Extracellular vesicles (EVs) in blood plasma are recognized as potential biomarkers for disease. Although blood plasma is easily obtainable, analysis of EVs at the single particle level is still... Show moreExtracellular vesicles (EVs) in blood plasma are recognized as potential biomarkers for disease. Although blood plasma is easily obtainable, analysis of EVs at the single particle level is still challenging due to the biological complexity of this body fluid. Besides EVs, plasma contains different types of lipoproteins particles (LPPs), that outnumber EVs by orders of magnitude and which partially overlap in biophysical properties such as size, density and molecular makeup. Consequently, during EV isolation LPPs are often co-isolated. Furthermore, physical EV-LPP complexes have been observed in purified EV preparations. Since co-isolation or association of LPPs can impact EV-based analysis and biomarker profiling, we investigated the presence and formation of EV-LPP complexes in biological samples by using label-free atomic force microscopy, cryo-electron tomography and synchronous Rayleigh and Raman scattering analysis of optically trapped particles and fluorescence-based high sensitivity single particle flow cytometry. Furthermore, we evaluated the impact on flow cytometric analysis in the presence of LPPs using in vitro spike-in experiments of purified tumour cell line-derived EVs in different classes of purified human LPPs. Based on orthogonal single-particle analysis techniques we demonstrate that EV-LPP complexes can form under physiological conditions. Furthermore, we show that in fluorescence-based flow cytometric EV analysis staining of LPPs, as well as EV-LPP associations, can influence quantitative and qualitative EV analysis. Lastly, we demonstrate that the colloidal matrix of the biofluid in which EVs reside impacts their buoyant density, size and/or refractive index (RI), which may have consequences for down-stream EV analysis and EV biomarker profiling. Show less
Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the formation of fluid-filled cysts within the kidney due to mutations in PKD1 or PKD2. Although the disease remains... Show moreAutosomal dominant polycystic kidney disease (ADPKD) is characterized by the formation of fluid-filled cysts within the kidney due to mutations in PKD1 or PKD2. Although the disease remains incompletely understood, one of the factors associated with ADPKD progression is the release of nucleotides (including ATP), which can initiate autocrine or paracrine purinergic signaling by binding to their receptors. Recently, we and others have shown that increased extracellular vesicle (EVs) release from PKD1 knockout cells can stimulate cyst growth through effects on recipient cells. Given that EVs are an important communicator between different nephron segments, we hypothesize that EVs released from PKD1 knockout distal convoluted tubule (DCT) cells can stimulate cyst growth in the downstream collecting duct (CD). Here, we show that administration of EVs derived from Pkd1(-/-) mouse distal convoluted tubule (mDCT15) cells result in a significant increase in extracellular ATP release from Pkd1(-/-) mouse inner medullary collecting duct (iMCD3) cells. In addition, exposure of Pkd1(-/-) iMCD3 cells to EVs derived from Pkd1(-/-) mDCT15 cells led to an increase in the phosphorylation of the serine/threonine-specific protein Akt, suggesting activation of proliferative pathways. Finally, the exposure of iMCD3 Pkd1(-/-) cells to mDCT15 Pkd1(-/-) EVs increased cyst size in Matrigel. These findings indicate that EVs could be involved in intersegmental communication between the distal convoluted tubule and the collecting duct and potentially stimulate cyst growth. Show less
Kapteijn, M.Y.; Zwaan, S.; Linden, E. ter; Laghmani, E.; Akker, R.F.P. van den; Rondon, A.M.R.; ... ; Buijs, J.T. 2023
Glioblastoma (GBM) patients have one of the highest risks of venous thromboembolism (VTE), which is even further increased upon treatment with chemotherapy. Tissue factor (TF) is the initiator of... Show moreGlioblastoma (GBM) patients have one of the highest risks of venous thromboembolism (VTE), which is even further increased upon treatment with chemotherapy. Tissue factor (TF) is the initiator of the extrinsic coagulation pathway and expressed by GBM cells. In this study, we aimed to examine the effect of routinely used chemotherapeutic agents Temozolomide (TMZ) and Lomustine (LOM) on TF procoagulant activity and expression in GBM cells in vitro. Three human GBM cell lines (U-251, U-87, U-118) were exposed to 100 µM TMZ or 30 µM LOM for 72 h. TF procoagulant activity was assessed via an FXa generation assay and TF gene and protein expression through qPCR and Western blotting. The