scholarly journals Bacteriophage uptake by Eukaryotic cell layers represents a major sink for phages during therapy

2020 ◽  
Author(s):  
Marion C. Bichet ◽  
Wai Hoe Chin ◽  
William Richards ◽  
Yu-Wei Lin ◽  
Laura Avellaneda-Franco ◽  
...  
Keyword(s):  
Shear Stress ◽  
Pharmacokinetic Model ◽  
Phage Therapy ◽  
Eukaryotic Cell ◽  
The Body ◽  
Innate Immune Responses ◽  
Uptake Rates ◽  
Cell Layers ◽  
Potential Impact ◽  
High Doses

AbstractFor over 100 years, bacteriophages have been known as viruses that infect bacteria. Yet it is becoming increasingly apparent that bacteriophages, or phages for short, have tropisms outside their bacterial hosts. During phage therapy, high doses of phages are directly administered and disseminated throughout the body, facilitating broad interactions with eukaryotic cells. Using live cell imaging across a range of cell lines we demonstrate that cell type plays a major role in phage internalisation and that smaller phages (< 100 nm) are internalised at higher rates. Uptake rates were validated under physiological shear stress conditions using a microfluidic device that mimics the shear stress to which endothelial cells are exposed to in the human body. Phages were found to rapidly adhere to eukaryotic cell layers, with adherent phages being subsequently internalised by macropinocytosis and functional phages accumulating and stably persisting intracellularly. Finally, we incorporate these results into an established pharmacokinetic model demonstrating the potential impact of phage accumulation by these cell layers, which represents a major sink for circulating phages in the body. Understanding these interactions will have important implications on innate immune responses, phage pharmacokinetics, and the efficacy of phage therapy.

scholarly journals Bacteriophage Transcytosis Provides a Mechanism To Cross Epithelial Cell Layers

mBio ◽  
2017 ◽  
Vol 8 (6) ◽  
Author(s):  
Sophie Nguyen ◽  
Kristi Baker ◽  
Benjamin S. Padman ◽  
Ruzeen Patwa ◽  
Rhys A. Dunstan ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Human Body ◽  
Cell Structure ◽  
Mechanistic Explanation ◽  
Eukaryotic Cell ◽  
The Body ◽  
Cell Layers ◽  
Confluent Cell ◽  
Bacterial Viruses

ABSTRACTBacterial viruses are among the most numerous biological entities within the human body. These viruses are found within regions of the body that have conventionally been considered sterile, including the blood, lymph, and organs. However, the primary mechanism that bacterial viruses use to bypass epithelial cell layers and access the body remains unknown. Here, we usedin vitrostudies to demonstrate the rapid and directional transcytosis of diverse bacteriophages across confluent cell layers originating from the gut, lung, liver, kidney, and brain. Bacteriophage transcytosis across cell layers had a significant preferential directionality for apical-to-basolateral transport, with approximately 0.1% of total bacteriophages applied being transcytosed over a 2-h period. Bacteriophages were capable of crossing the epithelial cell layer within 10 min with transport not significantly affected by the presence of bacterial endotoxins. Microscopy and cellular assays revealed that bacteriophages accessed both the vesicular and cytosolic compartments of the eukaryotic cell, with phage transcytosis suggested to traffic through the Golgi apparatus via the endomembrane system. Extrapolating from these results, we estimated that 31 billion bacteriophage particles are transcytosed across the epithelial cell layers of the gut into the average human body each day. The transcytosis of bacteriophages is a natural and ubiquitous process that provides a mechanistic explanation for the occurrence of phages within the body.IMPORTANCEBacteriophages (phages) are viruses that infect bacteria. They cannot infect eukaryotic cells but can penetrate epithelial cell layers and spread throughout sterile regions of our bodies, including the blood, lymph, organs, and even the brain. Yet how phages cross these eukaryotic cell layers and gain access to the body remains unknown. In this work, epithelial cells were observed to take up and transport phages across the cell, releasing active phages on the opposite cell surface. Based on these results, we posit that the human body is continually absorbing phages from the gut and transporting them throughout the cell structure and subsequently the body. These results reveal that phages interact directly with the cells and organs of our bodies, likely contributing to human health and immunity.

