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Project description:Immune cells play critical roles in causing host damage in various diseases, including infectious diseases. However, there is a paucity of human models to study immune-mediated host damage. Here, we systematically analyzed the changes in immune cell composition for COVID-19 pancreatic autopsy samples using the GeoMx spatial RNA and protein platform and found accumulation of proinflammatory macrophages. Single cell RNA-seq analysis of human islets upon SARS-CoV-2 or Coxsackievirus B4 (CVB4) infection identified the activation of proinflammatory macrophages and pyroptosis in β cells. To distinguish whether the virus or proinflammatory macrophages mediated β cell pyroptosis, we developed human pluripotent stem cell (hPSC)-derived vascularized macrophage-islet (VMI) organoids, containing pancreatic endocrine cells, endothelial cells, and macrophages. Both pancreatic β cells and endothelial cells in VMI organoids demonstrated improved marker expression and function compared to separately cultured cells. Additionally, proinflammatory macrophages in VMI organoids were found to induce β cell pyroptosis. Further mechanistic studies identified TNFSF12-TNFRSF12A as a contributor to proinflammatory macrophage-mediated β cell pyroptosis. Together, this study established a hPSC-derived VMI organoid as a valuable tool for studying immune cell-mediated host damage and uncovered previous unknown mechanism of β cell damage in viral infection.
2024-08-08 | GSE247808 | GEO
Project description:Immune cells play critical roles in causing host damage in various diseases, including infectious diseases. However, there is a paucity of human models to study immune-mediated host damage. Here, we systematically analyzed the changes in immune cell composition for COVID-19 pancreatic autopsy samples using the GeoMx spatial RNA and protein platform and found accumulation of proinflammatory macrophages. Single cell RNA-seq analysis of human islets upon SARS-CoV-2 or Coxsackievirus B4 (CVB4) infection identified the activation of proinflammatory macrophages and pyroptosis in β cells. To distinguish whether the virus or proinflammatory macrophages mediated β cell pyroptosis, we developed human pluripotent stem cell (hPSC)-derived vascularized macrophage-islet (VMI) organoids, containing pancreatic endocrine cells, endothelial cells, and macrophages. Both pancreatic β cells and endothelial cells in VMI organoids demonstrated improved marker expression and function compared to separately cultured cells. Additionally, proinflammatory macrophages in VMI organoids were found to induce β cell pyroptosis. Further mechanistic studies identified TNFSF12-TNFRSF12A as a contributor to proinflammatory macrophage-mediated β cell pyroptosis. Together, this study established a hPSC-derived VMI organoid as a valuable tool for studying immune cell-mediated host damage and uncovered previous unknown mechanism of β cell damage in viral infection.
2024-08-08 | GSE247807 | GEO
Project description:Immune cells play critical roles in causing host damage in various diseases, including infectious diseases. However, there is a paucity of human models to study immune-mediated host damage. Here, we systematically analyzed the changes in immune cell composition for COVID-19 pancreatic autopsy samples using the GeoMx spatial RNA and protein platform and found accumulation of proinflammatory macrophages. Single cell RNA-seq analysis of human islets upon SARS-CoV-2 or Coxsackievirus B4 (CVB4) infection identified the activation of proinflammatory macrophages and pyroptosis in β cells. To distinguish whether the virus or proinflammatory macrophages mediated β cell pyroptosis, we developed human pluripotent stem cell (hPSC)-derived vascularized macrophage-islet (VMI) organoids, containing pancreatic endocrine cells, endothelial cells, and macrophages. Both pancreatic β cells and endothelial cells in VMI organoids demonstrated improved marker expression and function compared to separately cultured cells. Additionally, proinflammatory macrophages in VMI organoids were found to induce β cell pyroptosis. Further mechanistic studies identified TNFSF12-TNFRSF12A as a contributor to proinflammatory macrophage-mediated β cell pyroptosis. Together, this study established a hPSC-derived VMI organoid as a valuable tool for studying immune cell-mediated host damage and uncovered previous unknown mechanism of β cell damage in viral infection.
