Selected Grantee Publications
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- 42 results found
- Infectious Diseases
- 2022
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.
Common and Divergent Features of T Cells From Blood, Gut, and Genital Tract of Antiretroviral Therapy–Treated HIV+ Women
Xie et al., Journal of Immunology. 2022.
https://www.doi.org/10.4049/jimmunol.2101102
T cells residing in mucosal tissues play important roles in homeostasis and defense against microbial pathogens, but how organ system environments affect the properties of resident T cells is relatively unknown. Researchers phenotyped T cells in the gut and reproductive tract using blood and tissue samples from women with HIV who have achieved viral suppression via antiretroviral therapy. The T cells exhibited differing expression of CD69 and CD103 markers, whereas resident memory CD8+ T cells from the female reproductive tract expressed PD1 preferentially. Additionally, CXCR4+ T inflammatory mucosal cells expressed multiple chemokine receptors differentially. These results suggest that T cells take on distinct properties in different mucosal sites, which allows them to tailor activities to their surrounding milieu. This study offers important insights for reproductive medicine in women. Supported by ORIP (S10OD018040), NHLBI, NIAID, and NIDDK.
Antibody-Peptide Epitope Conjugates for Personalized Cancer Therapy
Zhang et al., Cancer Research. 2022.
https://pubmed.ncbi.nlm.nih.gov/34965933/
Antibody-peptide epitope conjugates (APEC) are a new class of modified antibody-drug conjugates that redirect T cell viral immunity against tumor cells. Investigators developed an experimental pipeline to create patient-specific APECs and identified new preclinical therapies for ovarian carcinoma. Based on functional assessment of viral peptide antigen responses to common viruses like cytomegalovirus in ovarian cancer patients, a library of 192 APECs with distinct protease cleavage sequences was created using the anti-epithelial cell adhesion molecule (EpCAM) antibody. The streamlined and systemic approach includes assessing APEC function in vivo using a new zebrafish xenograft platform that facilitates high-resolution single-cell imaging to assess therapy responses and then validating top candidates using traditional mouse xenograft studies and primary patient samples. This study develops a high-throughput preclinical platform to identify patient-specific antibody-peptide epitope conjugates that target cancer cells and demonstrates the potential of this immunotherapy approach for treating ovarian carcinoma. Supported by ORIP (R24OD016761).
American Alligators Are Capable of West Nile Virus Amplification, Mosquito Infection and Transmission
Byas et al., Virology. 2022.
https://www.doi.org/10.1016/j.virol.2022.01.009
West Nile virus (WNV) overwintering is poorly understood and likely multifactorial. Interest in alligators as a potential amplifying host arose when it was shown that they develop viremias theoretically sufficient to infect mosquitoes. Researchers examined potential ways in which alligators may contribute to the natural ecology of WNV. They experimentally demonstrated that alligators are capable of WNV amplification with subsequent mosquito infection and transmission capability, that WNV-infected mosquitoes readily infect alligators, and that water can serve as a source of infection for alligators but does not easily serve as an intermediate means for transmission between birds and alligators. These findings indicate potential mechanisms for maintenance of WNV outside of the primary bird–mosquito transmission cycle. Supported by ORIP (T32OD010437) and NIAID.
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.