IL-13-induced epigenetic changes and propagate inflammatory memory as they mitotically replenish the epithelium causing GCM and abnormal epithelial function; we plan to address the following aims: Specific Aim 1: Identify mechanisms of IL-13-induced memory in human large and small airway epithelia basal cells using transcriptomic, epigenomic, and clonotype analysis; we will determine the effect of IL-13-induced memory on GCM and function of airway epithelia. Specific Aim 2: Determine epigenetic inflammatory memory in asthmatic nasal airway basal cells obtained non- invasively using nasal brushings and in vitro expansion; this will allow us to determine how memory acquired by basal cells in asthma contribute to GCM, and whether inflammatory memory in asthma is IL-13- driven. Specific Aim 3: Investigate whether epigenetic changes acquired by tracheobronchial airway basal cells in vivo determine response to IL-13 in vitro leveraging a biobank of primary tracheobronchial basal cells developed by the PI; we will determine the epigenetic, transcriptional and phenotypic memory of epithelia highly susceptible to and epithelia resistant to IL-13-induced GCM. We will also determine whether drugs targeting GCM revert epigenetic memory. With the completion of this proposal, we expect to have identified A) novel mechanisms, B) treatment targets, and C) biomarkers and precision medicine strategies in asthmatics and other chronic inflammatory lung diseases. This is a first step to enable curative asthma treatments. We will further the NHLBI’s mission to “translate basic discoveries into clinical practice” and to “enhance the health of all individuals so that they can live longer and more fulfilling lives.”

NIH Research Projects · FY 2025 · 2022-05

ABSTRACT The discovery of induced pluripotent stem cells (iPSCs) provided scientists with the opportunity to develop differentiated tissues from patients with inherited disease, and to use these in vitro models to study disease mechanisms and to test drug and gene-based therapeutics. However, current differentiation protocols often fail to accurately recapitulate the cellular organization present in the native tissue. For example, even state-of-the- art retinal differentiation protocols, which give rise to three dimensional retinal organoids, do not accurately recapitulate the cell-cell interactions that are present in the outer retina. Specifically, choroidal endothelial cells are rarely present and never form an organized layer beneath the RPE. Similarly, rather than forming a monolayer juxtaposed to newly developed photoreceptors, RPE cells are often found in clusters located at the edges of the neural retina. In this application we describe a program focused on the development and validation of a microphysiological system engineered to accurately recreate the complex architecture of the perfused outer retina. Specifically, we propose to combine ultra-high resolution, state-of-the-art 3D printing of retinal scaffolds, iPSC technology, and microfluidics to develop a next generation microphysiological system that recapitulates the outer retina unit. Completion of the aims outlined in this proposal will help pave the way for future studies focused on evaluating the pathophysiology of complex retinal degenerative disorders such as age-related macular degeneration and development of novel drug and gene-based therapeutics.

NIH Research Projects · FY 2025 · 2022-04

Project Summary/Abstract Despite highly effective anti-retroviral therapy (ART), the latent HIV-1 reservoir in resting CD4+ T cells is the major barrier to a functional cure of HIV-1 infection. Our overall objectives of this R61/R33 bi-phasic project are: to understand the mechanisms of post-transcriptional regulation of HIV-1 RNA in HIV-1-infected individuals who are on ART (Exploratory R61 phase), and to develop a novel therapeutic strategy to alter RNA post- transcriptional modifications as a potential therapeutic platform for inhibiting HIV-1 replication (Developmental R33 phase). Our multidisciplinary group is uniquely poised to address several key questions highlighted in this funding opportunity. My lab was among three groups that independently discovered that N6-methyladenosine (m6A) modifications of HIV-1 RNA modulate viral replication in CD4+ T cells in vitro. Using CD4+ T cell lines and primary CD4+ T cells from healthy donors, we investigated the mechanisms by which m6A modifications modulate HIV-1 infection. We also found that m6A modifications of HIV-1 RNA inhibit innate antiviral immune responses in primary macrophages from healthy donors. Our in vitro studies suggested that m6A modifications of HIV-1 RNA play a critical role in viral replication and innate immune responses to viral infection. However, the role of m6A modifications of HIV-1 RNA in regulating viral replication in HIV-1-infected individuals on ART remains unknown. We aim to fill this important knowledge gap and to translate the findings into potential anti- HIV-1 therapeutics. We hypothesize that m6A modifications of HIV-1 RNA help establish and maintain viral latency in CD4+ T cells and avoid innate antiviral immune responses in HIV-1 infected individuals on ART. To test this hypothesis and to facilitate the development of a novel strategy for HIV-1 cure, we designed three specific aims in two phases: (1) R61 phase (years 1-3): Aim 1. To determine m6A profile of HIV-1 RNA in subsets of CD4+ T cells from ART- treated patients; Aim 2. To identify cellular targets in the m6A pathway important for HIV-1 reactivation in primary CD4+ T cells; and (2) R33 phase (years 4-5): Aim 3. To examine anti-HIV-1 effects of small molecules inhibiting m6A modifications in primary CD4+ T cells. Overall Impact: These studies will reveal how m6A modifications of HIV-1 RNA regulate viral latency in ART- treated patients. The studies in the R61 phase will define new mechanisms of HIV-1 persistence and identify potential therapeutic targets. The R33 phase study will develop an m6A-specific strategy to inhibit HIV-1 replication in primary CD4+ T cells.

