scholarly journals Extracellular Vesicle Release Promotes Viral Replication during Persistent HCV Infection

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 984
Author(s):  
Yucel Aydin ◽  
Ali Riza Koksal ◽  
Venu Reddy ◽  
Dong Lin ◽  
Hanadi Osman ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Virus Replication ◽  
Cellular Response ◽  
Immune Escape ◽  
Extracellular Vesicle ◽  
Hcv Infection ◽  
Vesicle Release ◽  
Autophagic Degradation ◽  
Virus Survival ◽  
The Impact

Hepatitis C virus (HCV) infection promotes autophagic degradation of viral replicative intermediates for sustaining replication and spread. The excessive activation of autophagy can induce cell death and terminate infection without proper regulation. A prior publication from this laboratory showed that an adaptive cellular response to HCV microbial stress inhibits autophagy through beclin 1 degradation. The mechanisms of how secretory and degradative autophagy are regulated during persistent HCV infection is unknown. This study was performed to understand the mechanisms of viral persistence in the absence of degradative autophagy, which is essential for virus survival. Using HCV infection of a CD63-green fluorescence protein (CD63-GFP), labeled stable transfected Huh-7.5 cell, we found that autophagy induction at the early stage of HCV infection increased the degradation of CD63-GFP that favored virus replication. However, the late-stage of persistent HCV infection showed impaired autophagic degradation, leading to the accumulation of CD63-GFP. We found that impaired autophagic degradation promoted the release of extracellular vesicles and exosomes. The impact of blocking the release of extracellular vesicles (EVs) on virus survival was investigated in persistently infected cells and sub-genomic replicon cells. Our study illustrates that blocking EV and exosome release severely suppresses virus replication without effecting host cell viability. Furthermore, we found that blocking EV release triggers interferon lambda 1 secretion. These findings suggest that the release of EVs is an innate immune escape mechanism that promotes persistent HCV infection. We propose that inhibition of extracellular vesicle release can be explored as a potential antiviral strategy for the treatment of HCV and other emerging RNA viruses.

scholarly journals 695 Oral delivery of a microbial extracellular vesicle induces potent anti-tumor immunity in mice

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A737-A737
Author(s):  
Loise Francisco-Anderson ◽  
Loise Francisco-Anderson ◽  
Mary Abdou ◽  
Michael Goldberg ◽  
Erin Troy ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Growth ◽  
Extracellular Vesicles ◽  
Tumor Immunity ◽  
Extracellular Vesicle ◽  
The Body ◽  
Checkpoint Inhibition ◽  
Small Intestinal ◽  
The Impact

BackgroundThe small intestinal axis (SINTAX) is a network of anatomic and functional connections between the small intestine and the rest of the body. It acts as an immunosurveillance system, integrating signals from the environment that affect physiological processes throughout the body. The impact of events in the gut in the control of tumor immunity is beginning to be appreciated. We have previously shown that an orally delivered single strain of commensal bacteria induces anti-tumor immunity preclinically via pattern recognition receptor-mediated activation of innate and adaptive immunity. Some bacteria produce extracellular vesicles (EVs) that share molecular content with the parent bacterium in a particle that is roughly 1/1000th the volume in a non-replicating form. We report here an orally-delivered and gut-restricted bacterial EV which potently attenuates tumor growth to a greater extent than whole bacteria or checkpoint inhibition.MethodsEDP1908 is a preparation of extracellular vesicles produced by a gram-stain negative strain of bacterium of the Oscillospiraceae family isolated from a human donor. EDP1908 was selected for its immunostimulatory profile in a screen of EVs from a range of distinct microbial strains. Its mechanism of action was determined by ex vivo analysis of the tumor microenvironment (TME) and by in vitro functional studies with murine and human cells.ResultsOral treatment of tumor-bearing mice with EDP1908 shows superior control of tumor growth compared to checkpoint inhibition (anti-PD-1) or an intact microbe. EDP1908 significantly increased the percentage of IFNγ and TNF producing CD8+ CTLs, NK cells, NKT cells and CD4+ cells in the tumor microenvironment (TME). EDP1908 also increased tumor-infiltrating dendritic cells (DC1 and DC2). Analysis of cytokines in the TME showed significant increases in IP-10 and IFNg production in mice treated with EDP1908, creating an environment conducive to the recruitment and activation of anti-tumor lymphocytes.ConclusionsThis is the first report of striking anti-tumor effects of an orally delivered microbial extracellular vesicle. These data point to oral EVs as a new class of immunotherapeutic drugs. They are particularly effective at harnessing the biology of the small intestinal axis, acting locally on host cells in the gut to control distal immune responses within the TME. EDP1908 is in preclinical development for the treatment of cancer.Ethics ApprovalPreclinical murine studies were conducted under the approval of the Avastus Preclinical Services’ Ethics Board. Human in vitro samples were attained by approval of the IntegReview Ethics Board; informed consent was obtained from all subjects.

