scholarly journals Antigen B from Echinococcus granulosus enters mammalian cells by endocytic pathways

2017 ◽  
Author(s):  
Edileuza Danieli da Silva ◽  
Martin Cancela ◽  
Karina Mariante Monteiro ◽  
Henrique Bunselmeyer Ferreira ◽  
Arnaldo Zaha
Keyword(s):  
Hydatid Cyst ◽  
Echinococcus Granulosus ◽  
Mammalian Cells ◽  
A549 Cells ◽  
Cell Types ◽  
Parasite Development ◽  
Cellular Internalization ◽  
Cystic Hydatid Disease ◽  
Hydatid Fluid ◽  
Antigen B

AbstractCystic hydatid disease is a zoonosis caused by the larval stage (hydatid cyst) of Echinococcus granulosus (Cestoda, Taeniidae). The hydatid cyst develops in the viscera of intermediate host as a unilocular structure filled by the hydatid fluid, which contains parasitic excretory/secretory products. Antigen B (AgB) is the major component of E. granulosus metacestode hydatid fluid. Functionally, AgB has been implicated in immunomodulation and lipid transport. However, the mechanisms underlying AgB functions are not completely known. In this study, we investigated AgB interactions with different mammalian cell types and the pathways involved in its internalization. AgB uptake was observed in four different cell lines, NIH-3T3, A549, J774 and RH. Inhibition of raft-mediated endocytosis causes about 50 and 69% decrease in AgB internalization by RH and A549 cells, respectively. Interestingly, AgB colocalized with the raft endocytic marker, but also showed a partial colocalization with the clathrin endocytic marker. The results indicate that raft-mediated endocytosis is the main route to AgB internalization, and that a clathrin-mediated entry may also occur at a lower frequency. Cellular internalization could be a requirement for AgB functions as a lipid carrier and/or immunomodulatory molecule, contributing to create a more permissive microenvironment to metacestode development and survival.Author summaryAntigen B (AgB) is an oligomeric lipoprotein highly abundant in Echinococcus granulosus hydatid fluid. AgB has already been characterized as an immunomodulatory protein, capable of inducing a permissive immune response to parasite development. Also, an important role in lipid acquisition is attributed to AgB, because it has been found associated to different classes of host lipids. However, the mechanisms of interaction employed by AgB to perform its functions remain undetermined. In this study, we demonstrate that mammalian cells are able to internalize E. granulosus AgB in culture and found that specific mechanisms of endocytosis are involved. Our results extend the understanding of AgB biological role indicating cellular internalization as a mechanism of interaction, which in turn, may represent a target to intervention.

Ultrastructural immunocytochemical localization of two hydatid fluid antigens (antigen 5 and antigen B) in the brood capsules and protoscoleces of ovine and equine Echinococcus granulosus and E. multilocularis

Parasitology ◽  
1978 ◽  
Vol 77 (2) ◽  
pp. 143-152 ◽  
Author(s):  
Caroline Davies ◽  
M. D. Rickard ◽  
D. T. Bout ◽  
J. P. Smyth
Keyword(s):  
Echinococcus Granulosus ◽  
Periodic Acid ◽  
Ultrastructural Localization ◽  
Capsule Wall ◽  
Periodic Acid Schiff ◽  
Hydatid Fluid ◽  
Antigen B ◽  
Parenchyma Cells ◽  
Perinuclear Cytoplasm ◽  
Antigen 5

SummaryThe unlabelled antibody method was used in the ultrastructural localization of two hydatid fluid antigens, antigen 5 and antigen B, in brood capsules and protoscoleces of Echinococcus granulosus and E. multilocularis. Antigen 5 was found in the parenchyma cells of the protoscolex and brood capsule wall and to a lesser extent in the walls of the flame cells and collecting ducts of the excretory system and in the surrounding interstitial material. It is suggested that, while some excretion of this antigen may occur from the protoscolex, it could also be liberated into the cystic cavity by degeneration of protoscoleces and parenchymal cells of the brood capsule wall. Antigen B was found mainly in the distal cytoplasm and perinuclear cytoplasm of the tegument anterior to the suckers. It is apparently secreted to the outside and was present in the brood capsule contents; it adheres to the anterior surface and the posterior periodic acid–Schiff (PAS)-positive glycocalyx of the protoscolex and to the inner surface of the brood capsule wall. The protoscolex tegument posterior to the suckers was negative. The parenchyma cells of the protoscolex and brood capsule wall were also positive although the intensity of the reaction product was variable.

