scholarly journals Cellular MR Imaging

2005 ◽  
Vol 4 (3) ◽  
pp. 153535002005051 ◽  
Author(s):  
Michel Modo ◽  
Mathias Hoehn ◽  
Jeff W.M. Bulte
Keyword(s):  
Mr Imaging ◽  
Contrast Agents ◽  
Immune Cell ◽  
Late Phase ◽  
Superparamagnetic Iron Oxide ◽  
Cell Trafficking ◽  
Macrophage Activity ◽  
Active Research

Cellular MR imaging is a young field that aims to visualize targeted cells in living organisms. In order to provide a different signal intensity of the targeted cell, they are either labeled with MR contrast agents in vivo or prelabeled in vitro. Either (ultrasmall) superparamagnetic iron oxide [(U)SPIO] particles or (polymeric) paramagnetic chelates can be used for this purpose. For in vivo cellular labeling, Gd3+- and Mn2+- chelates have mainly been used for targeted hepatobiliary imaging, and (U)SPIO-based cellular imaging has been focused on imaging of macrophage activity. Several of these magneto-pharmaceuticals have been FDA-approved or are in late-phase clinical trials. As for prelabeling of cells in vitro, a challenge has been to induce a sufficient uptake of contrast agents into nonphagocytic cells, without affecting normal cellular function. It appears that this issue has now largely been resolved, leading to an active research on monitoring the cellular biodistribution in vivo following transplantation or transfusion of these cells, including cell migration and trafficking. New applications of cellular MR imaging will be directed, for instance, towards our understanding of hematopoietic (immune) cell trafficking and of novel guided (stem) cell-based therapies aimed to be translated to the clinic in the future.

scholarly journals Migration ofAntigen-Specific T Cells Away from CXCR4-Binding Human ImmunodeficiencyVirus Type 1gp120

2004 ◽  
Vol 78 (10) ◽  
pp. 5184-5193 ◽  
Author(s):  
Diana M. Brainard ◽  
William G. Tharp ◽  
Elva Granado ◽  
Nicholas Miller ◽  
Alicja K. Trocha ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Cell ◽  
Active Movement ◽  
Target Cells ◽  
Cell Mediated Immunity ◽  
Cell Trafficking ◽  
Hiv 1

ABSTRACT Cell-mediated immunity depends in part on appropriate migration and localization of cytotoxic T lymphocytes (CTL), a process regulated by chemokines and adhesion molecules. Many viruses, including human immunodeficiency virus type 1 (HIV-1), encode chemotactically active proteins, suggesting that dysregulation of immune cell trafficking may be a strategy for immune evasion. HIV-1 gp120, a retroviral envelope protein, has been shown to act as a T-cell chemoattractant via binding to the chemokine receptor and HIV-1 coreceptor CXCR4. We have previously shown that T cells move away from the chemokine stromal cell-derived factor 1 (SDF-1) in a concentration-dependent and CXCR4 receptor-mediated manner. Here, we demonstrate that CXCR4-binding HIV-1 X4 gp120 causes the movement of T cells, including HIV-specific CTL, away from high concentrations of the viral protein. This migratory response is CD4 independent and inhibited by anti-CXCR4 antibodies and pertussis toxin. Additionally, the expression of X4 gp120 by target cells reduces CTL efficacy in an in vitro system designed to account for the effect of cell migration on the ability of CTL to kill their target cells. Recombinant X4 gp120 also significantly reduced antigen-specific T-cell infiltration at a site of antigen challenge in vivo. The repellant activity of HIV-1 gp120 on immune cells in vitro and in vivo was shown to be dependent on the V2 and V3 loops of HIV-1 gp120. These data suggest that the active movement of T cells away from CXCR4-binding HIV-1 gp120, which we previously termed fugetaxis, may provide a novel mechanism by which HIV-1 evades challenge by immune effector cells in vivo.

Engineering Tools for Studying the Interplay Between Mechanics and Biology in Lymphatic Lipid Transport

2010 ◽  
Author(s):  
J. Brandon Dixon
Keyword(s):  
Immune Cell ◽  
Mechanical Load ◽  
Contractile Function ◽  
Lymphatic Vessels ◽  
Dietary Lipid ◽  
The Body ◽  
Lipid Transport ◽  
Cell Trafficking

The lymphatic vasculature extends through most tissues of the body and plays an essential role in maintaining fluid balance, immune cell trafficking, and lipid transport. Nearly all dietary lipid is transported from the intestine to the circulation via the lymphatic system in the form of triglyceride-rich lipoproteins called chylomicrons. This process can be described through two different mechanisms: 1) entry of the chylomicron into the initial lymphatic vessels of the small intestine, known as lacteals, and 2) the transport of these chylomicrons through the larger collecting lymphatics by a complex and coordinated system of individual contracting vessel units (lymphangions) and valve leaflets. We describe here a set of in vitro and in vivo tools we have developed to study the mechanisms that modulate lipid transport under these two different paradigms and show how these tools are uncovering important biological features involved in these mechanisms. Lymphatic pump function is known to be sensitive to the mechanical load on the vessel as the contractility of isolated vessels has been shown to be both shear and stretch sensitive [1], yet whether these mechanisms are important in regulating contractile function in vivo remains uncertain.

