Selected Grantee Publications
Longitudinal Characterization of Circulating Extracellular Vesicles and Small RNA During Simian Immunodeficiency Virus Infection and Antiretroviral Therapy
Huang et al., AIDS. 2023.
https://www.doi.org/10.1097/QAD.0000000000003487
Antiretroviral therapy is effective for controlling HIV infection but does not fully prevent early aging disorders or serious non-AIDS events among people with HIV. Using pigtail and rhesus macaques (sex not specified), researchers profiled extracellular vesicle small RNAs during different phases of simian immunodeficiency virus infection to explore the potential relationship between extracellular vesicle–associated small RNAs and the infection process. They reported that average particle counts correlated with infection, but the trend could not be explained fully by virions. These findings raise new questions about the distribution of extracellular vesicle RNAs in HIV latent infection. Supported by ORIP (U42OD013117), NIDA, NIMH, NIAID, NCI, and NINDS.
Infant Rhesus Macaques Immunized Against SARS-CoV-2 Are Protected Against Heterologous Virus Challenge 1 Year Later
Milligan et al., Science Translational Medicine. 2023.
https://doi.org/10.1126/scitranslmed.add6383
The Moderna and Pfizer–BioNTech mRNA vaccines received emergency use authorization for infants 6 months and older in June 2022, but questions remain regarding the durability of vaccine efficacy against emerging variants in this age group. Using a two-dose vaccine regimen consisting of stabilized prefusion Washington-strain spike protein encoded by mRNA and encapsulated in lipid nanoparticles, the investigators immunized 2-month-old rhesus macaques of both sexes. They found that the immune responses persisted and protected from severe disease after heterologous challenge with the Delta variant 1 year later. The decay kinetics of vaccine-induced neutralizing antibody responses in the infant monkeys are comparable to those observed in adult humans and nonhuman primates. Supported by ORIP (P51OD011107), NIAID, and NCI.
Fc-Mediated Pan-Sarbecovirus Protection After Alphavirus Vector Vaccination
Adams et al., Cell Reports. 2023.
https://pubmed.ncbi.nlm.nih.gov/37000623/
Group 2B β-coronaviruses (i.e., sarbecoviruses) have resulted in regional and global epidemics. Here, the authors evaluate the mechanisms of cross-sarbecovirus protective immunity using a panel of alphavirus-vectored vaccines covering bat to human strains. They reported that vaccination does not prevent virus replication, but it protects against lethal heterologous disease outcomes in SARS-CoV-2 and clade 2 bat sarbecovirus challenge models. Full-length spike vaccines elicited the broadest pan-sarbecovirus protection. Additionally, antibody-mediated cross-protection was lost in absence of FcR function, supporting a model for non-neutralizing, protective antibodies. Taken together, these findings highlight the value of universal sarbecovirus vaccine designs that couple FcR-mediated cross-protection with potent cross-neutralizing antibody responses. Supported by ORIP (K01OD026529), NIAID, and NCI.
Anti–Human Immunodeficiency Virus‑1 Activity of MoMo30 Protein Isolated from the Traditional African Medicinal Plant Momordica balsamina
Khan et al., Virology Journal. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10035133/
Momordica balsamina has been reported to produce a ribosome-inactivating protein with anti‑HIV-1 activity and is commonly used by traditional African healers for treatment of HIV. Investigators characterized the mechanism of action of the MoMo30 protein, as well as the sequence of the protein-coding gene. They reported that MoMo30 functions as a lectin or carbohydrate-binding agent (CBA) and inhibits HIV-1 at nanomolar levels, with minimal cellular toxicity at inhibitory levels. CBAs can block the binding of envelope glycoproteins with their target receptors on cells. Thus, this protein could represent a potential new treatment strategy for HIV. Supported by ORIP (R24OD010947), NCI, NIGMS, and NIMHD.
Late Gene Expression–Deficient Cytomegalovirus Vectors Elicit Conventional T Cells That Do Not Protect Against SIV
Hansen et al., Journal of Clinical Investigation Insight. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10070102/
Cytomegalovirus (CMV)–based vaccines aim to exploit unique immunological adaptations, including host manipulation and immune evasion strategies. Translating CMV-based vaccines from rhesus macaques to humans requires translating the immune factors responsible for efficacy, as well as vaccine vectors that are sufficiently safe for widespread use. Researchers examined the impact of a stringent attenuation strategy on vector-induced immune protection against simian immunodeficiency virus (SIV) in rhesus macaques of both sexes. They reported that elicited CD8+ T cells exclusively failed to protect against SIV challenge. These data suggest that late viral gene expression and/or residual in vivo spreading are required to induce protective CD8+ T cell responses. Supported by ORIP (P51OD011092, P51OD011107, S10OD016261), NCI, NIAID, and NCATS.
