Selected Grantee Publications
Tract Pathogen-Mediated Inflammation Through Development of Multimodal Treatment Regimen and Its Impact on SIV Acquisition in Rhesus Macaques
Bochart et al., PLOS Pathogens. 2021.
https://doi.org/10.1371/journal.ppat.1009565
In addition to being premier HIV models, rhesus macaques are models for other infectious diseases and colitis, where background colon health and inflammation may confound results. Starting with the standard specific-pathogen-free (SPF) model, researchers established a gastrointestinal pathogen-free (GPF) colony via multimodal therapy (enrofloxacin, azithromycin, fenbendazole, and paromomycin) to eliminate common endemic pathogens (EPs). This treatment combined with continued pathogen exclusion eliminated common EPs, improved mucosal barriers, and reduced mucosal and systemic inflammation without microbiota disruption. GPF animals challenged with SIV intrarectally demonstrated a more controlled and consistent rate of SIV acquisition, suggesting the value of this model for HIV studies. Supported by ORIP (U42OD023038, P51OD011092), NCI, and NIAID.
Postpubertal Spermatogonial Stem Cell Transplantation Restores Functional Sperm Production in Rhesus Monkeys Irradiated Before and After Puberty
Shetty et al., Andrology. 2021.
https://onlinelibrary.wiley.com/doi/10.1111/andr.13033
Cancer treatment of prepubertal patients impacts future fertility due to the abolition of spermatogonial stem cells (SSCs). Prepubertal rhesus monkeys (n=6) were unilaterally castrated, and the remaining testes irradiated twice to insure loss of SSCs; the animals were treated with a vehicle or GnRH antagonist for 8 weeks (n=3/treatment). The cryopreserved prepubertal testicular tissue was allergenically transplanted into the intact testes of the monkeys after puberty. Recovery of viable donor epididymal sperm was observed in half the monkeys. These results illustrate that sperm production can be restored in primates by transplantation of testicular cells from cryopreserved untreated prepubertal testes into seminiferous tubules of the remaining testes. Supported by ORIP (P51OD011092), NICHD, and NCI.
Modulation of MHC-E Transport by Viral Decoy Ligands Is Required for RhCMV/SIV Vaccine Efficacy
Verweij et al., Science. 2021.
https://doi.org/10.1126/science.abe9233
Rhesus cytomegalovirus (RhCMV) strain 68-1-vectored simian immunodeficiency virus (SIV) vaccines elicit strong CD8+ T cell responses that can clear SIV infections. Peptides targeted by these T cells are presented on major histocompatibility complex (MHC) II and MHC-E rather than MHC-Ia. Researchers showed that VL9 drives intracellular transport of MHC-E and recognition of RhCMV-infected targets by MHC-E-restricted CD8+ T cells. Specific-pathogen-free (SPF) rhesus macaques vaccinated with a mutant 68-1 RhCMV lacking VL9 showed no priming of MHC-E-restricted CD8+ T cells and no protection against SIV, suggesting that future effective CMV-based HIV vaccines will require MHC-E-restricted CD8+ T cell priming. Supported by ORIP (U42OD023038, P51OD011092), NIAID, and NCI.
Evidence in Primates Supporting the Use of Chemogenetics for the Treatment of Human Refractory Neuropsychiatric Disorders
Roseboom et al., Molecular Therapy. 2021.
https://doi.org/10.1016/j.ymthe.2021.04.021
A rhesus macaque model for pathological anxiety was used to investigate the feasibility of decreasing anxiety using chemogenetics, known as DREADDs (designer receptors exclusively activated by designer drugs), to reduce amygdala neuronal activity. A low-dose clozapine administration strategy was developed to induce DREADD-mediated amygdala inhibition. Compared to controls, clozapine selectively decreased anxiety-related freezing behavior in the human intruder paradigm in the chemogentic monkeys, while coo vocalizations and locomotion were unaffected. These results are an important step in establishing chemogenetic strategies for patients with refractory neuropsychiatric disorders in which amygdala alterations are central to disease pathophysiology. Supported by ORIP (P51OD011106), NIMH, and NICHD.
Functional Convergence of a Germline-Encoded Neutralizing Antibody Response in Rhesus Macaques Immunized with HCV Envelope Glycoproteins
Chen et al., Immunity. 2021.
https://doi.org/10.1016/j.immuni.2021.02.013
Immunoglobulin heavy chain variable gene IGHV1-69-encoded broadly neutralizing antibodies (bnAbs) targeting the hepatitis C virus (HCV) envelope glycoprotein (Env) E2 are important for protection against HCV infection in humans. An IGHV1-69 ortholog, VH1.36, is preferentially used for bnAbs isolated from rhesus macaques immunized against HCV Env. Researchers investigated the genetic, structural, and functional properties of VH1.36-encoded bnAbs generated by HCV Env vaccination of macaques and compared their findings to IGHV1-69-encoded bnAbs from HCV patients. The investigators found that macaque VH1.36- and human IGHV1-69-encoded bnAbs share many common features, which provides an excellent framework for rational HCV vaccine design and testing. Supported by ORIP (P51OD011133, U42OD010442), NIAID, NCI, and NIGMS.
