Selected Grantee Publications
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- 120 results found
- Vaccines/Therapeutics
- P51
Immune Variations Throughout the Course of Tuberculosis Treatment and its Relationship with Adrenal Hormone Changes in HIV-1 Patients Co-Infected with Mycobacterium tuberculosis
Vecchione et al., Tuberculosis. 2021.
https://doi.org/10.1016/j.tube.2020.102045
The probability of developing tuberculosis (TB) is 19 times higher in people infected with human immunodeficiency virus (HIV) compared to the general population. As host immune response defines the course of infection, researchers aimed to identify immuno-endocrine changes over six months of anti-TB chemotherapy in HIV+ people. Throughout the course of anti-TB/HIV treatment, plasma dehydroepiandrosterone (DHEA) and DHEA-sulfate levels increased while cortisol decreased. The balance between cortisol and DHEA, together with clinical assessment, served as a predictor of clinical outcome after anti-TB treatment. This research suggests that combined anti-HIV/TB therapies may partially restore both immune function and adrenal hormone levels. Supported by ORIP (P51OD011133).
Polyfunctional Tier 2–Neutralizing Antibodies Cloned Following HIV-1 Env Macaque Immunization Mirror Native Antibodies in a Human Donor
Spencer et al., Journal of Immunology. 2021.
https://doi.org/10.4049/jimmunol.2001082
HIV vaccine efforts are limited by viral strain diversity and the shielding of neutralization epitopes on the viral envelope, yet isolation of broadly neutralizing antibodies from infected individuals suggests the potential for eliciting protective antibodies through vaccination. Researchers cloned 58 monoclonal antibodies (mAbs) from a rhesus monkey immunized with envelope glycoprotein immunogens from an HIV-1 clade C–infected volunteer. Twenty mAbs exhibited some neutralizing activity. Cloned mAbs targeting the V3 region and CD4 binding site were capable of tier 2 (i.e., moderate) neutralization. This study demonstrates partial recapitulation of the human donor’s humoral immune response through nonhuman primate vaccination. Supported by ORIP (P51OD011092) and NIAID.
Modified Adenovirus Prime–Protein Boost Clade C HIV Vaccine Strategy Results in Reduced Viral DNA in Blood and Tissues Following Tier 2 SHIV Challenge
Malherbe et al., Frontiers in Immunology. 2021.
https://doi.org/10.3389/fimmu.2020.626464
Researchers conducted a comparative vaccine challenge study in rhesus macaques. One group of monkeys was vaccinated using co-immunization with DNA Gag and Env expression plasmids and trimeric Env gp140 glycoprotein. The other group was primed with two replicating simian adenovirus-vectored vaccines expressing Gag and boosted with trimeric Env gp140. Both strategies elicited antigen-specific humoral and cellular immune responses, but neither approach provided significant protection from viral acquisition upon repeated mucosal challenges with a heterologous Tier 2 SHIV. Nevertheless, both regimens significantly lowered cell-associated viral DNA in multiple tissues, thus potentially dampening the infection and providing clues for further vaccine development. Supported by ORIP (U42OD023038, P51OD011092) and NIAID.
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.
BNT162b Vaccines Protect Rhesus Macaques from SARS-CoV-2
Vogel et al., Nature. 2021.
https://www.nature.com/articles/s41586-021-03275-y
The preclinical development of two BNT162b vaccine candidates, which contain lipid-nanoparticle formulated nucleoside-modified mRNA encoding SARS-CoV-2 spike glycoprotein-derived immunogens, was performed in rhesus macaques at the Southwest National Primate Research Center (SNPRC). BNT162b1 encodes a soluble, secreted, trimerised receptor-binding domain. BNT162b2 encodes the full-length transmembrane spike glycoprotein, locked in its prefusion conformation. Prime/boost vaccination of rhesus macaques with BNT162b candidates elicits SARS-CoV-2 neutralizing antibody titers that are 8.2 to 18.2 times that of a SARS-CoV-2 convalescent human serum panel. The vaccine candidates protected macaques from SARS-CoV-2 challenge, with BNT162b2 protecting the lower respiratory tract from the presence of viral RNA and with no evidence of disease enhancement. The BNT162b2 vaccine recently received emergency use authorization from FDA and is being administered within the United States. The SNPRC is supported by ORIP (P51OD011103).
Modified Vaccinia Ankara Vector-Based Vaccine Protects Macaques from SARS-CoV-2 Infection, Immune Pathology and Dysfunction in the Lung
Routhu et al., Immunity. 2021.
https://doi.org/10.1016/j.immuni.2021.02.001
Any SARS-CoV-2 vaccine may have limitations such as need for ultracold storage, poor induction of CD8+ T cell response, or lack of cross-reactivity with emerging strains. Thus, multiple vaccines may be needed to bring COVID-19 under control. Using rhesus macaques, researchers showed that a modified vaccinia Ankara (MVA) vector-based SARS-CoV-2 vaccine expressing prefusion-stabilized spike protein induced strong neutralizing antibody and CD8+ T cell responses. The vaccine protected macaques from SARS-CoV-2 infection as well as infection-induced inflammation and B cell abnormalities in the lung. These results are promising considering the excellent safety and performance of MVA vector-based vaccines for other pathogens. Supported by ORIP (P51OD011132, S10OD026799) and NIAID.
