Selected Grantee Publications
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- HIV/AIDS
- Pediatrics
Dysregulation of mTOR Signalling Is a Converging Mechanism in Lissencephaly
Zhang et al., Nature. 2025.
https://pubmed.ncbi.nlm.nih.gov/39743596
Lissencephaly (smooth brain) is a rare genetic condition, with such symptoms as epilepsy and intellectual disability and a median life expectancy of 10 years. This study reveals that reduced activity of the mTOR pathway may be a common cause of lissencephaly. Researchers used laboratory-grown brain models (organoids) and sequencing and spectrometry techniques to identify decreased mTOR activation in two types of lissencephaly disorders: p53-induced death domain protein 1 and Miller–Dieker lissencephaly syndrome. Pharmacological activation of mTOR signaling with a brain-selective mTORC1 activator molecule, NV-5138, prevented and reversed the morphological and functional defects in organoids. These findings suggest that mTOR dysregulation contributes to the development of lissencephaly spectrum disorders and highlight a potential druggable pathway for therapy. Supported by ORIP (S10OD018034, S10OD019967, S10OD030363), NCATS, NHGRI, NICHD, NIDA, NIGMS, NIMH, and NINDS.
Single-Cell Transcriptomics Predict Novel Potential Regulators of Acute Epithelial Restitution in the Ischemia-Injured Intestine
Rose et al., American Journal of Physiology-Gastrointestinal and Liver Physiology. 2025.
https://pubmed.ncbi.nlm.nih.gov/39853303
Following ischemia in the small intestine, early barrier restoration relies on epithelial restitution to reseal the physical barrier and prevent sepsis. Pigs share a similar gastrointestinal anatomy, physiology, and microbiota with humans. Researchers used neonatal and juvenile, 2- to 6-week-old male and female Yorkshire cross pigs to determine upstream regulators of restitution. Single-cell sequencing of ischemia-injured epithelial cells demonstrated two sub-phenotypes of absorptive enterocytes, with one subset presenting a restitution phenotype. Colony-stimulating factor-1 (CSF1) was the only predicted upstream regulator expressed in juvenile jejunum compared with neonatal jejunum. An in vitro scratch wound assay using IPEC-J2 cells showed that BLZ945, a colony-stimulating factor 1 receptor antagonist, inhibited restitution. Ex vivo ischemia-injured neonatal pig jejunum treated with exogenous CSF1 displayed increased barrier function. This study could inform future research focused on developing novel therapeutics for intestinal barrier injury in patients. Supported by ORIP (T32OD011130, K01OD028207), NCATS, NICHD, and NIDDK.
Aberrant Activation of Wound-Healing Programs within the Metastatic Niche Facilitates Lung Colonization by Osteosarcoma Cells
Reinecke et al., Clinical Cancer Research. 2024.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11739783/
The leading cause of deaths in the pediatric osteosarcoma is due to lung metastasis. A current clinical need is the development of therapies that disrupt the later stages of metastasis. Researchers used 6- to 8-week-old female C57BL/6 and CB17-SCID mice to understand how tumor cells disrupt the lung microenvironment to promote tumor growth. Single-cell RNA sequencing and spatial transcriptomics demonstrated osteosarcoma–epithelial cell interactions in a chronic state of wound healing in the lung. Nintedanib administration significantly disrupted metastatic progression compared with the vehicle control, demonstrating a potential novel therapeutic for combating osteosarcoma lung metastasis. Supported by ORIP (K01OD031811), NCI, and NCATS.
Effects of Acute Femoral Head Ischemia on the Growth Plate and Metaphysis in a Piglet Model of Legg-Calvé-Perthes Disease
Armstrong et al., Osteoarthritis and Cartilage. 2023.
https://pubmed.ncbi.nlm.nih.gov/36696941/
Legg-Calvé-Perthes disease (LCPD) can lead to permanent deformity of the femoral head and premature osteoarthritis, but the underlying cause remains unknown. More work is needed to determine optimal treatment methods for LCPD. Using a piglet model for LCPD, researchers assessed the effects of acute femoral head ischemia on the proximal femoral growth plate and metaphysis. They reported that alterations to the growth plate zones and metaphysis occurred by 2 days post-ischemia and persisted at 7 days post-ischemia. These findings suggest that growth disruption may occur sooner after the onset of ischemia than researchers had hypothesized previously. Supported by ORIP (T32OD010993, K01OD021293), NIAMS, and NCATS.
Late Gene Expression–Deficient Cytomegalovirus Vectors Elicit Conventional T Cells That Do Not Protect Against SIV
Hansen et al., Journal of Clinical Investigation Insight. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10070102/
Cytomegalovirus (CMV)–based vaccines aim to exploit unique immunological adaptations, including host manipulation and immune evasion strategies. Translating CMV-based vaccines from rhesus macaques to humans requires translating the immune factors responsible for efficacy, as well as vaccine vectors that are sufficiently safe for widespread use. Researchers examined the impact of a stringent attenuation strategy on vector-induced immune protection against simian immunodeficiency virus (SIV) in rhesus macaques of both sexes. They reported that elicited CD8+ T cells exclusively failed to protect against SIV challenge. These data suggest that late viral gene expression and/or residual in vivo spreading are required to induce protective CD8+ T cell responses. Supported by ORIP (P51OD011092, P51OD011107, S10OD016261), NCI, NIAID, and NCATS.
