Selected Grantee Publications
Psychosocial Stress Alters the Immune Response and Results in Higher Viral Load During Acute SIV Infection in a Pigtailed Macaque Model of HIV
Guerrero-Martin et al., Journal of Infectious Diseases. 2021.
https://doi.org/10.1093/infdis/jiab252
Social distancing is an important countermeasure for a pandemic, but social isolation may also have adverse health outcomes in the context of infectious diseases, such as HIV. Researchers compared commonly measured parameters of HIV progression between singly and socially housed simian immunodeficiency virus (SIV)-infected pigtailed macaques. Throughout acute SIV infection, singly housed pigtailed macaques had a higher viral load in the plasma and cerebrospinal fluid and demonstrated greater CD4+ T cell declines and more CD4+ and CD8+ T cell activation compared to socially housed macaques. These findings suggest that psychosocial stress could augment the progression of HIV infection. Supported by ORIP (U42OD013117, P40OD013117, K01OD018244), NIAID, NINDS, and NIMH.
Combining In Vivo Corneal Confocal Microscopy With Deep Learning-Based Analysis Reveals Sensory Nerve Fiber Loss in Acute Simian Immunodeficiency Virus Infection
McCarron et al., Cornea. 2021.
https://doi.org/10.1097/ICO.0000000000002661
Researchers characterized corneal subbasal nerve plexus features of normal and simian immunodeficiency virus (SIV)-infected pigtail and rhesus macaques using in vivo confocal microscopy and a deep learning approach for automated assessments. Corneal nerve fiber length and fractal dimension measurements did not differ between species, but pigtail macaques had significantly higher baseline corneal nerve fiber tortuosity than rhesus macaques. Acute SIV infection induced decreased corneal nerve fiber length and fractal dimension in the pigtail macaque model for HIV. Adapting deep learning analyses to clinical corneal nerve assessments will improve monitoring of small sensory nerve fiber damage in numerous clinical contexts, including HIV. Supported by ORIP (U42OD013117) and NINDS.
MRI Characteristics of Japanese Macaque Encephalomyelitis (JME): Comparison to Human Diseases
Tagge et al., Journal of Neuroimaging. 2021.
https://onlinelibrary.wiley.com/doi/10.1111/jon.12868
Magnetic resonance imaging data (MRI) were obtained from 114 Japanese macaques, including 30 animals of both sexes that presented with neurological signs of Japanese macaque encephalomyelitis (JME). Quantitative estimates of blood-brain barrier permeability to gadolinium-based-contrast agent (GBCA) were obtained in acute, GBCA-enhancing lesions, and longitudinal imaging data were acquired for 15 JME animals. Intense, focal neuroinflammation was a key MRI finding in JME. Several features of JME compare directly to human inflammatory demyelinating diseases. The development and validation of noninvasive imaging biomarkers in JME provides the potential to improve diagnostic specificity and contribute to the understanding of human demyelinating diseases. Supported by ORIP (P51OD011092, S10OD018224), NINDS, and NIBIB.
Evidence in Primates Supporting the Use of Chemogenetics for the Treatment of Human Refractory Neuropsychiatric Disorders
Roseboom et al., Molecular Therapy. 2021.
https://doi.org/10.1016/j.ymthe.2021.04.021
A rhesus macaque model for pathological anxiety was used to investigate the feasibility of decreasing anxiety using chemogenetics, known as DREADDs (designer receptors exclusively activated by designer drugs), to reduce amygdala neuronal activity. A low-dose clozapine administration strategy was developed to induce DREADD-mediated amygdala inhibition. Compared to controls, clozapine selectively decreased anxiety-related freezing behavior in the human intruder paradigm in the chemogentic monkeys, while coo vocalizations and locomotion were unaffected. These results are an important step in establishing chemogenetic strategies for patients with refractory neuropsychiatric disorders in which amygdala alterations are central to disease pathophysiology. Supported by ORIP (P51OD011106), NIMH, and NICHD.
The High Affinity Dopamine D2 Receptor Agonist MCL-536: A New Tool for Studying Dopaminergic Contribution to Neurological Disorders
Subburaju et al., ACS Chemical Neuroscience. 2021.
https://pubs.acs.org/doi/full/10.1021/acschemneuro.1c00094
The dopamine D2 receptor exists in two different states, D2high and D2low; the former is the functional form of the D2 receptor and associates with intracellular G-proteins. The D2 agonist [3H]MCL-536 has high affinity for the D2 receptor (Kd 0.8 nM) and potently displaces the binding of (R-(-)-N-n-propylnorapomorphine (NPA; Ki 0.16 nM) and raclopride (Ki 0.9 nM) in competition binding assays. The authors characterized [3H]MCL-536. [3H]MCL-536 as metabolically stable. In vitro autoradiography on transaxial and coronal brain sections showed specific binding of [3H]MCL-536. [3H]MCL-536's unique properties make it a valuable tool for research on neurological disorders like Parkinson's disease or schizophrenia. Supported by ORIP (R43OD020186, R44OD024615) and NIMH.
