Selected Grantee Publications
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- 127 results found
- Nonhuman Primate Models
- HIV/AIDS
Early Treatment Regimens Achieve Sustained Virologic Remission in Infant Macaques Infected with SIV at Birth
Wang et al., Nature Communications. 2022.
https://www.doi.org/10.1038/s41467-022-32554-z
About 150,000 children are infected postnatally with HIV each year. Early antiretroviral therapy (ART) in infants with HIV can reduce viral reservoir size, but ART-free virologic remission has not been achieved. The researchers hypothesized that proviral reservoir seeding in infants exposed to HIV might differ from that in adults. They characterized viral reservoirs in neonatal rhesus macaques of both sexes inoculated with simian immunodeficiency virus (SIV) at birth and given combination ART. The researchers reported that 9 months of treatment initiated at day 3 resulted in a sustained virologic remission, suggesting that early intervention with proper treatment regimens could be an effective strategy. Supported by ORIP (P51OD011104), NIAID, NICHD, and NIDCR.
A Clade C HIV-1 Vaccine Protects Against Heterologous SHIV Infection by Modulating IgG Glycosylation and T Helper Response in Macaques
Sahoo et al., Science Immunology. 2022.
https://www.doi.org/10.1126/sciimmunol.abl4102
Vaccines for HIV-1 capable of generating a broadly cross-reactive neutralizing antibody response are needed urgently. The researchers tested the protective efficacy of a clade C HIV-1 vaccination regimen in male rhesus macaques. The vaccine was administered either orally using a needle-free injector or via parenteral injection. Significant protection was observed for both vaccination routes following the simian–human immunodeficiency virus (SHIV) challenge, with an estimated efficacy of 68% per exposure. The glycosylation profile of IgG and HIV-resistant helper T cell response contributes to the protection. Supported by ORIP (P51OD011132), NIAID, and NIDCR.
Allogeneic MHC‑Matched T‑Cell Receptor Α/Β‑Depleted Bone Marrow Transplants in SHIV‑Infected, ART‑Suppressed Mauritian Cynomolgus Macaques
Weinfurter et al., Scientific Reports. 2022.
https://www.doi.org/10.1038/s41598-022-16306-z
Allogeneic hematopoietic stem cell transplants are effective in reducing HIV reservoirs following antiretroviral therapy (ART). A better understanding of this mechanism could enable the development of safer and more efficacious HIV treatment regimens. In this study, the researchers used a Mauritian cynomolgus macaque model to study the effects of allogeneic major histocompatibility complex–matched α/β T cell–depleted bone marrow cell transplantation following infection with simian–human immunodeficiency virus (SHIV). The macaques began ART 6 to 16 weeks post-infection. In three of the four macaques, SHIV DNA was undetectable in blood but persisted in other tissues. These results suggest that extended ART likely is needed to eradicate the HIV reservoir following transplantation. In future studies, full donor engraftment should be balanced with suppression of graft-versus-host disease. Supported by ORIP (P51OD011106, R24OD021322), and NCI.
Myeloid Cell Tropism Enables MHC-E–Restricted CD8+ T Cell Priming and Vaccine Efficacy by the RhCMV/SIV Vaccine
Hansen et al., Science Immunology. 2022.
https://www.doi.org/10.1126/sciimmunol.abn9301
Simian immunodeficiency virus (SIV) vaccines based on strain 68-1 rhesus cytomegalovirus vectors have been shown to arrest viral replication early in primary infection. The specific characteristics underlying this effect are not understood fully. In this study, the researchers used host microRNA–mediated vector tropism restriction to demonstrate that the targeted responses are dependent on vector infection of distinct cell types in a rhesus macaque model. Only vectors programmed to elicit major histocompatibility complex E–restricted CD8+ T cell responses provided protection against SIV challenge. These findings could be applied in the development of other vaccines for cancers and infectious diseases. Supported by ORIP (P51OD011092), NCI, and NIAID.
A Cellular Trafficking Signal in the SIV Envelope Protein Cytoplasmic Domain Is Strongly Selected for in Pathogenic Infection
Lawrence et al., PLOS Pathogens. 2022.
https://www.doi.org/10.1371/journal.ppat.1010507
Envelope glycoproteins within the cytoplasmic domain of HIV and simian immunodeficiency virus (SIV) include a tyrosine-based motif that mediates endocytosis and polarized sorting in infected cells. Mutation of this tracking signal has been shown to lead to suppressed viral replication and failed systemic immune activation, but the mechanism has not been explored fully. Using rhesus and pigtail macaque models, the researchers demonstrated that molecular clones containing the mutations reconstitute signals for both endocytosis and polarized sorting. Their findings suggest strong selection pressure for these processes during pathogenic HIV and SIV infection. Supported by ORIP (P51OD011104), NCI, and NIAID.
