Exosomes and communication between tumours and the immune system: are all exosomes equal?

2013 ◽  
Vol 41 (1) ◽  
pp. 263-267 ◽  
Author(s):  
Angélique Bobrie ◽  
Clotilde Théry
Keyword(s):  
Immune System ◽  
Tumour Progression ◽  
Membrane Vesicles ◽  
Complex Structures ◽  
Soluble Factors ◽  
Extracellular Secretion ◽  
Direct Cell ◽  
Secretion Of Mediators

Communication between cells is particularly important during tumour progression. Communication can take place through direct cell–cell interactions, but also through extracellular secretion of mediators acting at a distance. These mediators can be either soluble molecules or more complex structures called membrane vesicles, enclosing soluble factors within a lipid bilayer. A variety of extracellular membrane vesicles have been described, for instance microvesicles, ectosomes and a subtype called exosomes. The role of exosomes in tumour progression has been studied extensively in the last 10 years. In the present mini-review, we discuss our recent results, first showing the heterogeneity of the vesicles called exosomes and the probable existence of subpopulations of these exosomes, and secondly demonstrating that in vivo secretion of exosomes by some tumours can promote tumour progression, but that such a function cannot be generalized to all tumours and all exosomes.

scholarly journals Immunity to pathogenic free-living amoebae: role of cell-mediated immunity

1980 ◽  
Vol 29 (2) ◽  
pp. 408-410
Author(s):  
R T Cursons ◽  
T J Brown ◽  
E A Keys ◽  
K M Moriarty ◽  
D Till
Keyword(s):  
Immune System ◽  
Inhibition Test ◽  
Delayed Hypersensitivity ◽  
Cell Mediated Immunity ◽  
Pathogenic Species ◽  
Free Living

The role of cell-mediated immunity in defense against pathogenic free-living amoebae was examined. Both the in vitro macrophage inhibition test and the in vivo delayed hypersensitivity test showed responses to both heterologous and homologous antigens, although homologous systems were the most efficient. It is suggested that exposure to nonpathogenic species of free-living amoebae can stimulate the immune system to be effective against pathogenic species. The significance of cell-mediated immunity as a defense against invasion by pathogenic free-living amoebae is discussed.

scholarly journals Thymosin alpha 1 mitigates cytokine storm in blood cells from COVID-19 patients

2020 ◽  
Author(s):  
Claudia Matteucci ◽  
Antonella Minutolo ◽  
Emanuela Balestrieri ◽  
Vita Petrone ◽  
Marialaura Fanelli ◽  
...  
Keyword(s):  
Immune System ◽  
Blood Cells ◽  
Ex Vivo ◽  
Cell Subset ◽  
Adverse Outcomes ◽  
Cytokine Signaling ◽  
Cytokine Storm ◽  
Thymosin Alpha 1

Abstract COVID-19 is characterized by immune-mediated lung injury and complex alterations of the immune system, such as lymphopenia and cytokine storm, that have been associated with adverse outcomes underlining a fundamental role of host response in SARS-CoV-2 infection and the pathogenesis of the disease. Thymosin alpha 1 (Tα1) is one of the molecules used in the management of COVID-19, since it is known to restore the homeostasis of the immune system during infections and cancer. Here we captured the interconnected biological processes regulated by Tα1 in CD8+ T cells under inflammatory conditions. Genes associated with cytokine signaling and production were found up-regulated in blood cells from COVID-19 patients and the ex-vivo treatment with Tα1 mitigated cytokines expression and inhibited lymphocytes activation in CD8+ T cell subset specifically, suggesting the potential role of Tα1 in modulating the immune response homeostasis and the cytokine storm in vivo.

