Selected Grantee Publications
Structural Mapping of Polyclonal IgG Responses to HA After Influenza Virus Vaccination or Infection
León et al., mBio. 2025.
https://pubmed.ncbi.nlm.nih.gov/39912630
Seasonal influenza viruses cause hundreds of thousands of deaths each year and up to a billion infections; under the proper circumstances, influenza A viruses with pandemic potential could threaten the lives of millions more. Many promising universal flu vaccine candidates currently focus on guiding immune responses to highly conserved epitopes on the central stem of the influenza hemagglutinin (HA) viral fusion protein. To support the further development of these stem-targeting vaccine candidates, researchers used negative stain electron microscopy to assess the prevalence of central stem-targeting antibodies in individuals (male and female) who were exposed to influenza antigens through traditional vaccination or natural infection during the 2018–2019 flu season. Results demonstrated humoral IgGs targeting highly conserved regions on both H1 and H3 subtype HAs found in both vaccinated and infected patients. Results from this study support the need for further characterization of protective responses toward conserved epitopes and provide a baseline for examining antibody responses. Supported by ORIP (K01OD036063) and NIAID.
Whole-Genome Sequences of Six Borrelia recurrentis Strains Obtained via PacBio Sequencing
Gaber et al., Microbiology Resource Announcements. 2025.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11895452
The spirochetal bacterium Borrelia recurrentis causes louse-borne relapsing fever (LBRF), which leads to significant morbidity and mortality in several African countries. Previous sequencing studies of B. recurrentis demonstrated discrepancies and did not accurately define the antigenic variation system. In this study, researchers used long-read PacBio technology to conduct whole-genome sequencing of six B. recurrentis strains that had been isolated from LBRF patients earlier. The resulting sequences of each genome included one linear chromosome and five linear plasmids, whose average size was 1,284,895 bp, with the mean GC content being 27.5%. Supported by ORIP (T32OD011083) and NIAID.
Structures of Respiratory Syncytial Virus G Bound to Broadly Reactive Antibodies Provide Insights into Vaccine Design
Juarez et al., Scientific Reports. 2025.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11906780
Respiratory syncytial virus (RSV) is one of the leading causes of severe lower respiratory infection in both infants and older adults. RSV viral entry and modulation of the host immunity is mediated by attachment glycoprotein RSV G binding to the chemokine receptor CX3CR1. Antibodies isolated from RSV-exposed individuals have shown great promise in host protection. Researchers using an ORIP-funded electron microscope, in conjunction with X-ray crystallography, have solved the structure of these antibodies bound to the RSV G protein and identified a novel dual antibody binding region. The presence of dual antibody binding sites indicates the potential to elicit antibody responses that resist virus escape. These findings will help develop next-generation RSV prophylactics and provide insight for new concepts in vaccine design. Supported by ORIP (S10OD027012, S10OD025097), NIAID, NHGRI, and NIGMS.
Small-Diameter Artery Grafts Engineered from Pluripotent Stem Cells Maintain 100% Patency in an Allogeneic Rhesus Macaque Model
Zhang et al., Cell Reports Medicine. 2025.
https://www.cell.com/cell-reports-medicine/fulltext/S2666-3791(25)00075-8
Globally, the leading cause of death is occlusive arterial disease, but surgical revascularization improves patient prognosis and reduces mortality. Vascular grafts often are needed in coronary bypass surgery for surgical revascularization. However, the clinically approved option for small-diameter revascularization is autologous vascular grafts, which require invasive harvesting methods, and many patients lack suitable vessels. Researchers developed a novel method for graft development using arterial endothelial cells (AECs), derived from pluripotent stem cells (PSCs), on expanded polytetrafluoroethylene using specific adhesion molecules. This study used a 6- to 13-year-old male rhesus macaque arterial interposition grafting model. The major histocompatibility complex mismatched wild-type (MHC-WT) AEC grafts were successful when implanted in rhesus macaques and attracted host cells to the engraftment, leading to 100% patency for 6 months. The results highlight a novel strategy for generating artery grafts from PSC-derived MHC-WT AECs that overcomes current challenges in graft development and may have future clinical applications. Supported by ORIP (P51OD011106, S10OD023526), NCI, and NHLBI.
Quorum Sensing LuxR Proteins VjbR and BabR Jointly Regulate Brucella abortus Survival During Infection
Caudill et al., Journal of Bacteriology. 2025.
https://pubmed.ncbi.nlm.nih.gov/40013834
Brucella abortus is a zoonotic bacterial pathogen that causes brucellosis, a persistent chronic infection that is globally endemic. B. abortus uses quorum sensing to escape immune clearance attempts, regulate virulence, and cause persistent infection within hosts. B. abortus quorum sensing system comprises two LuxR proteins, VjbR and BabR, as well as two signals, dodecanoyl (C12 AHL) and 3-oxododecanoyl (3-OXO-C12 AHL) homoserine lactone. Using chronic infection 6- to 7-week-old C57Bl/6 and BALB/c male and female mouse models, researchers found that the ΔvjbRΔbabR double-deletion strain was attenuated compared with single mutants. These results demonstrate that both quorum sensing proteins, VjbR and BabR, coordinate to maintain survival. This study helps further characterize the Brucella quorum sensing systems and indicates that further attention should be given to the joint interactions between VjbR and BabR in controlling virulence. Supported by ORIP (T32OD028239) and NIAID.
