Selected Grantee Publications
Gut Microbiome Dysbiosis in Antibiotic-Treated COVID-19 Patients Is Associated with Microbial Translocation and Bacteremia
Bernard-Raichon et al., Nature Communications. 2022.
https://www.doi.org/10.1038/s41467-022-33395-6
The investigators demonstrated that SARS-CoV-2 infection induced gut microbiome dysbiosis in male mice. Samples collected from human COVID-19 patients of both sexes also revealed substantial gut microbiome dysbiosis. Analysis of blood culture results testing for secondary microbial bloodstream infections with paired microbiome data indicated that bacteria might translocate from the gut into the systemic circulation of COVID-19 patients. These results were consistent with a direct role for gut microbiome dysbiosis in enabling dangerous secondary infections during COVID-19. Supported by ORIP (S10OD021747), NCI, NHLBI, NIAID, and NIDDK.
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.
Rapid Joule Heating Improves Vitrification Based Cryopreservation
Zhan et al., Nature Communications. 2022.
https://www.doi.org/10.1038/s41467-022-33546-9
Cryopreservation by vitrification is an effective approach for long-term preservation of biosystems, but effective vitrification often requires high concentrations of cryoprotective agent (CPA), which can be toxic. The investigators described a joule heating–based platform technology for rapid rewarming of biosystems, which allows the use of low concentrations of CPA. They demonstrated the success of this platform in cryopreservation of three model systems: adherent cells, Drosophila melanogaster embryos, and rat kidney slices with low CPA concentrations. This work provides a general solution to cryopreserve a broad spectrum of cells, tissues, organs, and organisms. Supported by ORIP (R21OD028758), NIDDK, NHLBI, and NIGMS.
Profiling Development of Abdominal Organs in the Pig
Gabriel et al., Scientific Reports. 2022.
https://www.doi.org/10.1038/s41598-022-19960-5
The pig is a model system for studying human development and disease due to its similarities to human anatomy, physiology, size, and genome. Moreover, advances in CRISPR gene editing have made genetically engineered pigs a viable model for the study of human pathologies and congenital anomalies. However, a detailed atlas illustrating pig development is necessary for identifying and modeling developmental defects. Here, the authors describe normal development of the pig abdominal system (i.e., kidney, liver, pancreas, spleen, adrenal glands, bowel, gonads) and compare them with congenital defects that can arise in gene-edited SAP130 mutant pigs. This atlas and the methods described here can be used as tools for identifying developmental pathologies of the abdominal organs in the pig at different stages of development. Supported by ORIP (U42OD011140), NHLBI, NIAID, NIBIB, NICHD, and NINDS.
X Chromosome Agents of Sexual Differentiation
Arnold et al., Nature Reviews Endocrinology. 2022.
https://www.doi.org/10.1038/s41574-022-00697-0
Many diseases affect one sex disproportionately. A major goal of biomedical research is to understand which sex-biasing factors influence disease severity and to develop therapeutic strategies to target these factors. Two groups of such agents are sex chromosome genes and gonadal hormones. Researchers use the “four core genotypes” model to enable comparisons among animals with different sex chromosomes but the same type of sex hormones, which allows investigators to distinguish disease mechanisms influenced by the sex chromosomes. Supported by ORIP (R01OD030496, R21OD026560), NICHD, NIDDK, and NHLBI.
Parallel Processing, Hierarchical Transformations, and Sensorimotor Associations along the “Where” Pathway
Doudlah et al., eLife. 2022.
https://www.doi.org/10.7554/eLife.78712
Visually guided behaviors require the brain to transform ambiguous retinal images into object-level spatial representations and map those representations to motor responses. These capabilities are supported by the dorsal “where” pathway in the brain, but the specific contributions of areas along this pathway have remained elusive. Using a rhesus macaque model, researchers compared neuronal activity in two areas along the “where” pathway that bridge the parieto-occipital junction: intermediate visual area V3A and the caudal intraparietal (CIP) area. Neuronal activity was recorded while the animals made perceptual decisions based on judging the tilt of 3D visual patterns. The investigators found that CIP shows higher-order spatial representations and more choice-correlated responses, which support a V3A-to-CIP hierarchy. The researchers also discovered modulation of V3A activity by extraretinal factors, suggesting that V3A might be better characterized as contributing to higher-order behavioral functions rather than low-level visual feature processing. Supported by ORIP (P51OD011106), NEI, NICHD, and NINDS.
