Diese Arbeit wurde durch ein Pilotprojekt Stipendium CREH Zentrum gesponsert durch NIEHS und National Natural Science Foundation of China (Nr. 31572626) unterstützt.

Alle Tierversuche wurden hingerichtet, unter Beachtung aller relevanten Richtlinien, Verordnungen und Aufsichtsbehörden. Das Protokoll wird gezeigt wurde unter der Leitung und Genehmigung der institutionellen Animal Care und Nutzung Committee (IACUC) von der Texas A & M Institut für Genomic Medizin durchgeführt.
1. Vorbereitung der Lösung
<ol><li>10 X Hank ausgeglichene Salzlösung, 1 X mit doppelt destilliertem H2O verdünnen und Lagerung bei 4 ° C.</li>
	<li>Bereiten Sie die Isolierungslösung indem HEPES (10 mM), MgCl2 (1 mM) und Glukose (5 mM). Einstellen Sie den pH-Wert 7,4 und halten Sie auf dem Eis.</li>
	<li>Bereiten Sie die Kollagenase-Lösung von Kollagenase Typ 4. Hinweis: Insbesondere enthält Kollagenase Typ 4 160 U pro mg Trockengewicht. 1 g Kollagenase Typ 4 wird in 5 mL doppelt destilliertem H2O mit einer Konzentration von 200 mg/mL verdünnt. 2 mL der verdünnten Kollagenase ist 30 mL Eis kalt isoliert Projektmappe hinzugefügt, und 6 mL Kollagenase-Lösung wird in ein 50 mL-Tube für jede Maus übertragen.</li>
	<li>Bereiten Sie die Waschlösung durch Zugabe von 1 mM CaCl2 zur Isolierungslösung.</li>
	<li>Bereiten Sie die Reinigung Lösung mit kalten Polysucrose/Natrium-Diatrizoate-Lösung (1,1119 g/mL, 5 mL).</li>
	<li>Bereiten Sie 500 mL Kulturmedium Inselchen durch Zugabe von L-Glutamin (20 mM), Penicillin (100 U/mL), Streptomycin (100 µg/mL) und fetalen bovine Serum (FBS) (10 %) in RPMI Medium vor.</li>
	<li>Vorbereiten der RLKV-DA-Stammlösung durch Auflösen des Pulvers in destilliertem Wasser bei 200 µM und Store bei-20 ° C. Hinweis: Die Färbelösung ROS wird durch Verdünnung RLKV-DA-Stammlösung auf die Endkonzentration von 5 µM in RPMI frisch zubereitet. Dieses Reagenz sollten vor Licht geschützt werden.</li>
</ol>2. chirurgische Vorbereitung
<ol><li>Intraperitoneale Injektion (i.p.) eine Maus mit avertin (2,5 % avertin, 0,4 mL/20 g). Nach die Maus völlig betäubt ist und nicht mehr reagiert zum hinteren Fuß drückt, einschläfern die Maus und die biologische Motorhaube.</li>
	<li>Platzieren Sie die euthanasierten Maus mit dem Bauch nach oben und sprühen Sie die Haut mit 70 % igem Ethanol für die Sterilisation.</li>
	<li>Öffnen der Bauchhöhle mit einem 1 cm U-Schnitt auf den Oberbauch aus- und Einfahren der Haut in Richtung rostral über der Brust, die Bauchhöhle verfügbar zu machen.</li>
</ol>3. die Bauchspeicheldrüse Perfusion und Entfernung
<ol><li>Wie in Abbildung 1dargestellt, finden Sie den Standort der Ampulle. Verwenden Sie ein paar gebogene Pinzetten, Klemmen Sie den Zwölffingerdarm nahe der Position des Sphincter Oddi. Verwenden Sie ein weiteres Paar gebogene Pinzetten, Klemmen Sie die Zwölffingerdarm Wand um den Weg der Galle in den Zwölffingerdarm zu blockieren. Hinweis: Der Ampulle wurde nicht in diesem Schritt eingefügt. Dieser Schritt soll die Galle Weg in den Zwölffingerdarm blockieren.</li>
	<li>Positionieren Sie die Maus mit dem Kopf proximalen und distalen in Bezug auf die Forscher die Füße.</li>
	<li>Finden Sie den hauptgallengang und injizieren Sie langsam 3 mL Kollagenase-Lösung mit einer 30 G Nadel und 5 mL Spritze. Sicherstellen Sie, dass der Gallengang und Bauchspeicheldrüse nach der Injektion aufgeblasen werden.</li>
	<li>Entfernen Sie die aufgeblähten Bauchspeicheldrüse mit den gebogenen Pinzette und feine Schere, um es von den absteigenden Dickdarm, Darm, Magen und Milz zu trennen. Die Bauchspeicheldrüse in einen 50-mL-Röhrchen mit 3 mL Kollagenase-Lösung und lassen Sie ihn auf Eis.</li>
