Selected Grantee Publications
Neutralizing Antibody Response to SARS‐CoV‐2 Bivalent mRNA Vaccine in SIV‐Infected Rhesus Macaques: Enhanced Immunity to XBB Subvariants by Two‐Dose Vaccination
Faraone, Journal of Medical Virology. 2024.
https://pubmed.ncbi.nlm.nih.gov/38528837/
Researchers have shown that mRNA vaccination is less effective for people with advanced or untreated HIV infection, but data on the efficacy of mRNA vaccination against SARS-CoV-2 in this population are limited. Using rhesus macaques (sex not specified) with simian immunodeficiency virus (SIV), investigators examined the neutralizing antibody (nAb) response to SARS-CoV-2 vaccination. They found that administration of the bivalent vaccine alone can generate robust nAb titers against Omicron subvariants. Additionally, dams that received antiretroviral therapy had lower nAb titers than untreated dams. Overall, these findings highlight the need for further investigations into the nAb response in people with HIV. Supported by ORIP (P51OD011104), NCI, NIAID, NICHD, and NIMH.
SIV Infection Is Associated With Transient Acute-Phase Steatosis in Hepatocytes In Vivo
Derby, Viruses. 2024.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10892327/
Metabolic dysfunction–associated fatty liver disease (MAFLD) in people with HIV has become an increasing concern, but little is known about liver-specific changes underlying HIV-related MAFLD. Using rhesus macaques (sex not specified), researchers examined the timing of pathogenic changes within the liver during simian immunodeficiency virus (SIV) infection. Their findings suggest differential pathologies associated with the acute and chronic phases of infection. This work highlights the early damage inflicted on the liver by SIV/HIV infection and indicates that damage to the hepatocytes plays a specific role. Overall, the authors conclude that therapeutic interventions targeting metabolic function may benefit liver health in people who have recently received an HIV diagnosis. Supported by ORIP (P51OD011107, P51OD011092) and NIAID.
Potent Antibody-Dependent Cellular Cytotoxicity of a V2-Specific Antibody Is Not Sufficient for Protection of Macaques Against SIV Challenge
Grunst et al., PLOS Pathogens. 2024.
https://pubmed.ncbi.nlm.nih.gov/38252675/
Antibody-dependent cellular cytotoxicity (ADCC) has been correlated with decreased risk of HIV acquisition. Researchers tested the ability of PGT145, an antibody that neutralizes genetically diverse HIV-1 isolates, to protect rhesus macaques against simian immunodeficiency virus (SIV) via ADCC activity. They found that a single amino acid substitution in the V2 core epitope of the SIV envelope increases PGT145 binding and confers sensitivity to neutralization. Peak and chronic phase viral loads were lower, and time to peak viremia was delayed. They concluded that ADCC is insufficient for protection by this antibody, but increasing the affinity of antibody binding could confer partial protection. Supported by ORIP (P51OD011106), NIAID, and NCI.
Induction of Durable Remission by Dual Immunotherapy in SHIV-Infected ART-Suppressed Macaques
Lim et al., Science. 2024.
https://pubmed.ncbi.nlm.nih.gov/38422185/
The latent viral reservoir is established within the first few days of HIV infection and remains a barrier to a clinical cure. Researchers characterized the effects of a combined Anktiva (N-803) treatment with broadly neutralizing antibodies (bNAbs) using male and female rhesus macaques infected with simian–human immunodeficiency virus infection. Their data suggest that these agents synergize to enhance CD8+ T-cell function, particularly when multiple bNAbs are used. Taken together, this work indicates that immune-mediated control of viral rebound is not a prerequisite for sustained remission after discontinuation of antiretroviral therapy and that immune-mediated control of viral rebound is achievable, sufficient, and sustainable in this model. Supported by ORIP (P51OD011106, P40OD028116, R24OD011195) and NIAID.
Epigenetic MLH1 Silencing Concurs With Mismatch Repair Deficiency in Sporadic, Naturally Occurring Colorectal Cancer in Rhesus Macaques
Deycmar et al., Journal of Translational Medicine. 2024.
https://pubmed.ncbi.nlm.nih.gov/38504345
Rhesus macaques serve as a useful model for colorectal cancer (CRC) in humans, but more data are needed to understand the molecular pathogenesis of these cancers. Using male and female rhesus macaques, researchers investigated mismatch repair status, microsatellite instability, genetic mutations, transcriptional differences, and epigenetic alterations associated with CRC. Their data indicate that epigenetic silencing suppresses MLH1 transcription, induces the loss of MLH1 protein, abrogates mismatch repair, and drives genomic instability in naturally occurring CRC in rhesus macaques. This work provides a uniquely informative model for human CRC. Supported by ORIP (P51OD011092, R24OD010947, R24OD021324, P40OD012217, U42OD010426, T35OD010946, T32OD010957), NCATS, and NCI.
