Selected Grantee Publications
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- 45 results found
- Infectious Diseases
- U42
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.
CD4+ T Cells Are Dispensable for Induction of Broad Heterologous HIV Neutralizing Antibodies in Rhesus Macaques
Sarkar et al., Frontiers in Immunology. 2021.
https://www.frontiersin.org/articles/10.3389/fimmu.2021.757811/full
Researchers investigated the humoral response in vaccinated rhesus macaques with CD4+ T cell depletion, using the VC10014 DNA protein co-immunization vaccine platform (with gp160 plasmids and gp140 trimeric proteins derived from an HIV-1 infected subject). Both CD4+-depleted and non-depleted animals developed comparable Tier 1 and 2 heterologous HIV-1 neutralizing plasma antibody titers. Thus, primates generate HIV neutralizing antibodies in the absence of robust CD4+ T cell help, which has important implications for vaccine development. Supported by ORIP (P51OD011092, P40OD028116, U42OD023038, U42OD010426), NIAID, and NIDCR.
A Large Repertoire of B Cell Lineages Targeting One Cluster of Epitopes in a Vaccinated Rhesus Macaque
Li et al., Vaccine. 2021.
https://www.sciencedirect.com/science/article/pii/S0264410X21010355?via%3Dihub=
A rhesus macaque that was serially immunized six times with the 8-mer epitope for human monoclonal antibody (mAb) 447-52D—specific to the V3 region of gp120 HIV-1—provided a rare opportunity to study the repertoire of antibodies produced upon vaccination against a particular antigenic site. From a blood sample taken 3 weeks after the last immunization, researchers produced 41 V3-specific recombinant mAbs by single B cell isolation and cloning. Sequence analysis revealed 21 B cell lineages (single and clonally related). The broad repertoire of Abs directed to a small antigenic site shows the targeting potency of a vaccine-elicited immune response in rhesus macaques. Supported by ORIP (P51OD011092, U42OD010246) and NIAID.
Blocking α4β7 Integrin Delays Viral Rebound in SHIVSF162P3-Infected Macaques Treated with Anti-HIV Broadly Neutralizing Antibodies
Frank et al., Science Translational Medicine. 2021.
https://doi.org/10.1126/scitranslmed.abf7201
To explore therapeutic potentials of combining anti-HIV broadly neutralizing antibodies (bNAbs) with α4β7 integrin blockade using the monoclonal antibody Rh-α4β7, investigators treated SHIVSF162P3-infected, viremic macaques with bNAbs only or bNAbs and Rh-α4β7. Treatment with bNAbs alone decreased viremia below 200 copies/ml in eight out of eight macaques, but seven of the monkeys rebounded within 3 weeks. In contrast, three of six macaques treated with both Rh-α4β7 and bNAbs maintained viremia below 200 copies/ml for 21 weeks, whereas three of those monkeys rebounded after 6 weeks. These findings suggest that α4β7 integrin blockade may prolong virologic control by bNAbs in SHIVSF162P3-infected macaques. Supported by ORIP (P51OD011104, U42OD010568, U42OD024282, P40OD028116), NIAID, and NCI.
Protection of Newborn Macaques by Plant-Derived HIV Broadly Neutralizing Antibodies: A Model for Passive Immunotherapy During Breastfeeding
Rosenberg et al., Journal of Virology. 2021.
https://doi.org/10.1128/JVI.00268-21
Preventing vertical transmission of HIV to newborns is an unmet medical need in resource poor countries. Using a breastfeeding macaque model with multiple simian-human immunodeficiency virus challenge, researchers assessed the protective efficacy of two human broadly neutralizing antibodies (bnAbs) against HIV, PGT121 and VRC07-523, which are produced by a plant expression system. Despite the transient presence of plasma viral RNA, the bnAbs prevented productive infection in all newborns with no sustained plasma viremia, compared to viral loads ranging from 103 to 5x108 in four untreated controls. Thus, plant-expressed antibodies show promise as passive immunoprophylaxis in a breastfeeding model in newborns. Supported by ORIP (U42OD023038, P51OD011092) and NIAID.