</ol>4. Bauchspeicheldrüse Verdauung
<ol><li>Legen Sie je 50-mL-Tube in einem 37 ° C-Wasserbad. 15-20 min inkubieren (Zeit variiert je nach Sorte und Alter der Mäuse).</li>
	<li>Schwingen Sie das Rohr mit einem Wirbel.</li>
	<li>Pool 4-5 verdaute Bauchspeicheldrüse in ein großes sterile Waschbecken Sieb und eine Kugel verwenden, um die Bauchspeicheldrüse gründlich auseinander zu fallen. Verwenden Sie eine 23 G Nadel und 10 mL Spritze mit Waschlösung, um mit Nachdruck die verdauten Zellen außerhalb des Bildschirms pipette. Sammeln Sie die Waschlösung in einen 50-mL-Tube.</li>
	<li>Zentrifugieren Sie die Rohre mit 97 X g bei 4 ° C für 1 min und Dekantieren Sie des Überstandes.</li>
	<li>Rohre fügen Sie 25 mL Waschlösung hinzu und erneut aussetzen Sie des Gewebes durch sanfte aufschütteln. Spin-down der Gewebe bei 97 X g bei 4 ° C für 1 min und den überstand abgießen. Für 3 Mal wiederholen. Achten Sie darauf, dass Sie nicht das gebeizte Gewebe verdrängen.</li>
</ol>5. Reinigung der kleinen Inseln
<ol><li>Das gewaschene Gewebe Pellet 10 mL Reinigung Lösung hinzu und Aufschwemmen Sie sanft des Inhalts.</li>
	<li>Überlagern Sie sanft 5 mL Lösung zur Isolierung auf die Reinigung Lösung. Achten Sie darauf, um eine scharfe flüssigen Schnittstelle zwischen den beiden Lösungen zu halten.</li>
	<li>Zentrifugieren Sie das Rohr auf 560 x g bei 4 ° C für 15 min mit der langsamen Beschleunigung und keine Bremse. Legen Sie die Pipette in die Schnittstelle und sammeln Sie die Inselchen Schicht in neuen 50 mL Röhrchen.</li>
	<li>Waschen Sie die kleinen Inseln, wie unter Punkt 3.5 beschrieben.</li>
</ol>(6) Beschichtung und Behandlung von Inselzellen
<ol><li>Die kleinen Inseln in 10 mL Inselchen Kulturlösung Aufschwemmen, sanft gut mischen und 100 µL/Well mit einer Mehrkanal-Pipette auf eine 96-Well-Platte zu platzieren. Platzieren Sie ca. 5 Inseln pro 96 gut.</li>
	<li>Legen Sie die Platte in der Gewebekultur-Inkubator für 12 h.</li>
	<li>Zentrifugieren Sie (112 X g) 96-Well-Platte und entfernen Sie das Kulturmedium zu.</li>
	<li>Verdünnen Sie die Umweltchemikalien in das Kulturmedium Inselchen. 100 µL der einzelnen chemischen Verdünnungsmitteln in separaten Vertiefungen der Platte hinzufügen. Aufschwemmen der Inseln in jede Vertiefung und inkubieren Sie für 12 h bei 37 ° C (die Konzentration variiert für verschiedenen Umweltchemikalien).</li>
</ol>(7) ROS Färbung und Messung
<ol><li>Nachbehandlung der Inselchen mit 1 X PBS waschen (200 µL für jede 96-Well). Hinweis: Die Konzentration der Chemikalien ist wie folgt: AFB1: 3 µM, Atrazin: 100 µM, BaP: 10 µM, BPA: 100 µM, β-Östrogen, PCB126: 10 µM, Nonylphenol und BPA: 100 µM.</li>
	<li>Verwenden Sie N-Acetyl-Cystein (NAC) als Antioxidans ROS zu stillen. Die ROS-induzierten chemischen Verdünnungsmittel 5 mM der NAK hinzu und 12 h bei 37 ° c inkubieren</li>
	<li>Die 96-Well-Platte bei 112 X g zentrifugieren und mit 5 µM-Lösung von fluoreszierenden Sonde (H2-RLKV-DA aufgelöst in RPMI Medien) bei 37 ° C für 60 min inkubieren.</li>
	<li>Die behandelten Inselzellen 3 Mal mit PBS waschen und Messung die Fluoreszenz mit Dozent Mikrotestplatte an 488 nm. Hinweis: Die Anhäufung von DCF in Zellen kann gemessen werden, durch eine Erhöhung der Fluoreszenz bei 530 nm, wenn die Probe bei 488 angeregt wird nm.</li>
	<li>Führen Sie die Glukose stimuliert Insulin-Sekretion (GSIS) Assay9 auf ROS-induzierende Harnblase behandelt Inselchen und unbehandelten Inselchen, die insbesondere Auswirkungen auf die physiologische Funktion der Bauchspeicheldrüsen Inselchen zu messen.</li>
</ol>

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Die Autoren erklären, dass sie keine finanziellen Interessenkonflikte.

