Selected Grantee Publications
Lymph-Node-Based CD3+ CD20+ Cells Emerge From Membrane Exchange Between T Follicular Helper Cells and B Cells and Increase Their Frequency Following Simian Immunodeficiency Virus Infection
Samer et al., Journal of Virology. 2023.
https://www.doi.org/10.1128/jvi.01760-22
CD4+ T follicular helper cells are known to persist during antiretroviral therapy (ART) and have been identified as key targets for viral replication and persistence. Researchers identified a lymphocyte population that expresses CD3 (i.e., T cell lineage marker) and CD20 (i.e., B cell lineage marker) on the cellular surface in lymphoid tissues from rhesus macaques of both sexes and humans of male and female sexes. In macaques, the cells increased following simian immunodeficiency virus infection, were reduced with ART, and increased in frequency after ART interruption. These cells represent a potential area for future therapeutic strategies. Supported by ORIP (P51OD011132, U42OD011023), NIAID, NCI, NIDDK, NIDA, NHLBI, and NINDS.
Infection of the Maternal–Fetal Interface and Vertical Transmission Following Low-Dose Inoculation of Pregnant Rhesus Macaques (Macaca mulatta) with an African-Lineage Zika Virus
Koenig et al., PLOS ONE. 2023.
https://doi.org/10.1371/journal.pone.0284964
Researchers examined transmission of Zika virus to nonhuman primate fetuses during pregnancy. Even with a low dosage of inoculation of the dams, the investigators found that the Zika virus infected fetuses, despite the presence of a “placental fortress,” which normally protects fetuses during gestation. This transmission illustrates the high level of infectivity threat that Zika poses, which may increase if mosquitoes expand their global habitats. Understanding how Zika breaches the placental barrier will help researchers develop strategies to prevent fetal infection during pregnancy and thereby prevent adverse outcomes, such as brain malformation defects. Supported by ORIP (P51OD011106, S10OD023526), NIAID, NCI, and NIGMS.
Cell-Type Memory in a Single-Cell Eukaryote Requires the Continuous Presence of a Specific Transcription Regulator
Lee et al., PNAS. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10214202/
Investigators studied the fundamental question and underlying mechanism of how a eukaryotic cell type can be stably maintained through many rounds of DNA replication and cell division in a fungal species where two different cell types (i.e., white and opaque) arise from the same genome. Investigators found that destruction of Wor1, the primary transcription activator of the opaque state, led opaque cells to irreversibly lose their memory and switch to the white-cell state within about 1 hour. This study demonstrates that the continuous presence of Wor1 is needed to maintain the opaque cell state. Data also suggested that a threshold concentration of Wor1 is needed to maintain the opaque state, indicating the importance of the transcription factor in maintaining cell-type memory. Supported by ORIP (S10OD028511), NIAID, and NIGMS.
CD8+ T Cells Promote HIV Latency by Remodeling CD4+ T Cell Metabolism to Enhance Their Survival, Quiescence, and Stemness
Mutascio et al., Immunity. 2023.
https://www.doi.org/10.1016/j.immuni.2023.03.010
An HIV reservoir persists following antiretroviral therapy, representing the main barrier to an HIV cure. Using a validated in vitro model, investigators explored the mechanism by which CD8+ T cells promote HIV latency and inhibit latency reversal in HIV-infected CD4+ T cells. They reported that CD8+ T cells favor the establishment of HIV latency by modulating metabolic, stemness, and survival pathways that correlate with the downregulation of HIV expression and promote HIV latency. In future studies, comparative analyses may provide insight into common molecular mechanisms in the silencing of HIV expression by CD8+ T cells and macrophages, which can be applied to new intervention strategies that target the HIV reservoir. Supported by ORIP (P51OD011132, S10OD026799), NIAID, NIDDK, NIDA, NHLBI, and NINDS.
Cannabinoid Enhancement of lncRNA MMP25-AS1/MMP25 Interaction Reduces Neutrophil Infiltration and Intestinal Epithelial Injury in HIV/SIV Infection
Premadasa et al., Journal of Clinical Investigation Insight. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10132162/
Gastrointestinal CD4+ T cell depletion during acute simian immunodeficiency virus (SIV) and HIV infection causes significant structural and functional damage, disrupting intestinal immune homeostasis and leading to intestinal epithelial barrier dysfunction. Oral phytocannabinoids are safe and well tolerated in people with HIV, but more information is needed regarding the effects of long-term tetrahydrocannabinol (THC) use on the intestinal epithelial compartment. Investigators profiled gene expression in the colonic epithelium of SIV-infected rhesus macaques of both sexes that were administered THC. They reported that low-dose THC can reduce neutrophil infiltration and intestinal epithelial injury, potentially by downregulating MMP25 expression through modulation of a long noncoding RNA, MMP25-AS1. Supported by ORIP (P51OD011104, P51OD011103), NIAID, and NIDA.
