Selected Grantee Publications
Elevated Inflammation Associated With Markers of Neutrophil Function and Gastrointestinal Disruption in Pilot Study of Plasmodium fragile Co-Infection of ART-Treated SIVmac239+ Rhesus Macaques
Nemphos et al., Viruses. 2024.
https://pubmed.ncbi.nlm.nih.gov/39066199/
Because of geographic overlap, a high potential exists for co-infection with HIV and malaria caused by Plasmodium fragile. Meta-analysis of data collected from 1991 to 2018 demonstrated co-incidence of these two infections to be 43%. Researchers used a male rhesus macaque (RM) model, 6–12 years of age, coinfected with P. fragile and antiretroviral (ART)-treated simian immunodeficiency virus (SIV) to mimic HIV/malaria co-infection observed in patients. ART-treated co-infected RMs demonstrated increased levels of inflammatory cytokines, shifts in neutrophil function, and gastrointestinal mucosal dysfunction. This model may be used to study molecular mechanisms of disease pathology and novel therapies, such as neutrophil-targeted interventions, for patients experiencing co-infection. Supported by ORIP (U42OD010568, U42OD024282, P51OD011104, R21OD031435) and NIGMS.
Vaccination Induces Broadly Neutralizing Antibody Precursors to HIV gp41
Schiffner et al., Nature Immunology. 2024.
https://pubmed.ncbi.nlm.nih.gov/38816615
Primary immunogens that induce rare broadly neutralizing antibody (bnAb) precursor B cells are needed to develop vaccines against viruses of high antigenic diversity. 10E8-class bnAbs must possess a long, heavy chain complementarity determining region 3 (HCDR3) with a specific binding motif. Researchers developed germline-targeting epitope scaffolds with an affinity for 10E8-class precursors that exhibited epitope structural mimicry and bound bnAb-precursor human naive B cells in ex vivo screens. Protein nanoparticles induced bnAb-precursor responses in stringent mouse models and rhesus macaques, and mRNA-encoded nanoparticles triggered similar responses in mice. This study showed that germline-targeting epitope scaffold nanoparticles can elicit rare bnAb-precursor B cells with predefined binding specificities and HCDR3 features. Supported by ORIP (P51OD011132, U42OD011023), NIAID, and NIGMS.
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.
Anti–Human Immunodeficiency Virus‑1 Activity of MoMo30 Protein Isolated from the Traditional African Medicinal Plant Momordica balsamina
Khan et al., Virology Journal. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10035133/
Momordica balsamina has been reported to produce a ribosome-inactivating protein with anti‑HIV-1 activity and is commonly used by traditional African healers for treatment of HIV. Investigators characterized the mechanism of action of the MoMo30 protein, as well as the sequence of the protein-coding gene. They reported that MoMo30 functions as a lectin or carbohydrate-binding agent (CBA) and inhibits HIV-1 at nanomolar levels, with minimal cellular toxicity at inhibitory levels. CBAs can block the binding of envelope glycoproteins with their target receptors on cells. Thus, this protein could represent a potential new treatment strategy for HIV. Supported by ORIP (R24OD010947), NCI, NIGMS, and NIMHD.
Presence of Natural Killer B Cells in Simian Immunodeficiency Virus–Infected Colon That Have Properties and Functions Similar to Those of Natural Killer Cells and B Cells but Are a Distinct Cell Population
Cogswell et al., mSphere. 2022.
https://www.doi.org/10.1128/jvi.00235-22
HIV infection of the gut is associated with increased mucosal inflammation, and the role of natural killer B (NKB) cells in this process requires further investigation. In this study, the researchers used rhesus and cynomolgus macaque models to characterize the function and characteristics of NKB cells in response to simian immunodeficiency virus (SIV) infection. They reported that NKB cells can kill target cells, proliferate, and express several inflammatory cytokines. The properties of NKB cells could provide insight into the inflammation observed in the gut during SIV infection, and the individual contributions of each cytokine and receptor–ligand interaction could be explored in a future study. Supported by ORIP (P51OD011106), NIAID, and NIGMS.
Evaluating a New Class of AKT/mTOR Activators for HIV Latency-Reversing Activity Ex Vivo and In Vivo
Gramatica et al., Journal of Virology. 2021.
https://doi.org/10.1128/JVI.02393-20
Activation of latent HIV-1 expression could benefit many HIV cure strategies. Researchers evaluated two AKT/mTOR activators, SB-216763 and tideglusib, as a potential new class of LRAs. The drugs reactivated latent HIV-1 present in blood samples from aviremic individuals on antiretroviral therapy without causing T cell activation or impaired effector function of cytotoxic T lymphocytes or NK cells. When tested in vivo in monkeys, tideglusib showed unfavorable pharmacodynamic properties and did not reverse SIV latency. The discordance between the ex vivo and in vivo results underscores the importance of developing novel LRAs that allow systemic drug delivery to relevant anatomical compartments. Supported by ORIP (P51OD011092), NIAID, NIGMS, NIMH, and NCI.