scholarly journals Bacteriophage uptake by mammalian cell layers represents a potential sink that may impact phage therapy

iScience ◽  
2021 ◽  
Vol 24 (4) ◽  
pp. 102287 ◽  
Author(s):  
Marion C. Bichet ◽  
Wai Hoe Chin ◽  
William Richards ◽  
Yu-Wei Lin ◽  
Laura Avellaneda-Franco ◽  
...  
Keyword(s):  
Mammalian Cell ◽  
Phage Therapy ◽  
Cell Layers

scholarly journals Cell-state transitions and collective cell movement generate an endoderm-like region in gastruloids

2020 ◽  
Author(s):  
Ali Hashmi ◽  
Sham Tlili ◽  
Pierre Perrin ◽  
Alfonso Martinez-Arias ◽  
Pierre-François Lenne
Keyword(s):  
Spatial Organization ◽  
Embryonic Stem ◽  
Cell Movement ◽  
Body Plan ◽  
The Body ◽  
State Transitions ◽  
Sequence Of Events ◽  
Complex Process ◽  
Cell Layers ◽  
Sorting Process

AbstractShaping the animal body plan is a complex process that involves the spatial organization and patterning of different cell layers. Recent advances in live imaging have started to unravel the cellular choreography underlying this process in mammals, however, the sequence of events transforming an unpatterned cell ensemble into structured territories is largely unknown. Here, using 3D aggregates of mouse embryonic stem cells, we study the formation of one of the three germ layers, the endoderm. We show that the endoderm is generated from an epiblast-like state by a three-step mechanism: a release of islands of Ecadherin expressing cells, their flow toward the aggregate tip, and their segregation. Unlike the prevailing view, this mechanism does not require epithelial-to-mesenchymal transitions and vice-versa but rather a fragmentation, which is mediated by Wnt/β-catenin, and a sorting process. Our data emphasize the role of signaling and cell flows in the establishment of the body plan.

Abstract 19144: Fish Oil and Cyclooxygenase Inhibitors: a Novel Strategy to Manage Obesity-linked Dyslipidemia

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Viswanathan Saraswathi ◽  
Curtis Perriotte-Olson ◽  
Robert D Heineman ◽  
Cyrus V Desouza
Keyword(s):  
Gene Expression ◽  
Fatty Acids ◽  
Fish Oil ◽  
Endothelial Activation ◽  
The Body ◽  
Cyclooxygenase Inhibitors ◽  
Pcr Analysis ◽  
Control Group ◽  
Cox Inhibitor ◽  
High Doses

Introduction: Dyslipidemia is a prevalent condition in obesity and type 2 diabetes. Although fish oil rich in omega-3 fatty acids (ω-3) is a widely used hypolipidemic agent, it is often required at high doses. At high doses, these fatty acids can induce oxidative stress or endothelial activation and therefore, strategies to improve their beneficial effects are needed. We previously reported that fish oil in combination with cyclooxygenase (COX) inhibitors exerts enhanced hypolipidemic and anti-inflammatory effects in low density lipoprotein receptor knock-out mice. Here, we sought to determine the effects of ω-3 fatty acids in combination with naproxen (NX), a COX inhibitor, on dyslipidemia and gene expression in subcutaneous adipose tissue (scAT) in humans. Methods: Obese dyslipidemic patients were randomly assigned to receive one of these interventions (n=8/group) for 12 wk: 1) Standard nutrition counseling (control), 2) ω-3 (2 g twice daily), 3) NX (220 mg twice daily), and 4) ω-3 (2 g twice daily) + NX (220 mg twice daily). Results: The body mass index, HOMA-IR, and plasma total, LDL, and HDL cholesterol levels were not altered significantly in any of the groups. The percent change in plasma triglycerides (TG) from baseline was 75% ( P <0.1) and 68% ( P <0.05) in ω-3 and ω3 + NX-treated subjects, respectively. Notably, 25% of subjects who received ω-3s alone did not show a reduction in TG whereas all the patients that received ω-3 + NX showed a reduction in TG. Realtime PCR analysis of scAT showed that the expression of glucose transporter 4 (GLUT-4), a marker of glucose uptake and a key regulator of glucose homeostasis was significantly reduced in ω-3 compared to control group ( P <0.01). However, combining NX with ω-3 abolished this effect. Moreover, the expression of MCP-1 and VCAM-1, markers of inflammatory response or endothelial activation, was significantly increased in ω-3 but not in ω-3 + NX group. The plasma levels of MCP-1 and E-selectin did not vary significantly in any of the groups. Conclusions: Our data reveal previously unrecognized effects of fish oil in scAT. Our data suggest that combining NX with ω-3 fatty acids will increase their effectiveness in reducing plasma TG and improve the benefits of ω-3 supplements by favorably altering gene expression in scAT.

