Faculty Opinions recommendation of Multicolor flow cytometry and nanoparticle tracking analysis of extracellular vesicles in the plasma of normal pregnant and pre-eclamptic women.

Abstract MET pathway is an important actionable target across many solid tumour types and several MET inhibitors have been developed. Extracellular vesicles (EVs) are proposed to be mini-maps of their cells of origin. However, the potential of EVs to report on the MET status of their cells of origin is unknown. After applying three proposed methods of EV separation from medium conditioned by three cell lines of known MET status, this study used an extensive range of methodologies to fundamentally characterise the resulting particles (nanoparticle tracking analysis, TEM, flow cytometry, immunoblotting) and their MET status (RT-qPCR and ELISAs). The results indicated that ultracentrifugation on density-gradient (UC-DG) consistently produced the most reliable data with regards to purest EVs. EV cargo reflected MET mRNA, total MET and pMET status of their cells of origin. In conclusion, to simply determine if the general contents of conditioned medium reflect the MET status of the conditioning cells, choice of method for initial EV separation may not be crucial. However, to be confident of specifically studying EVs and thus EV-MET cargo, UC-DG followed by extensive EV characterisation is necessary.

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Direct comparison of different therapeutic cell types susceptibility to inflammatory cytokines associated with COVID-19 acute lung injury

Stem Cell Research & Therapy ◽

10.1186/s13287-021-02699-7 ◽

2022 ◽

Vol 13 (1) ◽

Author(s):

Ramana Vaka ◽

Saad Khan ◽

Bin Ye ◽

Yousef Risha ◽

Sandrine Parent ◽

...

Keyword(s):

Flow Cytometry ◽

Cell Viability ◽

Disease Progression ◽

Extracellular Vesicles ◽

Inflammatory Cytokines ◽

Mesenchymal Stromal Cells ◽

Inflammatory Mediators ◽

Stromal Cells ◽

Nanoparticle Tracking Analysis ◽

The Impact

Abstract Background Although 90% of infections with the novel coronavirus 2 (COVID-19) are mild, many patients progress to acute respiratory distress syndrome (ARDS) which carries a high risk of mortality. Given that this dysregulated immune response plays a key role in the pathology of COVID-19, several clinical trials are underway to evaluate the effect of immunomodulatory cell therapy on disease progression. However, little is known about the effect of ARDS associated pro-inflammatory mediators on transplanted stem cell function and survival, and any deleterious effects could undermine therapeutic efficacy. As such, we assessed the impact of inflammatory cytokines on the viability, and paracrine profile (extracellular vesicles) of bone marrow-derived mesenchymal stromal cells, heart-derived cells, and umbilical cord-derived mesenchymal stromal cells. Methods All cell products were manufactured and characterized to established clinical release standards by an accredited clinical cell manufacturing facility. Cytokines and Extracellular vesicles in the cell conditioned media were profiled using proteomic array and nanoparticle tracking analysis. Using a survey of the clinical literature, 6 cytotoxic cytokines implicated in the progression of COVID-19 ARDS. Flow cytometry was employed to determine receptor expression of these 6 cytokines in three cell products. Based on clinical survey and flow cytometry data, a cytokine cocktail that mimics cytokine storm seen in COVID-19 ARDS patients was designed and the impact on cytokine cocktail on viability and paracrine secretory ability of cell products were assessed using cell viability and nanoparticle tracking analysis. Results Flow cytometry revealed the presence of receptors for all cytokines but IL-6, which was subsequently excluded from further experimentation. Despite this widespread expression, exposure of each cell type to individual cytokines at doses tenfold greater than observed clinically or in combination at doses associated with severe ARDS did not alter cell viability or extracellular vesicle character/production in any of the 3 cell products. Conclusions The paracrine production and viability of the three leading cell products under clinical evaluation for the treatment of severe COVID-19 ARDS are not altered by inflammatory mediators implicated in disease progression.

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Immune cell extracellular vesicles and their mitochondrial content decline with ageing

Immunity & Ageing ◽

10.1186/s12979-019-0172-9 ◽

2020 ◽

Vol 17 (1) ◽

Cited By ~ 8

Author(s):

Xin Zhang ◽

Monica Jeanne Hubal ◽

Virginia Byers Kraus

Keyword(s):