scholarly journals A Dynamic in vitro BBB Model for the Study of Immune Cell Trafficking into the Central Nervous System

2010 ◽  
Vol 31 (2) ◽  
pp. 767-777 ◽  
Author(s):  
Luca Cucullo ◽  
Nicola Marchi ◽  
Mohammed Hossain ◽  
Damir Janigro
Keyword(s):  
Immune Cells ◽  
Immune Cell ◽  
Cell Trafficking ◽  
In Vitro System ◽  
Immune Cell Trafficking ◽  
The Central Nervous System ◽  
In Vitro Bbb Model ◽  
The Brain

Although there is significant evidence correlating overreacting or perhaps misguided immune cells and the blood–brain barrier (BBB) with the pathogenesis of neuroinflammatory diseases, the mechanisms by which they enter the brain are largely unknown. For this purpose, we revised our humanized dynamic in vitro BBB model (DIV-BBBr) to incorporate modified hollow fibers that now feature transmural microholes (2 to 4 μm Ø) allowing for the transendothelial trafficking of immune cells. As with the original model, this new DIV-BBBr reproduces most of the physiological characteristics of the BBB in vivo. Measurements of transendothelial electrical resistance (TEER), sucrose permeability, and BBB integrity during reversible osmotic disruption with mannitol (1.6 mol/L) showed that the microholes do not hamper the formation of a tight functional barrier. The in vivo rank permeability order of sucrose, phenytoin, and diazepam was successfully reproduced in vitro. Flow cessation followed by reperfusion (Fc/Rp) in the presence of circulating monocytes caused a biphasic BBB opening paralleled by a significant increase of proinflammatory cytokines and activated matrix metalloproteinases. We also observed abluminal extravasation of monocytes but only when the BBB was breached. In conclusion, the DIV-BBBr represents the most realistic in vitro system to study the immune cell trafficking across the BBB.

In vivo tracking of superparamagnetic iron oxide nanoparticle–labeled mesenchymal stem cell tropism to malignant gliomas using magnetic resonance imaging

2008 ◽  
Vol 108 (2) ◽  
pp. 320-329 ◽  
Author(s):  
Xing Wu ◽  
Jin Hu ◽  
Liangfu Zhou ◽  
Ying Mao ◽  
Bojie Yang ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Malignant Gliomas ◽  
Superparamagnetic Iron Oxide ◽  
Iron Oxide Nanoparticle ◽  
Gradient Echo ◽  
Systemic Injection

Object Mesenchymal stem cells (MSCs) have been shown to migrate toward tumors, but their distribution pattern in gliomas has not been completely portrayed. The primary purpose of the study was to assay the tropism capacity of MSCs to gliomas, to delineate the pattern of MSC distribution in gliomas after systemic injection, and to track the migration and incorporation of magnetically labeled MSCs using 1.5-T magnetic resonance (MR) imaging. Methods The MSCs from Fischer 344 rats were colabeled with superparamagnetic iron oxide nanoparticles (SPIO) and enhanced green fluorescent protein (EGFP). The tropism capacity of MSCs was quantitatively assayed in vitro using the Transwell system. To track the migration of MSCs in vivo, MR imaging was performed both 7 and 14 days after systemic administration of labeled MSCs. After MR imaging, the distribution patterns of MSCs in rats with gliomas were examined using Prussian blue and fluorescence staining. Results The in vitro study showed that MSCs possessed significantly greater migratory capacity than fibroblast cells (p < 0.001) and that lysis of F98 glioma cells and cultured F98 cells showed a greater capacity to induce migration of cells than other stimuli (p < 0.05). Seven days after MSC transplantation, the SPIO–EGFP colabeled cells were distributed throughout the tumor, where a well-defined dark hypointense region was represented on gradient echo sequences. After 14 days, most of the colabeled MSCs were found at the border between the tumor and normal parenchyma, which was represented on gradient echo sequences as diluted amorphous dark areas at the edge of the tumors. Conclusions This study demonstrated that systemically transplanted MSCs migrate toward gliomas with high specificity in a temporal–spatial pattern, which can be tracked using MR imaging.

scholarly journals Detection of MUC1-Expressing Ovarian Cancer by C595 Monoclonal Antibody-Conjugated SPIONs Using MR Imaging