Enhanced RNA-Targeting CRISPR-Cas Technology in Zebrafish
Moreno-Sánchez et al., Nature Communications. 2025.
https://pubmed.ncbi.nlm.nih.gov/40091120
CRISPR-Cas13 RNA-targeting systems, widely used in basic and applied sciences, have generated controversy because of collateral activity in mammalian cells and mouse models. In this study, researchers optimized transient formulations as ribonucleoprotein complexes or mRNA-gRNA combinations to enhance the CRISPR-RfxCas13d system in zebrafish. Researchers used chemically modified gRNAs to allow more penetrant loss-of-function phenotypes, improve nuclear RNA targeting, and compare different computational models to determine the most accurate prediction of gRNA activity in vivo. Results demonstrate that transient CRISPR-RfxCas13d can effectively deplete endogenous mRNAs in zebrafish embryos without inducing collateral effects, except when targeting extremely abundant and ectopic RNAs. Their findings contribute to CRISPR-Cas technology optimization for RNA targeting in zebrafish through transient approaches and advance in vivo applications. Supported by ORIP (R21OD034161), NICHD, and NIGMS.
Early Results of an Infant Model of Orthotopic Cardiac Xenotransplantation
Mitchell et al., Journal of Heart and Lung Transplantation. 2025.
https://pubmed.ncbi.nlm.nih.gov/39778609
This study evaluated the potential of genetically engineered pig hearts for human pediatric heart failure patients, with 11 infantile pig heart transplants performed in size-matched infant baboons (Papio anubis) (sex not specified). All grafts supported normal cardiac functions post-operatively, and six animals survived beyond 3 months. While early cardiac function was not a limiting factor for survival, systemic inflammation led to pulmonary edema and pleural effusions, which impeded long-term outcomes. These findings highlight the feasibility of cardiac xenotransplantation in infants and underscore the need for targeted therapies to manage inflammation and improve survival. Supported by ORIP (P40OD024628) and NHLBI.
Dysregulation of mTOR Signalling Is a Converging Mechanism in Lissencephaly
Zhang et al., Nature. 2025.
https://pubmed.ncbi.nlm.nih.gov/39743596
Lissencephaly (smooth brain) is a rare genetic condition, with such symptoms as epilepsy and intellectual disability and a median life expectancy of 10 years. This study reveals that reduced activity of the mTOR pathway may be a common cause of lissencephaly. Researchers used laboratory-grown brain models (organoids) and sequencing and spectrometry techniques to identify decreased mTOR activation in two types of lissencephaly disorders: p53-induced death domain protein 1 and Miller–Dieker lissencephaly syndrome. Pharmacological activation of mTOR signaling with a brain-selective mTORC1 activator molecule, NV-5138, prevented and reversed the morphological and functional defects in organoids. These findings suggest that mTOR dysregulation contributes to the development of lissencephaly spectrum disorders and highlight a potential druggable pathway for therapy. Supported by ORIP (S10OD018034, S10OD019967, S10OD030363), NCATS, NHGRI, NICHD, NIDA, NIGMS, NIMH, and NINDS.
Establishing the Hybrid Rat Diversity Program: A Resource for Dissecting Complex Traits
Dwinell et al., Mammalian Genome. 2025.
https://pubmed.ncbi.nlm.nih.gov/39907792
Rat models have been extensively used for studying human complex disease mechanisms, behavioral phenotypes, and environmental factors and for discovering and developing drugs. Systems genetics approaches have been used to study the effects of both genetic variation and environmental factors. This approach recognizes the complexity of common disorders and uses intermediate phenotypes to find relationships between genetic variation and clinical traits. This article describes the Hybrid Rat Diversity Program (HDRP) at the Medical College of Wisconsin, which involves 96 inbred rat strains and aims to provide a renewable and reusable resource in terms of the HRDP panel of inbred rat strains, the genomic data derived from the HRDP strains, and banked resources available for additional studies. Supported by ORIP (R24OD024617) and NHLBI.
Liver-Specific Transgenic Expression of Human NTCP In Rhesus Macaques Confers HBV Susceptibility on Primary Hepatocytes
Rust et al., PNAS. 2025.
https://pubmed.ncbi.nlm.nih.gov/39937851
This study establishes the first transgenic nonhuman primate model for hepatitis B virus (HBV). Male and female rhesus macaques were engineered to express the human HBV receptor, NTCP (hNTCP), specifically in the liver. Researchers used PiggyBac transposon technology to introduce a liver-specific NTCP transgene into embryos, which were then implanted into surrogate females. The resulting offspring expressed hNTCP in hepatocytes and demonstrated high susceptibility to HBV infection. This model overcomes the species-specific limitations of HBV research, providing a powerful tool for studying HBV biology and evaluating HBV treatments in a clinically relevant model system. Supported by ORIP (P51OD011092), NIDA, and NIAID.