Selected Grantee Publications
Single-Component Multilayered Self-Assembling Protein Nanoparticles Presenting Glycan-Trimmed Uncleaved Prefusion Optimized Envelope Trimers as HIV-1 Vaccine Candidates
Zhang, Nature Communications. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10082823/
Researchers are interested in engineering protein nanoparticles to mimic virus-like particles for an HIV-1 vaccine. In this study, researchers explored a strategy that combines HIV envelope glycoprotein (Env) stabilization, nanoparticle display, and glycan trimming. They designed a panel of constructs for biochemical, biophysical, and structural characterization. Using female mice, female rabbits, and rhesus macaques of both sexes, they demonstrated that glycan trimming increases the frequency of vaccine responders and steers antibody responses away from immunodominant glycan holes and glycan patches. This work offers a potential strategy for overcoming the challenges posed by the Env glycan shield in vaccine development. Supported by ORIP (P51OD011133, P51OD011104, U42OD010442) and NIAID.
Deep Analysis of CD4 T Cells in the Rhesus CNS During SIV Infection
Elizaldi et al., PLOS Pathogens. 2023.
https://pubmed.ncbi.nlm.nih.gov/38060615/
Systemic HIV infection results in chronic inflammation that causes lasting damage to the central nervous system (CNS), despite long-term antiretroviral therapy (ART). Researchers studied neurocognitive outcomes in male and female rhesus macaques infected with simian immunodeficiency virus (SIV) using an ART regimen simulating suboptimal adherence; one group received no ART, and the other received ART with periodic interruptions. Using single-cell transcriptomic profiling, the researchers also identified molecular programs induced in the brain upon infection. They found that acute infection led to marked imbalance in the CNS CD4/CD8 T‑cell ratio, which persisted into the chronic phase. The studies provide insight into the role of CD4 T cells in the CNS during HIV infection. Supported by ORIP (P51OD011107, K01OD023034), NIA, NIAID, and NCI.
Cholera Toxin B Scaffolded, Focused SIV V2 Epitope Elicits Antibodies That Influence the Risk of SIVmac251 Acquisition in Macaques
Rahman et al., Frontiers in Immunology. 2023.
https://pubmed.ncbi.nlm.nih.gov/37153584/
Previous work has indicated that the production of antibodies against epitopes in the V2 loop of gp120—a protein component of the viral spikes used to infiltrate host cells—correlates with protection from viral acquisition. Researchers assessed the efficacy of a simian immunodeficiency virus (SIV) vaccine consisting of a V2c epitope scaffolded onto cholera toxin B in rhesus macaques of both sexes. Immunized animals generated V2c-specific antibody responses, and differences in the functional antibody and immune cell responses were observed and compared with responses in a historically protective vaccine regimen. Different responses also were observed when varying adjuvants were administered with the vaccines. Thus, full protection against SIV infection might require vaccines against multiple spike epitopes. Supported by ORIP (P51OD011104, R24OD010976) and NIAID.
Simian Immunodeficiency Virus and Storage Buffer: Field-Friendly Preservation Methods for RNA Viral Detection in Primate Feces
Wilde et al., mSphere. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10732032/
Simian immunodeficiency virus (SIV) infects more than 40 nonhuman primate (NHP) species in sub-Saharan Africa, but testing in wild NHP populations can be challenging. Researchers compared methods for SIV RNA preservation and recovery from NHP fecal samples stored in four different buffers. The goal of this work was to identify a robust “field-friendly” method (i.e., without freezing or refrigeration) for this effort, and the samples were collected from a mantled guereza colobus housed at the Columbus Zoo and Aquarium. The authors reported that the DNA/RNA shield is an optimal buffer for preserving SIV RNA in fecal samples in the field. Their findings will inform future fieldwork and facilitate improved approaches for studies of SIV and other RNA viruses. Supported by ORIP (P51OD011132) and NIAID.
Antiretroviral Therapy Reveals Triphasic Decay of Intact SIV Genomes and Persistence of Ancestral Variants
Fray et al., Cell Host & Microbe. 2023.
https://doi.org/10.1016/j.chom.2023.01.016
Antiretroviral therapy (ART) halts HIV-1 replication but is not curative; a pool of latently infected CD4+ T cells persists, and viremia rapidly rebounds if ART is stopped. Using an intact proviral DNA assay, researchers characterized quantitative and qualitative changes in CD4+ T cells for 4 years following ART initiation in rhesus macaques of both sexes. They found that viruses replicating at ART initiation had mutations conferring antibody escape, and sequences with large numbers of antibody escape mutations became less abundant at later time points. Together, these findings reveal that the population of simian immunodeficiency virus (SIV)–infected CD4+ T cells is dynamic and provide a framework for evaluating and interpreting intervention trials. Supported by ORIP (R01OD011095), NIAID, and NIDCR.