Influence of vascular and luminal hexoses on rat intestinal basolateral glucose transport

1994 ◽  
Vol 72 (4) ◽  
pp. 317-326 ◽  
Author(s):  
Raymond Tsang ◽  
Ziliang Ao ◽  
Chris Cheeseman
Keyword(s):  
Glucose Transport ◽  
Plasma Glucose ◽  
Intestinal Adaptation ◽  
Basolateral Membrane ◽  
Physiological Role ◽  
Intestinal Transport ◽  
Membrane Vesicles ◽  
Luminal Perfusion

The influence of luminal and vascular hexoses in rats on glucose transport across the jejunal basolateral membrane (BLM) was measured using isolated membrane vesicles prepared from infused animals. In vivo vascular infusions of glucose produced an increase in glucose transport across BLM vesicles. Sucrose, mannose, galactose, and fructose had no significant effect. Plasma glucose concentrations were unaffected by galactose and sucrose vascular infusions, while mannose and fructose produced a modest rise, and glucose increased plasma glucose to 20 mM. Insulin release was significantly increased by vascular infusion of glucose and fructose, while mannose produced only a small sustained rise. Sucrose and galactose had no effect. Perfusion through the lumen of the rat jejunum in vivo, for up to 4 h, with glucose, fructose, sucrose, or lactate (100 or 25 mM) produced a significant increase in the maximal rate of glucose transport (up to 4- to 5-fold) across BLMs. Galactose and mannose had no effect. Luminal glucose perfusion produced a small nonsignificant increase in glucose inhibitable cytochalasin B binding to BLM vesicles, and no change was seen in the microsomal pool of binding sites. The abundance of GLUT2 in the jejunal BLM, as determined by Western blotting, was unaffected by luminal perfusion of 100 mM glucose for 4 h. Fructose almost completely inhibited the carrier-mediated uptake of glucose in control and upregulated jejunal BLM vesicles. These results are discussed in relation to the physiological role of the upregulation of GLUT2 activity by luminal and vascular hexoses.Key words: intestinal transport, basolateral membrane, glucose transport, intestinal adaptation.

scholarly journals The antimicrobial peptide Defensin cooperates with Tumour Necrosis Factor to drive tumour cell death in Drosophila

2019 ◽  
Author(s):  
Jean-Philippe Parvy ◽  
Yachuan Yu ◽  
Anna Dostalova ◽  
Shu Kondo ◽  
Alina Kurjan ◽  
...  
Keyword(s):  
Cell Death ◽  
Tumour Necrosis Factor ◽  
Tumour Cell ◽  
Tumour Necrosis ◽  
Tumour Progression ◽  
Tumour Cells ◽  
Tumour Regression ◽  
Necrosis Factor

AbstractAntimicrobial peptides (AMPs) are small cationic molecules best known as mediators of the innate defence against microbial infection. While in vitro and ex vivo evidence suggest AMPs’ capacity to kill cancer cells, in vivo demonstration of an anti-tumour role of endogenous AMPs is lacking. Using a Drosophila model of tumourigenesis, we demonstrate a role for the AMP Defensin in the control of tumour progression. Our results reveal that Tumour Necrosis Factor mediates exposure of phosphatidylserine (PS), which makes tumour cells selectively sensitive to the action of Defensin remotely secreted from tracheal and fat tissues. Defensin binds tumour cells in PS-enriched areas, provoking cell death and tumour regression. Altogether, our results provide the first in vivo demonstration for a role of an endogenous AMP as an anti-cancer agent, as well as a mechanism that explains tumour cell sensitivity to the action of AMPs.

scholarly journals Immunomodulatory Effects of Adipose-Derived Stem Cells: Fact or Fiction?

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Angelo A. Leto Barone ◽  
Saami Khalifian ◽  
W. P. Andrew Lee ◽  
Gerald Brandacher
Keyword(s):  
Stem Cells ◽  
Immune Response ◽  
Clinical Trials ◽  
Immune System ◽  
Solid Organ ◽  
Adipose Derived Stem Cells ◽  
Adipose Derived Stromal Cells

Adipose-derived stromal cells (ASCs) are often referred to as adipose-derived stem cells due to their potential to undergo multilineage differentiation. Their promising role in tissue engineering and ability to modulate the immune system are the focus of extensive research. A number of clinical trials using ASCs are currently underway to better understand the role of such cell niche in enhancing or suppressing the immune response. If governable, such immunoregulatory role would find application in several conditions in which an immune response is present (i.e., autoimmune conditions) or feared (i.e., solid organ or reconstructive transplantation). Although allogeneic ASCs have been shown to prevent acute GvHD in both preclinical and clinical studies, their potential warrants further investigation. Well-designed and standardized clinical trials are necessary to prove the role of ASCs in the treatment of immune disorders or prevention of tissue rejection. In this paper we analyze the current literature on the role of ASCs in immunomodulationin vitroandin vivoand discuss their potential in regulating the immune system in the context of transplantation.