Sammeln Beweise deutet darauf hin, dass die Exposition zu Umweltchemikalien spielt eine wichtige Rolle bei der Entwicklung des T2DM. XENOBIOTIKA-induzierte ROS wurde als ein möglicher ätiologischer Faktor zur Entwicklung des T2DM anerkannt. Menschen ein breites Spektrum von XENOBIOTIKA Chemikalien ausgesetzt sind, und es gibt ein großer Bedarf an neuartigen Forschungstechniken, effektiv die Bauchspeicheldrüse Giftstoffe zu identifizieren und zu untersuchen, den Mechanismus der Toxizität für die Zellen der Bauchspei...

Anstieg der Prävalenz von T2DM geworden in den letzten Jahren stellt eine ernsthafte Bedrohung für öffentliche Gesundheit1einer weltweiten Gesundheitskrise. Viele Faktoren gefunden worden zur Entwicklung des T2DM, darunter kausal verknüpft werden wiederkehrende Ergebnisse deuten darauf hin, dass eine konvergente Gemeinsamkeit dieser Faktoren ist die Induktion von oxidativem Stress führt zu der Generation von übermäßigen ROS2 , 3.
Ein breites Spektrum von Umweltchemikalien wie PCB, Dioxine und BaP hat sich herausgestellt, induzieren oxidativen Stress beeinträchtigen die Funktion der Bauchspeicheldrüse β-Zellen und zu Insulin-Resistenz und T2DM4führen kann. Obwohl der physiologische Ebene von ROS in zellulären Funktionen eine wichtige Rolle spielt, ROS, die die Kapazität des antioxidativen Systems übersteigt führt zu Schäden an Zellen/Gewebe und führt zu Krankheiten5. Pankreatische β-Zellen express ein niedriges Niveau der antioxidativen Enzym, und somit ist eine sensible Zielgruppe für den oxidativen Stress-vermittelten Schäden6,7. Chronische Exposition gegenüber hohen Konzentrationen von ROS wurde gezeigt, dass Stress-induzierte Pankreas Zelle Dysfunktion5 verursachen sowie Insulinresistenz in der Leber und Fettgewebe8.
Das übergeordnete Ziel dieses Projektes ist es, eine zellbasierte Assays Bildschirm Chemikalien für ihre diabetogene Potenziale basierend auf ihre Induktion von ROS in Zellen der Bauchspeicheldrüse entwickeln. Die Bauchspeicheldrüse fehlt metabolische Entgiftung und ist ein sensibler Ziel für Fremdstoff-induzierten Schäden6,7. Daher soll dieser Assay durch direkte Messung der ROS erzeugt in den Zellen der Bauchspeicheldrüsen, eine direkte Annäherung an die chemisch induzierte Schädigung der Bauchspeicheldrüse. Um diese Methode zu entwickeln, wir Maus Pankreas Inseln isoliert, kultiviert die isolierte Insel unter Zelle Kultur Bedingung mit Chemikalien und genutzt, die chemisch induzierte ROS-Generation als das Auslesen. Dieses Verfahren ist einfach und effektiv bei der Identifizierung von ROS-induzierende Chemikalien in der isolierten Insel; Es kann für die Untersuchung der Mechanismen der Toxizität weiterentwickelt werden, die speziell für die Bauchspeicheldrüse in Vitro.

<table border="0" cellpadding="0" cellspacing="0" width="858">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:289px;">10&#215;Hank&#8217;s balanced salt solution&#160;</td>
			<td style="width:283px;">GIBCO</td>
			<td style="width:119px;">14185-052</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Collagenase Type 4</td>
			<td>Worthington Biochemical Corporation</td>
			<td>CLS-4</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">polysucrose/sodium diatrizoate solution&#160;</td>
			<td>Sigma</td>
			<td>10771</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">2&#8217;,7&#8217;-dichlorofluorescein (DCFH-DA)</td>
			<td>Sigma</td>
			<td>D6883-50MG</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">fluorescence microplate reader&#160;</td>
			<td>Biotek</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">L-glutamine</td>
			<td>Sigma</td>
			<td>G8540-25G</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">streptomycin</td>
			<td>GIBCO</td>
			<td>15140148</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">FBS</td>
			<td>GIBCO</td>
			<td>26140079</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">RPMI 1640</td>
			<td>GIBCO</td>
			<td>11875-085</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">avertin</td>
			<td>Sigma</td>
			<td>T48402-25G</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Rat/Mouse Insulin ELISA Kit</td>
			<td>Millipore</td>
			<td>EZRMI-13K</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Centrifuge</td>
			<td>Sorval</td>
			<td>Sorval RT7</td>
			<td>for 96-well plate centrifuge</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Microplate reader</td>
			<td>Biotek</td>
			<td>Epoch 2</td>
			<td>for fluorescence reading</td>
		</tr>
	</tbody>
</table>

a murine pancreatic islet cell-based screening for diabetogenic environmental chemicals

