Selected Grantee Publications
3D-Bioprinted Phantom With Human Skin Phototypes for Biomedical Optics
Yim et al., Advanced Materials. 2023.
https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202206385
Human skin offers important physical and immunological protection based on its makeup with diverse cell types, including melanocytes, and variations in skin phototypes controlled by melanin concentration have negatively affected many optic technologies and wearable health-tracking electronic devices. To mimic the effects of melanosome variation, investigators studied optical properties and photoacoustic signal of synthetic melanin to create a 3D bioprinting rendition of the human epidermal thin layers. The effect of skin phototypes on thin-layer skin imaging at different wavelengths was quantified. These data could serve as a benchmark calibration tool of light-mediated diagnostics toward clinical use and further underpin development of biomedical optics. Supported by ORIP (S10OD023527, S10OD021821).
Human Hematopoietic Stem Cell Engrafted IL-15 Transgenic NSG Mice Support Robust NK Cell Responses and Sustained HIV-1 Infection
Abeynaike et al., Viruses. 2023.
https://www.mdpi.com/1999-4915/15/2/365
A major obstacle to human natural killer (NK) cell reconstitution is the lack of human interleukin‑15 (IL-15) signaling, as murine IL-15 is a poor stimulator of the human IL-15 receptor. Researchers show that immunodeficient NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice expressing a transgene encoding human IL-15 (NSG-Tg(IL-15)) have physiological levels of human IL-15 and support long-term engraftment of human NK cells when transplanted with human umbilical cord blood–derived hematopoietic stem cells (HSCs). These mice demonstrate robust and long-term reconstitution with human immune cells but do not develop graft-versus-host disease, allowing long-term studies of human NK cells. The HSC-engrafted mice can sustain HIV-1 infection, resulting in human NK cell responses. This work provides a robust novel model to study NK cell responses to HIV-1. Supported by ORIP (R24OD026440), NIAID, NCI, and NIDDK.
PGRN Deficiency Exacerbates, Whereas a Brain Penetrant PGRN Derivative Protects, GBA1 Mutation–Associated Pathologies and Diseases
Zhao et al., Proc Natl Acad Sci USA. 2023.
https://www.pnas.org/doi/10.1073/pnas.2210442120
Mutations in GBA1 are associated with Gaucher disease (GD) and are also genetic risks in developing Parkinson’s disease (PD). Investigators created a mouse model and demonstrated that progranulin (PGRN) deficiency in Gba1 mutant mice caused early onset and exacerbated GD phenotypes, leading to substantial increases in substrate accumulation and inflammation in visceral organs and the central nervous system. These in vivo and ex vivo data demonstrated that PGRN plays a crucial role in the initiation and progression. In addition, the mouse model provides a clinically relevant system for testing therapeutic approaches for GD and PD. Supported by ORIP (R21OD033660), NIAMS, and NINDS.
Gigapixel Imaging With a Novel Multi-Camera Array Microscope
Thomson et al., eLife. 2022.
https://www.doi.org/10.7554/eLife.74988
The dynamics of living organisms are organized across many spatial scales. The investigators created assembled a scalable multi-camera array microscope (MCAM) that enables comprehensive high-resolution, large field-of-view recording from multiple spatial scales simultaneously, ranging from structures that approach the cellular scale to large-group behavioral dynamics. By collecting data from up to 96 cameras, they computationally generated gigapixel-scale images and movies with a field of view over hundreds of square centimeters at an optical resolution of 18 µm. This system allows the team to observe the behavior and fine anatomical features of numerous freely moving model organisms on multiple spatial scales (e.g., larval zebrafish, fruit flies, slime mold). Overall, by removing the bottlenecks imposed by single-camera image acquisition systems, the MCAM provides a powerful platform for investigating detailed biological features and behavioral processes of small model organisms. Supported by ORIP (R44OD024879), NIEHS, NCI, and NIBIB.
Two Neuronal Peptides Encoded from a Single Transcript Regulate Mitochondrial Complex III in Drosophila
Bosch et al., eLife. 2022.
https://www.doi.org/10.7554/eLife.82709
Transcripts with small open-reading frames (smORFs) are underrepresented in genome annotations. Functions of peptides encoded by smORFs are poorly understood. The investigators systematically characterized human-conserved smORF genes in Drosophila and found two peptides, Sloth1 and Sloth2, that are highly expressed in neurons. They showed that Sloth1 and Sloth2 are paralogs with high sequence similarity but are not functionally redundant. Loss of either peptide resulted in lethality, impaired mitochondrial function, and neurodegeneration. This work suggests the value of phenotypic analysis of smORFs using Drosophila as a model. Supported by ORIP (R24OD019847), NHGRI, and NIGMS.