An E1–E2 Fusion Protein Primes Antiviral Immune Signaling in Bacteria
Ledvina et al., Nature. 2023.
https://www.nature.com/articles/s41586-022-05647-4
Investigators show that the cGAS/DncV–like nucleotidyltransferase (CD‑NTase)–associated protein 2 (Cap2) primes bacterial CD-NTases for activation through a ubiquitin transferase–like mechanism. A cryo-electron microscopy structure of the Cap2-CD-NTase complex reveals Cap2 as an all-in-one ubiquitin transferase–like protein, with distinct domains resembling eukaryotic E1 and E2 proteins. The structure captures a reactive-intermediate state with the CD-NTase C terminus positioned in the Cap2 E1 active site and conjugated to AMP. Cap2 conjugates the CD-NTase C terminus to a target molecule that primes the CD-NTase for increased cGAMP production. The investigators further demonstrate bacteria control immune signaling using an ancient, minimized ubiquitin transferase–like system and provide insight into the evolution of the E1 and E2 machinery across domains of life. Supported by ORIP (S10OD023498, S10OD021527, S10OD025267) and NIGMS.
Resolution of Structural Variation in Diverse Mouse Genomes Reveals Chromatin Remodeling due to Transposable Elements
Ferraj et al., Cell Genomics. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10203049/
Diverse inbred mouse strains are important biomedical research models, yet genome characterization of many strains is fundamentally lacking in comparison with humans. Here, investigators used long-read whole genome sequencing to assemble the genomes of 20 diverse inbred laboratory strains of mice. From whole-genome comparisons, they generated a sequence-resolved callset of 413,758 structural variants. These data are presented as a comprehensive resource that can be used for future genomic studies, aid in modeling and studying the effects of genetic variation, and enhance genotype-to-phenotype research. Supported by ORIP (R24OD021325), NCI, NIGMS, and NHGRI.
Topologically Associating Domain Boundaries Are Required for Normal Genome Function
Rajderkar et al., Communications Biology. 2023.
https://www.nature.com/articles/s42003-023-04819-w
Eukaryotic genomes fold into topologically associating domains (TADs), sub-megabase-scale chromatin segments characterized by high intra-domain chromatin contact frequency. Investigators selected eight independent TAD boundaries in the vicinity of genes active during embryonic development, individually deleted these boundaries from the mouse genome, and systematically examined the consequences on survival, genome organization, gene expression, and development. Results of the studies demonstrate the importance of TAD boundary sequences for in vivo genome function and reinforce the critical need to consider the potential pathogenicity of deletions affecting TAD boundaries in clinical genetics screening. Supported by ORIP (UM1OD023221), NIGMS, and NHGRI.
Identification of a Heterogeneous and Dynamic Ciliome during Embryonic Development and Cell Differentiation
Elliott et al., Development. 2023.
Ciliopathies are a class of diseases that arise when the structure or function of the cilium is compromised. To definitively determine the extent of heterogeneity within the ciliome, investigators compared the ciliomes of six distinct embryonic domains. The data comprehensively revealed that about 30% of the ciliome is differentially expressed across analyzed tissues in the developing embryo. Furthermore, upregulation of numerous ciliary genes correlated with osteogenic cell-fate decisions, suggesting that changes in the ciliome contribute to distinct functions of cell types in vertebrate species. Supported by ORIP (UM1OD023222), NIDCR, and NIGMS.
Cerebrospinal Fluid Protein Markers Indicate Neuro-Damage in SARS-CoV-2-Infected Nonhuman Primates
Maity et al., Molecular & Cellular Proteomics. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9981268/
In this study, researchers examined the proteins expressed in cerebrospinal fluid (CSF) in nonhuman primates (NHPs) to better understand how COVID-19 infection can result in brain pathology, a common outcome. The study found that even in NHPs with minimal or mild COVID‑19, CSF proteins were significantly dysregulated compared with uninfected NHPs. Furthermore, the most affected proteins were enriched in the same brain regions that show lesions after COVID-19 infection, including the cerebral cortex, basal ganglia, and brain stem. Collectively, these regions have wide-ranging control over such crucial functions as cognition, motor control, and breathing, showing how even mild COVID-19 infection can result in significant neurological impairment. Supported by ORIP (P51OD011104, S10OD032453), NIGMS, NCI, and NICHD.