Effects of Ex Vivo Blood Anticoagulation and Preanalytical Processing Time on the Proteome Content of Platelets
Yunga et al., Journal of Thrombosis and Haemostasis. 2022.
https://www.doi.org/10.1111/jth.15694
The investigators studied how various blood anticoagulation options and processing times affect platelet function and protein content ex vivo. Using platelet proteome quantification and triple quadrupole mass spectrometry, they found that anticoagulant-specific effects on platelet proteomes included increased complement system and decreased α-granule proteins in platelets from EDTA-anticoagulated blood. Heparinized blood had higher levels of histone and neutrophil-associated proteins, as well as formation of platelet–neutrophil extracellular trap interactions in whole blood ex vivo. The study indicates that different anticoagulants and preanalytical processing times affect platelet function and platelet protein content ex vivo, suggesting more rigorous phenotyping strategies for platelet omics studies. Supported by ORIP (S10OD012246), NHLBI, NCI and NEI.
Generation of SIV-Resistant T Cells and Macrophages from Nonhuman Primate Induced Pluripotent Stem Cells with Edited CCR5 Locus
D’Souza et al., Stem Cell Reports. 2022.
https://www.doi.org/10.1016/j.stemcr.2022.03.003
Genetically modified T cells have shown promise as a potential therapy for HIV. A renewable source of T cells from induced pluripotent stem cells (iPSCs) could help to further research progress in this area. The researchers used Mauritian cynomolgus macaques to generate simian immunodeficiency virus (SIV)–resistant T cells and macrophages from iPSCs. These engineered cells demonstrated impaired capacity for differentiation into CD4+CD8+ T cells. T cells and macrophages from the edited iPSCs did not support SIV replication. These findings could be applied to the development of new HIV therapies. Supported by ORIP (R24OD021322, P51OD011106) and NHLBI.
Common and Divergent Features of T Cells From Blood, Gut, and Genital Tract of Antiretroviral Therapy–Treated HIV+ Women
Xie et al., Journal of Immunology. 2022.
https://www.doi.org/10.4049/jimmunol.2101102
T cells residing in mucosal tissues play important roles in homeostasis and defense against microbial pathogens, but how organ system environments affect the properties of resident T cells is relatively unknown. Researchers phenotyped T cells in the gut and reproductive tract using blood and tissue samples from women with HIV who have achieved viral suppression via antiretroviral therapy. The T cells exhibited differing expression of CD69 and CD103 markers, whereas resident memory CD8+ T cells from the female reproductive tract expressed PD1 preferentially. Additionally, CXCR4+ T inflammatory mucosal cells expressed multiple chemokine receptors differentially. These results suggest that T cells take on distinct properties in different mucosal sites, which allows them to tailor activities to their surrounding milieu. This study offers important insights for reproductive medicine in women. Supported by ORIP (S10OD018040), NHLBI, NIAID, and NIDDK.
A Potent Myeloid Response Is Rapidly Activated in the Lungs of Premature Rhesus Macaques Exposed to Intra-Uterine Inflammation
Jackson et al., Mucosal Immunology. 2022.
https://www.doi.org/10.1038/s41385-022-00495-x
Up to 40% of preterm births are associated with histological chorioamnionitis (HCA), which can lead to neonatal mortality, sepsis, respiratory disease, and neurodevelopmental problem. Researchers used rhesus macaques to comprehensively describe HCA-induced fetal mucosal immune responses and delineate the individual roles of IL-1β and TNFα in HCA-induced fetal pathology. Their data indicate that the fetal innate immune system can mount a rapid, multifaceted pulmonary immune response to in utero exposure to inflammation. Taken together, this work provides mechanistic insights into the association between HCA and the postnatal lung morbidities of the premature infant and highlights the therapeutic potential of inflammatory blockade in the fetus. Supported by ORIP (P51OD011107), NIEHS, NIDDK, NHLBI, and NICHD.