externalization of phosphatidylserine (PS) was studied using Annexin V flow cytometry. Treatment with TMZ and LOM resulted in increased procoagulant activity in all cell lines. Furthermore, both agents induced procoagulant activity in the supernatant and tumor-cell-secreted extracellular vesicles. In line, TF gene and protein expression were increased upon TMZ and LOM treatment. Additionally, PS externalization and induction of inflammatory-associated genes were observed. Overall, the chemotherapeutic modalities TMZ and LOM induced procoagulant activity and increased TF gene and protein expression in all GBM cell lines tested, which may contribute to the increased VTE risk observed in GBM patients undergoing chemotherapy. Show less
Schistosomes can survive in mammalian hosts for many years, and this is facilitated by released parasite products that modulate the host's immune system. Many of these products are glycosylated and... Show moreSchistosomes can survive in mammalian hosts for many years, and this is facilitated by released parasite products that modulate the host's immune system. Many of these products are glycosylated and interact with host cells via C-type lectin receptors (CLRs). We previously reported on specific fucose-containing glycans present on extracellular vesicles (EVs) released by schistosomula, the early juvenile life stage of the schistosome, and the interaction of these EVs with the C-type lectin receptor Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin (DC-SIGN or CD209). EVs are membrane vesicles with a size range between 30-1,000 nm that play a role in intercellular and interspecies communication. Here, we studied the glycosylation of EVs released by the adult schistosome worms. Mass spectrometric analysis showed that GalNAc beta 1-4GlcNAc (LacDiNAc or LDN) containing N-glycans were the dominant glycan type present on adult worm EVs. Using glycan-specific antibodies, we confirmed that EVs from adult worms were predominantly associated with LDN, while schistosomula EVs displayed a highly fucosylated glycan profile. In contrast to schistosomula EV that bind to DC-SIGN, adult worm EVs are recognized by macrophage galactose-type lectin (MGL or CD301), and not by DC-SIGN, on CLR expressing cell lines. The different glycosylation profiles of adult worm- and schistosomula-derived EVs match with the characteristic glycan profiles of the corresponding life stages and support their distinct roles in schistosome life-stage specific interactions with the host. Show less
Over the last decade, research interest in defining how extracellular vesicles (EVs) shape cross-species communication has grown rapidly. Parasitic helminths, worm species found in the phyla... Show moreOver the last decade, research interest in defining how extracellular vesicles (EVs) shape cross-species communication has grown rapidly. Parasitic helminths, worm species found in the phyla Nematoda and Platyhelminthes, are well-recognised manipulators of host immune function and physiology. Emerging evidence supports a role for helminth-derived EVs in these processes and highlights EVs as an important participant in cross-phylum communication. While the mammalian EV field is guided by a community-agreed framework for studying EVs derived from model organisms or cell systems [e.g., Minimal Information for Studies of Extracellular Vesicles (MISEV)], the helminth community requires a supplementary set of principles due to the additional challenges that accompany working with such divergent organisms. These challenges include, but are not limited to, generating sufficient quantities of EVs for descriptive or functional studies, defining pan-helminth EV markers, genetically modifying these organisms, and identifying rigorous methodologies for in vitro and in vivo studies. Here, we outline best practices for those investigating the biology of helminth-derived EVs to complement the MISEV guidelines. We summarise community-agreed standards for studying EVs derived from this broad set of non-model organisms, raise awareness of issues associated with helminth EVs and provide future perspectives for how progress in the field will be achieved. Show less
