Selected Grantee Publications
- 666 results found
Antiretroviral Therapy Timing Impacts Latent Tuberculosis Infection Reactivation in a Tuberculosis/Simian Immunodeficiency Virus Coinfection Model
Sharan et al., Journal of Clinical Investigation. 2021.
https://pubmed.ncbi.nlm.nih.gov/34855621/
In the rhesus macaque model for Mycobacterium tuberculosis plus simian immunodeficiency virus (SIV) co-infection, chronic immune activation rather than depletion of CD4+ T cells correlates with reactivation of latent tuberculosis infection (LTBI). Researchers administered combined antiretroviral therapy (cART) at 2 weeks post-SIV co-infection to study whether restoration of CD4+ T cell immunity occurred more broadly, and whether this prevented LTBI compared to cART initiated at 4 weeks post-SIV. Earlier initiation of cART enhanced survival led to better control of viral replication and reduced immune activation in the periphery and lung vasculature, thereby reducing the rate of SIV-induced reactivation. Supported by ORIP (K01OD031898, P51OD011133, P51OD011132, S10OD028653) and NIAID.
An NR2F1-Specific Agonist Suppresses Metastasis by Inducing Cancer Cell Dormancy
Khalil et al., The Journal of Experimental Medicine. 2021.
Researchers described the discovery of a nuclear receptor NR2F1 antagonist that specifically activates dormancy programs in malignant cells. Agonist treatment resulted in a self-regulated increase in NR2F1 mRNA and protein and downstream transcription of a novel dormancy program. This program led to growth arrest in multiple human cell lines, as well as patient-derived organoids. This effect was lost when NR2F1 was knocked out. In mice, agonist treatment resulted in inhibition of lung metastasis of head and neck squamous cell carcinomas, even after cessation of the treatment. This work provides proof of principle supporting the use of NR2F1 agonists to induce dormancy as a therapeutic strategy to prevent metastasis. Supported by ORIP (S10OD018522 and S10OD026880) and others.
Precise Visuomotor Transformations Underlying Collective Behavior in Larval Zebrafish
Harpaz et al., Nature Communications. 2021.
https://www.nature.com/articles/s41467-021-26748-0
Sensory signals from neighbors, analyzed in the visuomotor stream of animals, is poorly understood. The authors studied aggregation behavior in larval zebrafish and found that over development larvae transition from over dispersed groups to tight shoals. Young larvae turn away from virtual neighbors by integrating and averaging retina-wide visual occupancy within each eye, and by using a winner-take-all strategy for binocular integration. Observed algorithms accurately predict group structure over development. These findings allow testable predictions regarding the neuronal circuits underlying collective behavior in zebrafish. Supported by ORIP (R43OD024879, R44OD024879) and NINDS.
Deep Learning Is Widely Applicable to Phenotyping Embryonic Development and Disease
Naert et al., Development. 2021.
https://pubmed.ncbi.nlm.nih.gov/34739029/
Genome editing simplifies the generation of new animal models for congenital disorders. The authors illustrate how deep learning (U-Net) automates segmentation tasks in various imaging modalities. They demonstrate this approach in embryos with polycystic kidneys (pkd1 and pkd2) and craniofacial dysmorphia (six1). They provide a library of pre-trained networks and detailed instructions for applying deep learning to datasets and demonstrate the versatility, precision, and scalability of deep neural network phenotyping on embryonic disease models. Supported by ORIP (P40OD010997, R24OD030008), NICHD, NIDDK, and NIMH.
Monoclonal Antibodies Protect Aged Rhesus Macaques From SARS-CoV-2-Induced Immune Activation and Neuroinflammation
Verma et al., Cell Reports. 2021.
https://www.sciencedirect.com/science/article/pii/S2211124721014157?via%3Dihub
In aged diabetic female rhesus macaques, prophylactic administration of neutralizing monoclonal antibodies (mAbs) effectively limits SARS-CoV-2 replication in both the upper and lower respiratory tract, and decreases immune activation, including reducing interferon-induced chemokines and limiting effector CD4 T cell influx into the cerebrospinal fluid. These protective mechanisms took place in the areas of the body targeted by the virus and may prevent adverse inflammatory consequences of SARS-CoV-2 infection in high-risk populations. Supported by ORIP (P51OD011107), NIAID, and NIA.