Exposition gegenüber bestimmten Umweltchemikalien in Mensch und Tier wurde gefunden, um zelluläre Schäden der Bauchspeicheldrüse β-Zellen verursachen, die zu die Entwicklung von Diabetes Mellitus Typ 2 (T2DM) führt. Obwohl die Mechanismen für die chemisch induzierte β Zellschädigung unklar und wahrscheinlich zu komplex waren, ist eine immer wiederkehrende Erkenntnis, dass diese Chemikalien verursachen oxidativen Stress führt zu der Generation von übermäßigen reaktiven Sauerstoffspezies (ROS) die Schäden zu verursachen die β-Zelle. Ermittlung potenzieller diabetogene Umweltchemikalien, isoliert wir pankreatische Inselzellen von C57BL/6 Mäusen und kultivierten Inselzellen in 96-Well Zellplatten Kultur; dann wurden die Inselzellen mit Chemikalien dosiert und die ROS-Generation wurde von 2', 7'-dichlorofluoresceins (RLKV-DA) Fluoreszenzfarbstoff erkannt. Mit dieser Methode wir gefunden, dass Bisphenol A (BPA), Benzo [a] pyren (BaP) und polychlorierten Biphenylen (PCB), können hohe Konzentrationen von ROS, was darauf hindeutet, dass sie potenziell Schaden in Inselzellen induzieren können induzieren. Diese Methode sollte für das screening von diabetogene XENOBIOTIKA nützlich sein. Darüber hinaus können die kultivierten Inselzellen auch für in-vitro- Analyse der chemisch induzierten Toxizität in Zellen der Bauchspeicheldrüse angepasst werden.

Ein Schliffbild der gesunden isolierten Insel ist in Abbildung 2gezeigt, in dem kleinen Inseln eine Runde oder ovale Form mit relativ einheitliche Größe haben (obwohl Größe Einheitlichkeit von Stamm zu Stamm unterschiedlich sein kann). Wir als Nächstes untersucht pancreatic Islet-Funktionen in einer in-vitro- Assay durch das Inselchen zu isolieren und Stimulierung der Insulinsekretion in den Kultur-Inseln. Abbildung 3</stron...

Watch this Scientific Journal Video about A Murine Pancreatic Islet Cell-based Screening for Diabetogenic Environmental Chemicals at JoVE.com

A Murine Pancreatic Islet Cell-based Screening for Diabetogenic Environmental Chemicals

Hier präsentieren wir ein Protokoll zur Maus pankreatische Inselzellen für das screening von ROS Induktionen durch die XENOBIOTIKA Ermittlung der potenziellen diabetogene XENOBIOTIKA Chemikalien zu isolieren.

Ein murinen Pancreatic Islet Cell-basierte Screening für diabetogene Umweltchemikalien

Exposure to certain environmental chemicals in human and animals has been found to cause cellular damage of the pancreatic &#946; cells which will lead to ...

a-murine-pancreatic-islet-cell-based-screening-for-diabetogenic

Research

JoVE Journal

Immunology and Infection

7.2K Aufrufe.  Hunan Agriculture University. Hier präsentieren wir ein Protokoll zur Maus pankreatische Inselzellen für das screening von ROS Induktionen durch die XENOBIOTIKA Ermittlung der potenziellen diabetogene XENOBIOTIKA Chemikalien zu isolieren.

Serie: A Murine Pancreatic Islet Cell-based Screening for Diabetogenic Environmental Chemicals

A New Screening Method for the Directed Evolution of Thermostable Bacteriolytic Enzymes