scholarly journals Immune Escape Adaptive Mutations in the H7N9 Avian Influenza Hemagglutinin Protein Increase Virus Replication Fitness and Decrease Pandemic Potential

2020 ◽  
Vol 94 (19) ◽  
Author(s):  
Pengxiang Chang ◽  
Joshua E. Sealy ◽  
Jean-Remy Sadeyen ◽  
Sushant Bhat ◽  
Deimante Lukosaityte ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Avian Influenza ◽  
Virus Replication ◽  
Receptor Binding ◽  
Immune Escape ◽  
Influenza Viruses ◽  
Escape Mutant ◽  
Hemagglutinin Protein ◽  
Ha Protein ◽  
The Impact

ABSTRACT H7N9 avian influenza viruses (AIVs) continue to evolve and remain a huge threat to human health and the poultry industry. Previously, serially passaging the H7N9 A/Anhui/1/2013 virus in the presence of homologous ferret antiserum resulted in immune escape viruses containing amino acid substitutions alanine to threonine at residues 125 (A125T) and 151 (A151T) and leucine to glutamine at residue 217 (L217Q) in the hemagglutinin (HA) protein. These HA mutations have also been found in field isolates in 2019. To investigate the potential threat of serum escape mutant viruses to humans and poultry, the impact of these HA substitutions, either individually or in combination, on receptor binding, pH of fusion, thermal stability, and virus replication were investigated. Our results showed the serum escape mutant formed large plaques in Madin-Darby canine kidney (MDCK) cells and grew robustly in vitro and in ovo. They had a lower pH of fusion and increased thermal stability. Of note, the serum escape mutant completely lost the ability to bind to human-like receptor analogues. Further analysis revealed that N-linked glycosylation, as a result of A125T or A151T substitutions in HA, resulted in reduced receptor-binding avidity toward both human and avian-like receptor analogues, and the A125T+A151T mutations completely abolished human-like receptor binding. The L217Q mutation enhanced the H7N9 acid and thermal stability while the A151T mutation dramatically decreased H7N9 HA thermal stability. To conclude, H7N9 AIVs that contain A125T+A151T+L217Q mutations in the HA protein may pose a reduced pandemic risk but remain a heightened threat for poultry. IMPORTANCE Avian influenza H7N9 viruses have been causing disease outbreaks in poultry and humans. We previously determined that propagation of H7N9 virus in virus-specific antiserum gives rise to mutant viruses carrying mutations A125T+A151T+L217Q in their hemagglutinin protein, enabling the virus to overcome vaccine-induced immunity. As predicted, these immune escape mutations were also observed in the field viruses that likely emerged in the immunized or naturally exposed birds. This study demonstrates that the immune escape mutants also (i) gained greater replication ability in cultured cells and in chicken embryos as well as (ii) increased acid and thermal stability but (iii) lost preferences for binding to human-type receptor while maintaining binding for the avian-like receptor. Therefore, they potentially pose reduced pandemic risk. However, the emergent virus variants containing the indicated mutations remain a significant risk to poultry due to antigenic drift and improved fitness for poultry.

scholarly journals Effects of ATP9A on Extracellular Vesicle Release and Exosomal Lipid Composition

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xiao Xu ◽  
Limei Xu ◽  
Peng Zhang ◽  
Kan Ouyang ◽  
Yin Xiao ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Extracellular Vesicles ◽  
Lipid Composition ◽  
Extracellular Vesicle ◽  
Biological Processes ◽  
Vesicle Release ◽  
Endosomal Recycling ◽  
Intracellular Compartments ◽  
Intercellular Communications

