Selected Grantee Publications
Suppression of Viral Rebound by a Rev-Dependent Lentiviral Particle in SIV-Infected Rhesus Macaques
Hetrick et al., Gene Therapy. 2025.
https://pubmed.ncbi.nlm.nih.gov/39025983/
Viral reservoirs are a current major barrier that prevents an effective cure for patients with HIV. Antiretroviral therapy (ART) effectively suppresses viral replication, but ART cessation leads to viral rebound due to the presence of viral reservoirs. Researchers conducted in vivo testing of simian immunodeficiency virus (SIV) Rev-dependent vectors in SIVmac239-infected male and female Indian rhesus macaques, 3–6 years of age, to target viral reservoirs. Treatment with the SIV Rev-dependent vector reduced viral rebound and produced neutralizing antibodies following ART cessation. These results indicate the potential to self-control plasma viremia through a neutralizing antibody-based mechanism elicited by administration of Rev-dependent vectors. This research could guide future studies focused on investigating multiple vector injections and quantifying cell-mediated immune responses. Supported by ORIP (P51OD011104, P40OD028116), NIAID, and NIMH.
Single-Cell Transcriptomics Predict Novel Potential Regulators of Acute Epithelial Restitution in the Ischemia-Injured Intestine
Rose et al., American Journal of Physiology-Gastrointestinal and Liver Physiology. 2025.
https://pubmed.ncbi.nlm.nih.gov/39853303
Following ischemia in the small intestine, early barrier restoration relies on epithelial restitution to reseal the physical barrier and prevent sepsis. Pigs share a similar gastrointestinal anatomy, physiology, and microbiota with humans. Researchers used neonatal and juvenile, 2- to 6-week-old male and female Yorkshire cross pigs to determine upstream regulators of restitution. Single-cell sequencing of ischemia-injured epithelial cells demonstrated two sub-phenotypes of absorptive enterocytes, with one subset presenting a restitution phenotype. Colony-stimulating factor-1 (CSF1) was the only predicted upstream regulator expressed in juvenile jejunum compared with neonatal jejunum. An in vitro scratch wound assay using IPEC-J2 cells showed that BLZ945, a colony-stimulating factor 1 receptor antagonist, inhibited restitution. Ex vivo ischemia-injured neonatal pig jejunum treated with exogenous CSF1 displayed increased barrier function. This study could inform future research focused on developing novel therapeutics for intestinal barrier injury in patients. Supported by ORIP (T32OD011130, K01OD028207), NCATS, NICHD, and NIDDK.
Plural Molecular and Cellular Mechanisms of Pore Domain KCNQ2 Encephalopathy
Abreo et al., eLife. 2025.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11703504
This study investigates the cellular and molecular mechanisms underlying KCNQ2 encephalopathy, a severe type of early-onset epilepsy caused by mutations in the KCNQ2 gene. Researchers describe a case study of a child with a specific KCNQ2 gene mutation, G256W, and found that it disrupts normal brain activity, leading to seizures and developmental impairments. Male and female Kcnq2G256W/+ mice have reduced KCNQ2 protein levels, epilepsy, brain hyperactivity, and premature deaths. As seen in the patient study, ezogabine treatment rescued seizures in mice, suggesting a potential treatment avenue. These findings provide important insights into KCNQ2-related epilepsy and highlight possible therapeutic strategies. Supported by ORIP (U54OD020351, S10OD026804, U54OD030187), NCI, NHLBI, NICHD, NIGMS, NIMH, and NINDS.
Immune Restoration by TIGIT Blockade is Insufficient to Control Chronic SIV Infection
Webb et al., Journal of Virology. 2024.
https://pubmed.ncbi.nlm.nih.gov/38775481/
T-cell exhaustion from prolonged upregulation of immune checkpoint receptors (ICR) contributes to immune dysfunction and viral persistence of both human and simian immunodeficiency virus (HIV/SIV) infection. Previous in vitro research has demonstrated the potential use of ICR blockade as a therapeutic. Researchers used a monoclonal antibody targeting humanized T cell immunoreceptor with Ig and ITIM domain (TIGIT) in male and female cynomolgus macaque and female rhesus macaque SIV models, 4–14 years of age. TIGIT blockade was well tolerated, with moderately increased proliferation of T cells and natural killer cells, but a reduction in plasma viral load was not observed. Future research to eliminate SIV should combine ICR blockades with other immunotherapies. Supported by ORIP (P51OD011092), NIAID, and NIMH.
Immune Gene Regulation Is Associated With Age and Environmental Adversity in a Nonhuman Primate
Watowich et al., Molecular Ecology. 2024.
https://pubmed.ncbi.nlm.nih.gov/39032090
The mammalian aging process involves a decline in physiological function, influenced by molecular mechanisms like epigenetic changes. These processes have been studied in controlled settings, however the role of aging in naturalistic populations remains unclear. This study explored the effects of environmental stressors (i.e., Hurricane Maria) on DNA methylation in free-living male and female rhesus macaques in Cayo Santiago, Puerto Rico. Results showed that environmental adversity accelerated age-related molecular changes, especially in gene transcription regions, while primary aging mainly affected nonregulatory regions. These findings highlight how the biology of aging is influenced by environmental factors. Supported by ORIP (P40OD012217), NIA, and NIMH.