Inverse effect and receptor dynamics – Coffee, Opium and Wine's secondary pharmacology

2021 ◽  
Vol 13 (47) ◽  
pp. 125-129
Author(s):  
Andrea Maria Signorini
Keyword(s):  
Great Part ◽  
Small Sample ◽  
Point Of View ◽  
The Body ◽  
Time Dependent ◽  
Cell Sensitivity ◽  
Time Dependent Effect ◽  
Altered Cell ◽  
High Doses ◽  
Clinical Experiments

A homeopathic widespread belief is that the inversion of effect of the drugs in homeopathic medical practice is due to dilution or very low doses, but there are many homeopathic incoherencies. For example the first conception of the similia principle was obtained through planned, small sample, clinical experiments with ponderal/pharmacological doses in healthy and diseased subjects1. Furthermore the classical foundations of the similia principle in Organon2, the primary and secondary actions of drugs, were thought to be connected with opposite, time-dependent reactions of the body to high doses and the inversion of effect was seen in temporal sequence after a strong dose and not after changes of doses, so the idea that dilutions are responsible for inversion of effects is not suitable to the classical theory. And lastly homeopathic provings or pathogenetic trials have frequently mixed, unregarded to the doses, occasional toxicological symptoms and symptoms obtained through diluted substances3, reinforcing the idea that, on healthy subjects, in several cases many substances produce the same symptoms in pharmacological or infinitesimal doses. So at least the dose-dependent inversion of effect is not generalized in a great part of the collected symptoms. Biological foundations to similia principle have to be searched in other directions4, as in different sensitivity to drugs between health and disease, or in different time-dependent effect of drugs on specific, but different, cell sensitivity set point. In the vision described here both these possibilities represent the same phenomenon of altered cell sensitivity. It is aim of this article to show that the original hahnemannian idea to explain homeopathic similia principle starting from a pharmacological and biological point of view with ponderal doses, seems correct, rationally comprehensible and based on modern knowledges. The three pharmacologic examples that best illustrate this reasoning, coffe, opium and wine, will be discussed.

Limits to elastic response. Yielding and failure

2020 ◽  
pp. 357-368
Author(s):  
Lallit Anand ◽  
Sanjay Govindjee
Keyword(s):  
Shear Stress ◽  
Tensile Stress ◽  
Critical Value ◽  
Maximum Principal Stress ◽  
The Body ◽  
Elastic Response ◽  
Elastic Behaviour ◽  
Pressure Independent ◽  
Yield Conditions ◽  
Is Failure

This chapter presents conditions for determining the limits of elastic behaviour for isotropic materials. The stress invariants of equivalent pressure, equivalent shear stress, and equivalent tensile stress are defined. These are then used to define common yield conditions, viz. the pressure-independent Mises and Tresca yield conditions, as well as the pressure-dependent Coulomb-Mohr and the Drucker-Prager yield conditions. Rankine’s failure criterion for brittle materials in tension, that is failure in a brittle material will initiate when the maximum principal stress at a point in the body reaches a critical value, is also discussed.

scholarly journals Lipid defect underlies selective skin barrier impairment of an epidermal-specific deletion of Gata-3

