Selected Grantee Publications
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- 9 results found
- HIV/AIDS
- Microbiome
- Imaging
Administration of Anti-HIV-1 Broadly Neutralizing Monoclonal Antibodies With Increased Affinity to Fcγ Receptors During Acute SHIV AD8-EO Infection
Dias et al., Nature Communications. 2024.
https://www.nature.com/articles/s41467-024-51848-y
Anti-HIV broadly neutralizing antibodies (bNAbs) mediate virus neutralization and antiviral effector functions through Fab and Fc domains, respectively. This study investigated the efficacy of wild-type (WT) bNAbs and modified bNAbs with enhanced affinity for Fcγ receptors (S239D/I332E/A330L [DEL]) after acute simian-HIVAD8-EO (SHIVAD8-EO) infection in male and female rhesus macaques. The emergence of the virus in the plasma and lymph nodes occurred earlier in macaques given DEL bNAbs than in those given WT bNAbs. Overall, the administration of DEL bNAbs revealed higher levels of immune responses. The results suggest that bNAbs with an enhanced Fcγ receptor affinity offer a potential therapeutic strategy by targeting HIV more effectively during early infection stages. Supported by ORIP (P40OD028116), NCI, and NIAID.
Comparison of the Immunogenicity of mRNA-Encoded and Protein HIV-1 Env-ferritin Nanoparticle Designs
Mu et al., Journal of Virology. 2024.
https://journals.asm.org/doi/10.1128/jvi.00137-24
Inducing broadly neutralizing antibodies (bNAbs) against HIV-1 remains a challenge because of immune system limitations. This study compared the immunogenicity of mRNA-encoded membrane-bound envelope (Env) gp160 to HIV-1 Env-ferritin nanoparticle (NP) technology in inducing anti-HIV-1 bNAbs. Membrane-bound mRNA encoding gp160 was more immunogenic than the Env-ferritin NP design in DH270 UCA KI mice, but at lower doses. These results suggest further analysis of mRNA design expression and low-dose immunogenicity studies are necessary for anti-HIV-1 bNAbs. Supported by ORIP (P40OD012217, U42OD021458) and NIAID.
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.
Molecular Insights Into Antibody-Mediated Protection Against the Prototypic Simian Immunodeficiency Virus
Zhao et al., Nature Communications. 2022.
https://www.doi.org/10.1038/s41467-022-32783-2
Most simian immunodeficiency virus (SIV) vaccines have focused on inducing T cell responses alone or in combination with non-neutralizing antibody responses. To date, studies investigating neutralizing antibody (nAb) responses to protect against SIV have been limited. In this study, researchers isolated 12 potent monoclonal nAbs from chronically infected rhesus macaques of both sexes and mapped their binding specificities on the envelope trimer structure. They further characterized the structures using cryogenic electron microscopy, mass spectrometry, and computational modeling. Their findings indicate that, in the case of humoral immunity, nAb activity is necessary and sufficient for protection against SIV challenge. This work provides structural insights for future vaccine design. Supported by ORIP (P51OD011106), NIAID, and NCI.
Dynamics and Origin of Rebound Viremia in SHIV-Infected Infant Macaques Following Interruption of Long-Term ART
Obregon-Perko et al., JCI Insight. 2021.
https://pubmed.ncbi.nlm.nih.gov/34699383/
Animal models that recapitulate human COVID-19 disease are critical for understanding SARS-CoV-2 viral and immune dynamics, mechanisms of disease, and testing of vaccines and therapeutics. A group of male pigtail macaques (PTMs) were euthanized either 6- or 21-days after SARS-CoV-2 viral challenge and demonstrated mild-to-moderate COVID-19 disease. Pulmonary infiltrates were dominated by T cells, virus-targeting T cells were predominantly CD4+, increases in circulating inflammatory and coagulation markers, pulmonary pathologic lesions, and the development of neutralizing antibodies were observed. Collectively, the data suggests PTMs are a valuable model to study COVID-19 pathogenesis and may be useful for testing vaccines and therapeutics. Supported by ORIP (P51OD011104) and NIAID.
Tissue-Specific Transcriptional Profiling of Plasmacytoid Dendritic Cells Reveals a Hyperactivated State in Chronic SIV Infection
Lee et al., PLOS Pathogens. 2021.
https://doi.org/10.1371/journal.ppat.1009674
Persistent immune activation is an obstacle to optimal health for people living with HIV. Using RNA sequencing, researchers investigated the immunostimulatory potential of plasmacytoid dendritic cells (pDCs) in chronic SIV infection in rhesus macaques. They observed that pDCs have highly activated profiles in these animals. In contrast, pDCs from SIV-infected sooty mangabeys (natural hosts for SIV) had expression profiles similar to uninfected animals. In chronically infected rhesus macaques, interferon alpha transcripts were readily detected in lymph node-homing pDCs, but not those from blood. Therefore, pDCs are a major producer of type-I interferon in chronic SIV infection and could be a useful immunotherapy target. Supported by ORIP (R24OD010445, P51OD011132, P51OD011092, S10OD026799) and NIAID.
Gut Germinal Center Regeneration and Enhanced Antiviral Immunity by Mesenchymal Stem/Stromal Cells
Weber et al., JCI Insight. 2021.
https://doi.org/10.1172/jci.insight.149033
Researchers investigated the effects of mesenchymal stem/stromal cell (MSC) infusions on gut mucosal recovery, antiviral immunity, and viral suppression in SIV-infected rhesus macaques. MSC treatment heightened virus-specific responses and reduced viral load. Clearance of SIV-positive cells from gut mucosal effector sites was correlated with regeneration of germinal centers, restoration of follicular B cells and T follicular helper cells, and enhanced antigen presentation by viral trapping within the follicular dendritic cell network. These changes were associated with enhanced gene expression for type I/II interferon signaling, B cell proliferation, and interleukin 7. MSC treatment also activated metabolic pathways associated with enhanced immunity and viral reduction. Supported by ORIP (P51OD011107) and NIAID.
Combining In Vivo Corneal Confocal Microscopy With Deep Learning-Based Analysis Reveals Sensory Nerve Fiber Loss in Acute Simian Immunodeficiency Virus Infection
McCarron et al., Cornea. 2021.
https://doi.org/10.1097/ICO.0000000000002661
Researchers characterized corneal subbasal nerve plexus features of normal and simian immunodeficiency virus (SIV)-infected pigtail and rhesus macaques using in vivo confocal microscopy and a deep learning approach for automated assessments. Corneal nerve fiber length and fractal dimension measurements did not differ between species, but pigtail macaques had significantly higher baseline corneal nerve fiber tortuosity than rhesus macaques. Acute SIV infection induced decreased corneal nerve fiber length and fractal dimension in the pigtail macaque model for HIV. Adapting deep learning analyses to clinical corneal nerve assessments will improve monitoring of small sensory nerve fiber damage in numerous clinical contexts, including HIV. Supported by ORIP (U42OD013117) and NINDS.