Selected Grantee Publications
- Clear All
- 151 results found
- Immunology
- P51
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.
Innate Immune Regulation in HIV Latency Models
Olson et al., Retrovirology. 2022.
https://www.doi.org/10.1186/s12977-022-00599-z
Researchers are interested in developing therapeutic approaches to target latent HIV reservoirs, which are unaffected by antiretroviral therapy. Previous studies suggest that HIV latency might be related to viral RNA sensing, interferon (IFN) signaling, and IFN-stimulated gene (ISG) activation. In this study, the researchers evaluated responses to stimulation by retinoic acid–inducible gene I agonists and IFN in multiple CD4+ T cell line models for HIV latency. The models represented various aspects of latent infection and viral control. Several of the cell lines demonstrated reduced ISG induction, suggesting that long-term latency might be related to dysregulation of the downstream IFN response. These effects likely reflect transcriptional changes occurring within a core set of ISGs and altering IFN responses. Additional studies could provide insight into the functions of these ISGs in HIV latency. Supported by ORIP (P51OD010425), NCATS, and NIAID.
Substitutions in Nef That Uncouple Tetherin and SERINC5 Antagonism Impair Simian Immunodeficiency Virus Replication in Primary Rhesus Macaque Lymphocytes
Janaka et al., Journal of Virology. 2022.
https://www.doi.org/10.1128/jvi.00176-22
Tetherin inhibits the release of certain enveloped viruses from infected host cells. Most simian immunodeficiency viruses (SIVs) use Nef, a nonenzymatic accessory protein, to overcome this restriction. Nef also has been shown to enhance viral infectivity by preventing the incorporation of SERINC5 into virions. Researchers demonstrated previously that tetherin antagonism is necessary for efficient SIV replication in rhesus macaques. They explored this effect by defining substitutions within Nef that distinguish tetherin and SERINC5 antagonism. The researchers engineered an SIV molecular clone with substitutions that uncouple relevant Nef functions. This clone can be used to further study the effects of tetherin and adaptive immune responses. Supported by ORIP (P51OD011106) and NIAID.
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.
Large Comparative Analyses of Primate Body Site Microbiomes Indicate That the Oral Microbiome Is Unique Among All Body Sites and Conserved Among Nonhuman Primates
Asangba et al., Microbiology Spectrum. 2022.
https://www.doi.org/10.1128/spectrum.01643-21
Microbiomes are critical to host health and disease, but large gaps remain in the understanding of the determinants, coevolution, and variation of microbiomes across body sites and host species. Thus, researchers conducted the largest comparative study of primate microbiomes to date by investigating microbiome community composition at eight distinct body sites in 17 host species. They found that the oral microbiome is unique in exhibiting notable similarity across primate species while being distinct from the microbiomes of all other body sites and host species. This finding suggests conserved oral microbial niche specialization, despite substantial dietary and phylogenetic differences among primates. Supported by ORIP (P51OD010425, P51OD011107, P40OD010965, R01OD010980), NIA, NIAID, and NICHD.
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.
Adverse Biobehavioral Effects in Infants Resulting from Pregnant Rhesus Macaques’ Exposure to Wildfire Smoke
Capitanio et al., Nature Communications. 2022.
https://www.doi.org/10.1038/s41467-022-29436-9
Exposure to wildfire smoke (WFS) is a growing health concern as wildfires increase in number and size due to climate change. Researchers found that developing rhesus monkeys exposed to WFS from the Camp Fire in California (November 2018) during the first third of gestation exhibited greater inflammation, blunted cortisol, more passive behavior, and memory impairment compared to animals conceived after smoke had dissipated. Analysis of a historical control cohort did not support the alternative hypothesis that conception timing alone explained the results. These findings suggest that WFS may have a teratogenic effect on neural development in the primate fetus. Supported by ORIP (P51OD011107, R24OD010962) and NIEHS.