NIH Research Projects · FY 2025 · 2022-04

PROJECT SUMMARY Our lungs are continually exposed to bacteria, viruses, and toxic particles, often complicating common pulmonary disorders such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF). To protect the lungs from these challenges, mammals have evolved multiple innate airway defenses that include mucus production, antimicrobial factor secretion, and mucociliary transport (MCT). Both airway submucosal glands (SMG) and surface epithelia contribute to this first line of lung defense. However, the relative importance of their contributions or the interplay between these contributions is not well understood. Furthermore, these defenses depend on maintaining optimal pH and airway surface liquid (ASL) volume. Based on the abundance of SMG and their products, it has been hypothesized that SMG play a critical role in host defense. But that hypothesis has gone untested. We also do not know whether SMG serve host defense under basal conditions or only when they are stimulated to secrete by an airway challenge. Before we can develop novel therapeutic approaches for devastating lung diseases, we must: a) determine the contribution of airway surface epithelia and SMG to airway host defense and b) understand how pH and ASL volume regulate MCT and antimicrobial activity. In this proposal, we focus on the interplay of SMG and surface epithelia. We study pigs because they have airways and SMG like those in humans. We disrupted a gene (EDA) necessary for SMG development. Newborn EDA-KO pigs lack airway SMG, have disrupted MCT, and impaired bacterial killing. Because EDA-KO pigs lack SMG, they provide the exciting opportunity to test our overarching hypothesis that SMG are required for normal airway host defense and that their loss will lead to airway disease. We will test our hypothesis by investigating the following Specific Aims: Aim 1. What is the role of submucosal glands in ASL pH and volume regulation in the airway? Aim 2. How do submucosal glands contribute to large and small airway mucociliary transport? Aim 3. Does decreased antimicrobial peptide- mediated bacterial killing, due to lack of SMG, cause lung disease? Comparing pigs with and without SMG will provide the first direct evidence about whether and how SMG are required for respiratory host defense. The results will also lay a critical foundation for future tests of how SMG contribute to airway disease pathophysiology. Finally, increased scientific knowledge of SMG and interactions between surface epithelia/SMG will provide a better foundation for understanding how ASL is regulated, how MCT is controlled, and ultimately identify desperately needed new targets for lung diseases.

NIH Research Projects · FY 2026 · 2022-04

Neurodegenerative disorders represent a significant challenge to human health. Many therapeutic strategies revolve around suppressing death of the neuronal cell body. However, neuronal connectivity depends on long projections called axons that use specialized mechanisms to survive in isolation from the soma. The degeneration of axons is a common, sometimes initiating event in a variety of neurodegenerative disorders including Alzheimer’s disease, Parkinson’s disease, and peripheral neuropathies. Protecting axon health is necessary for sustaining functional connectivity and will have broad relevance to many diseases. Disease onset and severity can vary significantly between patients suggesting there are important, undiscovered factors that influence axon vulnerability to pathological degeneration. The goal of this project is to define novel pathways controlling the fate of a damaged axon. Axon injury stimulates a local self-destruct mechanism that promotes axon dismantling and clearance by the immune system. The enzymes NMNAT2 and SARM1 represent a critical regulatory node in this self-destruction program. Boosting NMNAT2 is neuroprotective and has therapeutic potential. We will define a new mechanism controlling NMNAT2 abundance in axon segments. We will also identify new contributions for autophagy in axon susceptibility and stress signaling. These studies will generate new insight on local mechanisms controlling axon health and reveal new treatment opportunities in neurodegenerative diseases.

