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.
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.
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.
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.
Induction and Characterization of Pancreatic Cancer in a Transgenic Pig Model
Boas et al., PLOS One. 2020.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0239391
Preclinical testing of new therapies for pancreatic cancer has been challenging due to lack of a suitable large animal model. Pigs, however, have similar physiology and immune response to humans. Boas et al report the development of a porcine model for pancreatic cancer. H&E and immunohistochemical stains revealed undifferentiated carcinomas, like those of human pancreatobiliary systems. In several pigs, angiographies revealed that the artery supplying the pancreatic tumor could be catheterized using a 2.4 F microcatheter. In summary, pancreatic cancer can be induced in a transgenic pig, and intra-arterial procedures using catheters designed for human interventions were feasible in this model. Supported by ORIP (U42OD011140) and NCI.