scholarly journals Attempt of Experimental Transmission of Hydatid Infection from Human to Dogs

2011 ◽  
Vol 35 (2) ◽  
pp. 11-13
Author(s):  
Amall Hassen Atia
Keyword(s):  
Chemical Composition ◽  
Hydatid Cyst ◽  
Echinococcus Granulosus ◽  
Experimental Infection ◽  
Human Origin ◽  
Intermediate Hosts ◽  
Experimental Transmission ◽  
Transmission Cycle ◽  
Hydatid Fluid

An experimental infection of 3 dogs with protoscoleces of human origin were carried out Hydatid cyst was surgical removed from 26 years old female. On autopsy all dogs were found not harbor any Echinococcus granulosus worms Infection with the metacestode stage in unusual intermediate hosts failure for procreation which do not play a role in the transmission cycle in Iraq. In conclusions: the reason could be related between the host and chemical composition of hydatid fluid failure of induces infection

scholarly journals Antigen B from Echinococcus granulosus enters mammalian cells by endocytic pathways

2018 ◽  
Vol 12 (5) ◽  
pp. e0006473 ◽  
Author(s):  
Edileuza Danieli da Silva ◽  
Martin Cancela ◽  
Karina Mariante Monteiro ◽  
Henrique Bunselmeyer Ferreira ◽  
Arnaldo Zaha
Keyword(s):  
Echinococcus Granulosus ◽  
Mammalian Cells ◽  
Antigen B ◽  
Endocytic Pathways

Ultrastructural Changes in Three Different Mammalian Cells Following Ultraviolet Laser Irradiation

1972 ◽  
Vol 30 ◽  
pp. 350-351
Author(s):  
K. Shankar Narayan ◽  
Kailash C. Gupta ◽  
Tohru Okigaki
Keyword(s):  
Ultraviolet Light ◽  
Mammalian Cells ◽  
Biological Effects ◽  
Survival Rates ◽  
Chinese Hamster ◽  
Cell Types ◽  
Differential Sensitivity ◽  
Ultrastructural Changes ◽  
Ultraviolet Laser

The biological effects of short-wave ultraviolet light has generally been described in terms of changes in cell growth or survival rates and production of chromosomal aberrations. Ultrastructural changes following exposure of cells to ultraviolet light, particularly at 265 nm, have not been reported.We have developed a means of irradiating populations of cells grown in vitro to a monochromatic ultraviolet laser beam at a wavelength of 265 nm based on the method of Johnson. The cell types studies were: i) WI-38, a human diploid fibroblast; ii) CMP, a human adenocarcinoma cell line; and iii) Don C-II, a Chinese hamster fibroblast cell strain. The cells were exposed either in situ or in suspension to the ultraviolet laser (UVL) beam. Irradiated cell populations were studied either "immediately" or following growth for 1-8 days after irradiation.Differential sensitivity, as measured by survival rates were observed in the three cell types studied. Pattern of ultrastructural changes were also different in the three cell types.

scholarly journals Human Immunodeficiency Viruses Pseudotyped with SARS-CoV-2 Spike Proteins Infect a Broad Spectrum of Human Cell Lines through Multiple Entry Mechanisms

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 953
Author(s):  
Chuan Xu ◽  
Annie Wang ◽  
Ke Geng ◽  
William Honnen ◽  
Xuening Wang ◽  
...  
Keyword(s):  
Cell Lines ◽  
Viral Entry ◽  
Broad Spectrum ◽  
A549 Cells ◽  
Cell Types ◽  
Pseudotyped Virus ◽  
Angiotensin Converting Enzyme 2 ◽  
Human Immunodeficiency Viruses ◽  
Tyrosine Protein Kinase ◽  
Overexpressing Cell

