John C Tigges

John C Tigges
Harvard Stem Cell Institute, Harvard University

About

43
Publications
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1,594
Citations

Publications

Publications (43)
Article
Full-text available
High‐sensitivity flow cytometers have been developed for multi‐parameter characterization of single extracellular vesicles (EVs), but performance varies among instruments and calibration methods. Here we compare the characterization of identical (split) EV samples derived from human colorectal cancer (DiFi) cells by three high‐sensitivity flow cyto...
Article
Full-text available
Extracellular vesicles (EVs) play a pivotal role in various biological pathways, such as immune responses and the progression of diseases, including cancer. However, it is challenging to isolate EVs at high purity from blood plasma and other biofluids due to their low abundance compared to more predominant biomolecular species such as lipoprotein p...
Article
Full-text available
Extracellular vesicles (EVs) are membrane‐bound structures released by cells and tissues into biofluids, involved in cell‐cell communication. In humans, circulating red blood cells (RBCs), represent the most common cell‐type in the body, generating daily large numbers of microvesicles. In vitro, RBC vesiculation can be mimicked by stimulating RBCs...
Article
Full-text available
Motivation: Extracellular particles (EPs) are the focus of a rapidly growing area of exploration due to the widespread interest in understanding their roles in health and disease. However, despite the general need for EP data sharing and established community standards for data reporting, no standard repository for EP Flow cytometry (EP-FC) data c...
Preprint
Full-text available
Post-transcriptional RNA modifications (PTxMs) present in small RNA species, specifically circulating extracellular RNAs, were recently identified as clinically relevant readouts, often more indicative of disease severity than the classical “up and down” changes in their copy number alone. While identification of PTxMs requires multiple and complex...
Article
Full-text available
Extracellular vesicles (EVs) mediate intercellular signaling by transferring their cargo to recipient cells, but the functional consequences of signaling are not fully appreciated. RBC-derived EVs are abundant in circulation and have been implicated in regulating immune responses. Here, we use a transgenic mouse model for fluorescence-based mapping...
Article
Full-text available
MicroRNAs are short, non-coding RNA sequences involved in gene expression regulation. Quantification of miRNAs in biological fluids involves time consuming and laborious methods such as Northern blotting or PCR-based techniques. Molecular beacons (MB) are an attractive means for rapid detection of miRNAs, although the need for sophisticated readout...
Article
Full-text available
Rationale: Previous translational studies implicate plasma extracellular microRNA-30d (miR-30d) as a biomarker in left ventricular (LV) remodeling and clinical outcome in heart failure (HF) patients, though precise mechanisms remain obscure. Objective: To investigate the mechanism of miR-30d-mediated cardioprotection in HF. Methods and Results: In...
Article
Full-text available
Extracellular vesicles (EVs) are small, heterogeneous and difficult to measure. Flow cytometry (FC) is a key technology for the measurement of individual particles, but its application to the analysis of EVs and other submicron particles has presented many challenges and has produced a number of controversial results, in part due to limitations of...
Article
Full-text available
Extracellular vesicles (EVs) have recently emerged as intercellular conveyors of biological information and disease biomarkers. Identification and characterization of RNA species in single EVs are currently challenging. Molecular beacons (MBs) represent an attractive means for detecting specific RNA molecules. Coupling the MBs to cell-penetrating p...
Article
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Background: Malignant gliomas are rapidly progressive brain tumors with high mortality. Fluorescence guided surgery (FGS) with 5-aminolevulinic acid (5-ALA) provides fluorescent delineation of malignant tissue, which helps achieve maximum safe resection. 5-ALA-based fluorescence is due to preferential accumulation of the fluorophore protoporphyrin...
Article
Full-text available
Biological nanoparticles, including viruses and extracellular vesicles (EVs), are of interest to many fields of medicine as biomarkers and mediators of or treatments for disease. However, exosomes and small viruses fall below the detection limits of conventional flow cytometers due to the overlap of particle-associated scattered light signals with...
Preprint
Full-text available
Extracellular vesicles (EV) mediate intercellular signaling by transferring their cargo to recipient cells. Red blood cell (RBC)-derived EVs constitute a significant proportion of circulating EVs and have been implicated in regulating immune responses. Here, we describe a transgenic mouse model for fluorescent-based mapping of RBC-EV target cells b...
Article
Background/Purpose: Exosomes may constitute a more practical alternative to live cells in select stem cell-based therapies. We sought to compare exosomes from two mesenchymal stem cell (MSC) sources relevant to perinatal and pediatric diseases. Methods: Exosomes were isolated by reagent-enhanced centrifugation from cell culture media of banked huma...
Article
Single cell sorting is commonly used for ensuring monoclonality and producing homogenous target cell populations. Current single cell verification methods involve manually confirming the existence of single cells or colonies in a well using a standard light microscope. However, the manual verification method is time-consuming and highly tedious, wh...
Chapter
Here, we describe a comprehensive methodology for the setup and standardization of EV analysis using nanoscale flow cytometry. Controls of different size ranges, fluorescent intensities, and materials can be used to set up distribution curves that are then used for instrument optimization and as a reference guide. Using these controls, flow cytomet...
Chapter