Directed evolution is defined as a method to harness natural selection in order to engineer proteins to acquire particular properties that are not associated with the protein in nature. Literature has provided numerous examples regarding the implementation of directed evolution to successfully alter molecular specificity and catalysis1. The primary advantage of utilizing directed evolution instead of more rational-based approaches for molecular engineering relates to the volume and diversity of variants that can be screened2. One possible application of directed evolution involves improving structural stability of bacteriolytic enzymes, such as endolysins. Bacteriophage encode and express endolysins to hydrolyze a critical covalent bond in the peptidoglycan (i.e. cell wall) of bacteria, resulting in host cell lysis and liberation of progeny virions. Notably, these enzymes possess the ability to extrinsically induce lysis to susceptible bacteria in the absence of phage and furthermore have been validated both in vitro and in vivo for their therapeutic potential3-5. The subject of our directed evolution study involves the PlyC endolysin, which is composed of PlyCA and PlyCB subunits6. When purified and added extrinsically, the PlyC holoenzyme lyses group A streptococci (GAS) as well as other streptococcal groups in a matter of seconds and furthermore has been validated in vivo against GAS7. Significantly, monitoring residual enzyme kinetics after elevated temperature incubation provides distinct evidence that PlyC loses lytic activity abruptly at 45 &deg;C, suggesting a short therapeutic shelf life, which may limit additional development of this enzyme. Further studies reveal the lack of thermal stability is only observed for the PlyCA subunit, whereas the PlyCB subunit is stable up to ~90 &deg;C (unpublished observation). In addition to PlyC, there are several examples in literature that describe the thermolabile nature of endolysins. For example, the Staphylococcus aureus endolysin LysK and Streptococcus pneumoniae endolysins Cpl-1 and Pal lose activity spontaneously at 42 &deg;C, 43.5 &deg;C and 50.2 &deg;C, respectively8-10. According to the Arrhenius equation, which relates the rate of a chemical reaction to the temperature present in the particular system, an increase in thermostability will correlate with an increase in shelf life expectancy11. Toward this end, directed evolution has been shown to be a useful tool for altering the thermal activity of various molecules in nature, but never has this particular technology been exploited successfully for the study of bacteriolytic enzymes. Likewise, successful accounts of progressing the structural stability of this particular class of antimicrobials altogether are nonexistent. In this video, we employ a novel methodology that uses an error-prone DNA polymerase followed by an optimized screening process using a 96 well microtiter plate format to identify mutations to the PlyCA subunit of the PlyC streptococcal endolysin that correlate to an increase in enzyme kinetic stability (Figure 1). Results after just one round of random mutagenesis suggest the methodology is generating PlyC variants that retain more than twice the residual activity when compared to wild-type (WT) PlyC after elevated temperature treatment.

A novel directed evolution method specific to the field of thermostability engineering was developed and consequently validated for bacteriolytic enzymes. After only one round of random mutagenesis, an evolved bacteriolytic enzyme, PlyC 29C3, displayed greater than twice the residual activity when compared to the wild-type protein after elevated temperature incubation.

Ein neues Screening-Verfahren für die gelenkte Evolution von thermostabilen Bakteriolytische Enzyme

Directed evolution is defined as a method to harness natural selection in order to engineer proteins to acquire particular properties that are not ...

Forschung

Immunologie und Infektion

Isolation, Identification, and Purification of Murine Thymic Epithelial Cells

The thymus is a vital organ for T lymphocyte development. Of thymic stromal cells, thymic epithelial cells (TECs) are particularly crucial at multiple stages of T cell development: T cell commitment, positive selection and negative selection. However, the function of TECs in the thymus remains incompletely understood. In the article, we provide a method to isolate TEC subsets from fresh mouse thymus using a combination of mechanical disruption and enzymatic digestion. The method allows thymic stromal cells and thymocytes to be efficiently released from cell-cell and cell-extracellular matrix connections and to form a single-cell suspension. Using the isolated cells, multiparameter flow cytometry can be applied to identification and characterization of TECs and dendritic cells. Because TECs are a rare cell population in the thymus, we also describe an effective way to enrich and purify TECs by depleting thymocytes, the most abundant cell type in the thymus. Following the enrichment, cell sorting time can be decreased so that loss of cell viability can be minimized during purification of TECs. Purified cells are suitable for various downstream analyses like Real Time-PCR, Western blot and gene expression profiling. The protocol will promote research of TEC function and as well as the development of in vitro T cell reconstitution.

Here we describe an efficient method for isolation, identification, and purification of mouse thymic epithelial cells (TECs). The protocol can be utilized for studies of thymus function for normal T cell development, thymus dysfunction, and T cell reconstitution.

Isolierung, Identifizierung und Reinigung von Murine Thymusepithelzellen

The thymus is a vital organ for T lymphocyte development. Of thymic stromal cells, thymic epithelial cells (TECs) are particularly crucial at multiple ...

A Rapid Strategy for the Isolation of New Faustoviruses from Environmental Samples Using Vermamoeba vermiformis

The isolation of giant viruses is of great interest in this new era of virology, especially since these giant viruses are related to protists. Giant viruses may be potentially pathogenic for many species of protists. They belong to the recently described order of Megavirales. The new lineage Faustovirus that has been isolated from sewage samples is distantly related to the mammalian pathogen African swine fever virus. This virus is also specific to its amoebal host, Vermamoeba vermiformis, a protist common in health care water systems. It is crucial to continue isolating new Faustovirus genotypes in order to enlarge its genotype collection and study its pan-genome. We developed new strategies for the isolation of additional strains by improving the use of antibiotic and antifungal combinations in order to avoid bacterial and fungal contaminations of the amoeba co-culture and favoring the virus multiplication. We also implemented a new starvation medium to maintain V. vermiformis in optimal conditions for viruses co-culture. Finally, we used flow cytometry rather than microscopic observation, which is time-consuming, to detect the cytopathogenic effect. We obtained two isolates from sewage samples, proving the efficiency of this method and thus widening the collection of Faustoviruses, to better understand their environment, host specificity and genetic content.

