Selected Grantee Publications
Allelic Strengths of Encephalopathy-Associated UBA5 Variants Correlate Between In Vivo and In Vitro Assays
Pan et al., eLife. 2023.
https://pubmed.ncbi.nlm.nih.gov/37502976/
The UBA5 gene is associated with developmental and epileptic encephalopathy 44 (DEE44), an autosomal recessive disorder, in humans. The link between UBA5 variants and severity of DEE44, however, is not established. Investigators developed humanized fly models carrying a series of patient UBA5 variants. These flies showed differences in survival rates, developmental progress, life span, and neurological well-being. The severity of these defects correlated strongly with functional defects of UBA5 variants, allowing the classification of UBA5 loss-of-function variants into mild, intermediate, and severe allelic strengths in patients. This study provides resources for systematic investigation of the mechanistic link between UBA5 variants and DEE44 and for developing diagnostic approaches. Supported by ORIP (R24OD022005, R24OD031447, U54OD035865) and NCATS.
Interferon Regulatory Factor 7 Modulates Virus Clearance and Immune Responses to Alphavirus Encephalomyelitis
Troisi et al., Journal of Virology. 2023.
https://pubmed.ncbi.nlm.nih.gov/37772825/
Interferon regulatory factor 7 (IRF7)–deficient mice develop fatal paralysis after CNS infection with Sindbis virus, while wild-type mice recover. Irf7-/- mice produce low levels of IFN-α but high levels of IFN-β with induction of IFN-stimulated genes, so the reason for this difference is not understood. The current study shows that Irf7-/- mice developed inflammation earlier but failed to clear virus from motor neuron–rich regions of the brainstem and spinal cord. Therefore, IRF7 is either necessary for the neuronal response to currently identified mediators of clearance or enables the production of additional antiviral factor(s) needed for clearance. Supported by ORIP (T32OD011089, R01OD01026529) NINDS, and NIAID.
AZD5582 Plus SIV-Specific Antibodies Reduce Lymph Node Viral Reservoirs in Antiretroviral Therapy–Suppressed Macaques
Dashti et al., Nature Medicine. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10579098/
Researchers are interested in targeting the HIV reservoir via a latency reversal and clearance approach. Previously, investigators demonstrated that AZD5582 induces systemic latency reversal in rhesus macaques and humanized mice, but a consistent reduction in the viral reservoir was not observed. In the current study, they combined AZD5582 with four simian immunodeficiency virus (SIV)–specific rhesus monoclonal antibodies using rhesus macaques of both sexes. They reported a reduction in total and replication-competent SIV DNA in lymph node–derived CD4+ T cells in the treated macaques. These findings provide proof of concept for the potential of the latency reversal and clearance HIV cure strategy. Supported by ORIP (P51OD011132, R01OD011095), NIAID, NCI, and NHLBI.
Biphasic Decay of Intact SHIV Genomes Following Initiation of Antiretroviral Therapy Complicates Analysis of Interventions Targeting the Reservoir
Kumar et al., PNAS. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10614214/
The latent HIV-1 reservoir persists with antiretroviral therapy (ART), and assays for quantifying intact proviruses in nonhuman primate models are needed. Researchers used a simian–human immunodeficiency virus (SHIV) intact proviral DNA assay to describe viral decay during the first year of ART in female rhesus macaques. Their results suggest that intact SHIV genomes in circulating CD4+ T cells undergo biphasic decay during the first year of ART, with a rapid first phase and a slower second phase. These findings can provide insight for future studies using SHIV models, as well as new cure interventions. Supported by ORIP (R01OD011095) and NIAID.
Spontaneous HIV Expression During Suppressive ART Is Associated With the Magnitude and Function of HIV-Specific CD4+ and CD8+ T Cells
Dubé et al., Cell Host Microbe. 2023.
https://linkinghub.elsevier.com/retrieve/pii/S1931-3128(23)00331-1
CD4+ and CD8+ T cells are essential in the control of simian immunodeficiency virus and HIV infections, but the mechanisms are not understood fully. Using multiplexed single-cell RNAflow-fluorescence in situ hybridization, researchers quantified and phenotyped viral reservoirs spontaneously expressing viral RNA and the p24 protein in primary clinical samples from men. They reported associations between active reservoirs and HIV-specific CD4+ and CD8+ T cells, and the active reservoirs were largely dominated by defective proviruses. Their findings suggest that viral reservoirs maintain HIV-specific responses during suppressive antiretroviral therapy (ART), and low-level viral gene expression by spontaneous reservoirs is sufficient to maintain anti-HIV adaptive immunity. Supported by ORIP (P51OD011092) and NIAID.