Long-Term Evolutionary Adaptation of SIVcpz toward HIV-1 Using a Humanized Mouse Model
Schmitt et al., Journal of Medical Primatology. 2022.
https://www.doi.org/10.1111/jmp.12616
Chimpanzee-derived simian immunodeficiency viruses (SIVcpz) are thought to have evolved into the highly pathogenic HIV-1 Group M, but the genetic adaptations required for SIV progenitor viruses to become pathogenic and established as HIVs in the human population have remained unclear. Using humanized mice of both sexes, researchers mimicked the evolution of SIVcpz into HIV-1 Group M through serial passaging. After four generations, the researchers observed increased initial viral load, increased CD4+ T cell decline, and nonsynonymous substitutions. Overall, these data indicate increased viral fitness and pathogenicity. This work also demonstrates the utility of humanized mice in recreating the adaptive pressures necessary for the evolution of SIVcpz into HIV-1. Supported by ORIP (P51OD011104, P51OD011106), NCATS, and NIAID.
Innate Immune Regulation in HIV Latency Models
Olson et al., Retrovirology. 2022.
https://www.doi.org/10.1186/s12977-022-00599-z
Researchers are interested in developing therapeutic approaches to target latent HIV reservoirs, which are unaffected by antiretroviral therapy. Previous studies suggest that HIV latency might be related to viral RNA sensing, interferon (IFN) signaling, and IFN-stimulated gene (ISG) activation. In this study, the researchers evaluated responses to stimulation by retinoic acid–inducible gene I agonists and IFN in multiple CD4+ T cell line models for HIV latency. The models represented various aspects of latent infection and viral control. Several of the cell lines demonstrated reduced ISG induction, suggesting that long-term latency might be related to dysregulation of the downstream IFN response. These effects likely reflect transcriptional changes occurring within a core set of ISGs and altering IFN responses. Additional studies could provide insight into the functions of these ISGs in HIV latency. Supported by ORIP (P51OD010425), NCATS, and NIAID.
Safety and Antiviral Activity of Triple Combination Broadly Neutralizing Monoclonal Antibody Therapy Against HIV-1: A Phase 1 Clinical Trial
Julg et al., Nature Medicine. 2022.
https://www.doi.org/10.1038/s41591-022-01815-1
Previous evidence suggests that at least three broadly neutralizing antibodies (bNAbs) targeting different epitope regions are needed for robust treatment and control of HIV. The investigators evaluated the safety, tolerability, and pharmacokinetics of PGDM1400, an HIV-1 V2-glycan–specific antibody, in a first-in-human trial. The primary endpoints were safety, tolerability, pharmacokinetics, and antiviral activity. The trial met the prespecified endpoints in male and female adults. These data will help advance understanding of the capabilities, limitations, and future role of bNAb combinations in HIV prevention and care. Supported by ORIP (R01OD024917), NIAID, and NCATS.
The Early Life Microbiota Mediates Maternal Effects on Offspring Growth in a Nonhuman Primate
Petrullo et al., iScience. 2022.
https://www.doi.org/10.1016/j.isci.2022.103948
Mammalian mothers influence offspring development by providing nutrients and other bioactive compounds through the placenta or milk. A relatively unexplored mechanism for maternal effects is vertical transmission of bacteria through milk to the infant gut. Infants that receive more glycan-utilizing bacteria from milk might better exploit oligosaccharides, which could improve nutrition and accelerate growth. Researchers found that first-time vervet mothers harbored a milk bacterial community that was less diverse due to the dominance of Bacteroides fragilis, a glycan-utilizing bacteria. These low-parity females had infants that grew faster, suggesting that vertical transmission of bacteria via milk can mediate maternal effects on growth. These results indicate non-nutritive milk constituents play important roles in development. Commercial milk formula might need to be improved or supplemented to better support infant health. Supported by ORIP (P40OD010965) and NCATS.
Safety, Pharmacokinetics and Antiviral Activity of PGT121, a Broadly Neutralizing Monoclonal Antibody Against HIV-1: A Randomized, Placebo-Controlled, Phase 1 Clinical Trial
Stephenson et al., Nature Medicine. 2021.
https://doi.org/10.1038/s41591-021-01509-0
Researchers carried out a double-blind trial of one administration of the HIV-1 V3-glycan-specific antibody (Ab) PGT121 in HIV-uninfected and HIV-infected adults on antiretroviral therapy (ART), as well as an open-label trial of one infusion of PGT121 in viremic HIV-infected adults not on ART. The investigators observed no treatment-related serious adverse events among the 48 participants, and neutralizing anti-drug Abs were not elicited. PGT121 reduced plasma HIV RNA by a median of 1.77 log in viremic participants. Two individuals experienced ART-free viral suppression for ≥168 days following Ab infusion. These findings motivate further investigation of Ab-based therapeutic strategies for long-term HIV suppression. Supported by ORIP (R01OD024917, R01OD011095), NIAID, and NCATS.