A Rapid Strategy for the Isolation of New Faustoviruses from Environmental Samples Using Vermamoeba vermiformis

We describe here the latest advances in viral isolation for the characterization of new genotypes of Faustovirus, a new asfarvirus-related lineage of giant viruses. This protocol can be applied to the high throughput isolation of viruses, especially giant viruses infecting amoeba.

Eine schnelle Strategie für die Isolierung neuer Faustoviruses von Umweltproben unter Verwendung von<em&gt; Vermamoeba vermiformis</em

The isolation of giant viruses is of great interest in this new era of virology, especially since these giant viruses are related to protists. Giant ...

Developing a Salivary Antibody Multiplex Immunoassay to Measure Human Exposure to Environmental Pathogens

The etiology and impacts of human exposure to environmental pathogens are of major concern worldwide and, thus, the ability to assess exposure and infections using cost effective, high-throughput approaches would be indispensable. This manuscript describes the development and analysis of a bead-based multiplex immunoassay capable of measuring the presence of antibodies in human saliva to multiple pathogens simultaneously. Saliva is particularly attractive in this application because it is noninvasive, cheaper and easier to collect than serum. Antigens from environmental pathogens were coupled to carboxylated microspheres (beads) and used to measure antibodies in very small volumes of human saliva samples using a bead-based, solution-phase assay. Beads were coupled with antigens from Campylobacter jejuni, Helicobacter pylori, Toxoplasma gondii, noroviruses (G I.1 and G II.4) and hepatitis A virus. To ensure that the antigens were sufficiently coupled to the beads, coupling was confirmed using species-specific, animal-derived primary capture antibodies, followed by incubation with biotinylated anti-species secondary detection antibodies and streptavidin-R-phycoerythrin reporter (SAPE). As a control to measure non-specific binding, one bead set was treated identically to the others except it was not coupled to any antigen. The antigen-coupled and control beads were then incubated with prospectively-collected human saliva samples, measured on a high throughput analyzer based on the principles of flow cytometry, and the presence of antibodies to each antigen was measured in Median Fluorescence Intensity units (MFI). This multiplex immunoassay has a number of advantages, including more data with less sample; reduced costs and labor; and the ability to customize the assay to many targets of interest. Results indicate that the salivary multiplex immunoassay may be capable of identifying previous exposures and infections, which can be especially useful in surveillance studies involving large human populations.

In the current climate of scarce resources, new technologies are emerging that allow researchers to conduct studies cheaper, faster and with more precision. Here we describe the development of a bead-based salivary antibody multiplex immunoassay to measure human exposure to multiple environmental pathogens simultaneously.

eine Speichel- Antikörper Multiplex-Immunoassay Entwicklung der Humanexposition Umwelt Pathogens zu messen

The etiology and impacts of human exposure to environmental pathogens are of major concern worldwide and, thus, the ability to assess exposure and ...

A Murine Model of Group B Streptococcus Vaginal Colonization

Streptococcus agalactiae (group B Streptococcus, GBS), is a Gram-positive, asymptomatic colonizer of the human gastrointestinal tract and vaginal tract of 10 - 30% of adults. In immune-compromised individuals, including neonates, pregnant women, and the elderly, GBS may switch to an invasive pathogen causing sepsis, arthritis, pneumonia, and meningitis. Because GBS is a leading bacterial pathogen of neonates, current prophylaxis is comprised of late gestation screening for GBS vaginal colonization and subsequent peripartum antibiotic treatment of GBS-positive mothers. Heavy GBS vaginal burden is a risk factor for both neonatal disease and colonization. Unfortunately, little is known about the host and bacterial factors that promote or permit GBS vaginal colonization. This protocol describes a technique for establishing persistent GBS vaginal colonization using a single &#946;-estradiol pre-treatment and daily sampling to determine bacterial load. It further details methods to administer additional therapies or reagents of interest and to collect vaginal lavage fluid and reproductive tract tissues. This mouse model will further the understanding of the GBS-host interaction within the vaginal environment, which will lead to potential therapeutic targets to control maternal vaginal colonization during pregnancy and to prevent transmission to the vulnerable newborn. It will also be of interest to increase our understanding of general bacterial-host interactions in the female vaginal tract.

A Murine Model of Group B Streptococcus Vaginal Colonization

The purpose of this protocol is to imitate human group B Streptococcus (GBS) vaginal colonization in a murine model. This method may be used to investigate host immune responses and bacterial factors contributing to GBS vaginal persistence, as well as to test therapeutic strategies.