Numerous biological processes are regulated by the intercellular communications arising from extracellular vesicles (EVs) released from cells. However, the mechanisms that regulate the quantity of EV discharged have yet to be understood. While it is known that ATP9A, a P4-ATPase, is involved in endosomal recycling, it is not clear whether it also contributes to the release of EVs and the makeup of exosomal lipids. This study is aimed at exploring the role of human ATP9A in the process of EV release and, further, to analyze the profiles of EV lipids regulated by ATP9A. Our results demonstrate that ATP9A is located in both the intracellular compartments and the plasma membrane. The percentage of ceramides and sphingosine was found to be significantly greater in the control cells than in the ATP9A overexpression and ATP9A knockout groups. However, EV release was greater in ATP9A knockout cells, indicating that ATP9A inhibits the release of EVs. This study revealed the effects of ATP9A on the release of EVs and the lipid composition of exosomes.

scholarly journals Bovine ephemeral fever virus triggers autophagy enhancing virus replication via upregulation of the Src/JNK/AP1 and PI3K/Akt/NF-κB pathways and suppression of the PI3K/Akt/mTOR pathway

2019 ◽  
Vol 50 (1) ◽  
Author(s):  
Ching-Yuan Cheng ◽  
Hsu-Hung Tseng ◽  
Hung-Chuan Chiu ◽  
Ching-Dong Chang ◽  
Brent L. Nielsen ◽  
...  
Keyword(s):  
Virus Replication ◽  
Cellular Response ◽  
Virus Production ◽  
Mtor Pathway ◽  
Fever Virus ◽  
Bovine Ephemeral Fever Virus ◽  
Virus Binding ◽  
Bovine Ephemeral Fever ◽  
Mtorc1 Pathway ◽  
The Impact

Abstract Autophagy plays an important role in cellular response to pathogens. However, the impact of the autophagy machinery on bovine ephemeral fever virus (BEFV) infection is not yet determined. A recent study in our laboratory demonstrated that BEFV triggers simultaneously the PI3K/Akt/NF-κB and Src/JNK-AP1 pathways in the stage of virus binding to enhance virus entry. In this work, we report that BEFV induces autophagy via upregulation of the PI3K/Akt/NF-κB and Src/JNK/AP1 pathways in the early to middle stages of infection and suppresses the PI3K/Akt/mTOR pathway at the late stage of infection. To activate NF-κB, BEFV promotes degradation of IκBα and activates Akt to stimulate NF-κB translocation into the nucleus. Immunoprecipitation assays revealed that BEFV disrupts Beclin 1 and Bcl-2 interaction by JNK-mediated Bcl-2 phosphorylation, thereby activating autophagy. Overexpression of Bcl-2 reversed the BEFV-induced increase in the LC3 II levels. Suppression of autophagy either by knockdown of autophagy-related genes with shRNAs or treatment with a pharmacological inhibitor 3-MA reduced BEFV replication, suggesting that BEFV-induced autophagy benefits virus replication. Our results revealed that the BEFV M protein is one of the viral proteins involved in inducing autophagy via suppression of the PI3K/Akt/mTORC1 pathway. Furthermore, degradation of p62 was observed by immunoblotting, suggesting that BEFV infection triggers a complete autophagic response. Disruption of autophagosome-lysosome fusion by depleting LAMP2 resulted in reduction of virus yield, suggesting that formation of autolysosome benefits virus production.

Placenta-derived extracellular vesicles: their cargo and possible functions

2017 ◽  
Vol 29 (3) ◽  
pp. 433 ◽  
Author(s):  
Mary Familari ◽  
Tina Cronqvist ◽  
Zahra Masoumi ◽  
Stefan R. Hansson
Keyword(s):  
Plasminogen Activator ◽  
Extracellular Vesicles ◽  
Meta Analysis ◽  
Plasminogen Activator Inhibitor ◽  
Extracellular Vesicle ◽  
Cell Type ◽  
Plasminogen Activator Inhibitor 1 ◽  
Vesicle Release ◽  
The Common ◽  
Activator Inhibitor