Severe acute respiratory syndrome-related coronavirus (SARS-CoV-2), the causative agent of coronavirus disease 19 (COVID-19), enters cells through attachment to the human angiotensin converting enzyme 2 (hACE2) via the receptor-binding domain (RBD) in the surface/spike (S) protein. Several pseudotyped viruses expressing SARS-CoV-2 S proteins are available, but many of these can only infect hACE2-overexpressing cell lines. Here, we report the use of a simple, two-plasmid, pseudotyped virus system comprising a SARS-CoV-2 spike-expressing plasmid and an HIV vector with or without vpr to investigate the SARS-CoV-2 entry event in various cell lines. When an HIV vector without vpr was used, pseudotyped SARS-CoV-2 viruses produced in the presence of fetal bovine serum (FBS) were able to infect only engineered hACE2-overexpressing cell lines, whereas viruses produced under serum-free conditions were able to infect a broader range of cells, including cells without hACE2 overexpression. When an HIV vector containing vpr was used, pseudotyped viruses were able to infect a broad spectrum of cell types regardless of whether viruses were produced in the presence or absence of FBS. Infection sensitivities of various cell types did not correlate with mRNA abundance of hACE2, TMPRSS2, or TMPRSS4. Pseudotyped SARS-CoV-2 viruses and replication-competent SARS-CoV-2 virus were equally sensitive to neutralization by an anti-spike RBD antibody in cells with high abundance of hACE2. However, the anti-spike RBD antibody did not block pseudotyped viral entry into cell lines with low abundance of hACE2. We further found that CD147 was involved in viral entry in A549 cells with low abundance of hACE2. Thus, our assay is useful for drug and antibody screening as well as for investigating cellular receptors, including hACE2, CD147, and tyrosine-protein kinase receptor UFO (AXL), for the SARS-CoV-2 entry event in various cell lines.

scholarly journals Echinococcus granulosus Antigen B binds to monocytes and macrophages modulating cell response to inflammation

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Valeria Silva-Álvarez ◽  
Ana Maite Folle ◽  
Ana Lía Ramos ◽  
Eduardo S. Kitano ◽  
Leo K. Iwai ◽  
...  
Keyword(s):  
Echinococcus Granulosus ◽  
Cell Response ◽  
Antigen B ◽  
Monocytes And Macrophages

Green chemical synthesis of gold nanoparticles by using Penicillium aculeatum and their scolicidal activity against hydatid cyst protoscolices of Echinococcus granulosus

2017 ◽  
Vol 24 (6) ◽  
pp. 5800-5810 ◽  
Author(s):  
Hamed Barabadi ◽  
Soheila Honary ◽  
Milad Ali Mohammadi ◽  
Ehsan Ahmadpour ◽  
Mohammad Taghi Rahimi ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Chemical Synthesis ◽  
Hydatid Cyst ◽  
Echinococcus Granulosus ◽  
Green Chemical Synthesis

Recombinant subunits as tools for the structural and functional characterization of Echinococcus granulosus antigen B

2008 ◽  
Vol 119 (4) ◽  
pp. 490-498 ◽  
Author(s):  
Karina M. Monteiro ◽  
Arnaldo Zaha ◽  
Henrique B. Ferreira
Keyword(s):  
Echinococcus Granulosus ◽  
Functional Characterization ◽  
Antigen B

scholarly journals EEA1, a Tethering Protein of the Early Sorting Endosome, Shows a Polarized Distribution in Hippocampal Neurons, Epithelial Cells, and Fibroblasts

2000 ◽  
Vol 11 (8) ◽  
pp. 2657-2671 ◽  
Author(s):  
Jean M. Wilson ◽  
Meltsje de Hoop ◽  
Natasha Zorzi ◽  
Ban-Hock Toh ◽  
Carlos G. Dotti ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Mammalian Cells ◽  
Hippocampal Neurons ◽  
Cell Types ◽  
Early Endosomes ◽  
Filamentous Material ◽  
Endocytic Vesicles ◽  
Fibroblastic Cells ◽  
Darby Canine Kidney ◽  
Endocytic Pathways