2006 ◽  
Vol 175 (4) ◽  
pp. 661-670 ◽  
Author(s):  
Cristina de Guzman Strong ◽  
Philip W. Wertz ◽  
Chenwei Wang ◽  
Fan Yang ◽  
Paul S. Meltzer ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Genomic Analysis ◽  
Skin Barrier ◽  
The Body ◽  
Toxic Substances ◽  
Innate Immune Responses ◽  
Environment Analysis ◽  
Epidermal Barrier ◽  
Specific Deletion

Skin lies at the interface between the complex physiology of the body and the external environment. This essential epidermal barrier, composed of cornified proteins encased in lipids, prevents both water loss and entry of infectious or toxic substances. We uncover that the transcription factor GATA-3 is required to establish the epidermal barrier and survive in the ex utero environment. Analysis of Gata-3 mutant transcriptional profiles at three critical developmental stages identifies a specific defect in lipid biosynthesis and a delay in differentiation. Genomic analysis identifies highly conserved GATA-3 binding sites bound in vivo by GATA-3 in the first intron of the lipid acyltransferase gene AGPAT5. Skin from both Gata-3−/− and previously characterized barrier-deficient Kruppel-like factor 4−/− newborns up-regulate antimicrobial peptides, effectors of innate immunity. Comparison of these animal models illustrates how impairment of the skin barrier by two genetically distinct mechanisms leads to innate immune responses, as observed in the common human skin disorders psoriasis and atopic dermatitis.

Mechanotransduction and endothelial cell homeostasis: the wisdom of the cell

2007 ◽  
Vol 292 (3) ◽  
pp. H1209-H1224 ◽  
Author(s):  
Shu Chien
Keyword(s):  
Shear Stress ◽  
Complex Geometry ◽  
Vascular Endothelial Cells ◽  
The Body ◽  
Mechanical Forces ◽  
Mechanical Stimuli ◽  
Molecular Signaling ◽  
Branch Points ◽  
Arterial Tree ◽  
The Face

Vascular endothelial cells (ECs) play significant roles in regulating circulatory functions. Mechanical stimuli, including the stretch and shear stress resulting from circulatory pressure and flow, modulate EC functions by activating mechanosensors, signaling pathways, and gene and protein expressions. Mechanical forces with a clear direction (e.g., the pulsatile shear stress and the uniaxial circumferential stretch existing in the straight part of the arterial tree) cause only transient molecular signaling of pro-inflammatory and proliferative pathways, which become downregulated when such directed mechanical forces are sustained. In contrast, mechanical forces without a definitive direction (e.g., disturbed flow and relatively undirected stretch seen at branch points and other regions of complex geometry) cause sustained molecular signaling of pro-inflammatory and proliferative pathways. The EC responses to directed mechanical stimuli involve the remodeling of EC structure to minimize alterations in intracellular stress/strain and elicit adaptive changes in EC signaling in the face of sustained stimuli; these cellular events constitute a feedback control mechanism to maintain vascular homeostasis and are atheroprotective. Such a feedback mechanism does not operate effectively in regions of complex geometry, where the mechanical stimuli do not have clear directions, thus placing these areas at risk for atherogenesis. The mechanotransduction-induced EC adaptive processes in the straight part of the aorta represent a case of the “Wisdom of the Cell,” as a part of the more general concept of the “Wisdom of the Body” promulgated by Cannon, to maintain cellular homeostasis in the face of external perturbations.

Preclinical toxicology studies with Y15, a novel focal adhesion kinase (FAK) inhibitor.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e13561-e13561
Author(s):  
William G. Cance ◽  
Leslie Curtin ◽  
Sandra Buitrago ◽  
Vita Golubovskaya
Keyword(s):  
Body Weight ◽  
Focal Adhesion Kinase ◽  
Focal Adhesion ◽  
Oral Delivery ◽  
Clinical Chemistry ◽  
Small Animal ◽  
The Body ◽  
Large Animal ◽  
Toxicology Study ◽  
High Doses

