scholarly journals Interplay between LPA2 and LPA3 in LPA-mediated phosphatidylserine cell surface exposure and extracellular vesicles release by erythrocytes

2021 ◽  
pp. 114667
Author(s):  
Stephan Hasse ◽  
Anne-Claire Duchez ◽  
Paul Fortin ◽  
Eric Boilard ◽  
Sylvain G. Bourgoin
Keyword(s):  
Cell Surface ◽  
Extracellular Vesicles

scholarly journals CD47 cross-dressing by extracellular vesicles expressing CD47 inhibits phagocytosis without transmitting cell death signals

2021 ◽  
Author(s):  
Yang Li ◽  
Yan Wu ◽  
Elena A Federzoni ◽  
Xiaodan Wang ◽  
Andre Dharmawan ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Surface ◽  
Extracellular Vesicles ◽  
Pluripotent Stem Cells ◽  
Cell Surfaces ◽  
Alternative Source ◽  
Xenograft Rejection ◽  
Cell Dysfunction ◽  
Cross Dressing ◽  
Harmful Effects

Transgenic CD47 overexpression is an encouraging approach to ameliorating xenograft rejection and alloresponses to pluripotent stem cells, and the efficacy correlates with the level of CD47 expression. However, CD47, upon ligation, also transmits signals leading to cell dysfunction or death, raising a concern that overexpressing CD47 could be harmful. Here, we unveiled an alternative source of cell surface CD47. We showed that extracellular vesicles (EVs), including exosomes (Exos), released from normal or tumor cells overexpressing CD47 (transgenic or native) can induce efficient CD47 cross-dressing on pig or human cells. Like the autogenous CD47, CD47 cross-dressed on cell surfaces is capable of interacting with SIRPα to inhibit phagocytosis. However, ligation of the autogenous, but not cross-dressed, CD47 induced cell death. Thus, CD47 cross-dressing provides an alternative source of cell surface CD47 that may elicit its anti-phagocytic function without transmitting harmful signals to the cells. CD47 cross-dressing also suggests a previously unidentified mechanism for tumor-induced immunosuppression. Our findings should help to further optimize the CD47 transgenic approach that may improve outcomes by minimizing the harmful effects of CD47 overexpression.

scholarly journals Cell Surface Processing of CD109 by Meprin β Leads to the Release of Soluble Fragments and Reduced Expression on Extracellular Vesicles

2021 ◽  
Vol 9 ◽  
Author(s):  
Wiebke Lückstädt ◽  
Simon Bub ◽  
Tomas Koudelka ◽  
Egor Pavlenko ◽  
Florian Peters ◽  
...  
Keyword(s):  
Cell Surface ◽  
Extracellular Vesicles ◽  
Structural Model ◽  
Molecular Model ◽  
Particle Analysis ◽  
Release Mechanism ◽  
Cleavage Sites ◽  
Structural Localization ◽  
Hematopoietic Stem ◽  
Bait Region

Cluster of differentiation 109 (CD109) is a glycosylphosphatidylinositol (GPI)-anchored protein expressed on primitive hematopoietic stem cells, activated platelets, CD4+ and CD8+ T cells, and keratinocytes. In recent years, CD109 was also associated with different tumor entities and identified as a possible future diagnostic marker linked to reduced patient survival. Also, different cell signaling pathways were proposed as targets for CD109 interference including the TGFβ, JAK-STAT3, YAP/TAZ, and EGFR/AKT/mTOR pathways. Here, we identify the metalloproteinase meprin β to cleave CD109 at the cell surface and thereby induce the release of cleavage fragments of different size. Major cleavage was identified within the bait region of CD109 residing in the middle of the protein. To identify the structural localization of the bait region, homology modeling and single-particle analysis were applied, resulting in a molecular model of membrane-associated CD109, which allows for the localization of the newly identified cleavage sites for meprin β and the previously published cleavage sites for the metalloproteinase bone morphogenetic protein-1 (BMP-1). Full-length CD109 localized on extracellular vesicles (EVs) was also identified as a release mechanism, and we can show that proteolytic cleavage of CD109 at the cell surface reduces the amount of CD109 sorted to EVs. In summary, we identified meprin β as the first membrane-bound protease to cleave CD109 within the bait region, provide a first structural model for CD109, and show that cell surface proteolysis correlates negatively with CD109 released on EVs.

scholarly journals Phenotyping of Leukocytes and Leukocyte-Derived Extracellular Vesicles

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Lotte Hatting Pugholm ◽  
Rikke Bæk ◽  
Evo Kristina Lindersson Søndergaard ◽  
Anne Louise Schacht Revenfeld ◽  
Malene Møller Jørgensen ◽  
...  
Keyword(s):  
Immune System ◽  
Cell Surface ◽  
Extracellular Vesicles ◽  
Cell Types ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Parent Cell ◽  
Phenotypic Differences ◽  
Immunological Markers ◽  
Cellular Expression