During their lifetime, like all other cell types, red blood cells (RBCs) release both exosomes and plasma membrane derived EVs (ectosomes). RBC exosomes are formed only during the development of RBCs in bone marrow, and are released following the fusion of microvesicular bodies (MVB) with the plasma membrane. On the other hand, RBC EVs are generat...
Article
Full-text available
Extracellular vesicles (EVs) serve an important function as mediators of intercellular communication. Exercise is protective for the heart, although the signaling mechanisms that mediate this cardioprotection have not been fully elucidated. Here using nano-flow cytometry, we found a rapid increase in plasma EVs in human subjects undergoing exercise...
Article
Extracellular vesicles (EVs) serve an important function as mediators of intercellular communication. Exercise is protective for the heart, although the signaling mechanisms that mediate this cardioprotection have not been fully elucidated. Here using nano-flow cytometry, we found a rapid increase in plasma EVs in human subjects undergoing exercise...
Article
Full-text available
A key function of human eosinophils is to secrete cytokines, chemokines and cationic proteins, trafficking, and releasing these mediators for roles in inflammation and other immune responses. Eosinophil activation leads to secretion of pre-synthesized granule-stored mediators through different mechanisms, but the ability of eosinophils to secrete e...
Article
Full-text available
The identification of extracellular vesicles (EVs) as intercellular conveyors of biological information has recently emerged as a novel paradigm in signaling, leading to the exploitation of EVs and their contents as biomarkers of various diseases. However, whether there are diurnal variations in the size, number, and tissue of origin of blood EVs i...
Data
The MoFlo XDP standard FSC photodiode and SSC PMT are compared to the NanoView FSC PMT and optical enhancements. The NanoView module shows enhanced dynamic range, better signal to noise ratio and overall better small particle detection based on nanoparticle sizing. (TIFF)
Data
Shedding of debris from commonly used copolymer tubes. PBS from the same batch was placed in microcentrigue tubes (USA Scientific, 1415–2500; A) or quick-seal tubes (Beckman Coulter, 342184; B) prior to flow cytometry analysis. Beckman Coulter tubes were found to shed debris within the size and scatter range of EVs and were not used for further exp...
Article
Full-text available
Lineage (CD3e, CD11b, GR1, B220 and Ly-76) negative hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) infiltrate islet allografts within 24 h posttransplantation. In fact, lineage(negative) Sca-1(+) cKit(+) ("LSK") cells, a classic signature for HSCs, were also detected among these graft infiltrating cells. Lineage negative...
Article
Full-text available
CD4(+) T cells are involved in the development of autoimmunity, including multiple sclerosis (MS). Here we show that nicotinamide adenine dinucleotide (NAD(+)) blocks experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, by inducing immune homeostasis through CD4(+)IFNγ(+)IL-10(+) T cells and reverses disease progression by restorin...
Article
Full-text available
Phosphohydrolysis of extracellular ATP and ADP is an essential step in purinergic signaling that regulates key pathophysiological processes, such as those linked to inflammation. Classically, this reaction has been known to occur in the pericellular milieu catalyzed by membrane bound cellular ecto-nucleotidases, which can be released in the form of...
Article
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To evaluate changes in endothelial progenitor cells (EPCs) and cytokines in patients with diabetic foot ulceration (DFU) in association with wound healing. We studied healthy subjects, diabetic patients not at risk of DFU, at risk of DFU and with active DFU. We prospectively followed the DFU patients over a 12-week period. We also investigated simi...
Article
Full-text available
THE opportunity for low cost, high quality training and supervision is an attractive one to most scientists in the cytometry field. Many have had little if any training, no exper-tise based locally, or may not have the funds to attend regional or international training courses. In addition, rather than gen-eral cytometry they may require assistance...
Article
Full-text available
Extracellular vesicles (ECVs) are nano-sized vesicles released by all cells in vitro as well as in vivo. Their role has been implicated mainly in cell–cell communication, but also in disease biomarkers and more recently in gene delivery. They represent a snapshot of the cell status at the moment of release and carry bioreactive macromolecules such...
Article
2A Peptide sequences are now being widely used to construct multicistronic expression vectors. It is suggested that when only the first 2A-linked protein bears a signal sequence, the signal-less protein(s) downstream of 2A can also be translocated into the mammalian endoplasmic reticulum system through a "slipstreaming" mechanism. By using flow cyt...
Article
Full-text available
Foxp3(+) regulatory T cells (Tregs) express both ectoenzymes CD39 and CD73, which in tandem hydrolyze pericellular ATP into adenosine, an immunoinhibitory molecule that contributes to Treg suppressive function. Using Foxp3GFP knockin mice, we noted that the mouse CD4(+)CD39(+) T-cell pool contains two roughly equal size Foxp3(+) and Foxp3(-) popula...
Article
Hsal 2 is a member of recently identified gene family in humans, a homologue of the Drosophila homoeotic gene. Sal. The Hsal genes are thought to encode developmental transcription factor(s) controlling specific pathways of human embryonic development. Evaluation of tissue expression for mRNAs led to an investigation of Hsal 2 in hematopoiesis. Hsa...
Article
Full-text available
Normal mature quiescent human B lymphocytes, isolated as a function of buoyant density, require activation for up-regulation of IL-13R constituents. Cell activation through a combination of surface Ig and CD40 receptor ligation leads to the most substantial message production for IL-13Ralpha1. Functional consequences of this receptor variation, in...

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