NIH Research Projects · FY 2026 · 2022-04

Mechanisms of voltage regulation of membrane transport SLC9 family of membrane transporters couple the import of sodium ions to export of protons. They are vital for regulation of cytoplasmic and endosomal pH, which in turn affect several physiological processes. Their disfunction has been linked to many diseases such as diabetes, hypertension, heart failure and cancer. Genetic mutations in specific SLC9 members have also been associated with Angelman-syndrome like disorders, ADHD, familial autism, epilepsies and male infertility. The SLC9C1 is a unique member of the SLC9 family. Unlike other SLC9s which feature a membrane delimited sodium-hydrogen exchange (NHE) domain and a usually short and relatively unstructured C-terminal soluble domain, SLC9C1 combines an NHE, a voltage-sensing domain (VSD) and a cyclic nucleotide binding domain (CNBD), interconnected via long, structured linkers, in a single polypeptide. Recent foundational experiments have revealed that membrane hyperpolarization and binding of cyclic nucleotides potentiates ion transport via SLC9C1. Its unique design makes it impossible to predict how voltage and ligand regulation of this protein is manifested at a structural level. SLC9C1 exhibits sperm-specific expression and has been shown to be critical for sperm motility in mouse and humans. Sperm motility is robustly modulated by changes in membrane voltage, intracellular cAMP levels and pH and all these stimuli influence SLC9C1 mediated ion exchange directly, making it vital to understand the molecular underpinnings of such diverse regulation. To this end, in this proposal we will integrate single- particle cryo-electron microscopy and reconstruction techniques with biochemical and electrophysiological methods to explore key biophysical mechanisms of SLC9C1. In Aim 1, we will determine the first high-resolution structure of SLC9C1 and identify the key interactions governing its organization. In Aim 2, we will elucidate the structural rearrangements in SLC9C1 triggered by cyclic nucleotide binding and use electrophysiology to test the role of a key interface in mediating the regulatory effects of the CNBD. In Aim 3, we will determine how pH and permeant ions affect the structure and function of SLC9C1. The proposal has a strong scientific foundation built on our rigorous preliminary studies. It is innovative as it will provide the first snapshots of a novel membrane protein in different conformations and test provocative hypotheses on the mechanisms of voltage and cyclic nucleotide regulation of a transporter. The insights obtained from our studies will aid structure-based drug design for treatment of male infertility. It will also have broad implications on the structural and functional mechanisms of SLC9 regulation by their cytoplasmic domains further underscoring its importance for human health.

NIH Research Projects · FY 2026 · 2022-04

PROJECT SUMMARY Acute Ischemic stroke (AIS) remains the leading cause of disability in the US. Large vessel occlusion (LVO) represents up to 20% of all ischemic strokes, but causes 90% of stroke-related death and severe disability. Both intravenous thrombolysis (IVT) and endovascular therapy (EVT) are effective time-sensitive treatments to prevent stroke-related morbidity and mortality. EVT is highly effective for LVOs, does not provide any benefit in non-LVO strokes and is available in less than 20% of US stroke centers. IVT is readily available, has a modest effect for LVOs and is the only therapeutic alternative for non-LVO strokes. The challenge for paramedics is to expedite EVT for eligible patients without harming a large proportion of non-qualified patients in need of IVT, in the context of initial diagnostic uncertainty. The current system triage criteria have lagged behind emerging therapies available to the sickest subset, and the disparity in stroke outcomes is exacerbated in rural areas and for ethnic minorities. Herein, we propose a study to foster the development of an innovative geospatial triage algorithm of stroke care in the U.S. health system through a multidisciplinary collaboration to maximize neurological recovery to all stroke patients. The model will be constructed to provide optimal predicted outcomes for individual patients, using a Bayesian framework to inform each link of the treatment decision tree, building on prior studies while overcoming their limitations and closing the implementation gap. First, the patient outcome model will be built using individual and hospital level data randomized trials, which will enable a context sensitive triage decision algorithm without reliance on overbroad assumptions about the treatment pathway. We will uniquely incorporate uncertainty through modelling of individual level data in a Bayesian framework, rather than relying on point estimates at an aggregate level. Additionally, our model will be adaptable; we will be able to incorporate emerging LVO diagnostic tools with improved diagnostic accuracy, as well as new therapeutic strategies as the stroke field evolves. Furthermore, the conditional structure will allow the modification of facility capabilities, including the introduction of new EVT-capable stroke centers. The clinical and cost-benefit algorithm impact will be assessed by comparing with the current real-world triage by incorporating local stroke center and EVT-capable center data on stroke flow metrics from Get-With-The Guidelines-Stroke registry to better estimate the probability of good outcomes and improve triage capabilities. Finally, the triage algorithm will be integrated into a point-of-care decision tool support readily available for all EMS to recommend the optimal destination for all the entire stroke population after their initial assessment. After appropriate refinement and adequate implementation in subsequent studies, this tool will not only have the potential to optimize stroke outcomes, but also reduce the actual geographic and racial disparities in the U.S.