Extracellular vesicles (EVs) have a demonstrated involvement in modulating the immune system. It has been proposed that EVs could be used as biomarkers for detection of inflammatory and immunological disorders. Consequently, it is of great interest to investigate EVs in more detail with focus on immunological markers. In this study, five major leukocyte subpopulations and the corresponding leukocyte-derived EVs were phenotyped with focus on selected immunological lineage-specific markers and selected vesicle-related markers. The leukocyte-derived EVs displayed phenotypic differences in the 34 markers investigated. The majority of the lineage-specific markers used for identification of the parent cell types could not be detected on EVs released from monocultures of the associated cell types. In contrast, the vesicular presentation of CD9, CD63, and CD81 correlated to the cell surface expression of these markers, however, with few exceptions. Furthermore, the cellular expression of CD9, CD63, and CD81 varied between leukocytes present in whole blood and cultured leukocytes. In summary, these data demonstrate that the cellular and vesicular presentation of selected lineage-specific and vesicle-related markers may differ, supporting the accumulating observations that sorting of molecular cargo into EVs is tightly controlled.

Cell Surface Labeling by Engineered Extracellular Vesicles

2020 ◽  
Vol 4 (12) ◽  
pp. 2000007
Author(s):  
Nicklas Hamilton ◽  
Natalie M. Claudio ◽  
Randall J. Armstrong ◽  
Ferdinando Pucci
Keyword(s):  
Cell Surface ◽  
Extracellular Vesicles

scholarly journals Trichomonas vaginalis extracellular vesicles are internalized by host cells using proteoglycans and caveolin-dependent endocytosis

2019 ◽  
Vol 116 (43) ◽  
pp. 21354-21360 ◽  
Author(s):  
Anand Kumar Rai ◽  
Patricia J. Johnson
Keyword(s):  
Cell Surface ◽  
Host Cell ◽  
Extracellular Vesicles ◽  
Mammalian Cells ◽  
Trichomonas Vaginalis ◽  
Host Cells ◽  
Titration Calorimetry ◽  
Mammalian Host ◽  
Target Cells ◽  
Host Cell Surface

Trichomonas vaginalis, a human-infective parasite, causes the most prevalent nonviral sexually transmitted infection worldwide. This pathogen secretes extracellular vesicles (EVs) that mediate its interaction with host cells. Here, we have developed assays to study the interface between parasite EVs and mammalian host cells and to quantify EV internalization by mammalian cells. We show that T. vaginalis EVs interact with glycosaminoglycans on the surface of host cells and specifically bind to heparan sulfate (HS) present on host cell surface proteoglycans. Moreover, competition assays using HS or removal of HS from the host cell surface strongly inhibit EV uptake, directly demonstrating that HS proteoglycans facilitate EV internalization. We identified an abundant protein on the surface of T. vaginalis EVs, 4-α-glucanotransferase (Tv4AGT), and show using isothermal titration calorimetry that this protein binds HS. Tv4AGT also competitively inhibits EV uptake, defining it as an EV ligand critical for EV internalization. Finally, we demonstrate that T. vaginalis EV uptake is dependent on host cell cholesterol and caveolin-1 and that internalization proceeds via clathrin-independent, lipid raft-mediated endocytosis. These studies reveal mechanisms used to drive host:pathogen interactions and further our understanding of how EVs are internalized by target cells to allow cross-talk between different cell types.

scholarly journals Multifunctional Roles of the N-Terminal Region of HIV-1SF2Nef Are Mediated by Three Independent Protein Interaction Sites

2019 ◽  
Vol 94 (1) ◽  
Author(s):  
Swetha Ananth ◽  
Katharina Morath ◽  
Birthe Trautz ◽  
Nadine Tibroni ◽  
Iart Luca Shytaj ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Surface ◽  
Host Cell ◽  
Disease Progression ◽  
Extracellular Vesicles ◽  
Protein Interaction ◽  
Terminal Region ◽  
Virus Spread ◽  
Mhc I ◽  
Hiv 1

