Selected Grantee Publications
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- 92 results found
- S10 [SIG, BIG, HEI]
Natural Killer–Like B Cells Are a Distinct but Infrequent Innate Immune Cell Subset Modulated by SIV Infection of Rhesus Macaques
Manickam et al., PLOS Pathogens. 2024.
https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1012223
Natural killer–like B (NKB) cells express both natural killer (NK) and B cell receptors. Intracellular signaling proteins and trafficking markers were expressed differentially on naive NKB cells. CD20+ NKG2A/C+ NKB cells were identified in organs and lymph nodes of naive rhesus macaques (RMs). Single-cell RNA sequencing (scRNAseq) of sorted NKB cells confirmed that NKB cells are unique, and transcriptomic analysis of naive splenic NKB cells by scRNAseq showed that NKB cells undergo somatic hypermutation and express Ig receptors, similar to B cells. Expanded NKB frequencies were observed in RM gut and buccal mucosa after simian immunodeficiency virus (SIV) infection, and mucosal and peripheral NKB cells were associated with colorectal cytokine milieu and oral microbiome changes. NKB cells gated on CD3-CD14-CD20+NKG2A/C+ cells were inclusive of transcriptomically conventional B and NK cells in addition to true NKB cells, confounding accurate phenotyping and frequency recordings. Supported by ORIP (P51OD011132, S10OD026799) and NIAID.
Persistence of a Skewed Repertoire of NK Cells in People With HIV-1 on Long-Term Antiretroviral Therapy
Anderko et al., Journal of Immunology. 2024.
https://pubmed.ncbi.nlm.nih.gov/38551350
HIV-1 infection alters the natural killer (NK) cell phenotypic and functional repertoire. A rare population of FcRγ−NK cells exhibiting characteristics of traditional immunologic memory expands in people with HIV. In a longitudinal analysis during the first 4 years of antiretroviral therapy (ART), a skewed repertoire of cytokine unresponsive FcRγ−memory-like NK cells persisted in people with HIV, and surface expression of CD57 and KLRG1 increased, suggesting progression toward immune senescence. These traits were linked to elevated serum inflammatory biomarkers and increasing antibody titers to human cytomegalovirus (CMV), with human CMV viremia detected in approximately one-third of people studied during the first 4 years of ART. About 40% of people studied displayed atypical NK cell subsets, representing intermediate stages of NK-poiesis. These findings indicate that NK cell irregularities persist in people with HIV despite long-term ART. Supported by ORIP (P51OD011132, S10OD026799), NIAID, and NHLBI.
Proof-of-Concept Studies With a Computationally Designed Mpro Inhibitor as a Synergistic Combination Regimen Alternative to Paxlovid
Papini et al., PNAS. 2024.
As the spread and evolution of SARS-CoV-2 continues, it is important to continue to not only work to prevent transmission but to develop improved antiviral treatments as well. The SARS-CoV-2 main protease (Mpro) has been established as a prominent druggable target. In the current study, investigators evaluate Mpro61 as a lead compound, utilizing structural studies, in vitro pharmacological profiling to examine possible off-target effects and toxicity, cellular studies, and testing in a male and female mouse model for SARS-CoV-2 infection. Results indicate favorable pharmacological properties, efficacy, and drug synergy, as well as complete recovery from subsequent challenge by SARS-CoV-2, establishing Mpro61 as a promising potential preclinical candidate. Supported by ORIP (R24OD026440, S10OD021527), NIAID, and NIGMS.
Obesity Causes Mitochondrial Fragmentation and Dysfunction in White Adipocytes Due to RalA Activation
Xia et al., Nature Metabolism. 2024.
https://pubmed.ncbi.nlm.nih.gov/38286821/
This study presents a molecular mechanism for mitochondrial dysfunction as a characteristic trait of obesity. Chronic activation of the small GTPase RalA in inguinal white adipocytes (iWAT), in male mice fed a high-fat diet (HFD) represses energy expenditure by shifting mitochondrial dynamics toward excessive fission, contributing to weight gain and metabolic dysfunction. Targeted deletion of RalA in iWAT attenuated HFD-induced obesity due to increased energy expenditure and mitochondrial oxidative phosphorylation. Mechanistically, RalA dephosphorylates inhibitory Serine637 on fission protein Drp1, leading to excessive fission in adipocytes and mitochondrial fragmentation. Expression of a human homolog of Drp1—DNM1L—in adipose tissue is positively correlated with obesity and insulin resistance. These findings open avenues to investigate RalA-Drp1 axis in energy homeostasis. Supported by ORIP (S10OD023527), NCI, NHLBI, and NIDDK.
Macrophages Derived From Human Induced Pluripotent Stem Cells (iPSCs) Serve As a High-Fidelity Cellular Model for Investigating HIV-1, Dengue, and Influenza viruses
Yang et al., Journal of Virology. 2024.
https://pubmed.ncbi.nlm.nih.gov/38323811/
Macrophages can be weaponized by viruses to host viral reproduction and support long-term persistence. The most common way of studying these cells is by isolating their precursors from donor blood and differentiating the isolated cells into macrophages. This method is costly and technically challenging, and it produces varying results. In this study, researchers confirmed that macrophages derived from iPSC cell lines—a model that is inexpensive, consistent, and modifiable by genome editing—are a suitable model for experiments involving HIV and other viruses. Macrophages derived from iPSCs are as susceptible to infection as macrophages derived from blood, with similar infection kinetics and phenotypes. This new model offers researchers an unlimited source of cells for studying viral biology. Supported by ORIP (R01OD034046, S10OD021601), NIAID, NIDA, NIGMS, and NHLBI.
