Selected Grantee Publications
CD8+ T Cells Control SIV Infection Using Both Cytolytic Effects and Non-Cytolytic Suppression of Virus Production
Policicchio et al., Nature Communications. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10589330/
HIV continuously evades and subdues the host immune responses through multiple strategies, and an understanding of these strategies can help inform research efforts. Using a mathematical model, investigators assessed whether CD8+ cells from male rhesus macaques exert a cytolytic response against infected cells prior to viral production. Their goal was to elucidate the possible mode of action of CD8+ cells on simian immunodeficiency virus (SIV)–infected cells. Models that included non‑cytolytic reduction of viral production best explained the viral profiles across all macaques, but some of the best models also included cytolytic mechanisms. These results suggest that viral control is best explained by the combination of cytolytic and non-cytolytic effects. Supported by ORIP (P40OD028116, R01OD011095), NIAID, NIDDK, and NHLBI.
Timing of Initiation of Anti-Retroviral Therapy Predicts Post-Treatment Control of SIV Replication
Pinkevych et al., PLOS Pathogens. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10558076/
Researchers are interested in approaches to reducing viral rebound following interruption of antiretroviral therapy, but more work is needed to understand major factors that determine the viral “setpoint” level. Researchers previously assessed how timing of treatment can affect the frequency of rebound from latency. In the current study, the authors analyzed data from multiple studies of simian immunodeficiency virus (SIV) infection in rhesus macaques to further explore the dynamics and predictors of post-treatment viral control. They determined that the timing of treatment initiation was a major predictor of both the level and the duration of post-rebound SIV control. These findings could help inform future treatments. Supported by ORIP (U42OD011023, P51OD011132, P51OD011092), NIAID, NCI, NIDA, NIDDK, NHLBI, NIMH, and NINDS
Increased Collective Migration Correlates With Germline Stem Cell Competition in a Basal Chordate
Fentress and De Tomaso et al., PLOS One. 2023.
https://pubmed.ncbi.nlm.nih.gov/37903140/
Cell competition is a process that compares the relative fitness of progenitor cells and results in healthier cells, contributing a higher proportion to the final tissue composition. Investigators are studying cell competition in a novel model organism, the colonial ascidian, Botryllus schlosseri. They demonstrated that winner germline stem cells show enhanced migratory ability to chemotactic cues ex vivo and that enhanced migration correlates with both expression of the Notch ligand, Jagged, and cluster size. The ability to study conserved aspects of cell migration makes Botryllus an excellent model for future studies on competition, chemotaxis, and collective cell migration. Supported by ORIP (R21OD030520) and NIGMS.
Enhanced IL-17 Producing and Maintained Cytolytic Effector Functions of Gut Mucosal CD161+ CD8+ T Cells in SIV-Infected Rhesus Macaques
Thirugnanam et al., Viruses. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10535321/
HIV infection is associated with the depletion of CD161-expressing CD4+ Th17 cells, but the effects on other IL-17–producing T cell subsets are not understood fully. Researchers characterized the functions of non-invariant CD161-expressing CD8+ T cell subpopulations in peripheral blood and mucosal tissues of rhesus macaques (sex not specified) during chronic simian immunodeficiency virus (SIV) infection. They demonstrated that cell frequencies and function were unaffected by infection, but enhanced IL-17 production capacity and sustained Th1-type and cytolytic functions were observed. This work suggests that CD161-expressing CD8+ T cells might have important functions in gut mucosal immunity during chronic HIV infection. Supported by ORIP (P51OD011104, S10OD026800), NIAID, NIDDK, and NIMH.
A Gut-Restricted Glutamate Carboxypeptidase II Inhibitor Reduces Monocytic Inflammation and Improves Preclinical Colitis
Peters et al., Science Translational Medicine. 2023.
https://www.science.org/doi/10.1126/scitranslmed.abn7491
Many patients with moderate-to-severe inflammatory bowel disease (IBD) do not have adequate disease control, and glutamate carboxypeptidase II (GCPII) offers a promising target for therapeutic development. Researchers generated a class of GCPII inhibitors. They demonstrated that the inhibitor reduced monocytic inflammation in mice and protected against the loss of barrier integrity in primary human colon epithelial air–liquid interface monolayers. Their findings suggest that local inhibition of GCPII could be applied for the development of IBD therapeutics. Supported by ORIP (K01OD030517, T32OD011089), NIGMS, and NCCIH.
