Selected Grantee Publications
Therapeutic Blocking of VEGF Binding to Neuropilin-2 Diminishes PD-L1 Expression to Activate Antitumor Immunity in Prostate Cancer
Wang et al., Science Translational Medicine. 2023.
Prostate cancers often escape immune detection and destruction. Investigators report that neuropilin-2 (NRP2), which functions as a vascular endothelial growth factor (VEGF) receptor on tumor cells, is an attractive target to activate antitumor immunity in prostate cancer. They found that NRP2 depletion increased T cell activation in vitro. Additionally, inhibition of the binding of VEGF to NRP2 using a mouse-specific anti-NRP2 monoclonal antibody resulted in necrosis and tumor regression. These findings provide justification for the initiation of clinical trials using this function-blocking antibody in treatment of prostate cancer, especially for patients with aggressive disease. Supported by ORIP (R24OD026440) and NCI.
CD8+ T Cells Promote HIV Latency by Remodeling CD4+ T Cell Metabolism to Enhance Their Survival, Quiescence, and Stemness
Mutascio et al., Immunity. 2023.
https://www.doi.org/10.1016/j.immuni.2023.03.010
An HIV reservoir persists following antiretroviral therapy, representing the main barrier to an HIV cure. Using a validated in vitro model, investigators explored the mechanism by which CD8+ T cells promote HIV latency and inhibit latency reversal in HIV-infected CD4+ T cells. They reported that CD8+ T cells favor the establishment of HIV latency by modulating metabolic, stemness, and survival pathways that correlate with the downregulation of HIV expression and promote HIV latency. In future studies, comparative analyses may provide insight into common molecular mechanisms in the silencing of HIV expression by CD8+ T cells and macrophages, which can be applied to new intervention strategies that target the HIV reservoir. Supported by ORIP (P51OD011132, S10OD026799), NIAID, NIDDK, NIDA, NHLBI, and NINDS.
Effect of Viral Strain and Host Age on Clinical Disease and Viral Replication in Immunocompetent Mouse Models of Chikungunya Encephalomyelitis
Anderson et al., Viruses. 2023.
https://pubmed.ncbi.nlm.nih.gov/37243143/
Chikungunya virus (CHIKV) is associated with neurologic complications, but studies in the central nervous system are challenging to perform in humans. Using a mouse model of both sexes, researchers established the relative severity of neurological disease across multiple stages of neurodevelopment in three strains of CHIKV. The disease was found to be strain dependent, with differences in severity of neurological disease, viral titers in the brain and spinal cord, and proinflammatory gene expression and CD4+ T cell infiltration in the brain. This work provides a mouse model for future studies of CHIKV pathogenesis and the host immune response. Supported by ORIP (K01OD026529), NIAID, and NCI.
Cannabinoid Enhancement of lncRNA MMP25-AS1/MMP25 Interaction Reduces Neutrophil Infiltration and Intestinal Epithelial Injury in HIV/SIV Infection
Premadasa et al., Journal of Clinical Investigation Insight. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10132162/
Gastrointestinal CD4+ T cell depletion during acute simian immunodeficiency virus (SIV) and HIV infection causes significant structural and functional damage, disrupting intestinal immune homeostasis and leading to intestinal epithelial barrier dysfunction. Oral phytocannabinoids are safe and well tolerated in people with HIV, but more information is needed regarding the effects of long-term tetrahydrocannabinol (THC) use on the intestinal epithelial compartment. Investigators profiled gene expression in the colonic epithelium of SIV-infected rhesus macaques of both sexes that were administered THC. They reported that low-dose THC can reduce neutrophil infiltration and intestinal epithelial injury, potentially by downregulating MMP25 expression through modulation of a long noncoding RNA, MMP25-AS1. Supported by ORIP (P51OD011104, P51OD011103), NIAID, and NIDA.
Effect of Passive Administration of Monoclonal Antibodies Recognizing Simian Immunodeficiency Virus (SIV) V2 in CH59-Like Coil/Helical or β-Sheet Conformations on Time of SIVmac251 Acquisition
Stamos et al., Journal of Virology. 2023.
https://journals.asm.org/doi/10.1128/jvi.01864-22
Research suggests that the SIV variable region 2 (V2) is a region of virus vulnerability, likely because of its exposure on the apex of virions and on the surfaces of SIV-infected cells. Researchers examined the effects of two monoclonal antibodies, NCI05 and NCI09, on the acquisition of SIV using rhesus macaques (sex not specified). They found that NCI05, but not NCI09, delays SIV acquisition, highlighting the complexity of antibody responses to V2. Both antibodies were unable to decrease the risk of viral acquisition. This study demonstrates that such antibodies as NCI05 alone are insufficient to protect against SIV acquisition. Supported by ORIP (S10OD027000), NIAID, and NCI.
