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.
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.
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.
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.
Cannabinoid Control of Gingival Immune Activation in Chronically SIV-Infected Rhesus Macaques Involves Modulation of the Indoleamine-2,3-Dioxygenase-1 Pathway and Salivary Microbiome
McDew-White et al., EBioMedicine. 2021.
https://pubmed.ncbi.nlm.nih.gov/34954656/
HIV-associated periodontal disease (PD) affects people living with HIV (PLWH) on combination anti-retroviral therapy (cART). Researchers used a systems biology approach to investigate the molecular, metabolome, and microbiome changes underlying PD and its modulation by phytocannabinoids (Δ9-THC) in rhesus macaques. Δ9-THC reduced IDO1 protein expression. The findings suggest that phytocannabinoids may help reduce gingival/systemic inflammation, salivary dysbiosis, and potentially metabolic disease in PLWH on cART. Supported by ORIP (P51OD011104, P51OD011133, U42OD010442), NIAID, NIDA, NIDDK, NIDCR, and NIMH.
The Pigtail Macaque (Macaca nemestrina) Model of COVID-19 Reproduces Diverse Clinical Outcomes and Reveals New and Complex Signatures of Disease
Melton et al., PLOS Pathogens. 2021.
https://pubmed.ncbi.nlm.nih.gov/34929014/
Animal models that recapitulate human COVID-19 disease are critical for understanding SARS-CoV-2 viral and immune dynamics, mechanisms of disease, and testing of vaccines and therapeutics. A group of male pigtail macaques (PTMs) were euthanized either 6- or 21-days after SARS-CoV-2 viral challenge and demonstrated mild-to-moderate COVID-19 disease. Pulmonary infiltrates were dominated by T cells, virus-targeting T cells were predominantly CD4+, increases in circulating inflammatory and coagulation markers, pulmonary pathologic lesions, and the development of neutralizing antibodies were observed. Collectively, the data suggests PTMs are a valuable model to study COVID-19 pathogenesis and may be useful for testing vaccines and therapeutics. Supported by ORIP (P51OD011104) and NIAID.
Dynamics and Origin of Rebound Viremia in SHIV-Infected Infant Macaques Following Interruption of Long-Term ART
Obregon-Perko et al., JCI Insight. 2021.
https://pubmed.ncbi.nlm.nih.gov/34699383/
Animal models that recapitulate human COVID-19 disease are critical for understanding SARS-CoV-2 viral and immune dynamics, mechanisms of disease, and testing of vaccines and therapeutics. A group of male pigtail macaques (PTMs) were euthanized either 6- or 21-days after SARS-CoV-2 viral challenge and demonstrated mild-to-moderate COVID-19 disease. Pulmonary infiltrates were dominated by T cells, virus-targeting T cells were predominantly CD4+, increases in circulating inflammatory and coagulation markers, pulmonary pathologic lesions, and the development of neutralizing antibodies were observed. Collectively, the data suggests PTMs are a valuable model to study COVID-19 pathogenesis and may be useful for testing vaccines and therapeutics. Supported by ORIP (P51OD011104) and NIAID.
Antiretroviral Therapy Timing Impacts Latent Tuberculosis Infection Reactivation in a Tuberculosis/Simian Immunodeficiency Virus Coinfection Model
Sharan et al., Journal of Clinical Investigation. 2021.
https://pubmed.ncbi.nlm.nih.gov/34855621/
In the rhesus macaque model for Mycobacterium tuberculosis plus simian immunodeficiency virus (SIV) co-infection, chronic immune activation rather than depletion of CD4+ T cells correlates with reactivation of latent tuberculosis infection (LTBI). Researchers administered combined antiretroviral therapy (cART) at 2 weeks post-SIV co-infection to study whether restoration of CD4+ T cell immunity occurred more broadly, and whether this prevented LTBI compared to cART initiated at 4 weeks post-SIV. Earlier initiation of cART enhanced survival led to better control of viral replication and reduced immune activation in the periphery and lung vasculature, thereby reducing the rate of SIV-induced reactivation. Supported by ORIP (K01OD031898, P51OD011133, P51OD011132, S10OD028653) and NIAID.