2024-08-08 | GSE247806 | GEO
Project description:Immune cells play critical roles in causing host damage in various diseases, including infectious diseases. However, there is a paucity of human models to study immune-mediated host damage. Here, we systematically analyzed the changes in immune cell composition for COVID-19 pancreatic autopsy samples using the GeoMx spatial RNA and protein platform and found accumulation of proinflammatory macrophages. Single cell RNA-seq analysis of human islets upon SARS-CoV-2 or Coxsackievirus B4 (CVB4) infection identified the activation of proinflammatory macrophages and pyroptosis in β cells. To distinguish whether the virus or proinflammatory macrophages mediated β cell pyroptosis, we developed human pluripotent stem cell (hPSC)-derived vascularized macrophage-islet (VMI) organoids, containing pancreatic endocrine cells, endothelial cells, and macrophages. Both pancreatic β cells and endothelial cells in VMI organoids demonstrated improved marker expression and function compared to separately cultured cells. Additionally, proinflammatory macrophages in VMI organoids were found to induce β cell pyroptosis. Further mechanistic studies identified TNFSF12-TNFRSF12A as a contributor to proinflammatory macrophage-mediated β cell pyroptosis. Together, this study established a hPSC-derived VMI organoid as a valuable tool for studying immune cell-mediated host damage and uncovered previous unknown mechanism of β cell damage in viral infection.
2024-08-08 | GSE247805 | GEO
Project description:Hemorrhagic viral diseases are distributed worldwide with important pathogens, such as dengue virus or hantaviruses. The lack of adequate in vivo infection models has limited the research on viral pathogenesis and the current understanding of the underlying infection mechanisms. Although hemorrhages have been associated with the infection of endothelial cells, other cellular types could be the main targets for hemorrhagic viruses. Our objective was to take advantage of the use of zebrafish larvae in the study of viral hemorrhagic diseases, focusing on the interaction between viruses and host cells. Cellular processes, such as transendothelial migration of leukocytes, virus-induced pyroptosis of macrophages. and interleukin-1? (Il-1?) release, could be observed in individual cells, providing a deeper knowledge of the immune mechanisms implicated in the disease. Furthermore, the application of these techniques to other pathogens will improve the current knowledge of host-pathogen interactions and increase the potential for the discovery of new therapeutic targets. Importance: Pathogenic mechanisms of hemorrhagic viruses are diverse, and most of the research regarding interactions between viruses and host cells has been performed in cell lines that might not be major targets during natural infections. Thus, viral pathogenesis research has been limited because of the lack of adequate in vivo infection models. The understanding of the relative pathogenic roles of the viral agent and the host response to the infection is crucial. This will be facilitated by the establishment of in vivo infection models using organisms such as zebrafish, which allows the study of the diseases in the context of a complete individual. The use of this animal model with other pathogens could improve the current knowledge on host-pathogen interactions and increase the potential for the discovery of new therapeutic targets against diverse viral diseases.
| S-EPMC4178746 | biostudies-literature
Project description:A host defense strategy against pathogens is the induction of cell death, thereby eliminating the pathogen's intracellular niche. Pyroptosis, one such form of cell death, is dependent on inflammasome activation. In a genetic screen to identify Listeria monocytogenes mutants that induced altered levels of host cell death, we identified a mutation in lmo2473 that caused hyperstimulation of IL-1beta secretion and pyroptosis following bacteriolysis in the macrophage cytosol. In addition, strains engineered to lyse in the cytosol by expression of both bacteriophage holin and lysin or induced to lyse by treatment with ampicillin stimulated pyroptosis. Pyroptosis was independent of the Nlrp3 and Nlrc4 inflammasome receptors but dependent on the inflammasome adaptor ASC and the cytosolic DNA sensor AIM2. Importantly, wild-type L. monocytogenes were also found to lyse, albeit at low levels, and trigger AIM2-dependent pyroptosis. These data suggested that pyroptosis is triggered by bacterial DNA released during cytosolic lysis.
| S-EPMC2947455 | biostudies-literature
Project description:Engineering vascularized tissue constructs and organoids has been historically challenging. Here we describe a novel method based on microfluidic bioprinting to generate a scaffold with multilayer interlacing hydrogel microfibers. To achieve smooth bioprinting, a core-sheath microfluidic printhead containing a composite bioink formulation extruded from the core flow and the crosslinking solution carried by the sheath flow, was designed and fitted onto the bioprinter. By blending gelatin methacryloyl (GelMA) with alginate, a polysaccharide that undergoes instantaneous ionic crosslinking in the presence of select divalent ions, followed by a secondary photocrosslinking of the GelMA component to achieve permanent stabilization, a microfibrous scaffold could be obtained using this bioprinting strategy. Importantly, the endothelial cells encapsulated inside the bioprinted microfibers can form the lumen-like structures resembling the vasculature over the course of culture for 16 days. The endothelialized microfibrous scaffold may be further used as a vascular bed to construct a vascularized tissue through subsequent seeding of the secondary cell type into the interstitial space of the microfibers. Microfluidic bioprinting provides a generalized strategy in convenient engineering of vascularized tissues at high fidelity.