Pharmacogenomics (PGx) entails the study of heritability of drug response. This may include both variability in genes related to pharmacokinetics (drug absorption, distribution, metabolism and... Show morePharmacogenomics (PGx) entails the study of heritability of drug response. This may include both variability in genes related to pharmacokinetics (drug absorption, distribution, metabolism and excretion) and pharmacodynamics (e.g., drug receptors or signaling pathways). Individualizing drug therapy taking into account the genetic profile of the patient has the potential to make drug therapy safer and more effective. Currently, this approach relies on the determination of genetic variants in pharmacogenes by genotyping. However, it is widely acknowledged that large variability in gene expression is attributed to non-structural genetic variants. Therefore, at least from a theoretical viewpoint individualizing drug therapy based upon expression of pharmacogenes rather than on genotype may be advantageous but has been difficult to implement in the clinical setting. Extracellular vesicles (EVs) are lipid encapsulated structures that contain cargo such as lipids, nucleic acids and proteins. Since their cargo is tissue- and cell-specific they can be used to determine the expression of pharmacogenes in the liver. In this review, we describe methods of EV isolation and the potential of EVs isolated from liquid biopsies as a tool to determine the expression of pharmacogenes for use in personalized medicine. Show less
Background Venous thromboembolism (VTE) is a frequent cardiovascular disease with severe complications, including recurrence and death. There is a great need for alternative prophylactic treatment... Show moreBackground Venous thromboembolism (VTE) is a frequent cardiovascular disease with severe complications, including recurrence and death. There is a great need for alternative prophylactic treatment options as anticoagulation is accompanied by increased bleeding risk. Statins are reported to reduce the risk of incident and recurrent VTE, but the mechanisms are elusive. Procoagulant phospholipids (PPL), and phosphatidylserine in particular, are crucial for efficient coagulation activation, but no studies have investigated the effect of statin treatment on plasma PPL activity. Objectives To investigate the impact of rosuvastatin treatment on plasma PPL activity and levels of extracellular vesicles (EVs). Patients/Methods Patients with a history of VTE (>= 18 years) allowed to stop anticoagulant treatment were randomized to either 20 mg/day of rosuvastatin treatment or no treatment for 28 days in the Statins Reduce Thrombophilia (NCT01613794) trial. Plasma samples were collected at baseline and study end. PPL activity was measured in samples from 245 participants using a factor Xa-dependent clotting assay and EV levels by flow cytometry. Results Rosuvastatin treatment yielded an overall 22% (95% confidence interval [CI] -38.2 to -5.8) reduction in PPL activity, and 37% (95% CI -62.9 to -11.2) reduction in PPL activity in participants with a history of pulmonary embolism. The effect of rosuvastatin on plasma PPL activity was not explained by changes in total cholesterol nor change in levels of total- or platelet-derived EVs. Conclusions Rosuvastatin treatment caused a substantial decrease in plasma PPL activity, suggesting that a PPL-dependent attenuation of coagulation activation may contribute to a reduced VTE risk following statin treatment. Show less
Emerging evidence suggests that immune cells not only communicatewith each other through cytokines, chemokines, and cell surface receptors, but also by releasing small membranous structures known... Show moreEmerging evidence suggests that immune cells not only communicatewith each other through cytokines, chemokines, and cell surface receptors, but also by releasing small membranous structures known as extracellular vesicles (EVs). EVs carry a variety of different molecules that can be taken up by recipient cells. Parasitic worms are well known for their immunomodulatory properties, but whether they can affect immune responses by altering EV-driven communication between host immune cells remains unclear. Here we provide evidence that stimulation of bone marrow-derived macrophages (BMDMs) with soluble products of Trichuris suis (TSPs), leads to the release of EVs with anti-inflammatory properties. Specifically, we found that EVs from TSP-pulsed BMDMs, but not those from unstimulated BMDMs can suppress TNF alpha and IL-6 release in LPS-stimulated BMDMs and BMDCs. However, no polarization toward M1 or M2 was observed in macrophages exposed to EVs. Moreover, EVs enhanced reactive oxygen species (ROS) production in the exposed BMDMs, which was associated with a deregulated redox homeostasis as revealed by pathway analysis of transcriptomic data. Proteomic analysis identified cytochrome p450 (CYP450) as a potential source of ROS in EVs from TSP-pulsed BMDMs. Finally, pharmacological inhibition of CYP450 activity could suppress ROS production in those BMDMs. In summary, we find that TSPs can modulate immune responses not only via direct interactions but also indirectly by eliciting the release of EVs from BMDMs that exert anti-inflammatory effects on recipient cells. Show less