Establishing an Immunocompromised Porcine Model of Human Cancer for Novel Therapy Development with Pancreatic Adenocarcinoma and Irreversible Electroporation
Hendricks-Wenger et al., Scientific Reports. 2021.
https://pubmed.ncbi.nlm.nih.gov/33828203/
Efficacious interventions to treat pancreatic cancer lack a preclinical model to recapitulate patients' anatomy and physiology. The authors developed RAG2/IL2RG deficient pigs using CRISPR/Cas9 with the novel application of cancer xenograft studies of human pancreatic adenocarcinoma. These pigs were successfully generated using on-demand genetic modifications in embryos. Human Panc01 cells injected into the ears of RAG2/IL2RG deficient pigs demonstrated 100% engraftment. The electrical properties and response to irreversible electroporation of the tumor tissue were found to be similar to excised human pancreatic cancer tumors. This model will be useful to bridge the gap of translating therapies from the bench to clinical application. Supported by ORIP (R21OD027062), NIBIB, and NCI.
The SARS-CoV-2 Receptor and Other Key Components of the Renin-Angiotensin-Aldosterone System Related to COVID-19 are Expressed in Enterocytes in Larval Zebrafish
Postlethwait et al., Biology Open. 2021.
https://bio.biologists.org/content/10/3/bio058172.article-info
Hypertension and respiratory inflammation are exacerbated by the Renin-Angiotensin-Aldosterone System (RAAS), which normally protects from dropping blood pressure via Angiotensin II (Ang II) produced by the enzyme Ace. The Ace paralog Ace2 degrades Ang II and serves as the SARS-CoV-2 receptor. To exploit zebrafish to understand the relationship of RAAS to COVID-19, the group conducted genomic and phylogenetic analyses. Results identified a type of enterocyte as the expression site of zebrafish orthologs of key RAAS components, including the SARS-CoV-2 co-receptor. Results identified vascular cell subtypes expressing Ang II receptors and identified cell types to exploit zebrafish as a model for understanding COVID-19 mechanisms. Supported by ORIP (R24OD026591, R01OD011116), NIGMS, NICHD.
Metabolomics Analysis of Follicular Fluid Coupled With Oocyte Aspiration Reveals Importance of Glucocorticoids in Primate Periovulatory Follicle Competency
Ravisankar et al., Scientific Reports. 2021.
https://www.nature.com/articles/s41598-021-85704-6
Assisted reproductive therapy in primates requires ovarian stimulation protocols, which result in multiple heterogeneous oocytes with variable capacity for fertilization, cleavage, and blastocyst formation. Recovered oocytes from rhesus macaque follicles (n=74 follicles) were fertilized in vitro and classified as failed to cleave, cleaved but arrested, or able to form blastocysts. Metabolomics analysis of the follicular fluid identified 60 metabolites that were different among embryo classifications; key was an increase in the intrafollicular ratio of cortisol to cortisone in the blastocyst group, which was associated with translocation of the glucocorticoid receptor, NR3C1. The data suggest a role for NR3C1 in the regulation of follicular processes, such as expansion of cumulus granulosa cells, via paracrine signaling. Supported by ORIP (P51OD011092) and NICHD.
A Chromosome-Level Genome of Astyanax mexicanus Surface Fish for Comparing Population-Specific Genetic Differences Contributing to Trait Evolution
Warren et al., Nature Communications. 2021.
https://pubmed.ncbi.nlm.nih.gov/33664263/
Identifying the genetic factors that underlie complex traits is central to understanding the mechanistic underpinnings of evolution. Cave-dwelling Astyanax mexicanus populations are well adapted to subterranean life and many populations appear to have evolved troglomorphic (morphological adaptation of an animal to living in the constant darkness of caves) traits independently, while the surface-dwelling populations can be used as a proxy for the ancestral form. Warren et al. present a high-resolution, chromosome-level surface fish genome, enabling the first genome-wide comparison between surface fish and cavefish populations. Using this resource, they performed quantitative trait locus (QTL) mapping analyses and found new candidate genes for eye loss (dusp26). They also generated the first genome-wide evaluation of deletion variability across cavefish populations to gain insight into this potential source of cave adaptation. The surface fish genome reference now provides a more complete resource for comparative, functional and genetic studies of drastic trait differences within a species. Supported by ORIP (R24OD011198), NIA, NICHD, NIGMS, amd NIDCR.
New SHIVs and Improved Design Strategy for Modeling HIV-1 Transmission, Immunopathogenesis, Prevention, and Cure
Li et al., Journal of Virology. 2021.
https://doi.org/10.1128/JVI.00071-21
Researchers knew that substitution of HIV-1 Env residue 375-serine by aromatic residues enhances binding to rhesus CD4 enabling primary HIV-1 Envs to support replication as simian-human immunodeficiency virus (SHIV) chimeras in rhesus monkeys. The investigators constructed SHIVs containing 10 primary Envs corresponding to HIV-1 subtypes A, B, C, AE, and AG. Only one with histidine at Env375 replicated efficiently in rhesus cells. Replacement of wild-type Env375 residues by tryptophan, tyrosine, phenylalanine, or histidine in the other 9 SHIVs led to efficient replication. These new SHIVs transmit via mucosal routes like HIV-1 and have use for vaccine testing in nonhuman primates. Supported by ORIP (U42OD021458, P40OD012217), NIAID, and NCI.