Host-Derived Growth Factors Drive ERK Phosphorylation and MCL1 Expression to Promote Osteosarcoma Cell Survival During Metastatic Lung Colonization
McAloney et al., Cellular Oncology. 2023.
https://pubmed.ncbi.nlm.nih.gov/37676378/
Mortality from osteosarcoma is closely linked to lung metastasis, even though the lung appears to be a hostile environment for tumor cells. Using female mice, researchers assessed changes in both host and tumor cells during colonization. Their findings suggest that the mitogen-activated protein kinase (MAPK) pathway is significantly elevated in early and established metastases, which correlates with expression of anti-apoptotic genes (e.g., MCL1). The authors conclude that niche-derived growth factors drive increased MAPK activity and MCL1 expression in osteosarcoma, promoting metastatic colonization. This gene is a promising target for future therapeutic development. Supported by ORIP (K01OD031811), NCI, and NCATS.
The Latent Reservoir of Inducible, Infectious HIV-1 Does Not Decrease Despite Decades of Antiretroviral Therapy
McMyn et al., The Journal of Clinical Investigation. 2023.
https://www.doi.org/10.1172/JCI171554
Antiretroviral therapy (ART) does not eliminate the latent HIV reservoir, but it is unknown whether sustained reservoir decay occurs with long-term ART. Researchers used a quantitative viral outgrowth assay, an intact proviral DNA assay, and proviral sequencing to characterize the latent reservoir in men and women with HIV who had maintained suppression of viral replication on ART for 14 to 27 years. They found that the reservoir decay did not continue with long-term ART. Further studies could provide insight into the mechanism underlying these findings. These results reinforce the need for lifelong ART and indicate that the reservoir remains a major barrier to an HIV-1 cure. Supported by ORIP (R01OD011095), NIAID, and NIDCR.
Large-Scale Production of Human Blastoids Amenable to Modeling Blastocyst Development and Maternal-Fetal Crosstalk
Yu et al., Cell Stem Cell. 2023.
https://www.sciencedirect.com/science/article/abs/pii/S1934590923002850?via%3Dihub=
Human blastoids provide a valuable model to study early human development and implantation with reduced genetic heterogeneity between samples. Investigators reported a protocol for efficient generation of high-fidelity human blastoids from naïve pluripotent stem cells. The similarities between blastoids and blastocysts in signaling activities—demonstrated using single-cell RNA sequencing—support the use of blastoids to model lineage differentiation and cavity formation. Additionally, endometrial stromal effects in promoting trophoblast cell survival, proliferation, and syncytialization during co-culture with blastoids demonstrated the capability to model maternal–fetal crosstalk. The protocol will facilitate broader use of human blastoids as an ethical model for human blastocysts. Supported by ORIP (S10OD028630) and others.
Antiretroviral Therapy Ameliorates Simian Immunodeficiency Virus–Associated Myocardial Inflammation by Dampening Interferon Signaling and Pathogen Response in the Heart
Robinson et al., The Journal of Infectious Diseases. 2023.
https://doi.org/10.1093/infdis/jiad105
HIV is associated with increased risk of cardiovascular disease, but the underlying mechanisms are not fully understood. Using RNA sequencing, investigators characterized the effects of simian immunodeficiency virus (SIV) infection on the hearts of male rhesus macaques. They demonstrated that SIV infection drives a canonical antiviral response in the heart, as well as dysregulation of genes involved in fatty acid shuttling and metabolism. Their findings suggest that antiretroviral therapy helps mitigate immune activation during viremic conditions and plays a cardioprotective role. Future studies are needed to assess the long-term effects of these dynamics. Supported by ORIP (P51OD011104), NIAID, NIMH, and NINDS.
Focused Ultrasound–Mediated Brain Genome Editing
Lao et al., PNAS. 2023.
https://www.pnas.org/doi/epdf/10.1073/pnas.2302910120
Gene editing in the brain has been challenging because of the restricted transport imposed by the blood–brain barrier (BBB). In this study, investigators described a safe and effective gene‑editing technique by using focused ultrasound (FUS) to transiently open the BBB for the transport of intravenously delivered CRISPR machinery to the brain in mice. By combining FUS with adeno-associated virus–mediated gene delivery, researchers can achieve more than 25% editing efficiency of particular cell types. This method has the potential to expand toolkit options for CRISPR delivery and opens opportunities for treating diseases of the brain, such as neurodegenerative disorders, with somatic genome editing. Supported by ORIP (U42OD026635) and NINDS.