Rhesus Macaques Build New Social Connections After a Natural Disaster
Testard et al., Current Biology. 2021.
https://www.sciencedirect.com/science/article/pii/S0960982221003687
Climate change has increased the frequency and intensity of weather-related disasters such as hurricanes and floods. In 2017, Puerto Rico suffered its worst natural disaster, Hurricane Maria, leaving 3,000 dead and provoking a mental health crisis. Cayo Santiago Island, home to a population of rhesus macaques (Macaca mulatta), was devastated by this storm. Testard et al. compared social networks of two groups of macaques before and after the hurricane and found an increase in affiliative social connections, driven largely by monkeys most socially isolated before Hurricane Maria. Further analysis revealed monkeys invested in building new relationships rather than strengthening existing ones. Supported by ORIP (P40OD012217), NIA, and NIMH.
Interneuron Origins in the Embryonic Porcine Medial Ganglionic Eminence
Casalia et al., Journal of Neuroscience. 2021.
https://pubmed.ncbi.nlm.nih.gov/33637558/
The authors report that transcription factor expression patterns in porcine embryonic subpallium are similar to rodents. Their findings reveal that porcine embryonic MGE progenitors could serve as a valuable source for interneuron-based xenotransplantation therapies. They demonstrate that porcine medial ganglionic eminence exhibits a distinct transcriptional and interneuron-specific antibody profile, in vitro migratory capacity, and are amenable to xenotransplantation. This is the first comprehensive examination of embryonic interneuron origins in the pig; because a rich neurodevelopmental literature on embryonic mouse medial ganglionic eminence exists (with some additional characterizations in monkeys and humans), their work allows direct neurodevelopmental comparisons with this literature. Supported by ORIP (U42OD011140) and NINDS.
Autologous Transplant Therapy Alleviates Motor and Depressive Behaviors in Parkinsonian Monkeys
Tao et al., Nature Medicine. 2021.
https://www.nature.com/articles/s41591-021-01257-1
Generation of induced pluripotent stem cells (iPSCs) enables standardized of dopamine (DA) neurons for autologous transplantation therapy to improve motor functions in Parkinson disease (PD). Adult male rhesus PD monkeys receiving autologous, but not allogenic, transplantation exhibited recovery from motor and depressive signs of PD over a 2-year period without immunosuppressive therapy. Mathematical modeling showed correlations between surviving DA neurons with PET signal intensity and behavior recovery regardless of autologous or allogeneic transplant, suggesting a predictive power of PET and motor behaviors for surviving DA neuron number. The results demonstrate favorable efficacy of the autologous transplant approach to treat PD. Supported by ORIP (P51OD011106) NINDS, and NICHD.
Larval Zebrafish Use Olfactory Detection of Sodium and Chloride to Avoid Salt Water
Herrera et al., Current Biology. 2021.
https://pubmed.ncbi.nlm.nih.gov/33338431/
Zebrafish are freshwater fish unable to tolerate high-salt environments and would benefit from neural mechanisms that enable the navigation of salt gradients to avoid high salinity. Yet zebrafish lack epithelial sodium channels, the primary conduit land animals use to taste sodium. This suggests fish may possess novel, undescribed mechanisms for salt detection. In the present study, the authors show that zebrafish indeed respond to small temporal increases in salt by reorienting more frequently. In summary, this study establishes that zebrafish larvae can navigate and thus detect salinity gradients and that this is achieved through previously undescribed sensory mechanisms for salt detection. Supported by ORIP (R43OD024879, R44OD024879) and NINDS.
Evaluating a New Class of AKT/mTOR Activators for HIV Latency-Reversing Activity Ex Vivo and In Vivo
Gramatica et al., Journal of Virology. 2021.
https://doi.org/10.1128/JVI.02393-20
Activation of latent HIV-1 expression could benefit many HIV cure strategies. Researchers evaluated two AKT/mTOR activators, SB-216763 and tideglusib, as a potential new class of LRAs. The drugs reactivated latent HIV-1 present in blood samples from aviremic individuals on antiretroviral therapy without causing T cell activation or impaired effector function of cytotoxic T lymphocytes or NK cells. When tested in vivo in monkeys, tideglusib showed unfavorable pharmacodynamic properties and did not reverse SIV latency. The discordance between the ex vivo and in vivo results underscores the importance of developing novel LRAs that allow systemic drug delivery to relevant anatomical compartments. Supported by ORIP (P51OD011092), NIAID, NIGMS, NIMH, and NCI.