scholarly journals A spatial and cellular distribution of neurotropic virus infection in the mouse brain revealed by fMOST and single cell RNA-seq

2021 ◽  
Author(s):  
Yachun Zhang ◽  
Xudong Xing ◽  
Ben Long ◽  
Yandi Cao ◽  
Simeng Hu ◽  
...  

Neurotropic virus infection can cause serious damage to the central nervous system (CNS) in both human and animals. The complexity of the CNS poses unique challenges to investigate the infection of these viruses in the brain using traditional techniques. In this study, we explore the use of fluorescence micro-optical sectioning tomography (fMOST) and single cell RNA sequencing (scRNA-seq) to map the spatial and cellular distribution of a representative neurotropic virus, rabies virus (RABV), in the whole brain. Mice were inoculated with a lethal dose of recombinant RABV expressing enhanced green fluorescent protein (EGFP) under different infection routes, and a three-dimensional view of the distribution of RABV in the whole mouse brain was obtained using fMOST. Meanwhile, we pinpointed the cellular distribution of RABV by utilizing scRNA-seq. Our fMOST data provide the first evidence that RABV can infect multiple nuclei related to fear independent of different infection routes. More surprisingly, scRNA-seq data indicate that besides neurons RABV can infect macrophages and NK cells in vivo. Collectively, this study draws a comprehensively spatial and cellular map of RABV infection in the mouse brain, providing a novel and insightful strategy to investigate the pathogenesis of neurotropic viruses.

2021 ◽  
Vol 7 (2) ◽  
pp. eabd2529
Author(s):  
Kazuki Okamoto ◽  
Teppei Ebina ◽  
Naoki Fujii ◽  
Kuniaki Konishi ◽  
Yu Sato ◽  
...  

Optical investigation and manipulation constitute the core of biological experiments. Here, we introduce a new borosilicate glass material that contains the rare-earth ion terbium(III) (Tb3+), which emits green fluorescence upon blue light excitation, similar to green fluorescent protein (GFP), and thus is widely compatible with conventional biological research environments. Micropipettes made of Tb3+-doped glass allowed us to target GFP-labeled cells for single-cell electroporation, single-cell transcriptome analysis (Patch-seq), and patch-clamp recording under real-time fluorescence microscopic control. The glass also exhibited potent third harmonic generation upon infrared laser excitation and was usable for online optical targeting of fluorescently labeled neurons in the in vivo neocortex. Thus, Tb3+-doped glass simplifies many procedures in biological experiments.


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 180
Author(s):  
Zorana Lopandić ◽  
Luka Dragačević ◽  
Dragan Popović ◽  
Uros Andjelković ◽  
Rajna Minić ◽  
...  

Fluorescently labeled lectins are useful tools for in vivo and in vitro studies of the structure and function of tissues and various pathogens such as viruses, bacteria, and fungi. For the evaluation of high-mannose glycans present on various glycoproteins, a three-dimensional (3D) model of the chimera was designed from the crystal structures of recombinant banana lectin (BanLec, Protein Data Bank entry (PDB): 5EXG) and an enhanced green fluorescent protein (eGFP, PDB 4EUL) by applying molecular modeling and molecular mechanics and expressed in Escherichia coli. BanLec-eGFP, produced as a soluble cytosolic protein of about 42 kDa, revealed β-sheets (41%) as the predominant secondary structures, with the emission peak maximum detected at 509 nm (excitation wavelength 488 nm). More than 65% of the primary structure was confirmed by mass spectrometry. Competitive BanLec-eGFP binding to high mannose glycans of the influenza vaccine (Vaxigrip®) was shown in a fluorescence-linked lectin sorbent assay (FLLSA) with monosaccharides (mannose and glucose) and wild type BanLec and H84T BanLec mutant. BanLec-eGFP exhibited binding to mannose residues on different strains of Salmonella in flow cytometry, with especially pronounced binding to a Salmonella Typhi clinical isolate. BanLec-eGFP can be a useful tool for screening high-mannose glycosylation sites on different microorganisms.


2021 ◽  
Vol 411 ◽  
pp. 128557
Author(s):  
Meishen Ren ◽  
Jiaojiao Zhou ◽  
Zhiyong Song ◽  
Hong Mei ◽  
Ming Zhou ◽  
...  

2019 ◽  
Author(s):  
Vlasta Lungova ◽  
Susan Thibeault

Abstract Development of treatments for vocal dysphonia has been inhibited by lack of human vocal fold (VF) mucosa models because of difficulty in procuring VF epithelial cells, epithelial cells’ limited proliferative capacity and absence of cell lines. We report development of engineered VF mucosae from hiPSC, transfected via TALEN constructs for green fluorescent protein, that mimic development of VF epithelial cells in utero. Modulation of FGF signaling achieves stratified squamous epithelium from definitive and anterior foregut derived cultures. Robust culturing of these cells on collagen-fibroblast constructs produces three-dimensional models comparable to in vivo VF mucosa.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Joern Pezoldt ◽  
Carolin Wiechers ◽  
Florian Erhard ◽  
Ulfert Rand ◽  
Tanja Bulat ◽  
...  

AbstractOur understanding of the composition and functions of splenic stromal cells remains incomplete. Here, based on analysis of over 20,000 single cell transcriptomes of splenic fibroblasts, we characterized the phenotypic and functional heterogeneity of these cells in healthy state and during virus infection. We describe eleven transcriptionally distinct fibroblastic cell clusters, reassuring known subsets and revealing yet unascertained heterogeneity amongst fibroblasts occupying diverse splenic niches. We further identify striking differences in innate immune signatures of distinct stromal compartments in vivo. Compared to other fibroblasts and to endothelial cells, Ly6C+ fibroblasts of the red pulp were selectively endowed with enhanced interferon-stimulated gene expression in homeostasis, upon systemic interferon stimulation and during virus infection in vivo. Collectively, we provide an updated map of fibroblastic cell diversity in the spleen that suggests a specialized innate immune function for splenic red pulp fibroblasts.