The literature on extracellular vesicles consists of rapidly expanding and often contradictory information. In this paper we attempt to review what is currently known regarding extracellular vesicles released specifically from human placental syncytiotrophoblast cells with a focus on the common but complex pregnancy-associated syndrome pre-eclampsia, where the level of syncytiotrophoblast extracellular vesicle release is significantly increased. We review common methods for syncytiotrophoblast extracellular vesicle derivation and isolation and we discuss the cargo of syncytiotrophoblast extracellular vesicles including proteins, RNA and lipids and their possible functions. A meta-analysis of available trophoblast-derived extracellular vesicle proteomic datasets revealed only three proteins in common: albumin, fibronectin-1 and plasminogen activator inhibitor-1, suggesting some variability in vesicle cargo, most likely reflecting stage and cell type of origin. We discuss the possible sources of variability that may have led to the low number of common markers, which has led us to speculate that markers and density in common use may not be strict criteria for identifying and isolating placenta-derived exosomes.

Dynamin-like proteins are essential for vesicle biogenesis in Mycobacterium tuberculosis

2020 ◽  
Author(s):  
Shamba Gupta ◽  
Ainhoa Palacios ◽  
Atul Khataokar ◽  
Brian Weinrick ◽  
Jose L. Lavín ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Extracellular Vesicles ◽  
Cell Envelope ◽  
Membrane Vesicle ◽  
Extracellular Vesicle ◽  
Dependent Manner ◽  
Surface Lipid ◽  
Cell Infection ◽  
Vesicle Release ◽  
Vesicle Biogenesis

ABSTRACTMycobacterium tuberculosis (Mtb) secretes pathogenicity factors and immunologically active molecules via membrane vesicles. However, nothing is known about the mechanisms involved in mycobacterial vesicle biogenesis. This study investigates molecular determinants of membrane vesicle production in Mtb by analyzing Mtb cells under conditions of high vesicle production: iron limitation and VirR restriction. Ultrastructural analysis showed extensive cell envelope restructuring in association with vesicle release that correlated with downregulation of cell surface lipid biosynthesis and peptidoglycan alterations. Comparative transcriptomics showed common upregulation of the iniBAC operon in association with high vesicle production in Mtb cells. Vesicle production analysis demonstrated that the dynamin-like proteins (DLPs) encoded by this operon, IniA and IniC, are necessary for release of EV by Mtb in culture and in infected macrophages. Isoniazid, a first-line antibiotic, used in tuberculosis treatment, was found to stimulate vesicle release in a DLP-dependent manner. Our results provide a new understanding of the function of mycobacterial DLPs and mechanistic insights into vesicle biogenesis. The findings will enable further understanding of the relevance of Mtb-derived extracellular vesicles in the pathogenesis of tuberculosis and may open new avenues for therapeutic research.IMPORTANCEIron is an essential nutrient that promotes survival and growth of M. tuberculosis, the bacterium that causes human tuberculosis (TB). Limited availability of iron, often encountered in the host environment, stimulates M. tuberculosis to secrete membrane-bound extracellular vesicles containing molecules that may help it evade the immune system. Characterizing the bacterial factors and mechanisms involved in the production of mycobacterial vesicles is important for envisioning ways to interfere with this process. Here, we report the discovery of proteins required by M. tuberculosis for vesicle biogenesis in culture and during host cell infection. We also demonstrate a connection between antibiotic response and extracellular vesicle production. The work provides insights into the mechanisms underlying vesicle biogenesis in M. tuberculosis and permits better understanding of the significance of vesicle production to M. tuberculosis-host interactions and antibiotic stress response.

scholarly journals Antibody Binding Alters the Characteristics and Contents of Extracellular Vesicles Released by Histoplasma capsulatum

mSphere ◽  
2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Ludmila Matos Baltazar ◽  
Ernesto S. Nakayasu ◽  
Tiago J. P. Sobreira ◽  
Hyungwon Choi ◽  
Arturo Casadevall ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Histoplasma Capsulatum ◽  
Extracellular Vesicle ◽  
Fungal Species ◽  
Antibody Binding ◽  
Common Pathway ◽  
Fungal Cell ◽  
Content Type ◽  
Protein Loading ◽  
The Impact

