Selected Grantee Publications
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- 190 results found
- Cardiovascular
- HIV/AIDS
Virus Control in Vaccinated Rhesus Macaques Is Associated with Neutralizing and Capturing Antibodies Against the SHIV Challenge Virus but Not with V1V2 Vaccine–Induced Anti-V2 Antibodies Alone
Hessell et al., Journal of Immunology. 2021.
https://doi.org/10.4049/jimmunol.2001010
In the RV144 human immunodeficiency virus (HIV) vaccine trial, the only immune response associated with reduced infection was a high level of antibodies (Abs) targeting the second variable (V2) loop of the HIV envelope protein (Env). The mechanism underlying this suggested contribution of V2 Abs to protection remains unknown. Researchers tested the role of vaccine-induced anti-V2 Abs in rhesus macaques. Three vaccines strategies were designed to induce only V1V2 Abs before simian-human immunodeficiency virus (SHIV) challenge. Vaccine-induced V2 Abs did not independently control SHIV infection. However, neutralizing and virus capture anti-Env Abs were found to correlate with SHIV control. Supported by ORIP (P51OD011092) and NIAID.
Persistence of Viral RNA in Lymph Nodes in ART-suppressed SIV/SHIV-Infected Rhesus Macaques
Cadena et al., Nature Communications. 2021.
https://doi.org/10.1038/s41467-021-21724-0
The long-lived viral reservoir is a key obstacle to curing HIV/AIDS, yet the features of that reservoir during antiretroviral therapy (ART) remain poorly understood. Researchers undertook a comprehensive analysis of the SIV/SHIV reservoir in multiple lymphoid and non-lymphoid tissues from SIV/SHIV-infected rhesus macaques suppressed with ART for one year. Their findings support a model in which the tissue viral reservoir is rapidly and broadly seeded early during acute infection. Viral RNA persists lymphoid tissues despite a long period of suppressive ART. Therefore, viral latency does not appear to be universally transcriptionally silent; the reservoir may include a spectrum of latency depths. Supported by ORIP (R01OD024917) and NIAID.
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.
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.
Antibody-Mediated Depletion of Viral Reservoirs is Limited in SIV-Infected Macaques Treated Early With Antiretroviral Therapy
Swanstrom et al., Journal of Clinical Investigation. 2021.
https://doi.org/10.1172/JCI142421
Virus-specific strategies to target the latent HIV reservoir in individuals on combination antiretroviral therapy (cART) have been limited by inefficient induction of viral protein expression. Researchers used rhesus macaques to investigate an antibody-mediated reservoir targeting strategy, targeting the CD4 molecule rather than a viral protein, to deplete potential viral target cells irrespective of infection status. Despite profound CD4+ T cell depletion in blood and lymph nodes, time to viral rebound following cART cessation was not delayed in anti-CD4 treated animals compared with controls, likely due to the limited antibody-mediated cell depletion that occurred in rectal tissue and lymphoid follicles. Supported by ORIP (R24OD010976), NCI, 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.