Selected Grantee Publications
Recreating the Heart’s Helical Structure–Function Relationship With Focused Rotary Jet Spinning
Chang et al., Science. 2022.
https://www.doi.org/10.1126/science.abl6395
The investigators developed a tissue engineering approach that enables rapid deposition of cardiomyocyte microfibers with programmable alignments in 3D geometries. Using this focused rotary jet spinning (FRJS) method, they reproduced tissue scaffolds with contractile cells' helical alignments, resembling complex structures of the musculature and properties of a natural heart. This work represents an important advance towards biofabrication of tissue models for healthy and diseased hearts by manipulating orientation of specific fibers. With the technological advancement over other competing methods, FRJS might provide a pathway towards fabricating other tissues and organs with diverse cell populations. Supported by ORIP (S10OD023519) and NCATS.
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.
Functional and Ultrastructural Analysis of Reafferent Mechanosensation in Larval Zebrafish
Odstrcil et al., Current Biology. 2022.
https://www.sciencedirect.com/science/article/pii/S096098222101530X
All animals need to differentiate between exafferent stimuli (caused by the environment) and reafferent stimuli (caused by their own movement). Researchers characterized how hair cells in zebrafish larvae discriminate between reafferent and exafferent signals. Dye labeling of the lateral line nerve and functional imaging was combined with ultra-structural electron microscopy circuit reconstruction to show that cholinergic signals originating from the hindbrain transmit efference copies, and dopaminergic signals from the hypothalamus may affect threshold modulation. Findings suggest that this circuit is the core implementation of mechanosensory reafferent suppression in these young animals. Supported by ORIP (R43OD024879, R44OD024879) and NINDS.
Neuroinflammatory Profiling in SIV-Infected Chinese-Origin Rhesus Macaques on Antiretroviral Therapy
Solis-Leal et al., Viruses. 2022.
https://www.doi.org/10.3390/v14010139
The central nervous system (CNS) HIV reservoir contributes to residual neuroimmune activation, which can lead to HIV-associated neurocognitive disorder. Researchers characterized the expression of signaling molecules associated with inflammation in plasma, cerebrospinal fluid, and basal ganglia of Chinese-origin rhesus macaques (sex not specified) with simian immunodeficiency virus (SIV). They reported a correlation between levels of CCL2 in plasma and cerebrospinal fluid, suggesting that researchers could infer the degree of CNS inflammation by testing CCL2 levels in peripheral blood. Overall, these findings provide insight into neuroinflammation and signaling associated with HIV persistence in the CNS. Supported by ORIP (P51OD011104, P51OD011133), NIMH, and NINDS.
AAV Capsid Variants with Brain-Wide Transgene Expression and Decreased Liver Targeting After Intravenous Delivery in Mouse and Marmoset
Goertsen et al., Nature Neuroscience. 2021.
https://www.nature.com/articles/s41593-021-00969-4
Genetic intervention is increasingly being explored as a therapeutic option for debilitating disorders of the central nervous system (CNS). This project focused on organ-specific targeting of adeno-associated virus (AAV) capsids after intravenous delivery. These results constitute an important step forward toward achieving the goal of engineered AAV vectors that can be used to broadly deliver gene therapies to the CNS in humans. Supported by ORIP (U24OD026638), NIMH, and NINDS.
Precise Visuomotor Transformations Underlying Collective Behavior in Larval Zebrafish
Harpaz et al., Nature Communications. 2021.
https://www.nature.com/articles/s41467-021-26748-0
Sensory signals from neighbors, analyzed in the visuomotor stream of animals, is poorly understood. The authors studied aggregation behavior in larval zebrafish and found that over development larvae transition from over dispersed groups to tight shoals. Young larvae turn away from virtual neighbors by integrating and averaging retina-wide visual occupancy within each eye, and by using a winner-take-all strategy for binocular integration. Observed algorithms accurately predict group structure over development. These findings allow testable predictions regarding the neuronal circuits underlying collective behavior in zebrafish. Supported by ORIP (R43OD024879, R44OD024879) and NINDS.
Collective Behavior Emerges from Genetically Controlled Simple Behavioral Motifs in Zebrafish
Harpaz et al., Science Advances. 2021.
https://www.science.org/doi/10.1126/sciadv.abi7460
Harpaz et al. report that zebrafish regulate their proximity and alignment with each other at early larval stages. Two visual responses (one measuring relative visual field occupancy and one accounting for global visual motion), account for emerging group behavior. Mutations in genes known to affect social behavior in humans perturb these reflexes in individual larval zebrafish and change their emergent collective behaviors. Model simulations show that changes in these two responses in individual mutant animals predict well the distinctive collective patterns that emerge in a group. Hence, group behaviors reflect in part genetically defined primitive sensorimotor “motifs” evident in young larvae. Supported by ORIP (R43OD024879, R44OD024879) and NINDS.
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.