Identification of an Anergic BND Cell–Derived Activated B Cell Population (BND2) in Young-Onset Type 1 Diabetes Patients
Stensland et al., The Journal of Experimental Medicine. 2023.
https://pubmed.ncbi.nlm.nih.gov/37184563/
B cells have been shown to play a role in the pathogenesis of type 1 diabetes (T1D), but the specificity, phenotype, and function of B cells in young-onset T1D is not understood fully. The investigators performed a cross-sectional analysis comparing insulin-reactive to tetanus-reactive B cells in the blood of male and female T1D patients and control participants using mass cytometry. They found elevated insulin-reactive BND2 cells in the blood and pancreatic lymph nodes of young-onset T1D donors. This work suggests that an antigen-specific B cell subset could contribute to the rapid progression of young-onset T1D. Supported by ORIP (K01OD028759) and NIDDK.
A Germ-Free Humanized Mouse Model Shows the Contribution of Resident Microbiota to Human-Specific Pathogen Infection
Wahl et al., Nature Biotechnology. 2023.
https://www.nature.com/articles/s41587-023-01906-5
Germ-free (GF) mice are of limited value in the study of human-specific pathogens because they do not support their replication. In this report, investigators developed a GF humanized mouse model using the bone marrow–liver–thymus platform to provide a robust and flexible in vivo model that can be used to study the role of resident microbiota in human health and disease. They demonstrated that resident microbiota promote viral acquisition and pathogenesis by using two human-specific pathogens, Epstein–Barr virus and HIV. Supported by ORIP (P40OD010995), FIC, NIAID, NCI, and NIDDK.
A Comprehensive Drosophila Resource to Identify Key Functional Interactions Between SARS-CoV-2 Factors and Host Proteins
Guichard et al., Cell Reports. 2023.
https://pubmed.ncbi.nlm.nih.gov/37480566/
To address how interactions between SARS-CoV-2 factors and host proteins affect COVID-19 symptoms, including long COVID, and facilitate developing effective therapies against SARS-CoV-2 infections, researchers reported the generation of a comprehensive set of resources, mainly genetic stocks and a human cDNA library, for studying viral–host interactions in Drosophila. Researchers further demonstrated the utility of these resources and showed that the interaction between NSP8, a SARS-CoV-2 factor, and ATE1 arginyltransferase, a host factor, causes actin arginylation and cytoskeleton disorganization, which may be relevant to several pathogenesis processes (e.g., coagulation, cardiac inflammation, fibrosis, neural damage). Supported by ORIP (R24OD028242, R24OD022005, R24OD031447), NIAID, NICHD, NIGMS, and NINDS.
Proteomic Profiling of Extracellular Vesicles Isolated From Plasma and Peritoneal Exudate in Mice Induced by Crotalus scutulatus scutulatus Crude Venom and Its Purified Cysteine-Rich Secretory Protein (Css-CRiSP)
Reyes et al., Toxins (Basel). 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10467150/
Toxins in viperid snakes can induce clinically heterogeneous effects, but most viper venoms are composed of only 10 main protein families. Researchers investigated the proteome expression profile of extracellular vesicles isolated from biofluid samples from male and female mice after injection with crude venom and cysteine-rich secretory proteins. They reported changes in the expression of proteins involved in cell adhesion, cytoskeleton rearrangement, signal transduction, immune responses, and vesicle-mediated transports. This work could be applied in future efforts for early detection and assessment of local effects. Supported by ORIP (P40OD010960), NIGMS, and NHLBI.
The Landscape of Tolerated Genetic Variation in Humans and Primates
Gao et al., Science. 2023.
Investigators created a whole-genome sequence database from 809 nonhuman primates (NHPs) of 233 species to test the hypothesis that gene variants that do not cause disease in NHPs would likely be benign also in humans. They found that 99% of the genetic variants that were benign in NHPs also were classified as benign in the human ClinVar database. In contrast, only 71% to 87% of genomic variants classified as benign in non-primate animals were benign in humans. Building on this approach, the authors reclassified more than 4 million human genetic variants of unknown health impact as likely being benign based on effects in NHPs. This work illustrates the power of comparative medicine approaches between NHPs and humans. Supported by ORIP (P40OD024628, P51OD011106) and NIGMS.