NIH Research Projects · FY 2026 · 2022-03

All eukaryotic cells produce and respond to prostaglandin (PG) signaling. PGs are lipid signaling molecules that have a wide range of functions from inflammation to fertility to wound healing. Imbalances in PG signaling underly many diseases, such as birth defects, cardiovascular disease, and cancer. PGs have such wide effects because there are 5 types of PGs, and each activates multiple signaling cascades. All PGs are produced by a multistep process that requires cyclooxygenase (COX) enzymes. COX enzymes are the targets of the commonly used non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin and ibuprofen. Thus, NSAIDs block all PG synthesis and signaling. To develop more specific therapies and to better understand the functions of PGs, it is essential to uncover the cellular roles of PG signaling. One understudied cellular function of PGs is to regulate actin remodeling to promote collective cell migration. While over 50,000 studies have uncovered critical regulators of cell migration, less than 60 studies have focused on the roles of PGs in this process. Thus, how PGs regulate actin remodeling and migration remains elusive. The roles of individual PG signaling pathways, and whether they act in the migratory cells or their substrate to coordinate cell migration are poorly understood. Further, the specific actin regulators that are the downstream effectors of PG signaling, and how they are modulated, are largely unknown. To overcome these knowledge gaps, we take advantage of the robust system of Drosophila and the in vivo, collective migration of the border cells during oogenesis. In the last five years, we found that PG synthesis in the border cells promotes on-time migration, whereas PG synthesis in the substrate controls border cell cluster cohesion. We identified that one downstream target of PGs in both the border cells and their substrate is Fascin. In addition to bundling actin, we found Fascin regulates the transmission of force to the nucleus by promoting the activity of the Linker of the Nucleoskeleton and Cytoskeleton (LINC) Complex, and the transmission of force between cells by inhibiting myosin. Using genetic, cellular, biochemical, and biophysical approaches, the proposed studies are expected to build a new paradigm for how PG signaling, and its effects on Fascin, coordinate the behaviors of migrating cells and their cellular substrates to promote collective cell migration. We propose to address: 1) Which PG signaling cascades act in the migratory cells versus their substrate to regulate collective cell migration? 2) How does PG signaling regulate Fascin? 3) What is the role of PG signaling in LINC Complex-mediated mechanotransduction during migration? 4) How does PG signaling control the balance of forces between the migratory cells and their substrate during collective cell migration? Through this work, we expect to fundamentally advance our mechanistic understanding of how multiple PG signaling pathways and Fascin mediate force transmission both inside cells to control nuclear dynamics and within tissues to control collective migration. This increased understanding can be applied to develop novel therapeutics to prevent/treat birth defects, wound healing complications, and cancer metastasis.

NIH Research Projects · FY 2026 · 2022-03

Iowa Summer Institute for Research Education in Biostatistics (ISIB) The central goal of this research education program is to expand the pool of future biostatisticians by targeting quantitatively skilled undergraduates who are less likely to have access to structured quantitative research experiences in biostatistics. We will recruit a cohort of 20 trainees each year with a focus on students from small liberal arts colleges and institutions that would not have otherwise been exposed to the field of biostatistics, for a 7-week research education program. Participation from all demographics is encouraged. Recruitment targets rising seniors from colleges and universities without graduate programs or an extensive undergraduate education in statistics or biostatistics, graduating senior students with no commitment to a graduate program six months following ISIB, highly promising juniors with a clear vision to pursue graduate degrees in biostatistics, some graduate students with a desire to pursue a second master’s or a PhD in Biostatistics, and a few medical students with the goal to pursue a MD/PhD research track in Biostatistics. The curriculum is a four-component model based on instruction; application; exposure; and research. The research education program is through case-based instruction of real biomedical study, consisting of classroom didactic courses; computer laboratory training; invited talk sessions; Zoom sessions; shadowing sessions; and clinical and translational research enrichment. As initiation to quantitative biomedical research, trainees undertake biostatistics-faculty-mentored projects on biomedical research. Students select from a pool of projects according to their interest, and are matched to a faculty mentor. Projects are based on the analysis of biomedical data, and/or the design of a biomedical experiment, and/or the statistical and computational issues associated with big data and artificial intelligence. The research teams present their research findings at the program’s concluding symposium. Trainees interact with biostatisticians in academia, industry, the pharmaceutical industry; biomedical researchers; biostatistics graduate students; biostatistics alumni and others. Guidance on how to successfully prepare for a GRE, how to prepare a successful admission application and how to apply to graduate schools is also provided.