Sogorb Gonzalez, M.; Vendrell-Tornero, C.; Snapper, J.; Stam, A.; Keskin, S.; Miniarikova, J.; ... ; Valles, A. 2021
The preclinical development of microRNA-based gene therapies for inherited neurodegenerative diseases is accompanied by translational challenges. Due to the inaccessibility of the brain to... Show moreThe preclinical development of microRNA-based gene therapies for inherited neurodegenerative diseases is accompanied by translational challenges. Due to the inaccessibility of the brain to periodically evaluate therapy effects, accessible and reliable biomarkers indicative of dosing, durability and therapeutic efficacy in the central nervous system are very much needed. This is particularly important for viral vector-based gene therapies, in which a one-time administration results in long-term expression of active therapeutic molecules in the brain. Recently, extracellular vesides have been identified as carriers of RNA species, including microRNAs, and proteins in all biological fluids, whilst becoming potential sources of biomarkers for diagnosis. In this study, we investigated the secretion and potential use of circulating miRNAs associated with extracellular vesicles as suitable sources to monitor the expression and durability of gene therapies in the brain. Neuronal cells derived from induced pluripotent stern cells were treated with adeno-associated viral vector serotype 5 carrying an engineered microRNA targeting huntingtin or ataxin3 gene sequences, the diseases-causing genes of Huntington disease and spinocerebellar ataxia type 3, respectively. After treatment, the secretion of mature engineered microRNA molecules was confirmed, with extracellular microRNA levels correlating with viral dose and cellular microRNA expression in neurons. We further investigated the detection of engineered microRNAs over time in the CSF of non-human primates after a single intrastriatal injection of adeno-associated viral vector serotype 5 carrying a huntingtin-targeting engineered microRNA. Quantifiable engineered microRNA levels enriched in extracellular vesicles were detected in the CSF up to 2 years after brain infusion. Altogether, these results confirm the long-term expression of adeno-associated viral vector serotype 5-delivered microRNAs and support the use of extracellular vesicle-associated microRNAs as novel translational pharmacokinetic markers in ongoing clinical trials of gene therapies for neurodegenerative diseases. Show less
Uil, M.; Hau, C.M.; Ahdi, M.; Mills, J.D.; Kers, J.; Saleem, M.A.; ... ; Roelofs, J.J.T.H. 2021
Background. Diabetic nephropathy (DN) is a major complication of diabetes and the main cause of end-stage renal disease. Extracellular vesicles (EVs) are small cell-derived vesicles that can alter... Show moreBackground. Diabetic nephropathy (DN) is a major complication of diabetes and the main cause of end-stage renal disease. Extracellular vesicles (EVs) are small cell-derived vesicles that can alter disease progression by microRNA (miRNA) transfer.Methods. In this study, we aimed to characterize the cellular origin and miRNA content of EVs in plasma samples of type 2 diabetes patients at various stages of DN. Type 2 diabetes patients were classified in three groups: normoalbuminuria, microalbuminuria and macroalbuminuria. The concentration and cellular origin of plasma EVs were measured by flow cytometry. A total of 752 EV miRNAs were profiled in 18 subjects and differentially expressed miRNAs were validated.Results. Diabetic patients with microalbuminuria and/or macroalbuminuria showed elevated concentrations of total EVs and EVs from endothelial cells, platelets, leucocytes and erythrocytes compared with diabetic controls. miR-99a-5p was upregulated in macroalbuminuric patients compared with normoalbuminuric and microalbuminuric patients. Transfection of miR-99a-5p in cultured human podocytes downregulated mammalian target of rapamycin (mTOR) protein expression and downregulated the podocyte injury marker vimentin.Conclusions. Type 2 diabetes patients with microalbuminuria and macroalbuminuria display differential EV profiles. miR-99a-5p expression is elevated in EVs from macroalbuminuria and mTOR is its validated mRNA target. Show less
Catapano, F.; Scaglioni, D.; Maresh, K.; Ala, P.; Domingos, J.; Selby, V.; ... ; Muntoni, F. 2020
