Selected Grantee Publications
CD8+ T Cells Promote HIV Latency by Remodeling CD4+ T Cell Metabolism to Enhance Their Survival, Quiescence, and Stemness
Mutascio et al., Immunity. 2023.
https://www.doi.org/10.1016/j.immuni.2023.03.010
An HIV reservoir persists following antiretroviral therapy, representing the main barrier to an HIV cure. Using a validated in vitro model, investigators explored the mechanism by which CD8+ T cells promote HIV latency and inhibit latency reversal in HIV-infected CD4+ T cells. They reported that CD8+ T cells favor the establishment of HIV latency by modulating metabolic, stemness, and survival pathways that correlate with the downregulation of HIV expression and promote HIV latency. In future studies, comparative analyses may provide insight into common molecular mechanisms in the silencing of HIV expression by CD8+ T cells and macrophages, which can be applied to new intervention strategies that target the HIV reservoir. Supported by ORIP (P51OD011132, S10OD026799), NIAID, NIDDK, NIDA, NHLBI, and NINDS.
Cerebrospinal Fluid Protein Markers Indicate Neuro-Damage in SARS-CoV-2-Infected Nonhuman Primates
Maity et al., Molecular & Cellular Proteomics. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9981268/
In this study, researchers examined the proteins expressed in cerebrospinal fluid (CSF) in nonhuman primates (NHPs) to better understand how COVID-19 infection can result in brain pathology, a common outcome. The study found that even in NHPs with minimal or mild COVID‑19, CSF proteins were significantly dysregulated compared with uninfected NHPs. Furthermore, the most affected proteins were enriched in the same brain regions that show lesions after COVID-19 infection, including the cerebral cortex, basal ganglia, and brain stem. Collectively, these regions have wide-ranging control over such crucial functions as cognition, motor control, and breathing, showing how even mild COVID-19 infection can result in significant neurological impairment. Supported by ORIP (P51OD011104, S10OD032453), NIGMS, NCI, and NICHD.
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.
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.
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.
In-Depth Virological and Immunological Characterization of HIV-1 Cure after CCR5A32/A32 Allogeneic Hematopoietic Stem Cell Transplantation
Jensen et al., Nature Medicine. 2023.
https://pubmed.ncbi.nlm.nih.gov/36807684/
Evidence suggests that CCR5Δ32/Δ32 hematopoietic stem cell transplantation (HSCT) can cure HIV-1, but the immunological and virological correlates are unknown. Investigators performed a longitudinal virological and immunological analysis of the peripheral blood and tissue compartments of a 53-year-old male patient more than 9 years after CCR5Δ32/Δ32 allogeneic HSCT and 48 months after analytical treatment interruption. Sporadic traces of HIV-1 DNA were detected in peripheral T cell subsets and tissue-derived samples, but repeated ex vivo quantitative and in vivo outgrowth assays in humanized mice of both sexes did not reveal replication-competent virus. This case provides new insights that could guide future cure strategies. Supported by ORIP (P51OD011092) and NIAID.
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.
Assessment of Anti-CD20 Antibody Pre-Treatment for Augmentation of CAR-T Cell Therapy in SIV-Infected Rhesus Macaques
Pampusch et al., Frontiers in Immunology. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9941136/
Chronic HIV replication occurs primarily within lymphoid follicles, and investigators hypothesized that temporary disruption of these follicles would create space for chimeric antigen receptor (CAR) T cell engraftment and lead to increased abundance and persistence of CAR T cells. They evaluated CAR T cell abundance and persistence in rhesus macaques of both sexes following simian immunodeficiency virus (SIV) infection and antiretroviral therapy suppression. Their results suggest that CAR T cells expanded to a greater extent in the depleted and CAR T cell–treated animals. Further studies are needed to evaluate strategies for engraftment and the persistence of HIV-specific CAR T cells. Supported by ORIP (P51OD011106, P51RR000167), NIAID, and NIDA.
SIV Infection Regulates Compartmentalization of Circulating Blood Plasma miRNAs within Extracellular Vesicles (EVs) and Extracellular Condensates (ECs) and Decreases EV-Associated miRNA-128
Kopcho et al., Viruses. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10059597/
MicroRNAs (miRNAs) are thought to be involved in HIV pathogenesis, but the effect of HIV on the compartmentalization of miRNAs within extracellular particles is unclear. Researchers sequenced the small RNA population of paired EVs and ECs from male rhesus macaques. They showed that extracellular miRNAs in blood plasma are not restricted to any type of extracellular particles but are associated with lipid‑based carriers, with a significant proportion associated with ECs. Further, simian immunodeficiency virus (SIV) infection altered the miRNAome profile of EVs and revealed miR‑128‑3p as a potential target of infection. This work suggests that EV‑ and EC‑associated miRNAs potentially could serve as biomarkers for various diseases. Supported by ORIP (P51OD011104, P51OD011133), NIAID, and NIDA.