scholarly journals Interaction of Bacillus subtilis CsaA with SecA and precursor proteins

2000 ◽  
Vol 348 (2) ◽  
pp. 367-373 ◽  
Author(s):  
Jörg P. MÜLLER ◽  
Jörg OZEGOWSKI ◽  
Stefan VETTERMANN ◽  
Jelto SWAVING ◽  
Karel H. M. VAN WELY ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Specific Interaction ◽  
Membrane Vesicles ◽  
Protein Export ◽  
E Coli ◽  
Bacterium Bacillus Subtilis ◽  
Bacterium Bacillus

CsaA from the Gram-positive bacterium Bacillus subtilis has been identified previously as a suppressor of the growth and protein-export defect of Escherichia coli secA(Ts) mutants. CsaA has chaperone-like activities in vivo and in vitro. To examine the role of CsaA in protein export in B. subtilis, expression of the csaA gene was repressed. While export of most proteins remained unaffected, export of at least two proteins was significantly reduced upon CsaA depletion. CsaA co-immunoprecipitates and co-purifies with the SecA proteins of E. coli and B. subtilis, and binds the B. subtilis preprotein prePhoB. Purified CsaA stimulates the translocation of prePhoB into E. coli membrane vesicles bearing the B. subtilis translocase, whereas it interferes with the SecB-mediated translocation of proOmpA into membrane vesicles of E. coli. The specific interaction with the SecA translocation ATPase and preproteins suggests that CsaA acts as a chaperone that promotes the export of a subset of preproteins in B. subtilis.

scholarly journals Role of Proteolysis in Determining Potency ofBacillus thuringiensis Cry1Ac δ-Endotoxin

2000 ◽  
Vol 66 (12) ◽  
pp. 5174-5181 ◽  
Author(s):  
Daniel J. Lightwood ◽  
David J. Ellar ◽  
Paul Jarrett
Keyword(s):  
Membrane Vesicles ◽  
Apparent Molecular Weight ◽  
Pieris Brassicae ◽  
Proteolytic Processing ◽  
Mamestra Brassicae ◽  
Ofbacillus Thuringiensis ◽  
Domain I

ABSTRACT Bacillus thuringiensis protein δ-endotoxins are toxic to a variety of different insect species. Larvicidal potency depends on the completion of a number of steps in the mode of action of the toxin. Here, we investigated the role of proteolytic processing in determining the potency of the B. thuringiensis Cry1Ac δ-endotoxin towards Pieris brassicae (family: Pieridae) andMamestra brassicae (family: Noctuidae). In bioassays, Cry1Ac was over 2,000 times more active against P. brassicae than against M. brassicae larvae. Using gut juice purified from both insects, we processed Cry1Ac to soluble forms that had the same N terminus and the same apparent molecular weight. However, extended proteolysis of Cry1Ac in vitro with proteases from both insects resulted in the formation of an insoluble aggregate. With proteases from P. brassicae, the Cry1Ac-susceptible insect, Cry1Ac was processed to an insoluble product with a molecular mass of ∼56 kDa, whereas proteases from M. brassicae, the non-susceptible insect, generated products with molecular masses of ∼58, ∼40, and ∼20 kDa. N-terminal sequencing of the insoluble products revealed that both insects cleaved Cry1Ac within domain I, butM. brassicae proteases also cleaved the toxin at Arg423 in domain II. A similar pattern of processing was observed in vivo. When Arg423 was replaced with Gln or Ser, the resulting mutant toxins resisted degradation by M. brassicae proteases. However, this mutation had little effect on toxicity to M. brassicae. Differential processing of membrane-bound Cry1Ac was also observed in qualitative binding experiments performed with brush border membrane vesicles from the two insects and in midguts isolated from toxin-treated insects.