SIV-Specific Antibodies Protect Against Inflammasome-Driven Encephalitis in Untreated Macaques
Castell et al., Cell Reports. 2024.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11552693
Viral infections are the most common infectious cause of encephalitis, and simian immunodeficiency virus (SIV)–infected macaques are a well-established model for HIV. Researchers investigated the protective effects of SIV-specific antibodies against inflammation-driven encephalitis in using untreated, SIV-infected, male and female pigtail and rhesus macaques. Findings indicate that these antibodies reduce neuroinflammation and encephalitis, highlighting the importance of antibodies in controlling neuroimmune responses, especially in the absence of antiretroviral therapy. This study provides insight into immune-modulatory approaches to combating inflammation-driven encephalopathies. Supported by ORIP (U42OD013117, T32OD011089), NIDA, NHLBI, NIAID, NINDS, and NIMH.
Transcriptomic Analysis of Skeletal Muscle Regeneration Across Mouse Lifespan Identifies Altered Stem Cell States
Walter et al., Nature Aging. 2024.
https://pubmed.ncbi.nlm.nih.gov/39578558
Age-related skeletal muscle regeneration dysfunction is poorly understood. Using single-cell transcriptomics and high-resolution spatial transcriptomics, researchers evaluated factors contributing to age-related decline in skeletal muscle regeneration after injury in young, old, and geriatric male and female mice (5, 20, and 26 months old). Eight immune cell types were identified and associated with age-related dynamics and distinct muscle stem cell states specific to old and geriatric tissue. The findings emphasize the role of extrinsic and intrinsic factors, including cellular senescence, in disrupting muscle repair. This study provides a spatial and molecular framework for understanding regenerative decline and cellular heterogeneity in aging skeletal muscle. Supported by ORIP (F30OD032097), NIA, NIAID, NIAMS, NICHD, and NIDA.
Placental Gene Therapy in Nonhuman Primates: A Pilot Study of Maternal, Placental, and Fetal Response to Non-Viral, Polymeric Nanoparticle Delivery of IGF1
Wilson et al., Molecular Human Reproduction. 2024.
https://academic.oup.com/molehr/article/30/11/gaae038/7876288#493719584
This study investigates a novel nanoparticle-mediated gene therapy approach for addressing fetal growth restriction (FGR) in pregnant female nonhuman primates. Using polymer-based nanoparticles delivering a human insulin-like growth factor 1 (IGF1) transgene, the therapy targets the placenta via ultrasound-guided injections. Researchers evaluated maternal, placental, and fetal responses by analyzing tissues, immunomodulatory proteins, and hormones (progesterone and estradiol). Findings highlight the potential of IGF1 nanoparticles to correct placental insufficiency by enhancing fetal growth, providing a groundbreaking advancement for in utero treatments. This research supports further exploration of nonviral gene therapies for improving pregnancy outcomes and combating FGR-related complications. Supported by ORIP (P51OD011106) and NICHD.
The Role of ATP Citrate Lyase in Myelin Formation and Maintenance
Schneider et al., Glia. 2024.
https://pubmed.ncbi.nlm.nih.gov/39318247/
Myelin formation by Schwann cells is critical for peripheral nervous system development and long-term neuronal function. The study examined how acetyl coenzyme A (acetyl-CoA), essential for lipid synthesis in myelin, is derived, with a focus on mitochondrial ATP citrate lysate (ACLY). By using both sexes in a Schwann cell–specific ACLY knockout mouse model, the authors reported that ACLY plays a role in acetyl-CoA supply for myelin maintenance but not myelin formation. ACLY is necessary for sustaining myelin gene expression and preventing nerve injury pathways. This work highlights a unique dependency on mitochondrial acetyl-CoA for Schwann cell integrity, providing insights into lipid metabolism in neuronal repair. Supported by ORIP (T35OD011078), NICHD, and NINDS.
Systematic Multi-trait AAV Capsid Engineering for Efficient Gene Delivery
Eid et al., Nature Communications. 2024.
https://doi.org/10.1038/s41467-024-50555-y
Engineering novel functions into proteins while retaining desired traits is a key challenge for developers of viral vectors, antibodies, and inhibitors of medical and industrial value. In this study, investigators developed Fit4Function, a generalizable machine learning (ML) approach for systematically engineering multi-trait adeno-associated virus (AAV) capsids. Fit4Function was used to generate reproducible screening data from a capsid library that samples the entire manufacturable sequence space. The Fit4Function data were used to train accurate sequence-to-function models, which were combined to develop a library of capsid candidates. Compared to AAV9, top candidates from the Fit4Function capsid library exhibited comparable production yields; more efficient murine liver transduction; up to 1,000-fold greater human hepatocyte transduction; and increased enrichment in a screen for liver transduction in macaques. The Fit4Function strategy enables prediction of peptide-modified AAV capsid traits across species and is a critical step toward assembling an ML atlas that predicts AAV capsid performance across dozens of traits. Supported by ORIP (P51OD011107, U42OD027094), NIDDK, NIMH, and NINDS.