High-Resolution Genomes of Multiple Xiphophorus Species Provide New Insights into Microevolution, Hybrid Incompatibility, and Epistasis
Lu et al., Genome Research. 2023.
https://pubmed.ncbi.nlm.nih.gov/37147111/
Existing Xiphophorus genome assemblies are not at the chromosomal level and are prone to sequence gaps, hindering advancement of evolutionary, comparative, and translational biomedical studies. Investigators assembled high-quality chromosome-level genome assemblies for three distantly related Xiphophorus species. They found that expanded gene families and positively selected genes associated with live bearing. Positively selected gene families were enriched in nonpolymorphic transposable elements, suggesting that dispersal has accompanied the evolution of the genes, possibly by incorporating new regulatory elements. The investigators also characterized interspecific polymorphisms, structural variants, and polymorphic transposable element insertions and assessed their association to interspecies hybridization-induced gene expression dysregulation related to specific disease states in humans. Supported by ORIP (R24OD011120, R24OD031467, R24OD011198) and NCI.
Resolution of Structural Variation in Diverse Mouse Genomes Reveals Chromatin Remodeling due to Transposable Elements
Ferraj et al., Cell Genomics. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10203049/
Diverse inbred mouse strains are important biomedical research models, yet genome characterization of many strains is fundamentally lacking in comparison with humans. Here, investigators used long-read whole genome sequencing to assemble the genomes of 20 diverse inbred laboratory strains of mice. From whole-genome comparisons, they generated a sequence-resolved callset of 413,758 structural variants. These data are presented as a comprehensive resource that can be used for future genomic studies, aid in modeling and studying the effects of genetic variation, and enhance genotype-to-phenotype research. Supported by ORIP (R24OD021325), NCI, NIGMS, and NHGRI.
Cerebrospinal Fluid Protein Markers Indicate Neuro-Damage in SARS-CoV-2-Infected Nonhuman Primates
Maity et al., Molecular & Cellular Proteomics. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9981268/
In this study, researchers examined the proteins expressed in cerebrospinal fluid (CSF) in nonhuman primates (NHPs) to better understand how COVID-19 infection can result in brain pathology, a common outcome. The study found that even in NHPs with minimal or mild COVID‑19, CSF proteins were significantly dysregulated compared with uninfected NHPs. Furthermore, the most affected proteins were enriched in the same brain regions that show lesions after COVID-19 infection, including the cerebral cortex, basal ganglia, and brain stem. Collectively, these regions have wide-ranging control over such crucial functions as cognition, motor control, and breathing, showing how even mild COVID-19 infection can result in significant neurological impairment. Supported by ORIP (P51OD011104, S10OD032453), NIGMS, NCI, and NICHD.
Hematopoietic Stem Cells Preferentially Traffic Misfolded Proteins to Aggresomes and Depend on Aggrephagy to Maintain Protein Homeostasis
Chua et al., Cell Stem Cell. 2023.
https://pubmed.ncbi.nlm.nih.gov/36948186/
Investigators studied the mechanism of hematopoietic stem cells (HSCs) being dependent on managing proteostasis. Their findings demonstrated that HSCs preferentially depend on aggrephagy, a form of autophagy, to maintain proteostasis. When aggrephagy is disabled, HSCs compensate by increasing proteasome activity, but proteostasis is ultimately disrupted as protein aggregates accumulate and HSC function is impaired. The investigators also showed that Bag3 deficiency blunts aggresome formation in HSCs, resulting in protein aggregate accumulation, myeloid-biased differentiation, and diminished self-renewal activity, thus demonstrating Bag3 as a regulator of HSC proteostasis. HSC aging is associated with loss of aggresomes and reduced autophagic flux. Protein degradation pathways are thus configured in young-adult HSCs to preserve proteostasis and fitness but become dysregulated during aging. Supported by ORIP (S10OD032316, S10OD021831), NCI, and NIDDK.
Pembrolizumab and Cabozantinib in Recurrent Metastatic Head and Neck Squamous Cell Carcinoma: A Phase 2 Trial
Saba et al., Nature Medicine. 2023.
https://www.doi.org/10.1038/s41591-023-02275-x
A multicenter clinical trial was conducted in 33 evaluable (36 enrolled) patients with recurrent metastatic head and neck squamous cell carcinoma (RMHNSCC) on a regimen combining cabozantinib, a tyrosine kinase inhibitor, with the standard of care of anti–programmed cell death protein 1 agent pembrolizumab. Results showed that 17 patients (52%) exhibited partial response and 13 (39%) exhibited stable disease, with an overall clinical benefit rate of 91%. Median progression-free survival (PFS) was 14.6 months, and the 1-year PFS was 54%. The pembrolizumab and cabozantinib regimen was well tolerated in patients with RMHNSCC. The promising clinical benefit warrants further investigation. Supported by ORIP (S10OD021644), NCI, and NIDCR.