scholarly journals PIDDosome Expression and the Role of Caspase-2 Activation for Chemotherapy-Induced Apoptosis in RCCs

2010 ◽  
Vol 32 (1-2) ◽  
pp. 29-42
Author(s):  
Sebastian Heikaus ◽  
Igor Pejin ◽  
Helmut Erich Gabbert ◽  
Uwe Ramp ◽  
Csaba Mahotka
Keyword(s):  
Tumour Progression ◽  
Chemotherapy Resistance ◽  
Clear Cell Type ◽  
Alternatively Spliced ◽  
Caspase 2 ◽  
Induced Apoptosis ◽  
Few Data

Background: The importance of caspase-2 activation for mediating apoptosis in cancer is not clear and seems to differ between different tumour types. Furthermore, only few data have been obtained concerning the expression of caspase-2, which can be alternatively spliced into caspase-2L and caspase-2S, and the other PIDDosome members PIDD and RAIDD in human tumours in vivo. We, therefore, investigated their expression in renal cell carcinomas (RCCs) of the clear cell type in vivo and analysed the role of caspase-2 in chemotherapy-induced apoptosis in RCCs in vitro.Methods: The analyses were performed by semiquantitative real-time PCR, Western Blot and Caspase-2 Assay.Results: Our in vivo results showed an overall decrease in proapoptotic caspase-2L expression during tumour progression due to an increase in the relative share of caspase-2S mRNA in total caspase-2 mRNA expression. Furthermore, an increase in the expression of PIDD and RAIDD could be observed. In contrast, antiapoptotic BCL-2 expression increased only during early tumour stages, whereas expression decreased in pT3 RCCs. In vitro, caspase-2 activation in RCC cell lines coincidenced with sensitivity of tumour cells towards Topotecan-induced apoptosis. However, inhibition of caspase-2 could not prevent Topotecan-induced apoptosis. Interestingly, Topotecan-resistance could be overcome by the apoptosis-sensitizing drug HA14-1.Conclusions: Our study confirms the concept of a shift towards a more antiapoptotic transcriptional context during tumour progression in RCCs. Furthermore, it shows that caspase-2 participates in chemotherapy-induced apoptosis in RCCs although it is not mandatory for it. Additionally, inhibition of antiapoptotic BCL-2 family members might provide a possible way to overcome chemotherapy resistance of RCCs.

scholarly journals Functional Role of AKNA: A Scoping Review

Biomolecules ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1709
Author(s):  
Abrahán Ramírez-González ◽  
Joaquín Manzo-Merino ◽  
Carla Olbia Contreras-Ochoa ◽  
Margarita Bahena-Román ◽  
José Manasés Aguilar-Villaseñor ◽  
...  
Keyword(s):  
Immune System ◽  
Scoping Review ◽  
Functional Role ◽  
Inflammatory Diseases ◽  
Data Extraction ◽  
Negative Regulator ◽  
Cellular Processes

Human akna encodes an AT-hook transcription factor whose expression participates in various cellular processes. We conducted a scoping review on the literature regarding the functional role of AKNA according to the evidence found in human and in vivo and in vitro models, stringently following the “PRISMA-ScR” statement recommendations. Methods: We undertook an independent PubMed literature search using the following search terms, AKNA OR AKNA ADJ gene OR AKNA protein, human OR AKNA ADJ functions. Observational and experimental articles were considered. The selected studies were categorized using a pre-determined data extraction form. A narrative summary of the evidence was produced. Results: AKNA modulates the expression of CD40 and CD40L genes in immune system cells. It is a negative regulator of inflammatory processes as evidenced by knockout mouse models and observational studies for several autoimmune and inflammatory diseases. Furthermore, AKNA contributes to the de-regulation of the immune system in cancer, and it has been proposed as a susceptibility genetic factor and biomarker in CC, GC, and HNSCC. Finally, AKNA regulates neurogenesis by destabilizing the microtubules dynamics. Conclusion: Our results provide evidence for the role of AKNA in various cellular processes, including immune response, inflammation, development, cancer, autoimmunity, and neurogenesis.

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