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Daryoush Shahbazi-Gahrouei ◽  
Mohammad Abdolahi
Keyword(s):  
Ovarian Cancer ◽  
Monoclonal Antibody ◽  
Mr Imaging ◽  
Imaging Modality ◽  
Superparamagnetic Iron Oxide ◽  
Blue Staining ◽  
Ovarian Cancer Cells ◽  
Tumor Accumulation

The aim of this study is to find out the development and application of MUC1-expressing ovarian cancer (OVCAR3) by C595 monoclonal antibody-conjugated superparamagnetic iron oxide nanoparticles (SPIONs) using MR imaging. At the end, its use as a nanosized contrast agent MR imaging probe for ovarian cancer detection was investigated. The strategy is to use SPIONs attached to C595 mAb that binds to the MUC1, to specifically detect ovarian cancer cells. Anticancer effects and MR imaging parameters of the prepared nanoconjugate was investigated both underin vitroandin vivoexperiments. The characterization of nanoconjugate includes its size, cell toxicity, flow cytometry, Prussian blue staining test and its cellular uptake as well as its biodistribution, and MR imaging was also investigated. The findings of the study showed good tumor accumulation and detection, noin vivotoxicity, and potential selective antiovarian cancer activity. Overall, based on the findings SPIONs-C595 nanosized probe is a selective ovarian molecular imaging modality. Further subsequent clinical trials appear warranted.

scholarly journals Cardiac macrophage subsets differentially regulate lymphatic network remodeling during pressure overload

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mathilde Bizou ◽  
Romain Itier ◽  
Mina Majdoubi ◽  
Dounia Abbadi ◽  
Estelle Pichery ◽  
...  
Keyword(s):  
Immune Cell ◽  
Pressure Overload ◽  
Gene Expression Signature ◽  
Cell Number ◽  
Cell Trafficking ◽  
Macrophage Subpopulations ◽  
Lymphatic Network ◽  
Macrophage Subsets

AbstractThe lymphatic network of mammalian heart is an important regulator of interstitial fluid compartment and immune cell trafficking. We observed a remodeling of the cardiac lymphatic vessels and a reduced lymphatic efficiency during heart hypertrophy and failure induced by transverse aortic constriction. The lymphatic endothelial cell number of the failing hearts was positively correlated with cardiac function and with a subset of cardiac macrophages. This macrophage population distinguished by LYVE-1 (Lymphatic vessel endothelial hyaluronic acid receptor-1) and by resident macrophage gene expression signature, appeared not replenished by CCR2 mediated monocyte infiltration during pressure overload. Isolation of macrophage subpopulations showed that the LYVE-1 positive subset sustained in vitro and in vivo lymphangiogenesis through the expression of pro-lymphangiogenic factors. In contrast, the LYVE-1 negative macrophage subset strongly expressed MMP12 and decreased the endothelial LYVE-1 receptors in lymphatic endothelial cells, a feature of cardiac lymphatic remodeling in failing hearts. The treatment of mice with a CCR2 antagonist during pressure overload modified the proportion of macrophage subsets within the pathological heart and preserved lymphatic network from remodeling. This study reports unknown and differential functions of macrophage subpopulations in the regulation of cardiac lymphatic during pathological hypertrophy and may constitute a key mechanism underlying the progression of heart failure.

IMMU-20. HYDROGEL-CXCL9 VACCINE RESULTS IN MRNA DELIVERY TO DENDRITIC CELLS AND POTENT ANTI-TUMOR RESPONSES IN GBM

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi96-vi96
Author(s):  
Farhad Dastmalchi ◽  
Aida Karachi ◽  
Yusuf Mehkri ◽  
Ashley O’Malley ◽  
Vignesh Subramaniam ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Single Dose ◽  
Nk Cells ◽  
Immune Cell ◽  
Control Group ◽  
Cell Trafficking ◽  
Fat Pad ◽  
Tumor Bearing