The Ex Vivo Pharmacology of HIV-1 Antiretrovirals Differs Between Macaques and Humans
Herrera et al., iScience. 2022.
https://www.doi.org/10.1016/j.isci.2022.104409
Nonhuman primates (NHPs) are used widely for studies of antiretroviral (ARV)–based pre‑exposure prophylaxis (PrEP), but more work is needed to address dose–efficacy discrepancies between NHP studies and human clinical trials of PrEP candidates. Investigators explored the use of colorectal and cervicovaginal ex vivo mucosal tissue explants as a bridging model between NHPs and humans. They reported differences in inhibitory potency of drug combinations between NHP and human mucosal tissue explants. These findings suggest that tissue explants can help researchers refine and interpret NHP ARV studies. Supported by ORIP (P51OD011104) and NIAID.
Altered Expression of ACE2 and Co-Receptors of SARS-CoV-2 in the Gut Mucosa of the SIV Model of HIV/AIDS
Hu et al., Frontiers in Microbiology. 2022.
https://www.doi.org/10.3389/fmicb.2022.879152
The investigators assessed the influence of pre-existing HIV infection—which is known to target the gut mucosal immune system—on the vulnerability to SARS-CoV-2 infection and disease. Using a rhesus macaque model (sex not specified), they investigated changes in the expression of ACE2 and other SARS-CoV-2 receptors and related pathways. Simian immunodeficiency virus (SIV) infection resulted in sustained or increased ACE2 expression in an inflamed and immune-impaired gut mucosal microenvironment. These changes are likely to increase susceptibility to SARS-CoV-2 infection and disease severity. Taken together, these results demonstrate the utility of SIV models to fill knowledge gaps related to HIV infection and coinfections. Supported by ORIP (P51OD011107) and NIAID.
Generation of SIV-Resistant T Cells and Macrophages from Nonhuman Primate Induced Pluripotent Stem Cells with Edited CCR5 Locus
D’Souza et al., Stem Cell Reports. 2022.
https://www.doi.org/10.1016/j.stemcr.2022.03.003
Genetically modified T cells have shown promise as a potential therapy for HIV. A renewable source of T cells from induced pluripotent stem cells (iPSCs) could help to further research progress in this area. The researchers used Mauritian cynomolgus macaques to generate simian immunodeficiency virus (SIV)–resistant T cells and macrophages from iPSCs. These engineered cells demonstrated impaired capacity for differentiation into CD4+CD8+ T cells. T cells and macrophages from the edited iPSCs did not support SIV replication. These findings could be applied to the development of new HIV therapies. Supported by ORIP (R24OD021322, P51OD011106) and NHLBI.
Early Post-Vaccination Gene Signatures Correlate With the Magnitude and Function of Vaccine-Induced HIV Envelope–Specific Plasma Antibodies in Infant Rhesus Macaques
Vijayan et al., Frontiers in Immunology. 2022.
https://www.doi.org/10.3389/fimmu.2022.840976
An effective vaccine is needed to reduce HIV infections, particularly among younger people. The initiation of an HIV vaccine regimen in early life could allow the development of mature HIV‑specific antibody responses that protect against infection. The investigators compared the effects of two vaccine regimens in infant rhesus macaques (sex not specified). Both vaccines induced a rapid innate response, indicated by elevated inflammatory plasma cytokines and altered gene expression. By performing a network analysis, the investigators identified differentially expressed genes associated with B cell activation. These findings suggest that vaccine-induced immunity can be optimized by modulating specific antibody and T cell responses. Supported by ORIP (P51OD011107), NCI, NIAID, and NIDCR.
Presence of Natural Killer B Cells in Simian Immunodeficiency Virus–Infected Colon That Have Properties and Functions Similar to Those of Natural Killer Cells and B Cells but Are a Distinct Cell Population
Cogswell et al., mSphere. 2022.
https://www.doi.org/10.1128/jvi.00235-22
HIV infection of the gut is associated with increased mucosal inflammation, and the role of natural killer B (NKB) cells in this process requires further investigation. In this study, the researchers used rhesus and cynomolgus macaque models to characterize the function and characteristics of NKB cells in response to simian immunodeficiency virus (SIV) infection. They reported that NKB cells can kill target cells, proliferate, and express several inflammatory cytokines. The properties of NKB cells could provide insight into the inflammation observed in the gut during SIV infection, and the individual contributions of each cytokine and receptor–ligand interaction could be explored in a future study. Supported by ORIP (P51OD011106), NIAID, and NIGMS.