IL-21-IgFc Immunotherapy Alters Transcriptional Landscape of Lymph Node Cells Leading to Enhanced Flu Vaccine Response in Aging and SIV Infection
Pallikkuth et al., Aging Cell. 2023.
https://pubmed.ncbi.nlm.nih.gov/37712598/
Aging is associated with increased risk of seasonal flu disease burden and serious flu-related complications, particularly for people with HIV. In this study, investigators aimed to elucidate the immunomodulation following flu vaccination in aging male and female rhesus macaques infected with simian immunodeficiency virus (SIV). Their results suggest that IL-21 treatment at the time of flu vaccination modulates the inductive lymph node germinal center activity to reverse SIV-associated immune dysfunction. The authors identified IL-21 as a potential candidate molecule for immunotherapy to enhance flu vaccine responses in affected populations. Further studies could examine the overall benefit of IL-21 immunotherapy on mucosal lung immunity and protection against infection. Supported by ORIP (R24OD010947), NIA, and NIAID.
Intradermal but Not Intramuscular Modified Vaccinia Ankara Immunizations Protect Against Intravaginal Tier2 Simian–Human Immunodeficiency Virus Challenges in Female Macaques
Bollimpelli et al., Nature Communications. 2023.
https://www.doi.org/10.1038/s41467-023-40430-7
Researchers have been exploring multiple strategies to develop an HIV vaccine. In this study, the investigators determined the immunogenicity and efficacy of intradermal and intramuscular routes of modified vaccinia Ankara (MVA) vaccination in female rhesus macaques. They found that both routes of MVA vaccination enabled control of viral replication, but only the intradermal vaccination was effective in protection against viral acquisition. Their findings suggest that the intradermal MVA vaccinations provide protection by modulating the innate and T helper responses. Taken together, this work underscores the importance of testing the influence of the route of immunization for HIV vaccines in humans. Supported by ORIP (P51OD011132, R24OD010976) and NIAID.
Very-Long-Chain Fatty Acids Induce Glial-Derived Sphingosine-1-Phosphate Synthesis, Secretion, and Neuroinflammation
Chung et al., Cell Metabolism. 2023.
https://pubmed.ncbi.nlm.nih.gov/37084732/
Very-long-chain fatty acids (VLCFAs) are the most abundant fatty acids in myelin. During age‑associated degeneration of myelin, glia are exposed to increased levels of VLCFAs. Investigators previously described a novel phenotype in patients that harbors a novel variant in the peroxisomal enzyme ACOX1. Here, they report that that glial loss of ACOX1 leads to an increase of VLCFAs, which results in a concomitant increase in sphingosine-1-phosphate (S1P). They found that suppressing S1P function attenuates the pathological phenotypes caused by excess VLCFAs. This work suggests that lowering of VLCFAs and S1P could be applied as a treatment avenue for multiple sclerosis. Supported by ORIP (R24OD022005, R24OD031447, P40OD018537), NINDS, and NICHD
Tenth Aquatic Models of Human Disease Conference 2022 Workshop Report: Aquatics Nutrition and Reference Diet Development
Sharpton et al., Zebrafish. 2023.
https://pubmed.ncbi.nlm.nih.gov/38117219/
Standard reference diets (SRDs) for aquatic model organisms, vital for supporting scientific rigor and reproducibility, are yet to be adopted. At this workshop, the authors presented findings from a 7-month diet test study conducted across three aquatic research facilities: Zebrafish International Resource Center (University of Oregon), Kent and Sharpton laboratories (Oregon State University), and Xiphophorus Genetic Stock Center (Texas State University). They compared the effects of two commercial diets and a suggested zebrafish SRD on general fish husbandry, microbiome composition, and health in three fish species (zebrafish, Xiphophorus, and medaka), and three zebrafish wild-type strains. They reported outcomes, gathered community feedback, and addressed the aquatic research community's need for SRD development. Discussions underscored the influence of diet on aquatic research variability, emphasizing the need for SRDs to control cross-experiment and cross-laboratory reproducibility. Supported by ORIP (P40OD011021, R24OD011120, and R24OD010998) and NICHD.
Age-Associated DNA Methylation Changes in Xenopus Frogs
Morselli et al., Epigenetics. 2023.
https://www.tandfonline.com/doi/full/10.1080/15592294.2023.2201517
Age-associated changes in DNA methylation have not been characterized yet in amphibians, which include widely studied model organisms. Here the authors present clear evidence that the aquatic vertebrate species Xenopus tropicalis displays patterns of age-associated changes in DNA methylation. Whole-genome bisulfite sequencing profiles from skin samples of frogs representing young, mature, and old adults demonstrated that many of the methylation features and changes they observed are consistent with what is known in mammalian species, suggesting that the mechanism of age-related changes is conserved. The results of this study will allow researchers to leverage the unique resources available for Xenopus to study how DNA methylation relates to other hallmarks of aging. Supported by ORIP (P40OD010997, R24OD031956, R24OD030008) and NICHD.