NIH Research Projects · FY 2026 · 2022-03

Summary/Abstract Malignant peripheral nerve sheath tumors (MPNSTs) are the leading cause of death in patients with neurofibromatosis-1 (NF1). MPNSTs arise in NF1 patients from benign plexiform neurofibromas (PNFs) but it is unclear why only ~30% of PNFs transform into MPNSTs. Recent studies suggest that inactivation of the INK4a/ARF/INK4b locus (called CDKN2A for INK4a and ARF; CDKN2B for INK4b) generates a pre-malignant lesion called an atypical neurofibromatous neoplasm of uncertain biology (ANNUBP). ANNUBPs are the newly recognized precursor to MPNSTs, but mechanisms that drive and classify this transitional intermediate are poorly defined. INK4a/ARF/INK4b disruption is the main alteration currently linked to ANNUBPs, besides NF1 loss and RABL6A upregulation. In MPNSTs, the locus is altered at one, two or all three genes, with worse patient survival associated with loss of all three. Each gene (INK4a, ARF, and INK4b) encodes a tumor suppressor, but their separate contributions and cooperativity with other factors in driving cancer remain incompletely understood. Given their prominent role, a better understanding of INK4a, ARF, and INK4b in MPNST development is needed, as drugs targeting the locus are either approved or showing promise in other cancers. Our central hypothesis is p16Ink4a, ARF and p15Ink4b act cooperatively in multiple pathways to suppress the transformation of benign PNFs and ANNUBPs to MPNSTs. Aim 1 will define significant genetic and proteomic events coinciding with INK4a, ARF and INK4b inactivation in human ANNUBPs and MPNSTs by genetic, molecular and histologic analyses. Results will be correlated to clinical variables such as survival. The prognostic value of a newly developed liquid biopsy assay evaluating locus status and other tumor markers will be determined in NF1 patients. Aim 2 employs CRISPR editing of p16Ink4a, ARF and/or p15Ink4b in human PNF-derived cells to determine their roles in PNF-ANNUBP-MPNST transformation. Directed analyses of suspected MPNST driver genes in cells and mouse models will identify genes that selectively cooperate with INK4a, ARF, or INK4b loss to drive ANNUBP-MPNST transformation in vitro and in vivo. Aim 3 establishes the biological significance of drugs targeting Ink4a/Arf/Ink4b relevant pathways in PNF-ANNUBP-MPNST therapy and prevention. Predicted mediators of acquired resistance to therapy will be verified using molecular and pharmacologic approaches. Studies will determine the value of targeted therapy against pre-MPNST models to prevent malignant progression. Impact: Studies will provide new insights into INK4a/ARF/INK4b, one of the most frequently inactivated loci in human cancers. Innovative animal models of PNF-ANNUBP-MPNST progression will be generated and mechanisms of transformation leading to MPNST will be defined. Preclinical studies will assess a new combination therapy targeting Ink4a/Arf/Ink4b pathways in preventing malignant progression. Results will advance our understanding of events driving MPNST development, facilitating earlier diagnosis and pre-emptive interventions targeting ANNUBPs.

NIH Research Projects · FY 2026 · 2022-02

Project Summary Infection with severe acute respiratory syndrome novel corona virus (SARS-CoV-2) causes COVID-19. In severe cases, COVID-19 leads to profound inflammation (“cytokine storm”) followed by coagulopathy and a prothrombotic-state with progression to multiple organ failure. Several cytokines, including IL6 are elevated. Further, a proinflammatory galectin, Galectin-3 (Gal-3) is also found elevated. Gal-3 upregulates IL6 and other cytokines, can directly activate platelets, neutrophils, and endothelial cells, and is known to mediate venous thrombosis via IL6 in a mouse model. A growing body of literature has implicated neutrophil, platelet and endothelial cell activation as potential drivers of thrombotic complications in COVID-19 patients. However, there are no direct mechanistic links established between inflammation, vascular cell activation, and thrombosis during SARS-CoV-2 infection. Our objective is to define the mediators that cause activation of neutrophils, platelets and/or endothelial cells during SARS-CoV-2 infection and their mechanistic roles in promoting thrombin generation and thrombosis. At the University of Iowa, we led a multicenter randomized clinical trial (RCT) comparing standard prophylactic dose to intermediate dose enoxaparin in hospitalized patients with COVID-19 (NCT04360824) and collected plasma samples for biomarkers and mechanistic studies. Given the upsurge in late thrombotic complications of COVID-19, we now propose to recruit additional patients to collect serial samples every week during hospitalization and thereafter every 3 months for up to 3 years. We hypothesize that thrombogenicity in COVID-19 is mediated by IL6- and Gal-3-driven activation of hematopoietic and endothelial cells and that the prothrombotic state persists even after recovery from viral infection. Our team has a unique combination of expertise and resources that will address the hypothesis in 2 well integrated but independent aims. In Aim 1, using serially collected patient’s samples, we will determine the mechanistic role of IL6, Gal-3, and NETs in mediating cellular activation and enhancing thrombin generation and thrombosis in COVID-19. Aim 2 will utilize a novel transgenic mouse model of SARS-CoV-2 infection to determine if targeting IL6, Gal-3, or NETs in vivo protects against cellular activation, thrombin generation and thrombosis. A strength of this proposal is in utilizing clinical samples and a novel preclinical model to identify critical mechanistic pathways for cellular activation, thrombin generation and in vivo thrombosis in COVID-19. Thus, the overall impact of the proposed research agenda is very high and is likely to provide therapeutic targets for decreasing thrombotic burden in COVID-19.

