scholarly journals Integrin-dependent Migratory Switches Regulate the Translocation of Toxoplasma-infected Dendritic Cells Across Brain Endothelial Monolayers

2021 ◽  
Author(s):  
Emily C Ross ◽  
Antonio Barragan
Keyword(s):  
Dendritic Cells ◽  
Collagen Matrix ◽  
Cell Monolayers ◽  
Cellular Processes ◽  
Endothelial Monolayers ◽  
Amoeboid Motility ◽  
Cellular Environment ◽  
Cell Metastasis ◽  
Coated Surfaces ◽  
Β2 Integrins

Abstract Multiple cellular processes, such as immune responses and cancer cell metastasis, crucially depend on the interconversion between distinct migratory states. However, knowledge is scarce on how infectious agents impact the processes of cell migration at restrictive biological barriers. In extracellular matrix, dendritic cells (DCs) infected by the obligate intracellular protozoan Toxoplasma gondii undergo mesenchymal-to-amoeboid transition (MAT) for rapid integrin-independent migration. Here, in a cellular model of the blood-brain barrier, we report that parasitised DCs shift to integrin-dependent motility and adhesion on polarised endothelium, accompanied by elevated transendothelial migration (TEM). Upon contact with endothelium, parasitised DCs dramatically reduced velocities and adhered under both static and shear stress conditions, thereby obliterating the infection-induced amoeboid motility displayed in collagen matrix. The motility of adherentparasitised DCs on endothelial monolayers was restored by blockade of β1 and β2 integrins or ICAM-1, which conversely reduced motility on collagen-coated surfaces. Moreover, parasitised DCs exhibited enhanced translocation across highly polarised primary murine brain endothelial cell monolayers. Blockade of β1, β2 integrins, ICAM-1 and PECAM-1 reduced TEM frequencies. Finally, gene silencing of the pan-integrin-cytoskeleton linker talin ( Tln1 ) or of β1 integrin ( Itgb1 ) in primary DCs resulted in increased motility on endothelium and decreased TEM. Adding to the paradigms of leukocyte diapedesis, the findings provide novel insights in how an intracellular pathogen modulates the migratory properties of leukocytes in response to the cellular environment, to promote infection-related dissemination.

scholarly journals Integrin-dependent migratory switches regulate the translocation of Toxoplasma-infected dendritic cells across brain endothelial monolayers

2021 ◽  
Author(s):  
Emily .C Ross ◽  
Arne L ten Hoeve ◽  
Antonio Barragan
Keyword(s):  
Dendritic Cells ◽  
Collagen Matrix ◽  
Cellular Processes ◽  
Endothelial Monolayers ◽  
Amoeboid Motility ◽  
Cellular Environment ◽  
Cell Adhesion And Migration ◽  
And Migration ◽  
Coated Surfaces ◽  
Β2 Integrins

Multiple cellular processes, such as immune responses and cancer cell metastasis, crucially depend on interconvertible migration modes. However, knowledge is scarce on how infectious agents impact the processes of cell adhesion and migration at restrictive biological barriers. In extracellular matrix, dendritic cells (DCs) infected by the obligate intracellular protozoan Toxoplasma gondii undergo mesenchymal-to- amoeboid transition (MAT) for rapid integrin-independent migration. Here, in a cellular model of the blood-brain barrier, we report that parasitised DCs adhere to polarised endothelium and shift to integrin-dependent motility, accompanied by elevated transendothelial migration (TEM). Upon contact with endothelium,parasitised DCs dramatically reduced velocities and adhered under both static and shear stress conditions, thereby obliterating the infection-induced amoeboid motility displayed in collagen matrix. The motility of adherent parasitised DCs on endothelial monolayers was restored by blockade of β1 and β2 integrins or ICAM-1, which conversely reduced motility on collagen-coated surfaces. Moreover, parasitised DCs exhibited enhanced translocation across highly polarised primary murine brain endothelial cell monolayers. Blockade of β1, β2 integrins, ICAM-1 and PECAM-1 reduced TEM frequencies. Finally, gene silencing of the pan-integrin-cytoskeleton linker talin ( Tln1 ) or of β1 integrin ( Itgb1 ) in primary DCs resulted in increased motility on endothelium and decreased TEM. Adding to the paradigms of leukocyte diapedesis, the findings provide novel insights in how an intracellular pathogen impacts the migratory plasticity of leukocytes in response to the cellular environment, to promote infection-related dissemination.

scholarly journals Integrin-dependent migratory switches regulate the translocation of Toxoplasma-infected dendritic cells across brain endothelial monolayers

2021 ◽  
Author(s):  
Emily C. Ross ◽  
Arne L. ten Hoeve ◽  
Antonio Barragan
Keyword(s):  
Dendritic Cells ◽  
Collagen Matrix ◽  
Cellular Processes ◽  
Endothelial Monolayers ◽  
Amoeboid Motility ◽  
Cellular Environment ◽  
Cell Adhesion And Migration ◽  
And Migration ◽  
Coated Surfaces ◽  
Β2 Integrins