Abstract INTRODUCTION Our group and others have shown mRNA-vaccines have significant anti-tumor efficacy in the treatment of brain tumors and are currently being tested in first-in-human trials. To further enhance mRNA delivery, a hydrogel platform was developed with the addition of CXCL9 to promote immune cell trafficking. METHODS We generated the vaccine by utilizing a hydrogel platform. CXCL9 and Nano-mRNA were loaded into the hydrogel. In vitro recruitment of DCs and NK was evaluated by fluorescence microscopy. In vivo recruitment of immune cells was analyzed by flowcytometry after collecting the fat pad, spleen, and tumor samples from KR158b-luc and Gl261-gp100 tumor-bearing animals 3, 5 and 10 days after vaccine delivery. The efficacy of the vaccine was evaluated by measuring overall survival, and tumor growth was measured by IVIS live-imaging. RESULTS Dendritic cells(DCs) and natural killer(NK) cells were able to efficiently migrate within the hydrogel-CXCL9 platform and uptake and express mRNA in vivo. In vitro, the hydrogel-CXCL9 was combined with nanoparticles loaded with total tumor RNA, and the vaccine was delivered to KR-158-luc and GL261-gp100 tumor-bearing animals via mammary fat pad SQ injection. Flow cytometry of the fat pad and draining lymph nodes demonstrated showed significant recruitment of endogenous DCs including inflammatory-DC(P= 0.0035), conventional-DC1(P= 0.0076), pDC(P=0.0028), NK(p= 0.0025 compared to the control group. In two different tumor models, a single dose of the vaccine resulted in significant survival benefits compared to control animals (n=10,P&lt; 0.0001). SQ injection was superior to intracranial injection of the vaccine. Vaccinated animals showed an increased number of antigen-specific CD8 T cells in spleen(P= 0.0001) and tumor-microenvironment(P= 0.0070). CONCLUSION The hydrogel-CXCL9 platform results in efficient delivery of mRNA loaded nanoparticles to endogenous DCs and also causes an upregulation of NK cells with resultant improved survival in murine GBM models including the highly resistant KR158 model with a single dose. Further studies are ongoing.

scholarly journals Ultrasonic Imaging of Carotid Inflammatory Plaque with Superparamagnetic Nanoparticles

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Wei Li ◽  
Jiang Wu ◽  
Mingjin Guo ◽  
Jing Shang
Keyword(s):  
Contrast Agents ◽  
Ultrasound Imaging ◽  
Superparamagnetic Iron Oxide ◽  
Superparamagnetic Nanoparticles ◽  
Iron Oxide Nanoparticle ◽  
Good Imaging ◽  
Arterial Plaque ◽  
Cell Adhesion Molecule 1

Chronic inflammation can stimulate the formation and progression of atherosclerotic plaques and increase the vulnerability of plaques. However, there are few studies on the changes of carotid inflammatory plaques during treatment. Our study attempted to investigate the use of superparamagnetic iron oxide nanoparticle (SPION) ultrasound imaging to detect the expression of vascular cell adhesion molecule-1 (VCAM-1) in patients with carotid plaques and analyze the effects of SPION ultrasound imaging in inflammatory plaque visualization effect. SPION microbubble contrast agents have good imaging effects both in vivo and in vitro. We conjugated the VCAM-1 protein to the microbubbles wrapped in SPIONs to form SPIONs carrying VCAM-1 antibodies. Observe the signal intensity of SPIONs carrying VCAM-1 antibody to arteritis plaque. The results showed that the SPION contrast agent carrying VCAM-1 antibody had higher peak gray-scale video intensity than the other two groups of contrast agents not carrying VCAM-1 antibody. It shows that SPIONs have excellent imaging effects in ultrasound imaging, can evaluate the inflammatory response of arterial plaque lesions, and are of great significance for the study of carotid inflammatory plaque changes.

Tantalum Oxide Nanoparticles as Versatile Contrast Agents for X-ray Computed Tomography

2020 ◽  
Author(s):  
Shatadru Chakravarty ◽  
Jeremy Hix ◽  
Kaitlyn Wieweora ◽  
Maximilian Volk ◽  
Elizabeth Kenyon ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Contrast Agents ◽  
Mesoporous Silica Nanoparticles ◽  
Sol Gel ◽  
Tantalum Oxide ◽  
High Signal ◽  
Drug Delivery Vehicles ◽  
X Ray Computed

Here we describe the synthesis, characterization and in vitro and in vivo performance of a series of tantalum oxide (TaOx) based nanoparticles (NPs) for computed tomography (CT). Five distinct versions of 9-12 nm diameter silane coated TaOx nanocrystals (NCs) were fabricated by a sol-gel method with varying degrees of hydrophilicity and with or without fluorescence, with the highest reported Ta content to date (78%). Highly hydrophilic NCs were left bare and were evaluated in vivo in mice for micro-CT of full body vasculature, where following intravenous injection, TaOx NCs demonstrate high CT contrast, circulation in blood for ~ 3 h, and eventual accumulation in RES organs; and following injection locally in the mammary gland, where the full ductal tree structure can be clearly delineated. Partially hydrophilic NCs were encapsulated within mesoporous silica nanoparticles (MSNPs; TaOx@MSNPs) and hydrophobic NCs were encapsulated within poly(lactic-co-glycolic acid) (PLGA; TaOx@PLGA) NPs, serving as potential CT-imagable drug delivery vehicles. Bolus intramuscular injections of TaOx@PLGA NPs and TaOx@MSNPs to mimic the accumulation of NPs at a tumor site produce high signal enhancement in mice. In vitro studies on bare NCs and formuated NPs demonstrate high cytocompatibility and low dissolution of TaOx. This work solidifies that TaOx-based NPs are versatile contrast agents for CT.

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