NIH Research Projects · FY 2025 · 2022-02

Peripheral neuropathy, the most prevalent chronic complication of diabetes may affect up to 50% of patients and critically contributes to increased pain and risk of amputations, lower physical functioning, increased daily living burden, reduced quality of life, increased health care costs, and high mortality risk. Although intensive glucose control was shown to delay the onset and progression of diabetic peripheral neuropathy (DPN) in patients with type 1 diabetes, similar evidence is not available for the very vast majority of patients who have type 2 diabetes (T2D). In spite of continuous research a disease modifying therapy to reverse human DPN is still not available. Work in our laboratories has provided evidence that omega-3 polyunsaturated fatty acids (PUFA) found in fish oil in combination with salsalate may be an effective treatment for DPN. Our pre-clinical studies have shown that fish oil and salsalate slows progression of DPN and initiates nerve damage repair and reverses DPN . We have also demonstrated that E and D series resolvins, metabolites of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively, reverses DPN to a similar extent as fish oil. These data provides the rationale to advance the fish oil-salsalate combination to DPN clinical trials. The studies proposed in this application are the first step in this endeavor. Using participants with T2D and DPN we will initially establish the most efficient dose of fish oil that will increase the omega-3 index (defined as the sum of EPA and DHA, as a percentage of total fatty acids in red blood cells) to at least 8 – 12% presumed to be therapeutic. Next, we will combine fish oil and salsalate to examine their effect on the production of pro-resolving metabolites derived from EPA and DHA. We hypothesize that fish oil in a concentration dependent manner will increase the omega-3 index to therapeutic levels independent of salsalate. We also hypothesize that combining fish oil and salsalate vs. fish oil alone will more effectively increase the circulating pro-resolving mediators of omega-3 PUFA and reduce markers of inflammation to a greater extent than fish oil alone. The lipidomics of omega-3 PUFA in human subjects has been understudied and not at all in subjects with diabetes and DPN. Limited studies in normal human subjects taking fish oil have demonstrated considerable variability in circulating levels of omega-3 PUFA and this variability could have an impact on their metabolic fate. The studies proposed will address this limitation and guide us in selecting the most effective and safe combination dose of fish oil and salsalate for increasing the omega-3 index to a therapeutic level and maximize production of pro-resolving lipid mediators. This will lead to design of a disease modifying trial for DPN, with the potential to improve the quality of life for all patients with diabetes. The excellent safety profiles of fish oil and salsalate make them an attractive choice for long-term clinical use.

NIH Research Projects · FY 2026 · 2022-02

SUMMARY Herpesvirus assembly is critically dependent on specific interactions between viral proteins. In nuclear egress, the NEC heterodimer, consisting of pUL31 and pUL34, performs multiple functions and interacts with multiple other viral factors. In many cases, however, the mechanistic consequence and significance of those interactions is unknown. Similarly, cytoplasmic envelopment depends upon interactions made by a few essential tegument proteins (VP16, pUL36 and pUL37 in HSV-1), but which of their interactions (other than with each other) are important for this process is unknown despite a wide array of interaction partners identified by proteomic and other approaches. Here we propose to use a novel directed evolution approach for functional identification of crucial interactions. We replace an essential HSV gene with its homolog from VZV and then perform a growth selection for viruses that can use the VZV homolog for assembly. Mapping of the mutations that have occurred during this directed evolution can identify novel functional interactions and establish the significance of others. We present preliminary data showing the utility of this approach using a chimeric virus in which HSV-1 UL34 is replaced by VZV ORF24. We have identified a novel functional interaction with HSV-1 ICP4 and validated the significance of a previously reported interaction with ICP22. We propose to determine the mechanism of action of these critical interactions and use the system to identify others. In addition, we propose to expand the use of this system another gene target relevant to nuclear egress, pUL31.