Aim: To perform cross-sectional and longitudinal miRNA profiling in plasma from Duchenne muscular dystrophy (DMD) subjects and find non-invasive biomarkers in DMD. Subjects/materials & methods:... Show moreAim: To perform cross-sectional and longitudinal miRNA profiling in plasma from Duchenne muscular dystrophy (DMD) subjects and find non-invasive biomarkers in DMD. Subjects/materials & methods: Plasma was collected from 14 age and sex matched controls and 46 DMD subjects. Free-circulating and extracellular vesicle (EV)-derived miRNA expression was measured by RT-qPCR. Results: Free-circulating and EVs derived miR-29c-3p and miR-133a-3p are dysregulated in DMD subjects. Free-circulating and EV-derived miR-29c-3p are reduced in DMD subjects undergoing daily corticosteroid treatment. Free-circulating miR-1-3p and miR-122-5p are longitudinally upregulated in ambulant DMD subjects. Conclusion: We detected novel free-circulating and EV-derived dysregulated miRNAs in plasma from DMD subjects and characterized the longitudinal profile of free-circulating miRNA on plasma from DMD subjects. Show less
Solinge, T.S. van; Abels, E.R.; Haar, L.L. van de; Hanlon, K.S.; Maas, S.L.N.; Schnoor, R.; ... ; Broekman, M.L.D. 2020
Introduction: Glioma cells exert influence over the tumor-microenvironment in part through the release of extracellular vesicles (EVs), membrane-enclosed structures containing proteins, lipids, and... Show moreIntroduction: Glioma cells exert influence over the tumor-microenvironment in part through the release of extracellular vesicles (EVs), membrane-enclosed structures containing proteins, lipids, and RNAs. In this study, we evaluated the function of Ras-associated protein 27a (Rab27a) in glioma and evaluated the feasibility of assessing its role in EV release in glioma cells in vitro and in vivo.Methods: Rab27a was knocked down via a short hairpin RNA (shRNA) stably expressed in mouse glioma cell line GL261, with a scrambled shRNA as control. EVs were isolated by ultracentrifugation and quantified with Nanoparticle Tracking Analysis (NTA) and Tunable Resistive Pulse Sensing (TRPS). CellTiter-Glo viability assays and cytokine arrays were used to evaluate the impact of Rab27a knockdown. GL261.shRab27a cells and GL261.shControl were implanted into the left striatum of eight mice to assess tumor growth and changes in the tumor microenvironment.Results: Knockdown of Rab27a in GL261 glioma cells decreased the release of small EVs isolated at 100,000 x g in vitro (p = 0.005), but not the release of larger EVs, isolated at 10,000 x g. GL261.shRab27a cells were less viable compared to the scramble control in vitro (p < 0.005). A significant increase in CCL2 expression in shRab27a GL261 cells was also observed (p < 0.001). However, in vivo there was no difference in tumor growth or overall survival between the two groups, while shRab27a tumors showed lower proliferation at the tumor borders. Decreased infiltration of IBA1 positive macrophages and microglia, but not FoxP3 positive regulatory T cells was observed.Conclusion: Rab27a plays an important role in the release of small EVs from glioma cells, and also in their viability and expression of CCL2 in vitro. As interference in Rab27a expression influences glioma cell viability and expression profiles, future studies should be cautious in using the knockdown of Rab27a as a means of studying the role of small EVs in glioma growth. Show less
Maas, S.L.N.; Solinge, T.S. van; Schnoor, R.; Yekula, A.; Senders, J.T.; Vrij, J. de; ... ; Broekman, M.L.D. 2020
Simple SummaryIn Glioblastoma (GB), a malignant tumor of the central nervous system, diagnosis can currently only be obtained via tissue biopsy. In this study we were able to isolate GB derived... Show moreSimple SummaryIn Glioblastoma (GB), a malignant tumor of the central nervous system, diagnosis can currently only be obtained via tissue biopsy. In this study we were able to isolate GB derived extracellular vesicles (EVs) in the blood, after patients received 5-aminolevulinic acid (5-ALA) before surgery. This isolation is based on fluorescence caused by the accumulation of fluorescent protoporphyrin IX (PpIX) in these EVs. We show that these EVs contain various GB-related micro RNAs. While there are many ways in which our technique needs to be improved before being able to be implemented in the clinic, this study shows that detecting and analyzing circulating GB-derived EVs based on PpIX fluorescence is feasible. In the future, our technique could be developed to diagnose and monitor GB via blood samples instead of a brain biopsy.Background: In glioblastoma (GB), tissue is required for accurate diagnosis and subtyping. Tissue can be obtained through resection or (stereotactic) biopsy, but these invasive procedures provide risks for patients. Extracellular vesicles (EVs) are small, cell-derived vesicles that contain miRNAs, proteins, and lipids, and possible candidates for liquid biopsies. GB-derived EVs can be found in the blood of patients, but it is difficult to distinguish them from circulating non-tumor EVs. 5-aminolevulinic acid (5-ALA) is orally administered to GB patients to facilitate tumor visualization and maximal resection, as it is metabolized to fluorescent protoporphyrin