Flow Cytometry ◽

Extracellular Vesicles ◽

Immune Cells ◽

Immune Cell ◽

Cell Types ◽

Specific Cell ◽

Surface Markers ◽

Multicolor Flow Cytometry ◽

Hematopoietic Stem ◽

Age Related

Abstract Background Although the mechanisms of action are not fully understood, extracellular vesicles (EVs) have emerged as key indicators and effectors of immune function. Characterizing circulating EVs associated with stem and immune cells across the lifespan of healthy individuals could aid an understanding of immunosenescence, a process of age-related decline of cells in both adaptive and innate immune systems. Results Using high resolution multicolor flow cytometry, we identified three major subsets of EVs of varying sizes in healthy control (HC) plasma. Multiple plasma EVs associated with immune cells declined with ageing in HCs. In addition, we observed age-associated declines of respiring mitochondria cargo in EVs of several types of immune cells, suggesting that these parent cells may experience a decline in mitophagy or a mitochondrial dysfunction-induced immunosenescence. By contrast, the number of CD34+ hematopoietic stem cell-associated EVs were high and carried respiring mitochondria, which did not decline with age. Conclusion As demonstrated here, multicolor flow cytometry simultaneously measures plasma EV size, surface markers and cargo that reflect biological processes of specific cell types. The distinct surface markers and cytokine cargo of plasma EVs suggest that they may carry different bio-messages and originate by different biogenesis pathways.

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Comparative Analysis of Platelet-Derived Extracellular Vesicles Using Flow Cytometry and Nanoparticle Tracking Analysis

International Journal of Molecular Sciences ◽

10.3390/ijms22083839 ◽

2021 ◽

Vol 22 (8) ◽

pp. 3839

Author(s):

Sobha Karuthedom Karuthedom George ◽

Lucia Lauková ◽

René Weiss ◽

Vladislav Semak ◽

Birgit Fendl ◽

...

Keyword(s):

Flow Cytometry ◽

Comparative Analysis ◽

Extracellular Vesicles ◽

High Throughput ◽

Single Particle ◽

Size Range ◽

Detection Limits ◽

Nanoparticle Tracking Analysis ◽

Fluorescent Beads ◽

Good Agreement

Growing interest in extracellular vesicles (EVs) has prompted the advancements of protocols for improved EV characterization. As a high-throughput, multi-parameter, and single particle technique, flow cytometry is widely used for EV characterization. The comparison of data on EV concentration, however, is hindered by the lack of standardization between different protocols and instruments. Here, we quantified EV counts of platelet-derived EVs, using two flow cytometers (Gallios and CytoFLEX LX) and nanoparticle tracking analysis (NTA). Phosphatidylserine-exposing EVs were identified by labelling with lactadherin (LA). Calibration with silica-based fluorescent beads showed detection limits of 300 nm and 150 nm for Gallios and CytoFLEX LX, respectively. Accordingly, CytoFLEX LX yielded 40-fold higher EV counts and 13-fold higher counts of LA+CD41+ EVs compared to Gallios. NTA in fluorescence mode (F-NTA) demonstrated that only 9.5% of all vesicles detected in scatter mode exposed phosphatidylserine, resulting in good agreement of LA+ EVs for CytoFLEX LX and F-NTA. Since certain functional characteristics, such as the exposure of pro-coagulant phosphatidylserine, are not equally displayed across the entire EV size range, our study highlights the necessity of indicating the size range of EVs detected with a given approach along with the EV concentration to support the comparability between different studies.

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Assessment of chilling injury in hypothermic stored boar spermatozoa by multicolor flow cytometry

Cytometry Part A ◽

10.1002/cyto.a.24301 ◽

2021 ◽

Author(s):

Helen Jäkel ◽

Heiko Henning ◽

Anne‐Marie Luther ◽

Karl Rohn ◽

Dagmar Waberski

Keyword(s):

Flow Cytometry ◽

Chilling Injury ◽

Multicolor Flow Cytometry ◽

Boar Spermatozoa

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Conventional, High-Resolution and Imaging Flow Cytometry: Benchmarking Performance in Characterisation of Extracellular Vesicles

Biomedicines ◽

10.3390/biomedicines9020124 ◽

2021 ◽

Vol 9 (2) ◽

pp. 124

Author(s):

Jaco Botha ◽

Haley R. Pugsley ◽

Aase Handberg

Keyword(s):

Flow Cytometry ◽

High Resolution ◽

Extracellular Vesicles ◽

Single Particles ◽

Multiple Parameters ◽

Imaging Flow Cytometry ◽

Highly Sensitive ◽

Individual Project ◽

Benchmarking Performance ◽

High Throughput Manner

Flow cytometry remains a commonly used methodology due to its ability to characterise multiple parameters on single particles in a high-throughput manner. In order to address limitations with lacking sensitivity of conventional flow cytometry to characterise extracellular vesicles (EVs), novel, highly sensitive platforms, such as high-resolution and imaging flow cytometers, have been developed. We provided comparative benchmarks of a conventional FACS Aria III, a high-resolution Apogee A60 Micro-PLUS and the ImageStream X Mk II imaging flow cytometry platform. Nanospheres were used to systematically characterise the abilities of each platform to detect and quantify populations with different sizes, refractive indices and fluorescence properties, and the repeatability in concentration determinations was reported for each population. We evaluated the ability of the three platforms to detect different EV phenotypes in blood plasma and the intra-day, inter-day and global variabilities in determining EV concentrations. By applying this or similar methodology to characterise methods, researchers would be able to make informed decisions on choice of platforms and thereby be able to match suitable flow cytometry platforms with projects based on the needs of each individual project. This would greatly contribute to improving the robustness and reproducibility of EV studies.

