Selected Grantee Publications
Cannabinoid Control of Gingival Immune Activation in Chronically SIV-Infected Rhesus Macaques Involves Modulation of the Indoleamine-2,3-Dioxygenase-1 Pathway and Salivary Microbiome
McDew-White et al., EBioMedicine. 2021.
https://pubmed.ncbi.nlm.nih.gov/34954656/
HIV-associated periodontal disease (PD) affects people living with HIV (PLWH) on combination anti-retroviral therapy (cART). Researchers used a systems biology approach to investigate the molecular, metabolome, and microbiome changes underlying PD and its modulation by phytocannabinoids (Δ9-THC) in rhesus macaques. Δ9-THC reduced IDO1 protein expression. The findings suggest that phytocannabinoids may help reduce gingival/systemic inflammation, salivary dysbiosis, and potentially metabolic disease in PLWH on cART. Supported by ORIP (P51OD011104, P51OD011133, U42OD010442), NIAID, NIDA, NIDDK, NIDCR, and NIMH.
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.
Challenges and Considerations During In Vitro Production of Porcine Embryos
Chen et al., Cells. 2021.
https://pubmed.ncbi.nlm.nih.gov/34685749/
Genetically modified pigs have become valuable tools for generating advances in animal agriculture and human medicine. Importantly, in vitro production and manipulation of embryos is an essential step in the process of creating porcine models. As the in vitro environment is still suboptimal, it is imperative to examine the porcine embryo culture system from several angles to identify methods for improvement. Understanding metabolic characteristics of porcine embryos and considering comparisons with other mammalian species is useful for optimizing culture media formulations. Furthermore, stressors arising from the environment and maternal or paternal factors must be taken into consideration to produce healthy embryos in vitro. In this review, Chen et al progress stepwise through in vitro oocyte maturation, fertilization, and embryo culture in pigs to assess the status of current culture systems and address points where improvements can be made. Supported by ORIP (U42OD011140).
Limited Expansion of Human Hepatocytes in FAH/RAG2-Deficient Swine
Nelson et al., Tissue Engineering – Part A. 2021.
https://pubmed.ncbi.nlm.nih.gov/34309416/
The mammalian liver's regenerative ability has led researchers to engineer animals as incubators for expansion of human hepatocytes. Nelson et al. engineered immunodeficient swine to support expansion of human hepatocytes and identify barriers to their clinical application. Immunodeficient swine were engineered by knockout of the recombinase-activating gene 2 (RAG2) and fumarylacetoacetate hydrolase (FAH). Immature human hepatocytes (ihHCs) were injected into fetal swine by intrauterine cell transplantation (IUCT) at day 40 of gestation. They identified the mechanism of the eventual graft rejection by the intact NK cell population. They confirmed the presence of residual adaptive immunity in this model of immunodeficiency. Supported by ORIP (U42OD011140).
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.