29. In vivo and in vitro effects of epsilon toxin mutants from Clostridium perfringens

Toxicon ◽  
2014 ◽  
Vol 91 ◽  
pp. 176
Author(s):  
J. Dorca-Arévalo ◽  
L. Díaz ◽  
M. Martín-Satué ◽  
J. Blasi
Keyword(s):  
Clostridium Perfringens ◽  
Epsilon Toxin ◽  
In Vitro Effects

scholarly journals A Novel Panel of Rabbit Monoclonal Antibodies and Their Diverse Applications Including Inhibition of Clostridium perfringens Epsilon Toxin Oligomerization

Antibodies ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 37 ◽  
Author(s):  
Jennifer Linden ◽  
Kiel Telesford ◽  
Samantha Shetty ◽  
Paige Winokour ◽  
Sylvia Haigh ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Death ◽  
Monoclonal Antibodies ◽  
Western Blot ◽  
Clostridium Perfringens ◽  
Specificity And Sensitivity ◽  
Epsilon Toxin ◽  
Blocking Antibodies

The pore-forming epsilon toxin (ETX) produced by Clostridium perfringens is among the most lethal bacterial toxins known. Sensitive antibody-based reagents are needed to detect toxin, distinguish mechanisms of cell death, and prevent ETX toxicity. Using B-cell immuno-panning and cloning techniques, seven ETX-specific monoclonal antibodies were generated from immunized rabbits. ETX specificity and sensitivity were evaluated via western blot, ELISA, immunocytochemistry (ICC), and flow cytometry. ETX-neutralizing function was evaluated both in vitro and in vivo. All antibodies recognized both purified ETX and epsilon protoxin via western blot with two capable of detecting the ETX-oligomer complex. Four antibodies detected ETX via ELISA and three detected ETX bound to cells via ICC or flow cytometry. Several antibodies prevented ETX-induced cell death by either preventing ETX binding or by blocking ETX oligomerization. Antibodies that blocked ETX oligomerization inhibited ETX endocytosis and cellular vacuolation. Importantly, one of the oligomerization-blocking antibodies was able to protect against ETX-induced death post-ETX exposure in vitro and in vivo. Here we describe the production of a panel of rabbit monoclonal anti-ETX antibodies and their use in various biological assays. Antibodies possessing differential specificity to ETX in particular conformations will aid in the mechanistic studies of ETX cytotoxicity, while those with ETX-neutralizing function may be useful in preventing ETX-mediated mortality.

scholarly journals Correlation between In Vitro Cytotoxicity and In Vivo Lethal Activity in Mice of Epsilon Toxin Mutants from Clostridium perfringens

PLoS ONE ◽  
2014 ◽  
Vol 9 (7) ◽  
pp. e102417 ◽  
Author(s):  
Jonatan Dorca-Arévalo ◽  
Serge Pauillac ◽  
Laura Díaz-Hidalgo ◽  
Mireia Martín-Satué ◽  
Michel R. Popoff ◽  
...  
Keyword(s):  
Clostridium Perfringens ◽  
In Vitro Cytotoxicity ◽  
Epsilon Toxin

scholarly journals In vitro potency test for evaluation of Clostridium perfringens type D epsilon toxoid

2013 ◽  
Vol 80 (4) ◽  
pp. 450-452 ◽  
Author(s):  
Felipe Masiero Salvarini ◽  
Zelia Ines Portela Lobato ◽  
Prhiscylla Sadana Pires ◽  
Rodrigo Otavio Silveira Silva ◽  
Guilherme Guerra Alves ◽  
...  
Keyword(s):  
Clostridium Perfringens ◽  
Neutralizing Antibodies ◽  
Mdck Cells ◽  
In Vitro Test ◽  
Type D ◽  
Epsilon Toxin ◽  
Vitro Test ◽  
Darby Canine Kidney

The control of enterotoxemia caused by the epsilon toxin, produced by Clostridium perfringens type D, is based on vaccination with epsilon toxoid. The potency test for this immunogen is conducted using seroneutralization in mice. Here, an in vitro test for detection of neutralizing antibodies with Madin-Darby Canine Kidney (MDCK) cells was standardized in order to study alternative methodologies for the potency test. Titers observed in the in vivo and in vitro seroneutralization tests had a correlation of 99.73%.

Anti-obesity role of Aster glehni extract: in vivo and in vitro effects

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
HM Lee ◽  
TG Ahn ◽  
CW Kim ◽  
HJ An
Keyword(s):  
In Vitro Effects

Comparison of Specific Antibody, D-Phe-Pro-Arg-CH2Cl and Aprotinin for Prevention of In Vitro Effects of Recombinant Tissue-Type Plasminogen Activator on Haemostasis Parameters

1987 ◽  
Vol 58 (03) ◽  
pp. 921-926 ◽  
Author(s):  
E Seifried ◽  
P Tanswell
Keyword(s):  
Specific Antibody ◽  
Plasma Concentrations ◽  
Fibrinolytic Therapy ◽  
Tissue Type ◽  
Control Value ◽  
Type Plasminogen Activator ◽  
In Vitro Effects ◽  
Fibrinolytic Parameters