Thresholds for Post-Rebound SHIV Control after CCR5 Gene-Edited Autologous Hematopoietic Cell Transplantation
Cardozo-Ojeda et al., eLife. 2021.
https://elifesciences.org/articles/57646
Investigators developed a mathematical model to project the minimum threshold of C-C chemokine receptor type 5 (CCR5) gene-edited cells necessary for a functional cure from HIV. This was based on blood T cell reconstitution and plasma simian-HIV (SHIV) dynamics from SHIV-1157ipd3N4-infected juvenile pig-tailed macaques that underwent autologous transplantation with CCR5 gene editing. The model predicts that viral control can be obtained following analytical treatment interruption (ATI) when: (1) transplanted hematopoietic stem and progenitor cells (HSPCs) are at least fivefold higher than residual endogenous HSPCs after total body irradiation and (2) the fraction of protected HSPCs in the transplant achieves a threshold (76–94%) sufficient to overcome transplantation-dependent loss of SHIV immunity. Under these conditions, if ATI is withheld until transplanted gene-modified cells engraft and reconstitute to a steady state, spontaneous viral control is projected to occur. Supported by ORIP (P51OD010425), NCATS and NIAID.
Increased Proviral DNA in Circulating Cells Correlates With Plasma Viral Rebound in SIV-Infected Rhesus Macaques after Antiretroviral Therapy Interruption
Ziani et al., Journal of Virology. 2021.
https://jvi.asm.org/content/early/2021/01/05/JVI.02064-20
Investigators longitudinally tracked dynamic decay of cell-associated viral RNA/DNA in systemic and lymphoid tissues in SIV-infected rhesus macaques on prolonged combined antiretroviral therapy (cART) to evaluate predictors of viral rebound after treatment cessation. Suppressive cART substantially reduced plasma SIV RNA, cell-associated unspliced, and multiply spliced SIV RNA to undetectable levels, yet viral DNA remained detectable in systemic tissues and lymphoid compartments throughout cART. A rapid increase of integrated proviral DNA in peripheral mononuclear cells was detected once cART was withdrawn, accompanied by the emergence of detectable plasma viral load. The increase of peripheral proviral DNA post cART interruption correlated with the emergence and degree of viral rebound. These results suggest that measuring total viral DNA in SIV infection may be a relatively simple surrogate marker of reservoir size, and may predict viral rebound after treatment interruption, and inform treatment strategies. Supported by ORIP (P51OD011104), NIAID and NICHD.
The Immune Landscape in Tuberculosis Reveals Populations Linked to Disease and Latency
Esaulova et al., Cell Host Microbe. 2020.
https://pubmed.ncbi.nlm.nih.gov/33340449/
Mycobacterium tuberculosis infection of adult rhesus macaques (RMs), predominantly males (81%), recapitulates both latent (LTBI) and active pulmonary TB (PTB) observed in humans. The immune characterization in lungs of RMs with PTB exhibited an influx of plasmacytoid dendritic cells, an interferon-responsive macrophage population, and activated T cell responses. In contrast, a CD27+ natural killer (NK) cell subset accumulated in the lungs of RMs with LTBI. This NK cell population was also detected in the circulation of humans with LTBI. This characterization of lung immune cells enhances our understanding of TB immunopathogenesis and provides potential targets for therapies and vaccines for TB control. Supported by ORIP (P51OD011104 and P51OD011133), NHLBI, and NIAID.
Antiretroviral Therapy Does Not Reduce Tuberculosis Reactivation in a Tuberculosis-HIV Coinfection Model
Ganatra et al., Journal of Clinical Investigation. 2020.
https://www.jci.org/articles/view/136502
Despite treatment of HIV with antiretroviral therapy (ART), the risk of tuberculosis (TB) reactivation is higher in HIV-infected than HIV-uninfected persons. Researchers used Mycobacterium tuberculosis/SIV-coinfected rhesus macaques to model the impact of ART on TB reactivation due to HIV-induced immunosuppression. ART significantly reduced viral loads and increased CD4+ T-cell counts in blood, spleen, and bronchoalveolar lavage samples, but it did not reduce the risk of SIV-induced TB reactivation during the early phase of treatment. This study offers a translational model for the investigation of TB/SIV coinfection and the evaluation of treatment regimens to prevent TB reactivation in HIV-infected individuals. Supported by ORIP (P51OD011133, P51OD011132) and NIAID.