AbstractMultiple cellular processes, such as immune responses and cancer cell metastasis, crucially depend on interconvertible migration modes. However, knowledge is scarce on how infectious agents impact the processes of cell adhesion and migration at restrictive biological barriers. In extracellular matrix, dendritic cells (DCs) infected by the obligate intracellular protozoan Toxoplasma gondii undergo mesenchymal-to-amoeboid transition (MAT) for rapid integrin-independent migration. Here, in a cellular model of the blood–brain barrier, we report that parasitised DCs adhere to polarised endothelium and shift to integrin-dependent motility, accompanied by elevated transendothelial migration (TEM). Upon contact with endothelium, parasitised DCs dramatically reduced velocities and adhered under both static and shear stress conditions, thereby obliterating the infection-induced amoeboid motility displayed in collagen matrix. The motility of adherent parasitised DCs on endothelial monolayers was restored by blockade of β1 and β2 integrins or ICAM-1, which conversely reduced motility on collagen-coated surfaces. Moreover, parasitised DCs exhibited enhanced translocation across highly polarised primary murine brain endothelial cell monolayers. Blockade of β1, β2 integrins, ICAM-1 and PECAM-1 reduced TEM frequencies. Finally, gene silencing of the pan-integrin-cytoskeleton linker talin (Tln1) or of β1 integrin (Itgb1) in primary DCs resulted in increased motility on endothelium and decreased TEM. Adding to the paradigms of leukocyte diapedesis, the findings provide novel insights in how an intracellular pathogen impacts the migratory plasticity of leukocytes in response to the cellular environment, to promote infection-related dissemination.

scholarly journals Disruption of Stress Granule Formation by the Multifunctional Cricket Paralysis Virus 1A Protein

2016 ◽  
Vol 91 (5) ◽  
Author(s):  
Anthony Khong ◽  
Craig H. Kerr ◽  
Clarence H. L. Yeung ◽  
Kathleen Keatings ◽  
Arabinda Nayak ◽  
...  
Keyword(s):  
Virus Infection ◽  
Stress Granule ◽  
Granule Formation ◽  
Viral Translation ◽  
Content Type ◽  
Cellular Processes ◽  
Cellular Environment ◽  
Viral Yield ◽  
Infected Cells ◽  
Paralysis Virus

ABSTRACT Stress granules (SGs) are cytosolic ribonucleoprotein aggregates that are induced during cellular stress. Several viruses modulate SG formation, suggesting that SGs have an impact on virus infection. However, the mechanisms and impact of modulating SG assembly in infected cells are not completely understood. In this study, we identify the dicistrovirus cricket paralysis virus 1A (CrPV-1A) protein that functions to inhibit SG assembly during infection. Moreover, besides inhibiting RNA interference, CrPV-1A also inhibits host transcription, which indirectly modulates SG assembly. Thus, CrPV-1A is a multifunctional protein. We identify a key R146A residue that is responsible for these effects, and mutant CrPV(R146A) virus infection is attenuated in Drosophila melanogaster S2 cells and adult fruit flies and results in increased SG formation. Treatment of CrPV(R146A)-infected cells with actinomycin D, which represses transcription, restores SG assembly suppression and viral yield. In summary, CrPV-1A modulates several cellular processes to generate a cellular environment that promotes viral translation and replication. IMPORTANCE RNA viruses encode a limited set of viral proteins to modulate an array of cellular processes in order to facilitate viral replication and inhibit antiviral defenses. In this study, we identified a viral protein, called CrPV-1A, within the dicistrovirus cricket paralysis virus that can inhibit host transcription, modulate viral translation, and block a cellular process called stress granule assembly. We also identified a specific amino acid within CrPV-1A that is important for these cellular processes and that mutant viruses containing mutations of CrPV-1A attenuate virus infection. We also demonstrate that the CrPV-1A protein can also modulate cellular processes in human cells, suggesting that the mode of action of CrPV-1A is conserved. We propose that CrPV-1A is a multifunctional, versatile protein that creates a cellular environment in virus-infected cells that permits productive virus infection.

Three-dimensional two-layer collagen matrix gel culture model for evaluating complex biological functions of monocyte-derived dendritic cells

2004 ◽  
Vol 287 (1-2) ◽  
pp. 79-90 ◽  
Author(s):  
Akira Tasaki ◽  
Naoki Yamanaka ◽  
Makoto Kubo ◽  
Kotaro Matsumoto ◽  
Hideo Kuroki ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Three Dimensional ◽  
Collagen Matrix ◽  
Biological Functions ◽  
Culture Model ◽  
Gel Culture

Nanomechanochemical Delivery of Nanoparticles for Nanomechanics Inside Living Cells