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Cord Blood Extracellular Vesicles Analyzed by Flow Cytometry with Thresholding Using 405 nm or 488 nm Laser Leads to Concurrent Results

Diagnostics ◽

10.3390/diagnostics11081320 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1320

Author(s):

Kristýna Pekárková ◽

Jakub Soukup ◽

Marie Kostelanská ◽

Jan Širc ◽

Zbyněk Straňák ◽

...

Keyword(s):

Flow Cytometry ◽

Cord Blood ◽

Extracellular Vesicles ◽

Correlation Coefficients ◽

Flow Cytometer ◽

Liquid Biopsies ◽

Physiological Conditions ◽

Flow Cytometric ◽

Term Births ◽

And Control

Extracellular vesicles (EVs) from liquid biopsies are extensively analyzed by flow cytometry, a technology that is continuously evolving. Thresholding utilizing a violet 405 nm laser side scatter (VSSC) has recently been implemented. Here, we collected set of large EV (lEV) samples from cord blood, which we analyzed using a standard flow cytometer improved via a 405 nm laser side scatter. Samples were analyzed using two distinct thresholding methods—one based on VSSC, and one based on VSSC combined with fluorescence thresholding on stained phosphatidylserine. Through these thresholding methods, we compared lEVs from pre-term births and control cord blood. Double-labeled lEVs with platelet CD36+/CD41+, activated platelet CD41+/CD62P+ and endothelial CD31+/CD105+ antibodies were used. Apart from comparing the two groups together, we also correlated measured lEVs with the thresholding methods. We also correlated the results of this study with data analyzed in our previous study in which we used a conventional 488 nm laser SSC. We did not find any difference between the two cord blood groups. However, we found highly concurrent data via our correlation of the thresholding methods, with correlation coefficients ranging from 0.80 to 0.96 even though the numbers of detected lEVs differed between thresholding methods. In conclusion, our approaches to thresholding provided concurrent data and it seems that improving the cytometer with the use of a VSSC increases its sensitivity, despite not being particularly critical to the validity of flow cytometric studies that compare pathological and physiological conditions in liquid biopsies.

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Comparison of Lethal and Nonlethal Mouse Models of Orientia tsutsugamushi Infection Reveals T-Cell Population-Associated Cytokine Signatures Correlated with Lethality and Protection

Tropical Medicine and Infectious Disease ◽

10.3390/tropicalmed6030121 ◽

2021 ◽

Vol 6 (3) ◽

pp. 121

Author(s):

Alison Luce-Fedrow ◽

Suchismita Chattopadhyay ◽

Teik-Chye Chan ◽

Gregory Pearson ◽

John B. Patton ◽

...

Keyword(s):

Flow Cytometry ◽

T Cell ◽

Host Response ◽

Cd8 T Cell ◽

Cd4 T Cell ◽

Cell Populations ◽

Murine Models ◽

Orientia Tsutsugamushi ◽

Multicolor Flow Cytometry ◽

Interstrain Difference

The antigenic diversity of Orientia tsutsugamushi as well as the interstrain difference(s) associated with virulence in mice impose the necessity to dissect the host immune response. In this study we compared the host response in lethal and non-lethal murine models of O. tsutsugamushi infection using the two strains, Karp (New Guinea) and Woods (Australia). The models included the lethal model: Karp intraperitoneal (IP) challenge; and the nonlethal models: Karp intradermal (ID), Woods IP, and Woods ID challenges. We monitored bacterial trafficking to the liver, lung, spleen, kidney, heart, and blood, and seroconversion during the 21-day challenge. Bacterial trafficking to all organs was observed in both the lethal and nonlethal models of infection, with significant increases in average bacterial loads observed in the livers and hearts of the lethal model. Multicolor flow cytometry was utilized to analyze the CD4+ and CD8+ T cell populations and their intracellular production of the cytokines IFNγ, TNF, and IL2 (single, double, and triple combinations) associated with both the lethal and nonlethal murine models of infection. The lethal model was defined by a cytokine signature of double- (IFNγ-IL2) and triple-producing (IL2-TNF-IFNγ) CD4+ T-cell populations; no multifunctional signature was identified in the CD8+ T-cell populations associated with the lethal model. In the nonlethal model, the cytokine signature was predominated by CD4+ and CD8+ T-cell populations associated with single (IL2) and/or double (IL2-TNF) populations of producers. The cytokine signatures associated with our lethal model will become depletion targets in future experiments; those signatures associated with our nonlethal model are hypothesized to be related to the protective nature of the nonlethal challenges.

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