Selected Grantee Publications
Brain Microglia Serve as a Persistent HIV Reservoir Despite Durable Antiretroviral Therapy
Tang et al., The Journal of Clinical Investigation. 2023.
https://www.doi.org/10.1172/JCI167417
Brain microglia are likely to play a role in rebound viremia following the cessation of antiretroviral therapy, but more work is needed to fully understand HIV persistence in the central nervous system (CNS). The investigators developed a protocol to isolate highly pure populations of brain myeloid cells and microglia from the tissues of male rhesus macaques, as well as from rapid autopsies of men and women with HIV. Their observations support the concept that brain microglia are a stable reservoir of quiescent infection. Thus, this work provides a physiologically relevant platform for studies of the biology of CNS reservoirs. Supported by ORIP (P51OD011132), NIAID, and NIMH.
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.
Duration of Antiretroviral Therapy Impacts the Degree of Residual SIV Infection in the Gut in Long‐Term Non‐Progressing Chinese Rhesus Macaques
Solis-Leal et al., Journal of Medical Virology. 2023.
https://onlinelibrary.wiley.com/doi/abs/10.1002/jmv.28185
HIV and simian immunodeficiency virus (SIV) reservoirs have been shown to persist with antiretroviral therapy (ART), particularly in the gut‐associated lymphoid tissues in the intestine. The effects of ART on the reservoir size, however, had not been explored fully. In this study, researchers used male Chinese‐origin rhesus macaques to assess the effects of long- and short-term ART on gut infection—across segments of the small and large intestines—in long‐term non‐progressors (LTNPs). They reported that although ART does not eliminate SIV in LTNPs, a longer ART period dramatically reduces SIV infection and diversity in the gut. Further studies are needed to better understand the reduction of HIV gut reservoirs in this context. Supported by ORIP (P51OD011133, P51OD011104), NIAID, NIMH, and NINDS.
Maternal Western-Style Diet Reduces Social Engagement and Increases Idiosyncratic Behavior in Japanese Macaque Offspring
Mitchell et al., Brain, Behavior, and Immunity. 2022.
https://www.doi.org/10.1016/j.bbi.2022.07.004
Evidence points to an association between maternal obesity and risk of early-emerging neurodevelopmental disorders in offspring, yet few preclinical studies have tested for associations between maternal Western-style diet (mWSD) and offspring behavior. Using Japanese macaques, researchers found that mWSD offspring exhibited less proximity to peers and initiated fewer affiliative social behaviors. These outcomes appear to be mediated by increased maternal interleukin-12 during the third trimester of pregnancy. Additionally, mWSD offspring displayed increased idiosyncratic behavior, which was related to alterations in maternal adiposity and leptin. These findings suggest specific prevention and intervention targets for early-emerging neurodevelopmental disorder in humans. Supported by ORIP (P51OD011092), NIMH, and NICHD.
Molecular and Cellular Evolution of the Primate Dorsolateral Prefrontal Cortex
Ma et al., Science. 2022.
https://www.doi.org/10.1126/science.abo7257
The dorsolateral prefrontal cortex (dlPFC) exists only in primates, lies at the center of high-order cognition, and is a locus of pathology underlying many neuropsychiatric diseases. The investigators generated single-nucleus transcriptome data profiling more than 600,000 nuclei from the dlPFC of adult humans, chimpanzees, rhesus macaques, and common marmosets of both sexes. Postmortem human samples were obtained from tissue donors. The investigators’ analyses delineated dlPFC cell-type homology and transcriptomic conservation across species and identified species divergence at the molecular and cellular levels, as well as potential epigenomic mechanisms underlying these differences. Expression patterns of more than 900 genes associated with brain disorders revealed a variety of conserved, divergent, and group-specific patterns. The resulting data resource will help to vertically integrate marmoset and macaque models with human-focused efforts to develop treatments for neuropsychiatric conditions. Supported by ORIP (P51OD011133), NIA, NICHD, NIDA, NIGMS, NHGRI, NIMH, and NINDS.
A Molecularly Integrated Amygdalo-Fronto-Striatal Network Coordinates Flexible Learning and Memory
Li et al., Nature Neuroscience. 2022.
https://www.doi.org/10.1038/s41593-022-01148-9
Behavioral flexibility is critical for navigating dynamic environments and requires the durable encoding and retrieval of new memories to guide future choice. The orbitofrontal cortex (OFC) supports outcome-guided behaviors, but the coordinated neural circuitry and cellular mechanisms by which OFC connections sustain flexible learning and memory are not understood fully. Using a mouse model, researchers demonstrated that the OFC neuronal ensembles store a memory trace for newly learned information. They describe the directional transmission of information within an integrated amygdalo-fronto-striatal circuit across time. Supported by ORIP (P51OD011132), NIDA, NIMH, and NINDS.
Heritability of Social Behavioral Phenotypes and Preliminary Associations with Autism Spectrum Disorder Risk Genes in Rhesus Macaques: A Whole Exome Sequencing Study
Gunter et al., Autism Research. 2022.
https://onlinelibrary.wiley.com/doi/full/10.1002/aur.2675
Investigators quantified individual variation in social interactions among juvenile rhesus macaques of both sexes using both a standard macaque ethogram (a catalogue of animal behavior over time) and a macaque-relevant modification of the human Social Responsiveness Scale to study genetic influences on key aspects of social behavior and interactions. The analyses demonstrate that various aspects of juvenile social behavior exhibit significant genetic heritability, with quantitative genetic effects similar to autism spectrum disorder (ASD) in human children. The significant genetic and sequencing data may be used to examine potential genetic associations with human ASD. Supported by ORIP (P51OD011132), NHGRI and NIMH.
Neuroinflammatory Profiling in SIV-Infected Chinese-Origin Rhesus Macaques on Antiretroviral Therapy
Solis-Leal et al., Viruses. 2022.
https://www.doi.org/10.3390/v14010139
The central nervous system (CNS) HIV reservoir contributes to residual neuroimmune activation, which can lead to HIV-associated neurocognitive disorder. Researchers characterized the expression of signaling molecules associated with inflammation in plasma, cerebrospinal fluid, and basal ganglia of Chinese-origin rhesus macaques (sex not specified) with simian immunodeficiency virus (SIV). They reported a correlation between levels of CCL2 in plasma and cerebrospinal fluid, suggesting that researchers could infer the degree of CNS inflammation by testing CCL2 levels in peripheral blood. Overall, these findings provide insight into neuroinflammation and signaling associated with HIV persistence in the CNS. Supported by ORIP (P51OD011104, P51OD011133), NIMH, and NINDS.
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.
Comparative Cellular Analysis of Motor Cortex in Human, Marmoset and Mouse
Bakken et al., Nature. 2021.
https://pubmed.ncbi.nlm.nih.gov/34616062/
Investigators used high-throughput transcriptomic and epigenomic profiling of more than 450,000 single nuclei in humans, marmosets, and mice, to characterize the cellular makeup of the primary motor cortex (M1), which exhibits similarities that mirror evolutionary distance and are consistent between the transcriptome and epigenome. Despite the overall conservation, many species-dependent specializations are apparent. These results demonstrate the robust molecular foundations of cell-type diversity in M1 across mammals and point to the genes and regulatory pathways responsible for the functional identity of cell types and their species-specific adaptations. Supported by ORIP (P51OD010425), NIMH, NCATS, NINDS, and NIDA.