NIH Research Projects · FY 2026 · 2022-01

Malaria, caused by Plasmodium species, is an unresolved global health burden. Although insecticide treated bed nets and antimalarial drugs have reduced the incidence and severity of malaria in some regions, >200,000,000 cases still occur annually with >400,000 fatalities, most of which occur in young children in sub-Saharan Africa. Thus, effective vaccines remain an as yet unrealized but critical goal to combat the global threat of malaria. However, development of potent and translatable vaccines against malaria has been hampered by our incomplete understanding of the mechanisms by which the immune system can be trained to control Plasmodium infections. We have been studying CD8 T cell immunity to liver-stage (LS) malaria for ~13 years. During this time, we studied immunity against whole parasite immunizations (RAS and late-arresting GAP) and studied epitope-specific prime-boost immunization strategies that were capable of generating sterilizing immunity to sporozoite challenge in mice. A major finding from the latter studies was that sterilizing immunity occurred when the immunization generated circulating malaria-specific memory CD8 T cells (hereon called Tcircm) that exceeded a large, but definable frequency. We also showed that large numbers of epitope-specific CD8 T cells were present in the livers of immunized mice. In contrast, studies from our group and others showed that sterilizing RAS immunization generated relatively small Tcircm responses, although these responses were enriched in the liver. This apparent conundrum was recently explained by the discovery that RAS immunization generates a very potent liver CD8 T resident memory population (from here, called liver Trm) that is essential for sterilizing immunity in this vaccination model. Trm, occupy many tissues and play important roles in tissue specific immunity. These findings have galvanized the malaria field to focus on novel immunization strategies to generate Trm to improve LS vaccines. While the importance of liver Trm in RAS vaccine induced protection from Plasmodium cannot be overstated, it remains unclear to what degree, if any, Tcircm contribute to protection against LS infection. Here, in unpublished preliminary data, we provide evidence that Tcircm can indeed provide protective immunity against LS Plasmodium infection using an as yet undefined mechanism for rapid recruitment to the liver. The long-term goals of this proposal are to dissect mechanisms leading to generation and function of memory CD8 T cells that can provide potent immunity to Plasmodium LS infection in order to inform development of human vaccines. We will address these goals with the following Specific Aims: SA 1. Determine the mechanisms underlying rapid recruitment of Tcircm to the liver SA 2. Dissect the mechanisms of liver-stage protection by Tcircm SA 3. Determine if and how Tcircm cooperate with Trm in control of liver-stage malaria

NIH Research Projects · FY 2026 · 2022-01

ABSTRACT Age-related macular degeneration (AMD) is a common cause of severe vision loss. Recent studies have shown that a layer of capillaries called the choriocapillaris is affected in AMD, both in “dry” AMD in which the blood vessels degenerate, depriving the retina of nourishment, and in “wet” AMD in which the cells become activated to grow abnormally, damaging the retina. To a large extent the biochemical changes in the choriocapillaris that accompany AMD are poorly understood. In this proposal we will study how a gene that is affected by the complement system and is enriched in AMD cells contributes to the processes associated with the choriocapillaris in AMD. We will also utilize a new technology (single cell RNA-sequencing) to discover the molecular signatures of endothelial cells from the choroid at the single cell level of resolution in health and different forms of AMD. A better understanding of how these cells are altered in disease will provide insight into how to protect them from damage and death.

NIH Research Projects · FY 2026 · 2021-12

Project Summary/Abstract Epilepsy is a common neurological disorder that affects approximately 70 mln people. For many patients, epilepsy can be controlled through pharmaceutical therapies; however, approximately 30% of patients develop refractory epilepsy that cannot be controlled with current pharmaceutical interventions. Refractory epilepsy is associated with a high risk for sudden unexpected death in epilepsy (SUDEP), which is the leading cause of death in this patient population. In addition, uncontrolled epilepsy and frequent seizures are associated with progressive cognitive decline, as well as significant behavioral and psychiatric comorbidities. Thus, it is of paramount importance to identify novel critical therapeutic targets for patients with refractory epilepsy. The main objective of this proposal is to establish the role of the mitochondrial Ca2+ uniporter (MCU) in regulating synaptic function, neural network activity and seizure susceptibility. MCU is the core component of the mitochondrial Ca2+ uptake complex and is involved in the regulation of Ca2+ signaling, bioenergetics and cell death. Our focus on MCU is inspired by several novel observations we made during our pilot studies. First, we found that MCU knockout (KO) produces robust anticonvulsant effects both in vivo and in vitro. Second, deleting MCU specifically in GABAergic, but not in glutamatergic, neurons was sufficient to produce an anticonvulsant effect. Third, MCU deletion enhanced GABAergic synaptic transmission, but did not alter glutamatergic transmission or intrinsic neuronal excitability. Fourth, MCU deletion protected neurons from glutamate-induced Ca2+ deregulation and toxicity. The latter is important because excitotoxicity contributes significantly to neuronal damage in epilepsy. Collectively, these data suggest that inhibiting MCU would provide a dual benefit in the context of epilepsy, first by increasing seizure threshold, and second, by protecting neurons from excitotoxicity associated with seizures. We hypothesize that MCU plays an important role in regulating GABAergic synaptic transmission and neural activity, and that MCU deletion produces anticonvulsant effects by enhancing GABAergic synaptic transmission and preventing neural network hyperexcitability. We also hypothesize that MCU deletion provides protection from neurotoxicity associated with seizures. These central hypotheses will be tested in 3 specific aims. Aim 1 will establish the roles of GABAergic and glutamatergic neurons in the anticonvulsant effect of MCU deletion. Aim 2 will determine the role of MCU at inhibitory and excitatory central synapses. Aim 3 will determine the role of MCU in epilepsy-induced neuronal toxicity. The proposed studies will provide mechanistic insight into a previously unrecognized role of mitochondrial Ca2+ transport in regulating the activities of synaptic networks and susceptibility to hyperexcitability and seizures, and could lead to development of new strategies targeting mitochondrial Ca2+ transport and MCU for the treatment of epilepsy as well as other neurological disorders associated with aberrant neural activity.