Ein Mausmodell der Gruppe B<em&gt; Streptococcus</em&gt; Vaginal Colonization

Streptococcus agalactiae (group B Streptococcus, GBS), is a Gram-positive, asymptomatic colonizer of the human gastrointestinal tract and vaginal tract of ...

A Fluorescence-based Lymphocyte Assay Suitable for High-throughput Screening of Small Molecules

High-throughput screening (HTS) is currently the mainstay for the identification of chemical entities capable of modulating biochemical reactions or cellular processes. With the advancement of biotechnologies and the high translational potential of small molecules, a number of innovative approaches in drug discovery have evolved, which explains the resurgent interest in the use of HTS. The oncology field is currently the most active research area for drug screening, with no major breakthrough made for the identification of new immunomodulatory compounds targeting transplantation-related complications or autoimmune ailments. Here, we present a novel in vitro murine fluorescent-based lymphocyte assay easily adapted for the identification of new immunomodulatory compounds. This assay uses T or B cells derived from a transgenic mouse, in which the Nur77 promoter drives GFP expression upon T- or B-cell receptor stimulation. As the GFP intensity reflects the activation/transcriptional activity of the target cell, our assay defines a novel tool to study the effect of given compound(s) on cellular/biological responses. For instance, a primary screening was performed using 4,398 compounds in the absence of a &#34;target hypothesis&#34;, which led to the identification of 160 potential hits displaying immunomodulatory activities. Thus, the use of this assay is suitable for drug discovery programs exploring large chemical libraries prior to further in vitro/in vivo validation studies.

We present in the current study a novel fluorescence-based assay using lymphocytes derived from a transgenic mouse. This assay is suitable for high-throughput screening (HTS) of small molecules endowed with the capacity of either inhibiting or promoting lymphocyte activation.

Ein Fluoreszenz-basierte Lymphocyte Assay geeignet für Hochdurchsatz-Screening von kleinen Molekülen

High-throughput screening (HTS) is currently the mainstay for the identification of chemical entities capable of modulating biochemical reactions or ...

A Method to Test the Efficacy of Handwashing for the Removal of Emerging Infectious Pathogens

Handwashing is widely recommended to prevent infectious disease transmission. However, little comparable evidence exists on the efficacy of handwashing methods in general. Additionally, little evidence exists comparing handwashing methods to determine which are most efficacious at removing infectious pathogens. Research is needed to provide evidence for the different approaches to handwashing that may be employed during infectious disease outbreaks. Here, a laboratory method to assess the efficacy of handwashing methods at removing microorganisms from hands and their persistence in rinse water is described. Volunteers' hands are first spiked with the test organism and then washed with each handwashing method of interest. Generally, surrogate microorganisms are used to protect human subjects from disease. The number of organisms remaining on volunteers' hands after washing is tested using a modified "glove juice" method: the hands are placed in gloves with an eluent and are scrubbed to suspend the microorganisms and make them available for analysis by membrane filtration (bacteria) or plaque assay (viruses/bacteriophages). Rinse water produced from the handwashing is directly collected for analysis. Handwashing efficacy is quantified by comparing the log reduction value between samples taken after handwashing to samples with no handwashing. Rinse water persistence is quantified by comparing rinse water samples from various handwashing methods to samples collected after handwashing with just water. While this method is limited by the need to use surrogate organisms to preserve the safety of human volunteers, it captures aspects of handwashing that are difficult to replicate in an in vitro study and fills research gaps on handwashing efficacy and the persistence of infectious organisms in rinse water.

Handwashing is widely recommended to prevent infectious disease transmission. However, there is little evidence on which handwashing methods are most efficacious at removing infectious disease pathogens. We developed a method to assess the efficacy of handwashing methods at removing microorganisms.

Eine Methode, um die Wirksamkeit der Handwäsche für die Entfernung von auftauchenden infektiösen Pathogenen zu testen

Handwashing is widely recommended to prevent infectious disease transmission. However, little comparable evidence exists on the efficacy of handwashing ...

Electrochemiluminescence Assays for Human Islet Autoantibodies

Pinpointing islet autoantibodies associated with type 1 diabetes (T1D) leads the way to project and deter this disease in the general population. A novel ECL assay is a nonradioactive fluid phase assay for islet autoantibodies with higher sensitivity and specificity than the current 'gold' standard radio-binding assay (RBA). ECL assays can more precisely define the onset of presymptomatic T1D by distinguishing the high-risk, high-affinity autoantibodies from the low-risk, low-affinity autoantibodies generated in RBAs, and conventional enzyme-linked immunosorbent assays (ELISA). The antigen protein used in this ECL assay is labeled with Sulfo-tag and Biotin, respectively. Each ECL autoantibody assay that uses a particular antigen protein needs an optimization step before it can be used for laboratory application. This step is especially vital in determining the requirements for serum acid treatments, concentrations, and ratios of the two different antigens labeled with Sulfo-tag and Biotin. To perform the assay, serum samples are mixed with Sulfo-tag-conjugated and biotinylated capture antigen protein in phosphate buffered solution (PBS), containing 5% Bovine Serum Albumin (BSA). Afterwards, the samples are incubated overnight at 4 &#176;C. The same day, a streptavidin-coated plate is prepared with blocker buffer and incubated overnight at 4 &#176;C. On the second day, wash the streptavidin plate and transfer the serum-antigen mixture onto the plate. Place the plate on the plate shaker, set it at low speed, and incubate at room temperature for 1 h. Subsequently, the plate is washed again, and reader buffer is added. The plate is then counted on the plate reader machine. The results are conveyed through an index, which is generated from internal standard positive and negative control serum samples.