Author(s):  
Wenqing Jiang ◽  
Junrong Cai ◽  
Jingyan Guan ◽  
Yunjun Liao ◽  
Feng Lu ◽  
...  

Background: Autologous fat grafting has been a widely used technique; however, the role of adipose-derived stem cells (ASCs), extracellular matrix (ECM), and microenvironment in fat regeneration are not fully understood.Methods: Lipoaspirates were obtained and processed by inter-syringe shifting to remove adipocytes, yielding an adipocyte-free fat (Aff). Aff was then exposed to lethal dose of radiation to obtain decellularized fat (Df). To further remove microenvironment, Df was rinsed with phosphate-buffered saline (PBS) yielding rinsed decellularized fat (Rdf). Green fluorescent protein (GFP) lentivirus (LV-GFP)-transfected ASCs were added to Df to generate cell-recombinant decellularized fat (Crdf). Grafts were transplanted subcutaneously into nude mice and harvested over 3 months.Results: Removal of adipocytes (Aff) didn’t compromise the retention of fat grafts, while additional removal of stromal vascular fraction (SVF) cells (Df) and microenvironment (Rdf) resulted in poor retention by day 90 (Aff, 82 ± 7.1% vs. Df, 28 ± 6.3%; p < 0.05; vs. Rdf, 5 ± 1.2%; p < 0.05). Addition of ASCs to Df (Crdf) partially restored its regenerative potential. Aff and Crdf exhibited rapid angiogenesis and M2-polarized macrophages infiltration, in contrast to impaired angiogenesis and M1-polarized inflammatory pattern in Df. GFP + ASCs participated in angiogenesis and displayed a phenotype of endothelial cells in Crdf.Conclusion: Adipose ECM and microenvironment have the capacity to stimulate early adipogenesis while ECM alone cannot induce adipogenesis in vivo. By directly differentiating into endothelial cells and regulating macrophage polarization, ASCs coordinate early adipogenesis with angiogenesis and tissue remodeling, leading to better long-term retention and greater tissue integrity.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Vlasta Lungova ◽  
Xia Chen ◽  
Ziyue Wang ◽  
Christina Kendziorski ◽  
Susan L. Thibeault

Abstract Development of treatments for vocal dysphonia has been inhibited by lack of human vocal fold (VF) mucosa models because of difficulty in procuring VF epithelial cells, epithelial cells’ limited proliferative capacity and absence of cell lines. Here we report development of engineered VF mucosae from hiPSC, transfected via TALEN constructs for green fluorescent protein, that mimic development of VF epithelial cells in utero. Modulation of FGF signaling achieves stratified squamous epithelium from definitive and anterior foregut derived cultures. Robust culturing of these cells on collagen-fibroblast constructs produces three-dimensional models comparable to in vivo VF mucosa. Furthermore, we demonstrate mucosal inflammation upon exposure of these constructs to 5% cigarette smoke extract. Upregulation of pro-inflammatory genes in epithelium and fibroblasts leads to aberrant VF mucosa remodeling. Collectively, our results demonstrate that hiPSC-derived VF mucosa is a versatile tool for future investigation of genetic and molecular mechanisms underlying epithelium-fibroblasts interactions in health and disease.


2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi260-vi261
Author(s):  
Anirudh Sattiraju ◽  
Valerie Marallano ◽  
Roland Friedel ◽  
Hongyan Zou

Abstract Glioblastoma (GBM) is the most common and lethal brain cancer that invariably recurs after therapy due to presence of resistant GBM cells within hypoxic and peri-necrotic regions. Eradicating such GBM cells, which constitute a major source of tumor recurrence, is important to curb disease relapse. An endogenously expressed, spatially sensitive hypoxia reporter would therefore be a valuable tool to evaluate hypoxic zones in GBM in detail, and to measure the efficacy of hypoxia-activated drugs. For this purpose, we engineered a lentiviral vector that carries a hypoxia reporter, consisting of HIF response elements (HRE) that drive expression of UnaG fluorescent protein, which fluoresces independent of oxidative maturation. We validated the sensitivity of our reporter in vitro using U87MG, GBM2, and patient-derived GBM stem cell lines, and we performed intracranial transplantations of GBM cells in SCID mice to identify cells undergoing hypoxic stress in in vivo microenvironment. In addition, GL261 murine GBM cells with hypoxia reporter were intracranially implanted in C57BL/6 mice as syngeneic model for studies on immune responses. Brains from our transplant studies were dissociated and single-cell RNA sequencing (Drop-Seq) was performed to investigate heterogeneity in response to hypoxia within GBM cells and the cellular composition of microenvironment. We will also apply a hypoxia-activated prodrug, Evofosfamide (Evo), in our ongoing studies that can potentially eradicate hypoxic tumor cells and increase T cell infiltration and reverse immune suppression. As hypoxic niches are thought to confer resistance to radiation therapy (XRT), combining XRT with Evo could thus improve therapy efficacy. Our hypoxia gene reporter, combined with single-cell transcriptomics, could therefore serve as an effective tool to enable fundamental investigation of GBM microenvironment and could be used to evaluate therapies targeting tumor microenvironment to enhance GBM patient survival.


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