SARS-CoV-2 Infects Neurons and Induces Neuroinflammation in a Non-Human Primate Model of COVID-19
Beckman et al., Cell Reports. 2022.
https://www.doi.org/10.1016/j.celrep.2022.111573
SARS-CoV-2 causes brain fog and other neurological complications in some patients. It has been unclear whether SARS-CoV-2 infects the brain directly or whether central nervous system sequelae result from systemic inflammatory responses triggered in the periphery. Using a rhesus macaque model, researchers detected SARS-CoV-2 in the olfactory cortex and interconnected regions 7 days after infection, demonstrating that the virus enters the brain through the olfactory nerve. Neuroinflammation and neuronal damage were more severe in elderly monkeys with type 2 diabetes. The researchers found that in aged monkeys, SARS-CoV-2 traveled farther along nerve pathways to regions associated with Alzheimer's disease. Supported by ORIP (P51OD011107) and NIA.
Cell-Specific Regulation of Gene Expression Using Splicing-Dependent Frameshifting
Ling et al., Nature Communications. 2022.
https://www.doi.org/10.1038/s41467-022-33523-2
Precise and reliable cell-specific gene delivery remains technically challenging. Investigators report a splicing-based approach for controlling gene expression whereby separate translational reading frames are coupled to the inclusion or exclusion of mutated, frameshifting cell-specific alternative exons. Candidate exons are identified by analyzing thousands of publicly available RNA sequencing datasets and filtering by cell specificity, conservation, and local intron length. This method, which they denote as splicing-linked expression design (SLED), can be combined in a Boolean manner with such existing techniques as minipromoters and viral capsids. SLED can use strong constitutive promoters, without sacrificing precision, by decoupling the tradeoff between promoter strength and selectivity. AAV-packaged SLED vectors can selectively deliver fluorescent reporters and calcium indicators to various neuronal subtypes in vivo. The authors also demonstrate gene therapy utility by creating SLED vectors that can target PRPH2 and SF3B1 mutations. The flexibility of SLED technology enables creative avenues for basic and translational research. Supported by ORIP (T32OD011089, S10OD026859), NEI, and NIMH.
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.
System-Wide Identification of Myeloid Markers of TB Disease and HIV-Induced Reactivation in the Macaque Model of Mtb Infection and Mtb/SIV Co-Infection
Gough et al., Frontiers in Immunology. 2022.
https://www.doi.org/10.3389/fimmu.2022.777733
HIV is known to catalyze the reactivation of latent tuberculosis (TB) infection. The investigators characterized Mycobacterium tuberculosis (Mtb) and simian immunodeficiency virus (SIV) coinfection using a rhesus macaque model of both sexes, with a focus on pathways relevant to myeloid origin cells (e.g., macrophages). They identified gene signatures of host disease state and progression, as well as clustering algorithms for differentiation between host disease states and relationships among genes. The gene signatures were associated with pathways relevant to apoptosis, adenosine triphosphate production, phagocytosis, cell migration, and type I interferon, which are related to macrophage function. Collectively, these findings suggest that novel macrophage functions influence Mtb infection both with and without SIV coinfection. Supported by ORIP (P51OD011104, P51OD011103, U42OD010442) and NIAID.
Mendelian Gene Identification through Mouse Embryo Viability Screening
Cacheiro et al., Genome Medicine. 2022.
https://www.doi.org/10.1186/s13073-022-01118-7
The investigators dissected phenotypic similarities between patients and model organisms by assessing the embryonic stage at which homozygous loss of function results in lethality in mice of both sexes obtained from the International Mouse Phenotyping Consortium. Information on knockout mouse embryo lethality can be used to prioritize candidate genes associated with certain disorders. Access to unsolved cases from rare-disease genome sequencing programs allows for the screening of those genes for potentially pathogenic variants, which could lead to a diagnosis and new potential treatment options to inform the management of human disease. Supported by ORIP (UM1OD023221, UM1OD023222, U42OD011174) and NHGRI.