IX (PpIX) that accumulates in glioma cells. In this study, we assessed whether PpIX accumulates in GB-derived EVs and whether these EVs could be isolated and characterized to enable a liquid biopsy in GB. Methods: EVs were isolated from the conditioned media of U87 cells treated with 5-ALA by differential ultracentrifugation. Blood samples were collected and processed from healthy controls and patients undergoing 5-ALA guided surgery for GB. High-resolution flow cytometry (hFC) enabled detection and sorting of PpIX-positive EVs, which were subsequently analyzed by digital droplet PCR (ddPCR). Results: PpIX-positive EVs could be detected in conditioned cell culture media as well as in patient samples after administration of 5-ALA. By using hFC, we could sort the PpIX-positive EVs for further analysis with ddPCR, which indicated the presence of EVs and GB-associated miRNAs. Conclusion: GB-derived EVs can be isolated from the plasma of GB patients by using 5-ALA induced fluorescence. Although many challenges remain, our findings show new possibilities for the development of blood-based liquid biopsies in GB patients. Show less
Protozoan pathogens secrete nanosized particles called extracellular vesicles (EVs) to facilitate their survival and chronic infection. Here, we show the inhibition by Plasmodium berghei NK65 blood... Show moreProtozoan pathogens secrete nanosized particles called extracellular vesicles (EVs) to facilitate their survival and chronic infection. Here, we show the inhibition by Plasmodium berghei NK65 blood stage-derived EVs of the proliferative response of CD4(+) T cells in response to antigen presentation. Importantly, these results were confirmed in vivo by the capacity of EVs to diminish the ovalbumin-specific delayed type hypersensitivity response. We identified two proteins associated with EVs, the histamine releasing factor (HRF) and the elongation factor 1 alpha (EF-1 alpha) that were found to have immunosuppressive activities. Interestingly, in contrast to WT parasites, EVs from genetically HRF- and EF-1 alpha-deficient parasites failed to inhibit T cell responses in vitro and in vivo. At the level of T cells, we demonstrated that EVs from WT parasites dephosphorylate key molecules (PLC gamma 1, Akt, and ERK) of the T cell receptor signalling cascade. Remarkably, immunisation with EF-1 alpha alone or in combination with HRF conferred a long-lasting antiparasite protection and immune memory. In conclusion, we identified a new mechanism by which P. berghei-derived EVs exert their immunosuppressive functions by altering T cell responses. The identification of two highly conserved immune suppressive factors offers new conceptual strategies to overcome EV-mediated immune suppression in malaria-infected individuals. Show less
Background Cell injury signal-induced activation and release of tissue factor (TF) on extracellular vesicles (EVs) from immune and vessel wall cells propagate local and systemic coagulation... Show moreBackground Cell injury signal-induced activation and release of tissue factor (TF) on extracellular vesicles (EVs) from immune and vessel wall cells propagate local and systemic coagulation initiation. TF trafficking and release on EVs occurs in concert with the release of cell adhesion receptors, including integrin beta(1) heterodimers, which control trafficking of the TF-activated factor VII (FVIIa) complex. Activation of the TF signaling partner, protease-activated receptor (PAR) 2, also triggers TF release on integrin beta(+)(1) EVs from endothelial cells, but the physiological signals for PAR2-dependent EV generation at the vascular interface remain unknown. Objective To define relevant protease ligands of TF contributing to PAR2-dependent release on EVs from endothelial cells. Methods In endothelial cells with balanced expression of TF and PAR2, we evaluated TF release on EVs by using a combination of activity and antigen assays, immunocapture, and confocal imaging. Results and Conclusions PAR2 stimulation generated time-dependent release of distinct TF+ EVs with high coagulant activity (early) and high antigen levels (late). Whereas PAR2 agonist peptide and a stabilized TF-FVIIa-activated FX complex triggered TF+ EV release, stimulation with FVIIa alone promoted cellular retention of TF, despite comparable PAR2 activation. On endothelial cells, FVIIa uniquely induced formation of a complex of TF with integrin alpha(5)beta(1). Internalization of TF by FVIIa or anti-TF and activating antibodies against integrin beta(1) prevented PAR2 agonist-induced release of TF on EVs. These data demonstrate that intracellular trafficking controlled by FVIIa forcing interaction with integrin beta(1) regulates TF availability for release on procoagulant EVs. Show less