Mechanism of STMN2 Cryptic Splice-Polyadenylation and its Correction for TDP-43 Proteinopathies
Baughn et al., Science. 2023.
Loss of the RNA-binding protein TDP-43 from the nuclei of affected neurons is a hallmark of neurodegeneration in TDP-43 proteinopathies (e.g., amyotrophic lateral sclerosis, frontotemporal dementia). Loss of functional TDP-43 is accompanied by misprocessing of the stathmin-2 (STMN2) RNA precursor. Investigators determined the elements through which TDP‑43 regulates STMN2 pre‑mRNA processing and identified steric binding antisense oligonucleotides that are capable of restoring normal STMN2 protein and RNA levels. This approach is potentially applicable for human therapy. Supported by ORIP (U42OD010921), NIA, NCI, NIGMS, and NINDS.
Chronic Immune Activation and Gut Barrier Dysfunction Is Associated with Neuroinflammation in ART-Suppressed SIV+ Rhesus Macaques
Byrnes et al., PLOS Pathogens. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10085024/
About 40% of people with HIV develop neurocognitive disorders, potentially resulting from persistent infection in the brain and neuroinflammation. Investigators characterized the central nervous system reservoir and immune environment of simian immunodeficiency virus (SIV)–infected rhesus macaques of both sexes during acute, chronic, or antiretroviral therapy (ART)–suppressed infection. They reported that neuroinflammation and blood–brain barrier dysfunction correlated with viremia and immune activation in the gut. Their findings suggest that gastrointestinal tract damage can contribute to neuroimmune activation and inflammation, even in the absence of SIV or HIV infection. This work also has implications for other neurological disorders where chronic inflammation is associated with pathogenesis. Supported by ORIP (P51OD011132, P51OD011092, U42OD011023, R24OD010445), NIAID, NCI, and NIMH.
Characterizing a Photoacoustic and Fluorescence Imaging Platform for Preclinical Murine Longitudinal Studies
Thompson et al., Journal of Biomedical Optics . 2023.
https://pubmed.ncbi.nlm.nih.gov/36895414/
Preclinical studies using animal models require medical imaging technology with sufficient resolution and sensitivity for anatomical, functional, and molecular assessments. Photoacoustic (PA) tomography provides high resolution and specificity, and fluorescence (FL) molecular tomography provides high sensitivity; the combination of these imaging modalities capitalizes on their strengths and mitigates disadvantages. In this publication, the authors describe TriTom, a preclinical imaging system that integrates PA and FL. They characterized the PA spatial resolution, PA sensitivity, PA spectral accuracy, optical spatial resolution, and FL sensitivity of the platform and demonstrated anatomical imaging in mice. This report demonstrates TriTom’s suitability for biomedical imaging applications. Supported by ORIP (R43OD023029) and NCI.
Cannabinoids Modulate the Microbiota–Gut–Brain Axis in HIV/SIV Infection by Reducing Neuroinflammation and Dysbiosis while Concurrently Elevating Endocannabinoid and Indole-3-Propionate Levels
McDew-White et al., Journal of Neuroinflammation. 2023.
https://jneuroinflammation.biomedcentral.com/articles/10.1186/s12974-023-02729-6
Chronic neuroinflammation is thought to be a significant contributor to HIV-associated neurocognitive disorders. Using rhesus macaques of both sexes, researchers investigated the effects of simian immunodeficiency virus (SIV) infection on the microbiota–gut–brain axis (MGBA), as well as the use of low-dose cannabinoids to reverse MGBA dysregulation. They reported that tetrahydrocannabinol reduced neuroinflammation and dysbiosis and increased plasma endocannabinoid, endocannabinoid-like, glycerophospholipid, and indole-3-propionate levels. This study offers a potential strategy to promote brain health in people with HIV. Supported by ORIP (P51OD011104, P51OD011103), NIAID, and NIDA.
A Class of Anti-Inflammatory Lipids Decrease with Aging in the Central Nervous System
Tan et al., Nature Chemical Biology. 2023.
https://doi.org/10.1038/s41589-022-01165-6
Impaired lipid metabolism in the brain has been implicated in neurological disorders of aging, yet analyses of lipid pathway changes with age have been lacking. The researchers examined the brain lipidome of mice of both sexes across the lifespan using untargeted lipidomics. They found that 3-sulfogalactosyl diacylglycerols (SGDGs) are structural components of myelin and decline with age in the central nervous system. The researchers discovered that SGDGs also are present in male human and rhesus macaque brains, demonstrating their evolutionary conservation in mammals. The investigators showed that SGDGs possess anti-inflammatory activity, suggesting a potential role for this lipid class in age-related neurodegenerative diseases. Supported by ORIP (P51OD011092), NIA, NCI, NIDDK, and NINDS.