Selected Grantee Publications
Loss of Gap Junction Delta-2 (GJD2) Gene Orthologs Leads to Refractive Error in Zebrafish
Quint et al., Communications Biology. 2021.
https://pubmed.ncbi.nlm.nih.gov/34083742/
Myopia is the most common developmental disorder of juvenile eyes. Although little is known about the functional role of GJD2 in refractive error development, the authors find that depletion of gjd2a (Cx35.5) or gjd2b (Cx35.1) orthologs in zebrafish cause changes in eye biometry and refractive status. Their immunohistological and scRNA sequencing studies show that Cx35.5 (gjd2a) is a retinal connexin; its depletion leads to hyperopia and electrophysiological retina changes. They found a lenticular role; lack of Cx35.1 (gjd2b) led to a nuclear cataract that triggered axial elongation. The results provide functional evidence of a link between gjd2 and refractive error. Supported by ORIP (R24OD026591), NIGMS, and NINDS.
A Participant-Derived Xenograft Model of HIV Enables Long-Term Evaluation of Autologous Immunotherapies
McCann et al., Journal of Experimental Medicine. 2021.
https://doi.org/10.1084/jem.20201908
HIV-specific CD8+ T cells partially control viral replication but rarely provide lasting protection due to immune escape. Investigators showed that engrafting NSG mice with memory CD4+ T cells from HIV+ donors enables evaluation of autologous T cell responses while avoiding graft-versus-host disease. Treating HIV-infected mice with clinically relevant T cell products reduced viremia. In vivo activity was significantly enhanced when T cells were engineered with surface-conjugated nanogels carrying an Interleukin-15 superagonist but was ultimately limited by the pervasive selection of escape mutations, recapitulating human patterns. This “participant-derived xenograft” model provides a powerful tool for developing T cell-based therapies for HIV. Supported by ORIP (R01OD011095), NIAID, NIDA, NIMH, NINDS, and NCATS.
Cell-Specific Transcriptional Control of Mitochondrial Metabolism by TIF1γ Drives Erythropoiesis
Rossmann et al., Science. 2021.
https://pubmed.ncbi.nlm.nih.gov/33986176/
Transcription and metabolism both influence cell function but dedicated transcriptional control of metabolic pathways that regulate cell fate has rarely been defined. The authors discovered that inhibition of the pyrimidine biosynthesis enzyme dihydroorotate dehydrogenase (DHODH) rescues erythroid differentiation in bloodless zebrafish moonshine (mon) mutant embryos defective for transcriptional intermediary factor 1 gamma (tif1γ). Upon tif1γ loss, CoQ levels are reduced, and a high succinate/α-ketoglutarate ratio leads to increased histone methylation. A CoQ analog rescues mon's bloodless phenotype. These results demonstrate that mitochondrial metabolism is a key output of a lineage transcription factor that drives cell fate decisions in the early blood lineage. Supported by ORIP (R24OD017870), NIGMS, NHLBI, and NCI.
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.
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.
Cryopreservation Method for Drosophila melanogaster Embryos
Zhan et al., Nature Communications. 2021.
https://www.nature.com/articles/s41467-021-22694-z
Drosophila melanogaster is a premier model for biomedical research. However, preservation of Drosophila stocks is labor intensive and costly. Researchers at University of Minnesota reported an efficient method for cryopreservation by optimizing key steps including embryo permeabilization and cryoprotectant agent loading. This method resulted in more than 10% of embryos developing into fertile adults after cryopreservation for 25 distinct strains from different sources. The further optimization and wide adoption of this protocol will solve the long-standing issue in reliably preserving Drosophila stocks and will significantly impact Drosophila as a model organism for biomedical research. Supported by ORIP (R21OD028758) and NIGMS.
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.
Characterization of Axolotl Lampbrush Chromosomes by Fluorescence In Situ Hybridization and Immunostaining
Keinath et al., Experimental Cell Research. 2021.
https://pubmed.ncbi.nlm.nih.gov/33675804/
The lampbrush chromosomes (LBCs) in oocytes of the Mexican axolotl (Ambystoma mexicanum) were identified by their relative lengths and predicted centromeres; they have never been associated completely with the mitotic karyotype, linkage maps, or genome assembly. The authors identified 9 of the axolotl LBCs using RNA sequencing to identify actively transcribed genes and 13 bacterial artificial clone probes containing pieces of active genes. This study presents a simple and reliable way to identify each axolotl LBC cytologically and to anchor chromosome-length sequences to the LBCs by immunostaining and fluorescence in situ hybridization. This data will facilitate a more detailed analysis of LBC loops. Supported by ORIP (P40OD019794, R24OD010435) and NIGMS.
Functional Convergence of a Germline-Encoded Neutralizing Antibody Response in Rhesus Macaques Immunized with HCV Envelope Glycoproteins
Chen et al., Immunity. 2021.
https://doi.org/10.1016/j.immuni.2021.02.013
Immunoglobulin heavy chain variable gene IGHV1-69-encoded broadly neutralizing antibodies (bnAbs) targeting the hepatitis C virus (HCV) envelope glycoprotein (Env) E2 are important for protection against HCV infection in humans. An IGHV1-69 ortholog, VH1.36, is preferentially used for bnAbs isolated from rhesus macaques immunized against HCV Env. Researchers investigated the genetic, structural, and functional properties of VH1.36-encoded bnAbs generated by HCV Env vaccination of macaques and compared their findings to IGHV1-69-encoded bnAbs from HCV patients. The investigators found that macaque VH1.36- and human IGHV1-69-encoded bnAbs share many common features, which provides an excellent framework for rational HCV vaccine design and testing. Supported by ORIP (P51OD011133, U42OD010442), NIAID, NCI, and NIGMS.
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.