ABSTRACT Diverse fungal species release extracellular vesicles, indicating that this is a common pathway for the delivery of molecules to the extracellular space. However, there has been no study reporting the impact of antibody binding to the fungal cell on extracellular vesicle release. In the present work, we observed that treatment of H. capsulatum cells with Hsp60-binding MAbs significantly changed the size and cargo of extracellular vesicles, as well as the enzymatic activity of certain virulence factors, such as laccase and phosphatase. Furthermore, this finding demonstrates that antibody binding can directly impact protein loading in vesicles and fungal metabolism. Hence, this work presents a new role for antibodies in the modification of fungal physiology. Histoplasma capsulatum produces extracellular vesicles containing virulence-associated molecules capable of modulating host machinery, benefiting the pathogen. Treatment of H. capsulatum cells with monoclonal antibodies (MAbs) can change the outcome of infection in mice. We evaluated the sizes, enzymatic contents, and proteomic profiles of the vesicles released by fungal cells treated with either protective MAb 6B7 (IgG1) or nonprotective MAb 7B6 (IgG2b), both of which bind H. capsulatum heat shock protein 60 (Hsp60). Our results showed that treatment with either MAb was associated with changes in size and vesicle loading. MAb treatments reduced vesicle phosphatase and catalase activities compared to those of vesicles from untreated controls. We identified 1,125 proteins in vesicles, and 250 of these manifested differences in abundance relative to that of proteins in vesicles isolated from yeast cells exposed to Hsp60-binding MAbs, indicating that surface binding of fungal cells by MAbs modified protein loading in the vesicles. The abundance of upregulated proteins in vesicles upon MAb 7B6 treatment was 44.8% of the protein quantities in vesicles from fungal cells treated with MAb 6B7. Analysis of orthologous proteins previously identified in vesicles from other fungi showed that different ascomycete fungi have similar proteins in their extracellular milieu, many of which are associated with virulence. Our results demonstrate that antibody binding can modulate fungal cell responses, resulting in differential loading of vesicles, which could alter fungal cell susceptibility to host defenses. This finding provides additional evidence that antibody binding modulates microbial physiology and suggests a new function for specific immunoglobulins through alterations of fungal secretion. IMPORTANCE Diverse fungal species release extracellular vesicles, indicating that this is a common pathway for the delivery of molecules to the extracellular space. However, there has been no study reporting the impact of antibody binding to the fungal cell on extracellular vesicle release. In the present work, we observed that treatment of H. capsulatum cells with Hsp60-binding MAbs significantly changed the size and cargo of extracellular vesicles, as well as the enzymatic activity of certain virulence factors, such as laccase and phosphatase. Furthermore, this finding demonstrates that antibody binding can directly impact protein loading in vesicles and fungal metabolism. Hence, this work presents a new role for antibodies in the modification of fungal physiology.

scholarly journals Extracellular Vesicle-Mediated Communication between the Glioblastoma and Its Microenvironment

Cells ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 96 ◽  
Author(s):  
Esperanza R. Matarredona ◽  
Angel M. Pastor
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Progression ◽  
Extracellular Vesicles ◽  
Brain Cancer ◽  
Extracellular Vesicle ◽  
Soluble Proteins ◽  
Glioblastoma Cells ◽  
Mediated Communication ◽  
Non Coding Rnas ◽  
The Impact

The glioblastoma is the most malignant form of brain cancer. Glioblastoma cells use multiple ways of communication with the tumor microenvironment in order to tune it for their own benefit. Among these, extracellular vesicles have emerged as a focus of study in the last few years. Extracellular vesicles contain soluble proteins, DNA, mRNA and non-coding RNAs with which they can modulate the phenotypes of recipient cells. In this review we summarize recent findings on the extracellular vesicles-mediated bilateral communication established between glioblastoma cells and their tumor microenvironment, and the impact of this dialogue for tumor progression and recurrence.

Study of NSCLC cell migration promoted by NSCLC-Derived Extracellular Vesicle using atomic force microscopy

2021 ◽  
Author(s):  
Shuwei Wang ◽  
Jiajia Wang ◽  
Tuoyu Ju ◽  
Kaige Qu ◽  
Fan Yang ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Cell Migration ◽  
Cancer Cells ◽  
Extracellular Vesicles ◽  
Extracellular Vesicle ◽  
Cancer Microenvironment ◽  
Biological Processes ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cellular Components

Extracellular Vesicles (EVs) secreted by cancer cells have a key role in the cancer microenvironment and progression. Previous studies have mainly focused on molecular functions, cellular components and biological processes...

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