SummaryIn vitro, concentration-dependent effects of rt-PA on a range of coagulation and fibrinolytic assays in thawed plasma samples were investigated. In absence of a fibrinolytic inhibitor, 2 μg rt-PA/ml blood (3.4 μg/ml plasma) caused prolongation of clotting time assays and decreases of plasminogen (to 44% of the control value), fibrinogen (to 27%), α2-antiplasmin (to 5%), FV (to 67%), FVIII (to 41%) and FXIII (to 16%).Of three inhibitors tested, a specific polyclonal anti-rt-PA antibody prevented interferences in all fibrinolytic and most clotting assays. D-Phe-Pro-Arg-CH2Cl (PPACK) enabled correct assays of fibrinogen and fibrinolytic parameters but interfered with coagulometric assays dependent on endogenous thrombin generation. Aprotinin was suitable only for a restricted range of both assay types.Most in vitro effects were observed only with rt-PA plasma concentrations in excess of therapeutic values. Nevertheless it is concluded that for clinical application, collection of blood samples on either specific antibody or PPACK is essential for a correct assessment of in vivo effects of rt-PA on the haemostatic system in patients undergoing fibrinolytic therapy.

scholarly journals In Vitro Effects of Sulforaphane on Interferon-Driven Inflammation and Exploratory Evaluation in Two Healthy Volunteers

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3602
Author(s):  
Elena Genova ◽  
Maura Apollonio ◽  
Giuliana Decorti ◽  
Alessandra Tesser ◽  
Alberto Tommasini ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Supportive Therapy ◽  
P Value ◽  
Type I ◽  
Interferon Signature ◽  
Interferon Stimulated Genes ◽  
Immune System Activation ◽  
In Vitro Effects

Interferonopathies are rare genetic conditions defined by systemic inflammatory episodes caused by innate immune system activation in the absence of pathogens. Currently, no targeted drugs are authorized for clinical use in these diseases. In this work, we studied the contribution of sulforaphane (SFN), a cruciferous-derived bioactive molecule, in the modulation of interferon-driven inflammation in an immortalized human hepatocytes (IHH) line and in two healthy volunteers, focusing on STING, a key-component player in interferon pathway, interferon signature modulation, and GSTM1 expression and genotype, which contributes to SFN metabolism and excretion. In vitro, SFN exposure reduced STING expression as well as interferon signature in the presence of the pro-inflammatory stimulus cGAMP (cGAMP 3 h vs. SFN+cGAMP 3 h p value < 0.0001; cGAMP 6 h vs. SFN+cGAMP 6 h p < 0.001, one way ANOVA), restoring STING expression to the level of unstimulated cells. In preliminary experiments on healthy volunteers, no appreciable variations in interferon signature were identified after SFN assumption, while only in one of them, presenting the GSTM1 wild type genotype related to reduced SFN excretion, could a downregulation of STING be recorded. This study confirmed that SFN inhibits STING-mediated inflammation and interferon-stimulated genes expression in vitro. However, only a trend towards the downregulation of STING could be reproduced in vivo. Results obtained have to be confirmed in a larger group of healthy individuals and in patients with type I interferonopathies to define if the assumption of SFN could be useful as supportive therapy.

A Detailed Examination of the in vivo and in vitro Effects of ACTH on Gonadotropin Secretion in the Adult Rat

1985 ◽  
Vol 40 (4) ◽  
pp. 297-302 ◽  
Author(s):  
David R. Mann ◽  
Diane Evans ◽  
Festus Edoimioya ◽  
Freja Kamel ◽  
George M. Butterstein
Keyword(s):  
Detailed Examination ◽  
Gonadotropin Secretion ◽  
Adult Rat ◽  
In Vitro Effects

scholarly journals Contamination of erythropoietin by endotoxin: in vivo and in vitro effects on murine erythropoiesis

Blood ◽  
1979 ◽  
Vol 54 (1) ◽  
pp. 146-158 ◽  
Author(s):  
KS Zuckerman ◽  
PJ Quesenberry ◽  
J Levin ◽  
R Sullivan
Keyword(s):  
Significant Inhibition ◽  
Erythropoietic Activity ◽  
Limulus Amebocyte Lysate ◽  
Endogenous Erythropoietin ◽  
Significant Change ◽  
In Vitro Effects ◽  
Stimulation Of

Abstract Endotoxin was detected in all erythropoietin preparations tested and was removed from four lots, without loss of erythropoietic activity, by adsorption with limulus amebocyte lysate. Comparison of adsorbed (endotoxin-depleted) and nonadsorbed (endotoxin-containing) erythropoietin preparations demonstrated significant inhibition of CFU- e and BFU-e in vitro by nonadsorbed erythropoietin at concentrations higher than 0.25 U/ml and 2.0 U/ml, respectively. CFU-e and BFU-e were inhibited significantly by readdition in vitro of 10(-5)-10(-3) mug of endotoxin per unit of limulus-adsorbed erythropoietin. Administration of saline or 6 U of nonadsorbed or adsorbed erythropoietin twice a day for 4 days of CF1 mice resulted in reticulocyte counts of 2.1%, 9.9%, and 15.9%, respectively. Nonadsorbed erythropoietin resulted in a 29% decrease in erythropoiesis, a 42% decrease in CFU-e, and a 16% increase in granulopoiesis in the marrow, whereas adsorbed erythropoietin caused a 28% increase in erythropoiesis, no significant change in CFU-e and a 19% decrease in granulopoiesis in the marrow. Both preparations resulted in marked increases in splenic erythropoiesis and granulopoiesis. The effects of adsorbed erythropoietin are similar to those produced following stimulation of hematopoiesis by endogenous erythropoietin. Hemopoietic changes induced by nonadsorbed erythropoietin in vivo and in vitro are affected substantially by contamination of the erythropoietin preparations with endotoxin.

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