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.
Functional Differences Between Rodent and Human PD-1 Linked to Evolutionary Divergence
Masubuchi et al., Science Immunology. 2025.
https://pubmed.ncbi.nlm.nih.gov/39752535/
Programmed cell death protein 1 (PD-1), an immune checkpoint receptor, regulates immunity against cancer. Rodent models (e.g., mice) do not exhibit the same response rates and immune-related adverse effects to PD-1 blocking drugs as patients with cancer. Only 59.6% amino acid sequence identity is conserved in human PD-1 (hu PD-1) and mouse PD-1 (mo PD-1). Researchers used mouse tumor models, coculture assays, and biophysical assays to determine key functional and biochemical differences between hu PD-1 and mo PD-1. HuPD-1 demonstrates stronger suppressive activity of interleukin-2 secretion and CD69 expression than mo PD-1 because of the ectodomain and intracellular domain, but not the transmembrane domain. Analysis of rodent evolution demonstrated that other inhibitory immunoreceptors were positively selected or had selection intensification over PD-1. Understanding the conservation and divergence of PD-1 signaling at the molecular level in humans compared with mice is needed to properly translate preclinical data to clinical therapeutics. Supported by ORIP (S10OD026929), NCI, and NIA.
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.
Matrikine Stimulation of Equine Synovial Fibroblasts and Chondrocytes Results in an In Vitro Osteoarthritis Phenotype
Gagliardi et al., Journal of Orthopaedic Research. 2025.
https://pubmed.ncbi.nlm.nih.gov/39486895
Advancements in therapy development for osteoarthritis (OA) currently are limited due to a lack of physiologically relevant in vitro models. This study aimed to understand the effect of matrikine stimulation, using human recombinant fibronectin fragment containing domains 7–10 (FN7–10), on equine synovial fibroblasts and chondrocytes. Inflammatory cytokines, chemokines, and matrix degradation genes in equine synovial fibroblasts and chondrocytes were significantly altered in response to FN7–10 stimulation; marked upregulation was observed in interleukin-6 (IL-6), IL-4, IL-10, matrix metalloproteinase 1 (MMP1), MMP3, MMP13, CCL2/MCP1, and CXCL6/GCP-2 gene expression. Only IL-6 protein production was significantly increased in media isolated from cells stimulated with FN7–10. These results support the potential use of equine synovial fibroblasts and chondrocytes—employing FN7–10—as representative in vitro models to study OA. Supported by ORIP (T32OD011130) and NIAMS.
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.
Mechanical Force of Uterine Occupation Enables Large Vesicle Extrusion From Proteostressed Maternal Neurons
Wang et al., eLife. 2024.
https://pubmed.ncbi.nlm.nih.gov/39255003
This study investigates how mechanical forces from uterine occupation influence large vesicle extrusion (exopher production) from proteostressed maternal neurons in Caenorhabditis elegans. Exophers, previously found to remove damaged cellular components, are poorly understood. Researchers demonstrate that mechanical stress significantly increases exopher release from touch receptor neurons (i.e., ALMR) during peak reproductive periods, coinciding with egg production. Genetic disruptions reducing reproductive activity suppress exopher extrusion, whereas interventions promoting egg retention enhance it. These findings reveal that reproductive and mechanical factors modulate neuronal stress responses, providing insight on how systemic physiological changes affect neuronal health and proteostasis, with broader implications for reproductive-neuronal interactions. Supported by ORIP (R24OD010943, P40OD010440), NIA, and NIGMS.
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.
Impaired Skeletal Development by Disruption of Presenilin-1 in Pigs and Generation of Novel Pig Models for Alzheimer's Disease
Uh et al., Journal of Alzheimer's Disease. 2024.
https://pubmed.ncbi.nlm.nih.gov/39177593/
This study explored the effects of presenilin 1 (PSEN1) disruption on vertebral malformations in male and female PSEN1 mutant pigs. Researchers observed significant skeletal impairments and early deaths in pigs with a PSEN1 null mutation, mirroring phenotypes seen in mouse models of Alzheimer’s disease (AD). This porcine model provides valuable insights into pathological hallmarks of PSEN1 mutations in AD, offering a robust platform of therapeutic exploration. The findings establish pigs as an essential translational model for AD, enabling advanced studies on pathophysiology and treatment development for human skeletal and neurological conditions. Supported by ORIP (U42OD011140), NHLBI, NIA, NIAID.