2010 ◽  
Author(s):  
Kyungsuk Yum ◽  
Sungsoo Na ◽  
Yang Xiang ◽  
Ning Wang ◽  
Min-Feng Yu
Keyword(s):  
Single Molecule ◽  
Living Cells ◽  
Endocytic Pathway ◽  
Great Promise ◽  
Biological Processes ◽  
Temporal Precision ◽  
Single Molecule Level ◽  
Cellular Processes ◽  
Cellular Environment ◽  
Biological Studies

Studying biological processes and mechanics in living cells is challenging but highly rewarding. Recent advances in experimental techniques have provided numerous ways to investigate cellular processes and mechanics of living cells. However, most of existing techniques for biomechanics are limited to experiments outside or on the membrane of cells, due to the difficulties in physically accessing the interior of living cells. On the other hand, nanomaterials, such as fluorescent quantum dots (QDs) and magnetic nanoparticles, have shown great promise to overcome such limitations due to their small sizes and excellent functionalities, including bright and stable fluorescence and remote manipulability. However, except a few systems, the use of nanoparticles has been limited to the study of biological studies on cell membranes or related to endocytosis, because of the difficulty of delivering dispersed and single nanoparticles into living cells. Various strategies have been explored, but delivered nanoparticles are often trapped in the endocytic pathway or form aggregates in the cytoplasm, limiting their further use. Here we show a nanoscale direct delivery method, named nanomechanochemical delivery, where we manipulate a nanotube-based nanoneedle, carrying “cargo” (QDs in this study), to mechanically penetrate the cell membrane, access specific areas inside cells, and release the cargo [1]. We selectively delivered well-dispersed QDs into either the cytoplasm or the nucleus of living cells. We quantified the dynamics of the delivered QDs by single-molecule tracking and demonstrated the applicability of the QDs as a nanoscale probe for studying nanomechanics inside living cells (by using the biomicrorhology method), revealing the biomechanical heterogeneity of the cellular environment. This method may allow new strategies for studying biological processes and mechanics in living cells with spatial and temporal precision, potentially at the single-molecule level.

scholarly journals Direct staining and visualization of endothelial monolayers cultured on synthetic polycarbonate filters.

1988 ◽  
Vol 36 (5) ◽  
pp. 551-554 ◽  
Author(s):  
P G Phillips ◽  
M F Tsan
Keyword(s):  
Morphological Data ◽  
Protein Distribution ◽  
Experimental Conditions ◽  
Rhodamine Phalloidin ◽  
Cell Monolayers ◽  
Functional Studies ◽  
Endothelial Monolayers ◽  
Morphological Studies ◽  
Pulmonary Artery Endothelial Cell ◽  
Cells Cultured

Endothelial and epithelial cells cultured on synthetic filter supports have been used to study permeability and transport under various experimental conditions. However, because of the non-transparent nature of these filters, morphological studies using light microscopy are not possible. Presently, investigators circumvent this problem by using cells cultured on glass coverslips, extrapolating morphological data from a system clearly different from that used for functional studies. We describe here a useful technique for direct staining and visualization of cells grown on polycarbonate filter supports, using fluorochrome probes and fluorescence microscopy. We have utilized acridine orange, rhodamine phalloidin, and an anti-vimentin monoclonal antibody to provide information about cell shape, monolayer configuration, and cytoskeletal protein distribution in cultured calf pulmonary artery endothelial cell monolayers. Comparison staining of coverslip and filter preparations revealed a number of clear differences in these parameters. This technique should enable investigators to perform the necessary studies to obtain direct correlations between functional and morphological data.

Dendritic cells lower permeability of endothelial cell monolayers

2010 ◽  
Vol 213 (1) ◽  
pp. e17
Author(s):  
C.M. Warboys ◽  
D.R. Overby ◽  
P.D. Weinberg
Keyword(s):  
Dendritic Cells ◽  
Endothelial Cell ◽  
Cell Monolayers ◽  
Lower Permeability

scholarly journals New approaches to manipulating the epigenome

2014 ◽  
Vol 16 (3) ◽  
pp. 345-357 ◽  
Keyword(s):  
Epigenetic Mechanisms ◽  
Temporal Precision ◽  
Cellular Processes ◽  
Disease States ◽  
Cellular Environment ◽  
Health And Disease ◽  
Potential Impact ◽  
Epigenetic Editing ◽  
Insight Into ◽  
Epigenetic Processes

Cellular processes that control transcription of genetic information are critical for cellular function, and are often implicated in psychiatric and neurological disease states. Among the most critical of these processes are epigenetic mechanisms, which serve to link the cellular environment with genomic material. Until recently our understanding of epigenetic mechanisms has been limited by the lack of tools that can selectively manipulate the epigenome with genetic, cellular, and temporal precision, which in turn diminishes the potential impact of epigenetic processes as therapeutic targets. This review highlights an emerging suite of tools that enable robust yet selective interrogation of the epigenome. In addition to allowing site-specific epigenetic editing, these tools can be paired with optogenetic approaches to provide temporal control over epigenetic processes, allowing unparalleled insight into the function of these mechanisms. This improved control promises to revolutionize our understanding of epigenetic modifications in human health and disease states.

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