Here, we presented the methods to detect human islet autoantibodies using electrochemiluminescence (ECL) assays. The protocol, used to predict type 1 diabetes, can be expanded upon to detect autoantibodies for other autoimmune diseases.

Electrochemiluminescence-Assays für menschliche Insel-Autoantikörper

Pinpointing islet autoantibodies associated with type 1 diabetes (T1D) leads the way to project and deter this disease in the general population. A novel ...

A High-throughput Platform for the Screening of Salmonella spp./Shigella spp.

Fecal-oral transmission of acute gastroenteritis occurs from time to time, especially when people who handled food and water are infected by Salmonella spp./Shigella spp. The gold standard method for the detection of Salmonella spp./Shigella spp. is direct culture but this is labor-intensive and time-consuming. Here, we describe a high-throughput platform for Salmonella spp./Shigella spp. screening, using real-time polymerase chain reaction (PCR) combined with guided culture. There are two major stages: real-time PCR and the guided culture. For the first stage (real-time PCR), we explain each step of the method: sample collection, pre-enrichment, DNA extraction and real-time PCR. If the real-time PCR result is positive, then the second stage (guided culture) is performed: selective culture, biochemical identification and serological characterization. We also illustrate representative results generated from it. The protocol described here would be a valuable platform for the rapid, specific, sensitive and high-throughput screening of Salmonella spp./Shigella spp.

A High-throughput Platform for the Screening of Salmonella spp./Shigella spp.

Salmonella spp./Shigella spp. are common pathogens attributed to diarrhea. Here, we describe a high-throughput platform for the screening of Salmonella spp./Shigella spp. using real-time PCR combined with guided culture.

Eine High-Throughput-Plattform für das Screening von Salmonella spp. /Shigella spp.

Fecal-oral transmission of acute gastroenteritis occurs from time to time, especially when people who handled food and water are infected by Salmonella ...

Arbovirus Infections As Screening Tools for the Identification of Viral Immunomodulators and Host Antiviral Factors

RNA interference- and genome editing-based screening platforms have been widely used to identify host cell factors that restrict virus replication. However, these screens are typically conducted in cells that are naturally permissive to the viral pathogen under study. Therefore, the robust replication of viruses in control conditions may limit the dynamic range of these screens. Furthermore, these screens may be unable to easily identify cellular defense pathways that restrict virus replication if the virus is well-adapted to the host and capable of countering antiviral defenses. In this article, we describe a new paradigm for exploring virus-host interactions through the use of screens that center on naturally abortive infections by arboviruses such as vesicular stomatitis virus (VSV). Despite the ability of VSV to replicate in a wide range of dipteran insect and mammalian hosts, VSV undergoes a post-entry, abortive infection in a variety of cell lines derived from lepidopteran insects, such as the gypsy moth (Lymantria dispar). However, these abortive VSV infections can be &#34;rescued&#34; when host cell antiviral defenses are compromised. We describe how VSV strains encoding convenient reporter genes and restrictive L. dispar cell lines can be paired to set-up screens to identify host factors involved in arbovirus restriction. Furthermore, we also show the utility of these screening tools in the identification of virally encoded factors that rescue VSV replication during coinfection or through ectopic expression, including those encoded by mammalian viruses. The natural restriction of VSV replication in L. dispar cells provides a high signal-to-noise ratio when screening for the conditions that promote VSV rescue, thus enabling the use of simplistic luminescence- and fluorescence-based assays to monitor the changes in VSV replication. These methodologies are valuable for understanding the interplay between host antiviral responses and viral immune evasion factors.

Here, we present the protocols to identify 1) virus-encoded immunomodulators that promote arbovirus replication and 2) eukaryotic host factors that restrict arbovirus replication. These fluorescence- and luminescence-based methods allow researchers to rapidly obtain quantitative readouts of arbovirus replication in simplistic assays with low signal-to-noise ratios.

Arboviren Infektionen als Screening-Tools für die Identifizierung von viralen Immunmodulatoren und Host antiviralen Faktoren

RNA interference- and genome editing-based screening platforms have been widely used to identify host cell factors that restrict virus replication. ...