Effect of Hormone Replacement Therapy on Amyloid Beta (Aβ) Plaque Density in the Rhesus Macaque Amygdala
Appleman et al., Frontiers in Aging Neuroscience. 2024.
https://www.frontiersin.org/articles/10.3389/fnagi.2023.1326747/full
Amyloid beta plaque density is associated with Alzheimer’s disease. In this study, the authors examined its concentration in aged female nonhuman primates’ cerebrospinal fluid, as well as in the amygdala, an area of the brain involved with emotion and memory. They set out to test the hypothesis that estrogen hormone replacement therapy can beneficially affect amygdala Aβ plaque density in “surgically menopausal” females (i.e., aged rhesus macaques that had undergone ovariectomy). Female rhesus macaques that received estrogen replacement therapy showed fewer amyloid plaques than those that did not receive the hormone. This effect was observed regardless of the type of diet that the animals consumed. These findings suggest that hormone replacement might be a helpful treatment to consider for Alzheimer’s disease. Supported by ORIP (P51OD011092, R24OD011895, S10OD025002) and NIA.
Cytomegalovirus Infection Facilitates the Costimulation of CD57+CD28- CD8 T Cells in HIV Infection and Atherosclerosis via the CD2–LFA-3 Axis
Winchester et al., Journal of Immunology. 2024.
https://pubmed.ncbi.nlm.nih.gov/38047900/
People with HIV are at increased risk of developing atherosclerosis and other cardiovascular diseases, and HIV coinfection with cytomegalovirus (CMV) is associated with immune activation and inflammation. In this study, researchers explored the role of the CD2–LFA-3 axis in driving activation and proliferation of CD57+CD28- CD8 T cells using clinical samples from patients with or without HIV. They propose a model in which CMV infection is linked to enhanced CD2 expression on the T cells, enabling the activation via LFA-3 signals and potentially leading to cardiopathogenic interactions with vascular endothelial cells that express LFA-3. This work provides a potential therapeutic target in atherosclerosis development and progression, especially for people with HIV. Supported by ORIP (P51OD011132, U24OD011023) and NIAID.
Stable HIV Decoy Receptor Expression After In Vivo HSC Transduction in Mice and NHPs: Safety and Efficacy in Protection From SHIV
Li, Molecular Therapy. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10124088/
Autologous hematopoietic stem cell (HSC) gene therapy offers a promising HIV treatment strategy, but cost, complexity, and toxicity remain significant challenges. Using female mice and female nonhuman primates (NHPs) (i.e., rhesus macaques), researchers developed an approach based on the stable expression of eCD4-Ig, a secreted decoy protein for HIV and simian–human immunodeficiency virus (SHIV) receptors. Their goals were to (1) assess the kinetics and serum level of eCD4-Ig, (2) evaluate the safety of HSC transduction with helper-dependent adenovirus–eCD4-Ig, and (3) test whether eCD4-Ig expression has a protective effect against viral challenge. They found that stable expression of the decoy receptor was achieved at therapeutically relevant levels. These data will guide future in vivo studies. Supported by ORIP (P51OD010425) and NHLBI.
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.
Vpr Attenuates Antiviral Immune Responses and Is Critical for Full Pathogenicity of SIVmac239 in Rhesus Macaques
Laliberté et al., iScience. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10679897/
The accessory viral protein R (Vpr) exhibits multilayered functions, and more work is needed to understand its roles in viral replication, immune evasion, and pathogenicity in vivo. Using male and female rhesus macaques, researchers examined how deletion of vpr affects simian immunodeficiency virus (SIV) replication kinetics, innate immune activation, B- and T-cell responses, and neutralizing activity. They found that lack of Vpr delays and attenuates viral replication during acute infection, allowing most animals to mount efficient and persisting immune responses and higher levels of neutralizing antibodies. Overall, these results suggest that Vpr promotes viral replication and innate immune evasion during acute SIV infection. Supported by ORIP (P51OD011133, P51OD011132, S10OD026799).