Tumor Explants Elucidate a Cascade of Paracrine SHH, WNT, and VEGF Signals Driving Pancreatic Cancer Angiosuppression
Hasselluhn et al., Cancer Discovery. 2024.
https://pubmed.ncbi.nlm.nih.gov/37966260/
This study presents a key mechanism that prevents pancreatic ductal adenocarcinoma (PDAC) from undergoing neoangiogenesis, which affects its development, pathophysiology, metabolism, and treatment response. Using human and murine PDAC explants, which effectively retain the complex cellular interactions of native tumor tissues, and single-cell regulatory network analysis, the study identified a cascade of three paracrine pathways bridging between multiple cell types and acting sequentially, Hedgehog to WNT to VEGF, as a key suppressor of angiogenesis in KRAS-mutant PDAC cells. This study provides an experimental paradigm for dissecting higher-order cellular interactions in tissues and has implications for PDAC treatment strategies. Supported by ORIP (S10OD012351, S10OD021764), NCI, and NIDDK.
Targeting Pancreatic Cancer Metabolic Dependencies Through Glutamine Antagonism
Encarnación-Rosado et al., Nature Cancer. 2024.
https://pubmed.ncbi.nlm.nih.gov/37814010/
Pancreatic ductal adenocarcinoma (PDAC) cells thrive in the austere, complex tumor microenvironment by reprogramming their metabolism and relying on scavenging pathways, but more work is needed to translate this knowledge into clinically relevant therapeutic interventions. Investigators demonstrated that treating PDAC cells with a Gln antagonist, 6‑diazo-5-oxo-l-norleucine (DON), caused a metabolic crisis by globally impairing Gln metabolism, resulting in a significant decrease in proliferation. They observed a profound decrease in tumor growth in several in vivo models using sirpiglenastat (DRP-104), a pro-drug version of DON that was designed to circumvent DON-associated toxicity. These proof-of-concept studies suggested that broadly targeting Gln metabolism could provide a therapeutic avenue for PDAC. Combining this therapeutic with an extracellular-signal-regulated kinase (or ERK) signaling pathway inhibitor could further improve it. Supported by ORIP (S10OD021747), NCI, and NIAID.
Molecular Basis of Human Trace Amine-Associated Receptor 1 Activation
Zilberg et al., Nature Communications. 2024.
https://www.nature.com/articles/s41467-023-44601-4
The authors reported the cryogenic electron microscopy structure of human trace amine-associated receptor 1 (hTAAR1, hTA1) signaling complex, a key modulator in monoaminergic neurotransmission, as well as its similarities and differences with other TAAR members and rodent TA1 receptors. This discovery has elucidated hTA1’s molecular mechanisms underlining the strongly divergent pharmacological properties of human and rodent TA1 and therefore will boost the translation of preclinical studies to clinical applications in treating disorders of dopaminergic dysfunction, metabolic disorders, cognitive impairment, and sleep-related dysfunction. Supported by ORIP (S10OD019994, S10OD026880, and S10OD030463), NIDA, NIGMS, NIMH, and NCATS.
Effect of Hormone Replacement Therapy on Amyloid Beta (Aβ) Plaque Density in the Rhesus Macaque Amygdala
Appleman et al., Frontiers in Aging Neuroscience. 2024.
https://www.frontiersin.org/articles/10.3389/fnagi.2023.1326747/full
Amyloid beta plaque density is associated with Alzheimer’s disease. In this study, the authors examined its concentration in aged female nonhuman primates’ cerebrospinal fluid, as well as in the amygdala, an area of the brain involved with emotion and memory. They set out to test the hypothesis that estrogen hormone replacement therapy can beneficially affect amygdala Aβ plaque density in “surgically menopausal” females (i.e., aged rhesus macaques that had undergone ovariectomy). Female rhesus macaques that received estrogen replacement therapy showed fewer amyloid plaques than those that did not receive the hormone. This effect was observed regardless of the type of diet that the animals consumed. These findings suggest that hormone replacement might be a helpful treatment to consider for Alzheimer’s disease. Supported by ORIP (P51OD011092, R24OD011895, S10OD025002) and NIA.
Plasticity of Intragraft Alloreactive T Cell Clones in Human Gut Correlates With Transplant Outcomes
Fu et al., Journal of Experimental Medicine. 2024.
https://pubmed.ncbi.nlm.nih.gov/38091025/
This study provides novel insights into tissue-resident memory T-cell (TRM) biology. The authors performed single-cell immune profiling to integrate clonotype, alloreactivity, and gene expression profiles of graft-repopulating recipient T cells in the intestinal mucosa after transplantation. They found that preexisting host-versus-graft (HvG)–reactive T cells were heterogenous and identified a trajectory from TRM to effector T/TRM profiles for rejection and dominant TRM profiles with tolerance in the quiescent allografts. Putative de novo HvG-reactive T cells showed a transcriptional profile skewed to cytotoxic effectors in rejecting grafts. Analysis of the inferred protein regulon network revealed upstream regulons for alloreactive T-cell tolerance and effector functions, opening opportunities for future translational studies to induce immune tolerance and overcome rejection. Supported by ORIP (S10OD020056) and NIAID.