In Vitro and In Vivo Functions of SARS-CoV-2 Infection-Enhancing and Neutralizing Antibodies
Li et al., Cell. 2021.
https://doi.org/10.1016/j.cell.2021.06.021
Antibody-dependent enhancement of infection is a concern for clinical use of antibodies. Researchers isolated neutralizing antibodies against the receptor-binding domain (RBD) or N-terminal domain (NTD) of SARS-CoV-2 spike from COVID-19 patients. Cryo-electron microscopy of RBD and NTD antibodies demonstrated function-specific binding modes. RBD and NTD antibodies mediated both neutralization and infection enhancement in vitro. However, infusion of these antibodies into mice or macaques resulted in suppression of virus replication, demonstrating that antibody-enhanced infection in vitro does not necessarily predict enhanced infection in vivo. RBD-neutralizing antibodies having cross-reactivity against coronaviruses were protective against SARS-CoV-2, the most potent of which was DH1047. Supported by ORIP (P40OD012217, U42OD021458, S10OD018164), NIAID, NCI, NIGMS, and NIH Common Fund.
Neutralizing Antibody Vaccine for Pandemic and Pre-Emergent Coronaviruses
Saunders et al., Nature. 2021.
https://doi.org/10.1038/s41586-021-03594-0
SARS-CoV-2 is a new member of the betacoronavirus (beta-CoV) genus, which also includes two common mild beta-CoVs and the life-threatening SARS-CoV-1 and MERS-CoV. Vaccines that elicit protective immunity against SARS-CoV-2 and beta-CoVs that circulate in animals could prevent future pandemics. Researchers designed a novel 24-mer SARS-CoV-2 receptor binding domain-sortase A conjugated nanoparticle vaccine (RBD-scNP). Investigators demonstrated that the immunization of macaques with RBD-scNP, and adjuvanted with 3M-052 and alum, elicits cross-neutralizing antibody responses against bat coronaviruses, SARS-CoV, and multiple SARS-CoV-2 variants of concern. This pioneering approach serves as a multimeric protein platform for the further development of generalized anti-beta-CoV vaccines. Supported by ORIP (U42OD021458), NIAID, and NCI.
Tract Pathogen-Mediated Inflammation Through Development of Multimodal Treatment Regimen and Its Impact on SIV Acquisition in Rhesus Macaques
Bochart et al., PLOS Pathogens. 2021.
https://doi.org/10.1371/journal.ppat.1009565
In addition to being premier HIV models, rhesus macaques are models for other infectious diseases and colitis, where background colon health and inflammation may confound results. Starting with the standard specific-pathogen-free (SPF) model, researchers established a gastrointestinal pathogen-free (GPF) colony via multimodal therapy (enrofloxacin, azithromycin, fenbendazole, and paromomycin) to eliminate common endemic pathogens (EPs). This treatment combined with continued pathogen exclusion eliminated common EPs, improved mucosal barriers, and reduced mucosal and systemic inflammation without microbiota disruption. GPF animals challenged with SIV intrarectally demonstrated a more controlled and consistent rate of SIV acquisition, suggesting the value of this model for HIV studies. Supported by ORIP (U42OD023038, P51OD011092), NCI, and NIAID.
Psychosocial Stress Alters the Immune Response and Results in Higher Viral Load During Acute SIV Infection in a Pigtailed Macaque Model of HIV
Guerrero-Martin et al., Journal of Infectious Diseases. 2021.
https://doi.org/10.1093/infdis/jiab252
Social distancing is an important countermeasure for a pandemic, but social isolation may also have adverse health outcomes in the context of infectious diseases, such as HIV. Researchers compared commonly measured parameters of HIV progression between singly and socially housed simian immunodeficiency virus (SIV)-infected pigtailed macaques. Throughout acute SIV infection, singly housed pigtailed macaques had a higher viral load in the plasma and cerebrospinal fluid and demonstrated greater CD4+ T cell declines and more CD4+ and CD8+ T cell activation compared to socially housed macaques. These findings suggest that psychosocial stress could augment the progression of HIV infection. Supported by ORIP (U42OD013117, P40OD013117, K01OD018244), NIAID, NINDS, and NIMH.
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.