e13561 Background: Focal Adhesion Kinase (FAK) is overexpressed in many types of tumors and plays a major role in survival signaling. Recently, we developed a FAK scaffolding inhibitor, Y15 that targeted the main FAK autophosphorylation site (Y397) and had high efficacy in blocking tumor growth in many xenograft mice models. We performed a small animal toxicology study of Y15 and detected the maximal tolerated dose of this drug in mice. Methods: The toxicology study was performed in CD-1 albino [Hsd:ICR(CD-1)] mice with Y15 inhibitor delivered either by intraperitoneal injection (IP) or by oral delivery. Clinical chemistry data were collected by Hemagen Analyst II automatic Chemistry analyzer. In addition, hematology, body weight, mortality, and histopathology on different organs were analyzed in all mice. Results: We delivered Y15 by IP injection at 15 (low), 30 (medium) and 45 mg/kg (high) doses daily for 5 days/week during a 28 day study, or orally by gavage at 100 and 200 mg/kg daily during a 7 day study. The maximal tolerated dose by IP during 28 day study was 30 mg/kg. The maximal tolerated dose during single oral dose administration was 200 mg/kg and 100 mg/kg during 7 day study. Y15 did not cause any mortality or statistically significant differences in the body weight at 30mg/kg IP delivery during a 28-day study and at 100 mg/kg by oral delivery during a 7 day study. There were no significant clinical chemistry changes in alkaline phosphatase, gamma glutamyltransferase, aspartate aminotransferase, alanine aminotransferase, amylase, blood urea nitrogen, glucose, phosphorus, calcium, albumin, cholesterol, creatine kinase, total bilirubin, total protein and globulin. Finally, no significant histopathological changes were observed by necropsy in different organs at 30 mg/kg by IP and at 100 mg/kg dose by oral delivery. Conclusions: The Y15 FAK autophosphorylation inhibitor is well tolerated in mice and caused no significant toxicity by IP and oral delivery, suggesting it is a promising candidate for further large animal toxicology study prior to human trials.

scholarly journals Unrestricted Hepatocyte Transduction with Adeno-Associated Virus Serotype 8 Vectors in Mice

2005 ◽  
Vol 79 (1) ◽  
pp. 214-224 ◽  
Author(s):  
Hiroyuki Nakai ◽  
Sally Fuess ◽  
Theresa A. Storm ◽  
Shin-ichi Muramatsu ◽  
Yuko Nara ◽  
...  
Keyword(s):  
Portal Vein ◽  
Dose Response ◽  
Smooth Muscles ◽  
The Body ◽  
Specific Gene ◽  
High Dose ◽  
Adeno Associated Virus ◽  
Virus Serotype ◽  
High Doses ◽  
Dose Response Study

ABSTRACT Recombinant adeno-associated virus (rAAV) vectors can mediate long-term stable transduction in various target tissues. However, with rAAV serotype 2 (rAAV2) vectors, liver transduction is confined to only a small portion of hepatocytes even after administration of extremely high vector doses. In order to investigate whether rAAV vectors of other serotypes exhibit similar restricted liver transduction, we performed a dose-response study by injecting mice with β-galactosidase-expressing rAAV1 and rAAV8 vectors via the portal vein. The rAAV1 vector showed a blunted dose-response similar to that of rAAV2 at high doses, while the rAAV8 vector dose-response remained unchanged at any dose and ultimately could transduce all the hepatocytes at a dose of 7.2 × 1012 vector genomes/mouse without toxicity. This indicates that all hepatocytes have the ability to process incoming single-stranded vector genomes into duplex DNA. A single tail vein injection of the rAAV8 vector was as efficient as portal vein injection at any dose. In addition, intravascular administration of the rAAV8 vector at a high dose transduced all the skeletal muscles throughout the body, including the diaphragm, the entire cardiac muscle, and substantial numbers of cells in the pancreas, smooth muscles, and brain. Thus, rAAV8 is a robust vector for gene transfer to the liver and provides a promising research tool for delivering genes to various target organs. In addition, the rAAV8 vector may offer a potential therapeutic agent for various diseases affecting nonhepatic tissues, but great caution is required for vector spillover and tight control of tissue-specific gene expression.

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