EEA1 is an early endosomal Rab5 effector protein that has been implicated in the docking of incoming endocytic vesicles before fusion with early endosomes. Because of the presence of complex endosomal pathways in polarized and nonpolarized cells, we have examined the distribution of EEA1 in diverse cell types. Ultrastructural analysis demonstrates that EEA1 is present on a subdomain of the early sorting endosome but not on clathrin-coated vesicles, consistent with a role in providing directionality to early endosomal fusion. Furthermore, EEA1 is associated with filamentous material that extends from the cytoplasmic surface of the endosomal domain, which is also consistent with a tethering/docking role for EEA1. In polarized cells (Madin-Darby canine kidney cells and hippocampal neurons), EEA1 is present on a subset of “basolateral-type” endosomal compartments, suggesting that EEA1 regulates specific endocytic pathways. In both epithelial cells and fibroblastic cells, EEA1 and a transfected apical endosomal marker, endotubin, label distinct endosomal populations. Hence, there are at least two distinct sets of early endosomes in polarized and nonpolarized mammalian cells. EEA1 could provide specificity and directionality to fusion events occurring in a subset of these endosomes in polarized and nonpolarized cells.

scholarly journals Annexin A2 Mediates Mycoplasma pneumoniae Community-Acquired Respiratory Distress Syndrome Toxin Binding to Eukaryotic Cells

mBio ◽  
2014 ◽  
Vol 5 (4) ◽  
Author(s):  
Sudha R. Somarajan ◽  
Fadi Al-Asadi ◽  
Kumaraguruparan Ramasamy ◽  
Lavanya Pandranki ◽  
Joel B. Baseman ◽  
...  
Keyword(s):  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Mammalian Cells ◽  
Distress Syndrome ◽  
Protein A ◽  
A549 Cells ◽  
Surfactant Protein ◽  
Annexin A2 ◽  
Toxin Binding ◽  
Cards Toxin

ABSTRACT Mycoplasma pneumoniae synthesizes a novel human surfactant protein A (SP-A)-binding cytotoxin, designated community-acquired respiratory distress syndrome (CARDS) toxin, that exhibits ADP-ribosylating and vacuolating activities in mammalian cells and is directly linked to a range of acute and chronic airway diseases, including asthma. In our attempt to detect additional CARDS toxin-binding proteins, we subjected the membrane fraction of human A549 airway cells to affinity chromatography using recombinant CARDS toxin as bait. A 36-kDa A549 cell membrane protein bound to CARDS toxin and was identified by time of flight (TOF) mass spectroscopy as annexin A2 (AnxA2) and verified by immunoblotting with anti-AnxA2 monoclonal antibody. Dose-dependent binding of CARDS toxin to recombinant AnxA2 reinforced the specificity of the interaction, and further studies revealed that the carboxy terminus of CARDS toxin mediated binding to AnxA2. In addition, pretreatment of viable A549 cells with anti-AnxA2 monoclonal antibody or AnxA2 small interfering RNA (siRNA) reduced toxin binding and internalization. Immunofluorescence analysis of CARDS toxin-treated A549 cells demonstrated the colocalization of CARDS toxin with cell surface-associated AnxA2 upon initial binding and with intracellular AnxA2 following toxin internalization. HepG2 cells, which express low levels of AnxA2, were transfected with a plasmid expressing AnxA2 protein, resulting in enhanced binding of CARDS toxin and increased vacuolization. In addition, NCI-H441 cells, which express both AnxA2 and SP-A, upon AnxA2 siRNA transfection, showed decreased binding and subsequent vacuolization. These results indicate that CARDS toxin recognizes AnxA2 as a functional receptor, leading to CARDS toxin-induced changes in mammalian cells. IMPORTANCE Host cell susceptibility to bacterial toxins is usually determined by the presence and abundance of appropriate receptors, which provides a molecular basis for toxin target cell specificities. To perform its ADP-ribosylating and vacuolating activities, community-acquired respiratory distress syndrome (CARDS) toxin must bind to host cell surfaces via receptor-mediated events in order to be internalized and trafficked effectively. Earlier, we reported the binding of CARDS toxin to surfactant protein A (SP-A), and here we show how CARDS toxin uses an alternative receptor to execute its pathogenic properties. CARDS toxin binds selectively to annexin A2 (AnxA2), which exists both on the cell surface and intracellularly. Since AnxA2 regulates membrane dynamics at early stages of endocytosis and trafficking, it serves as a distinct receptor for CARDS toxin binding and internalization and enhances CARDS toxin-induced vacuolization in mammalian cells.

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