Selected Grantee Publications
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.
The Widely Used Ucp1-Cre Transgene Elicits Complex Developmental and Metabolic Phenotypes
Halurkar et al., Nature Communications. 2025.
https://pubmed.ncbi.nlm.nih.gov/39824816
Bacterial artificial chromosome technology is instrumental to mouse transgenics, including in studies of highly thermogenic brown adipose tissue and energy-storing white adipose tissue. Researchers discovered that male and female Ucp1-CreEvdr transgenic mice, which are commonly used to study fat tissue, may have unintended effects on metabolism and development. Findings revealed that these mice show changes in both brown and white fat function and disruptions in gene activity, suggesting broader physiological impacts than previously thought. This study emphasizes the need for careful validation of genetic tools in research to ensure accurate results, highlighting the potential concerns in using the Ucp1-CreEvdr model in metabolic and developmental studies. Supported by ORIP (R21OD034470, R21OD031907) NCATS, NIDCR, and NIDDK.
Comparative Cellular Analysis of Motor Cortex in Human, Marmoset and Mouse
Bakken et al., Nature. 2021.
https://pubmed.ncbi.nlm.nih.gov/34616062/
Investigators used high-throughput transcriptomic and epigenomic profiling of more than 450,000 single nuclei in humans, marmosets, and mice, to characterize the cellular makeup of the primary motor cortex (M1), which exhibits similarities that mirror evolutionary distance and are consistent between the transcriptome and epigenome. Despite the overall conservation, many species-dependent specializations are apparent. These results demonstrate the robust molecular foundations of cell-type diversity in M1 across mammals and point to the genes and regulatory pathways responsible for the functional identity of cell types and their species-specific adaptations. Supported by ORIP (P51OD010425), NIMH, NCATS, NINDS, and NIDA.
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.
A Participant-Derived Xenograft Model of HIV Enables Long-Term Evaluation of Autologous Immunotherapies
McCann et al., Journal of Experimental Medicine. 2021.
https://doi.org/10.1084/jem.20201908
HIV-specific CD8+ T cells partially control viral replication but rarely provide lasting protection due to immune escape. Investigators showed that engrafting NSG mice with memory CD4+ T cells from HIV+ donors enables evaluation of autologous T cell responses while avoiding graft-versus-host disease. Treating HIV-infected mice with clinically relevant T cell products reduced viremia. In vivo activity was significantly enhanced when T cells were engineered with surface-conjugated nanogels carrying an Interleukin-15 superagonist but was ultimately limited by the pervasive selection of escape mutations, recapitulating human patterns. This “participant-derived xenograft” model provides a powerful tool for developing T cell-based therapies for HIV. Supported by ORIP (R01OD011095), NIAID, NIDA, NIMH, NINDS, and NCATS.
Thresholds for Post-Rebound SHIV Control after CCR5 Gene-Edited Autologous Hematopoietic Cell Transplantation
Cardozo-Ojeda et al., eLife. 2021.
https://elifesciences.org/articles/57646
Investigators developed a mathematical model to project the minimum threshold of C-C chemokine receptor type 5 (CCR5) gene-edited cells necessary for a functional cure from HIV. This was based on blood T cell reconstitution and plasma simian-HIV (SHIV) dynamics from SHIV-1157ipd3N4-infected juvenile pig-tailed macaques that underwent autologous transplantation with CCR5 gene editing. The model predicts that viral control can be obtained following analytical treatment interruption (ATI) when: (1) transplanted hematopoietic stem and progenitor cells (HSPCs) are at least fivefold higher than residual endogenous HSPCs after total body irradiation and (2) the fraction of protected HSPCs in the transplant achieves a threshold (76–94%) sufficient to overcome transplantation-dependent loss of SHIV immunity. Under these conditions, if ATI is withheld until transplanted gene-modified cells engraft and reconstitute to a steady state, spontaneous viral control is projected to occur. Supported by ORIP (P51OD010425), NCATS and NIAID.