ABSTRACT HIV-1 Nef promotes virus spread and disease progression by altering host cell transport and signaling processes through interaction with multiple host cell proteins. The N-terminal region in HIV-1 Nef encompassing residues 12 to 39 has been implicated in many Nef activities, including disruption of CD4 T lymphocyte polarization and homing to lymph nodes, antagonism of SERINC5 restriction to virion infectivity, downregulation of cell surface CD4 and major histocompatibility complex class I (MHC-I), release of Nef-containing extracellular vesicles, and phosphorylation of Nef by recruitment of the Nef-associated kinase complex (NAKC). How this region mediates these pleiotropic functions is unclear. Characterization of a panel of alanine mutants spanning the N-terminal region to identify specific functional determinants revealed this region to be dispensable for effects of Nef from HIV-1 strain SF2 (HIV-1SF2Nef) on T cell actin organization and chemotaxis, retargeting of the host cell kinase Lck to the trans-Golgi network, and incorporation of Nef into extracellular vesicles. MHC-I downmodulation was specific to residue M20, and inhibition of T cell polarization by Nef required the integrity of the entire region. In contrast, downmodulation of cell surface CD4 and SERINC5 antagonism were mediated by a specific motif encompassing residues 32 to 39 that was also essential for efficient HIV replication in primary CD4 T lymphocytes. Finally, Nef phosphorylation via association with the NAKC was mediated by two EP repeats within residues 24 to 29 but was dispensable for other functions. These results identify the N-terminal region as a multifunctional interaction module for at least three different host cell ligands that mediate independent functions of HIV-1SF2Nef to facilitate immune evasion and virus spread. IMPORTANCE HIV-1 Nef critically determines virus spread and disease progression in infected individuals by acting as a protein interaction adaptor via incompletely defined mechanisms and ligands. Residues 12 to 39 near the N terminus of Nef have been described as an interaction platform for the Nef-associated kinase complex (NAKC) and were recently identified as essential determinants for a broad range of Nef activities. Here, we report a systematic mapping of this amino acid stretch that revealed the presence of three independent interaction motifs with specific ligands and activities. While downmodulation of cell surface MHC-I depends on M20, two EP repeats are the minimal binding site for the NAKC, and residues 32 to 39 mediate antagonism of the host cell restriction factor SERINC5 as well as downmodulation of cell surface CD4. These results reveal that the N-terminal region of HIV-1SF2Nef is a versatile and multifunctional protein interaction module that exerts essential functions of the pathogenicity factor via independent mechanisms.

High-level secretion of tissue factor-rich extracellular vesicles from ovarian cancer cells mediated by filamin-A and protease-activated receptors

2016 ◽  
Vol 115 (02) ◽  
pp. 299-310 ◽  
Author(s):  
Shin Ito ◽  
Yusuke Yoshioka ◽  
Tomohiko Kanayama ◽  
Yoshiyasu Nakamura ◽  
Mitsuyo Yoshihara ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cell Surface ◽  
Cancer Cells ◽  
Cancer Patients ◽  
Tissue Factor ◽  
Extracellular Vesicles ◽  
Actin Binding ◽  
Ovarian Cancer Cells ◽  
Filamin A ◽  
Protease Activated Receptors

SummaryThromboembolic events occur frequently in ovarian cancer patients. Tissue factor (TF) is often overexpressed in tumours, including ovarian clear-cell carcinoma (CCC), a subtype with a generally poor prognosis. TF-coagulation factor VII (fVII) complexes on the cell surface activate downstream coagulation mechanisms. Moreover, cancer cells secrete extracellular vesicles (EVs), which act as vehicles for TF. We therefore examined the characteristics of EVs produced by ovarian cancer cells of various histological subtypes. CCC cells secreted high levels of TF within EVs, while the high-TF expressing breast cancer cell line MDA-MB-231 shed fewer TF-positive EVs. We also found that CCC tumours with hypoxic tissue areas synthesised TF and fVII in vivo, rendering the blood of xenograft mice bearing these tumours hypercoagulable compared with mice bearing MDA-MB-231 tumours. Incorporation of TF into EVs and secretion of EVs from CCC cells exposed to hypoxia were both dependent on the actin-binding protein, filamin-A (filA). Furthermore, production of these EVs was dependent on different protease-activated receptors (PARs) on the cell surface. These results show that CCC cells could produce large numbers of TF-positive EVs dependent upon filA and PARs. This phenomenon may be the mechanism underlying the increased incidence of venous thromboembolism in ovarian cancer patients.Supplementary Material to this article is available online at www.thrombosis-online.com.

scholarly journals Extracellular vesicles as a platform to study cell-surface membrane proteins

Methods ◽  
2020 ◽  
Vol 180 ◽  
pp. 35-44 ◽  
Author(s):  
Vincent Delauzun ◽  
Beatrice Amigues ◽  
Anais Gaubert ◽  
Philippe Leone ◽  
Magali Grange ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Cell Surface ◽  
Extracellular Vesicles ◽  
Surface Membrane ◽  
Cell Surface Membrane

Influence of Calcium Ions on the Plant Cell Surface: Membrane Fusions and Conformational Changes

1974 ◽  
Vol 32 ◽  
pp. 154-155
Author(s):  
D. James Morré ◽  
Charles E. Bracker ◽  
William J. VanDerWoude
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Conformational Changes ◽  
Calcium Ions ◽  
Surface Membrane ◽  
Carboxyl Groups ◽  
Cross Linking ◽  
Ultrastructural Evidence ◽  
Glycine Max L ◽  
Wall Extensibility

Calcium ions in the concentration range 5-100 mM inhibit auxin-induced cell elongation and wall extensibility of plant stems. Inhibition of wall extensibility requires that the tissue be living; growth inhibition cannot be explained on the basis of cross-linking of carboxyl groups of cell wall uronides by calcium ions. In this study, ultrastructural evidence was sought for an interaction of calcium ions with some component other than the wall at the cell surface of soybean (Glycine max (L.) Merr.) hypocotyls.

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