NIH Research Projects · FY 2026 · 2021-12

ABSTRACT Sleep apnea is a common and underdiagnosed syndrome that impacts at least 4% of American adults and is associated with heart disease, stroke, diabetes, and cancer mortality. In patients with sleep apnea, arterial oxygen saturation intermittently falls. Cyclic episodes are typically followed by rapid re-oxygenation. This cycle occurs as often as 60 times per hour, resulting in chronic intermittent hypoxia (CIH), a dynamic physiology that is distinct from static hypoxia. Our lab is pioneering the study of CIH’s effects on the bone marrow, immunity, and the development of hematological malignancies and we now propose the critical studies necessary to translate our work to human patients. We propose that CIH can cause resistance to chemotherapy by increasing the abundance of tumor-associated macrophages (TAMs). In this proposal, we aim: Aim 1: Test the hypothesis that severity of nighttime chronic intermittent hypoxia promotes TAMs burden Aim 2: Test the hypothesis that continuous positive airway pressure (CPAP) treatment modulates the abundance and gene expression of CD163+ CD206+ macrophages, and Aim 3: Test the hypothesis that chronic intermittent hypoxia decreases the probability of complete remission in newly diagnosed myeloma. By the end of the project period, we will have established that CIH has a clinically meaningful impact on the bone marrow, we will have performed the first deep characterization of TAMs in the context of CIH, and we will have determined the degree to which CIH severity is linked to poor response to chemotherapy.

NIH Research Projects · FY 2025 · 2021-09

ABSTRACT There is currently a lack of mechanistic understanding of why humoral immunity against malaria is not efficiently induced and why Plasmodium infections are associated immune failures, even following repeated infections. Our long-term goal is to determine how Plasmodium parasites, and potentially other protozoan infections, co-opt and subvert humoral immunity, which will help with the identification and development of new immune-based interventions against devastating diseases like malaria. The objectives of this project are to define mechanisms that trigger initial humoral immune dysregulation and study the consequences of these events on the formation of durable humoral immune memory. Our central hypothesis is that robust humoral immunity does not develop efficiently because polyclonal B cell activation events establish a nutrient sink that impairs the metabolic, transcriptional and epigenetic programming and function of Plasmodium-specific memory B cells. The rationale for this project is linked to our recent discovery that Plasmodium infection results in a massive polyclonal expansion of B cells that function as a nutrient sink that limits protective memory B cell responses. Deletion of these B cells accelerates blood-stage Plasmodium parasite clearance and enhances humoral immune memory. Supplementing the diet of infected mice with a single amino acid is sufficient to overcome the nutrient sink and metabolic constraints imposed by these B cells and results in enhanced humoral immune memory responses. Despite our new findings, the molecular mechanisms governing the activation and function of immunoinhibitory B cells and the impact of these cells on the affinity and longevity of memory B cells remain critical knowledge gaps in our quest to improve humoral immunity against malaria. Two Aims address these priority questions. In the first Aim we will determine the molecular and cellular mechanisms that govern the expansion of these immunosuppressive B cells and investigate whether these populations are relevant to other infections associated with dysregulated humoral immunity. In the second Aim we will investigate the molecular and cellular consequences of immunosuppressive B cell expansions on the genetic and epigenetic programming of memory B cells. We have developed several innovative new reagents that afford unprecedented resolution for the study anti-malarial humoral immunity. The significance of this project is directly linked to our new findings showing that pathophysiological changes that occur during Plasmodium infection durably imprints on B cell fate and function. Thus, determining how these pathways coordinately regulate polyclonal B cell activation, development and humoral immunity will be broadly important to those studying infectious disease immunology and vaccinology.