Blastocyst Development After Fertilization with In Vitro Spermatids Derived From Nonhuman Primate Embryonic Stem Cells
Khampang et al., F & Science. 2021.
https://www.sciencedirect.com/science/article/pii/S2666335X21000665?via%3Dihub
Rhesus macaque pluripotent stem cells were differentiated into spermatogenic germ cell linages and matured in vitro to form spermatids that were capable of fertilizing oocytes (female or germ cells involved in reproduction) by intracytoplasmic spermatid injection (i.e., the egg is fertilized outside the body and the sperm is injected through a needle into the egg). Successful in vitro preimplantation embryo development was observed in approximately 12% of zygotes. The data suggest potential mechanisms to address male infertility. Supported by ORIP (R21OD020182, R01OD028223, P51OD011092).
Deciphering the Role of Mucosal Immune Responses and the Cervicovaginal Microbiome in Resistance to HIV Infection in HIV-Exposed Seronegative Women
Ponnan et al., Microbiology Spectrum. 2021.
https://journals.asm.org/doi/10.1128/Spectrum.00470-21
Identifying correlates of protection in HIV-exposed seronegative (HESN) individuals requires identification of HIV-specific local immune responses. Researchers performed a comprehensive investigation of the vaginal mucosa and cervicovaginal microbiome in HESN women. They found elevated antiviral cytokines, soluble immunoglobulins, activated NK cells, CXCR5+ CD8+ T cells, and T follicular helper cells in HESN women compared to HIV-unexposed healthy women. They also found greater bacterial diversity and increased abundance of Gardnerella species in the mucosa of HESN women. These findings suggest that the genital tract of HESN women contains innate immune factors, antiviral mediators, and T cell subsets that protect against HIV. Supported by ORIP (P51OD011132) and NIAID.
Selective G Protein Signaling Driven by Substance P–Neurokinin Receptor Dynamics
Harris et al., Nature Chemical Biology. 2021.
https://www.nature.com/articles/s41589-021-00890-8
Investigators determined the cryogenic-electron microscopy structures of active neurokinin-1 receptor (NK1R) bound to neuropeptide substance P (SP) or the G protein q (Gq)-biased peptide SP6–11. Peptide interactions deep within NK1R are critical for receptor activation. Conversely, interactions between SP and NK1R extracellular loops are required for potent Gs-signaling but not Gq-signaling. Molecular dynamics simulations showed that these superficial contacts restrict SP flexibility. SP6–11, which lacks these interactions, is dynamic while bound to NK1R. Structural dynamics of NK1R agonists therefore depend on interactions with the receptor extracellular loops and regulate G protein signaling selectivity. This data unveils the molecular mechanism of how two stimuli (SP and Neurokinin A) yield distinct G protein signaling at the same G protein-coupled receptor. Supported by ORIP (S10OD021741, S10OD020054) and others.
Negative Inotropic Mechanisms of β-cardiotoxin in Cardiomyocytes by Depression of Myofilament ATPase Activity without Activation of the Classical β-Adrenergic Pathway
Lertwanakarn et al., Scientific Reports. 2021.
https://www.nature.com/articles/s41598-021-00282-x
Beta-cardiotoxin (β-CTX) from the king cobra venom (Ophiophagus hannah) was previously proposed as a novel β-adrenergic blocker. However, the involvement of β-adrenergic signaling by this compound has never been elucidated. The objectives of this study were to investigate the underlying mechanisms of β-CTX as a β-blocker and its association with the β-adrenergic pathway. Healthy Sprague Dawley rats were used for cardiomyocytes isolation. In summary, the negative inotropic mechanism of β-CTX was discovered. β-CTX exhibits an atypical β-blocker mechanism. These properties of β-CTX may benefit in developing a novel agent aid to treat hypertrophic cardiomyopathy. Supported by ORIP (P40OD010960) and NHLBI.
CD4+ T Cells Are Dispensable for Induction of Broad Heterologous HIV Neutralizing Antibodies in Rhesus Macaques
Sarkar et al., Frontiers in Immunology. 2021.
https://www.frontiersin.org/articles/10.3389/fimmu.2021.757811/full
Researchers investigated the humoral response in vaccinated rhesus macaques with CD4+ T cell depletion, using the VC10014 DNA protein co-immunization vaccine platform (with gp160 plasmids and gp140 trimeric proteins derived from an HIV-1 infected subject). Both CD4+-depleted and non-depleted animals developed comparable Tier 1 and 2 heterologous HIV-1 neutralizing plasma antibody titers. Thus, primates generate HIV neutralizing antibodies in the absence of robust CD4+ T cell help, which has important implications for vaccine development. Supported by ORIP (P51OD011092, P40OD028116, U42OD023038, U42OD010426), NIAID, and NIDCR.