| S-EPMC5614273 | biostudies-literature
Project description:Islet-1 (Isl-1) is essential for the survival and ensuing differentiation of pancreatic endocrine progenitors. Isl-1 remains expressed in all adult pancreatic endocrine lineages; however, its specific function in the postnatal pancreas is unclear. Here we determine whether Isl-1 plays a distinct role in the postnatal β-cell by performing physiological and morphometric analyses of a tamoxifen-inducible, β-cell-specific Isl-1 loss-of-function mouse: Isl-1(L/L); Pdx1-CreER(Tm). Ablating Isl-1 in postnatal β-cells reduced glucose tolerance without significantly reducing β-cell mass or increasing β-cell apoptosis. Rather, islets from Isl-1(L/L); Pdx1-CreER(Tm) mice showed impaired insulin secretion. To identify direct targets of Isl-1, we integrated high-throughput gene expression and Isl-1 chromatin occupancy using islets from Isl-1(L/L); Pdx1-CreER(Tm) mice and βTC3 insulinoma cells, respectively. Ablating Isl-1 significantly affected the β-cell transcriptome, including known targets Insulin and MafA as well as novel targets Pdx1 and Slc2a2. Using chromatin immunoprecipitation sequencing and luciferase reporter assays, we found that Isl-1 directly occupies functional regulatory elements of Pdx1 and Slc2a2. Thus Isl-1 is essential for postnatal β-cell function, directly regulates Pdx1 and Slc2a2, and has a mature β-cell cistrome distinct from that of pancreatic endocrine progenitors.
| S-EPMC4237994 | biostudies-literature
Project description:Viral-bacterial co-infections are associated with severe exacerbations of COPD. Epithelial antimicrobial peptides, including human β-defensin-2 (HBD-2), are integral to innate host defenses. In this study, we examined how co-infection of airway epithelial cells with rhinovirus and Pseudomonas aeruginosa modulates HBD-2 expression, and whether these responses are attenuated by cigarette smoke and in epithelial cells obtained by bronchial brushings from smokers with normal lung function or from COPD patients. When human airway epithelial cells from normal lungs were infected with rhinovirus, Pseudomonas aeruginosa, or the combination, co-infection with rhinovirus and bacteria resulted in synergistic induction of HBD-2 (p<0.05). The combination of virus and flagellin replicated this synergistic increase (p<0.05), and synergy was not seen using a flagella-deficient mutant Pseudomonas (p<0.05). The effects of Pseudomonas aeruginosa were mediated via interactions of flagellin with TLR5. The effects of HRV-16 depended upon viral replication but did not appear to be mediated via the intracellular RNA helicases, retinoic acid-inducible gene-I or melanoma differentiation-associated gene-5. Cigarette smoke extract significantly decreased HBD-2 production in response to co-infection. Attenuated production was also observed following co-infection of cells obtained from healthy smokers or COPD patients compared to healthy controls (p<0.05). We conclude that co-exposure to HRV-16 and Pseudomonas aeruginosa induces synergistic production of HBD-2 from epithelial cells and that this synergistic induction of HBD-2 is reduced in COPD patients. This may contribute to the more severe exacerbations these patients experience in response to viral-bacterial co-infections.
| S-EPMC5425185 | biostudies-literature
Project description:Brain organoids have been used to recapitulate the processes of brain development and related diseases. However, the lack of vasculatures, which regulate neurogenesis and brain disorders, limits the utility of brain organoids. In this study, we induced vessel and brain organoids, respectively, and then fused two types of organoids together to obtain vascularized brain organoids. The fused brain organoids were engrafted with robust vascular network-like structures and exhibited increased number of neural progenitors, in line with the possibility that vessels regulate neural development. Fusion organoids also contained functional blood-brain barrier-like structures, as well as microglial cells, a specific population of immune cells in the brain. The incorporated microglia responded actively to immune stimuli to the fused brain organoids and showed ability of engulfing synapses. Thus, the fusion organoids established in this study allow modeling interactions between the neuronal and non-neuronal components in vitro, particularly the vasculature and microglia niche.
| S-EPMC9246368 | biostudies-literature