Los autores reconocen la asistencia de Ander Lopez y Miren Telletxea para video grabación y edición. ACR es financiado por una beca de Ikerbasque y un proyecto de investigación de Asociación de Celiacos de Madrid (ACM). OCR es financiado por el proyecto ISCIII-PI16/00258 y cofinanciado por el Unión Europea FEDER/FSE "Una manera de hacer Europa". ES financiado por una subvención de proyecto de investigación 2015111068 del Departamento vasco de sanidad. IRG y AJM son apoyados por becas de beca predoctoral de la UPV/EHU y el Departamento vasco de educación, respectivamente.

Este estudio fue aprobado por el Consejo de ética de Hospital de Universitario de Cruces y los análisis se realizaron después de que se obtuvo consentimiento informado de todos los sujetos o a sus padres.
1. biopsia de la colección
Nota: Especímenes de la biopsia de duodeno distal de pacientes se obtienen durante la endoscopia de diagnóstico rutinaria gestión de biopsias que varían entre 2 y 10 mg de peso. Tejido hecho una biopsia es un tejido complejo compuesto por diversos tipos celulares incluyendo células epiteliales, inmunes y endoteliales. Gastroenterólogos clínicos realizan la endoscopia siguiente establecido guías de práctica clínicas.
<ol><li>Colocar la biopsia en un papel de filtro estéril justo después de la endoscopia.</li>
	<li>Utilice pinzas para transferir las biopsias en tubos de 1,5 mL, remójelos con PBS y colóquelo en un criotubo.</li>
	<li>Mantener los tubos en hielo hasta que llegan al laboratorio.<ol>
<li>Iniciar proceso de biopsias frescas inmediatamente.</li>
	</ol>
</li>
	<li>De biopsias congeladas, flash congelación de la biopsia que contienen tubos y almacenar en nitrógeno líquido hasta su utilización. Nota: Es importante mantener la muestra congelada hasta que se añade el buffer suplementado frío 1.</li>
</ol>2. preparación de buffer
Nota: Antes de iniciar, complementar los buffers como sigue.
<ol><li>Añadir 1 mM TDT (concentración final) y proteasa y fosfatasa inhibidor de cóctel (1 x concentración final) en el búfer hipotónico hipertónico y 1 Tampón 2 (tabla 1).<ol>
<li>Preparar 1,5 mL de tampón 1 y 150 μL de tampón 2 por muestra. TDT previene la oxidación de las muestras.</li>
	</ol>
</li>
	<li>Preparar el tampón de lavado núcleos mediante la adición de detergente al 1% (nonil phenoxypolyethoxylethanol) a una concentración final de 0.1% en el búfer ya completado 1. Preparar 1 mL de tampón de lavado núcleos por muestra.</li>
</ol>3. biopsia de la homogeneización
<ol><li>
Biopsias frescas
	<ol>
<li>Coloque el mortero descartable en el mezclador motorizado. Garantizar que el mortero llegue a la parte inferior del tubo.</li>
		<li>Sacar la biopsia desde el criotubo y colóquelo en un tubo de 1,5 mL con una pipeta.</li>
		<li>Añadir 200 μL de buffer suplementado 1 al tubo de 1,5 mL.</li>
		<li>Homogeneizar la biopsia con la mano del mortero hasta que el tejido es totalmente trastornado y mantenerlo en hielo.</li>
		<li>Una vez que todas las biopsias son homogeneizadas continúe con el paso 4. Nota: Disponibles Pisones deben cambiarse entre las biopsias.</li>
	</ol>
</li>
	<li>
Biopsias congeladas PRECAUCIÓN: Manipule nitrógeno líquido cuidadosamente; contacto del nitrógeno líquido con la piel o los ojos puede causar daños de congelación. Proteger las manos y los ojos siempre con nitrógeno líquido.<ol>
<li>Tomar algunos nitrógeno líquido en una caja para almacenar criotubos obtenido desde el tanque de nitrógeno.</li>
		<li>Encontrar la biopsia en el tanque de nitrógeno y el criotubo en la caja con el nitrógeno líquido. Repita este paso para todas las biopsias.</li>
		<li>Transferencia de la biopsia de la criotubo a un tubo de 1,5 mL. Nota: Las biopsias se unirá al tubo de congelados. Empuje la biopsia con una pipeta estéril para que se desprenda del tubo.</li>
		<li>Añadir 200 μL de buffer suplementado 1.</li>
		<li>Homogeneizar el tejido con la maja y el mortero hasta que el tejido se interrumpe totalmente, manteniendo la temperatura a 4 ° C a lo largo de todo el procedimiento. Nota: No deje que las biopsias descongelar antes de agregar el buffer.</li>
	</ol>
</li>
</ol>4. citoplasma aislamiento
<ol><li>Incubar la biopsia homogeneizada en hielo durante 10 minutos.</li>
	<li>Añadir 10 μl de detergente al 1% (nonil phenoxypolyethoxylethanol) a cada muestra a una concentración final de 0.05%. Nota: Las células se hinchan y estallan por lisis osmótica como el detergente, se interrumpirán la membrana celular.</li>
	<li>Incubar en hielo durante 5 minutos.</li>
	<li>Mezclar brevemente y centrifugar a 400 x g a 4 ° c por 2 min.</li>
	<li>Después de Vortex, quite el sobrenadante y transferir a un tubo limpio de 1.5 mL nuevo; se trata de la fracción citoplasmática. Deseche los pellets.</li>
</ol>5. nuclear aislamiento
<ol><li>Resuspender el precipitado del paso anterior con 200 μL de tampón de lavado de núcleos.</li>
	<li>Centrifugar el tubo durante 2 min a 400 x g a 4 ° C.</li>
	<li>Deseche el sobrenadante y repetir el lavado dos veces más. Nota: El lavado eliminará contaminación citoplásmica en la fracción nuclear.</li>
	<li>Después del tercer lavado, Resuspender el precipitado en 100 μl de buffer 2.</li>
	<li>Agitar la muestra vigorosamente a 4 ° c durante 30 minutos o bien, incubar la muestra en hielo y agitar cada 5 min.</li>
	<li>Después de agitar, centrifugar la muestra 10 min a velocidad máxima (> 12.000 x g) y 4 ° C.</li>
	<li>Después de Vortex, transferir el sobrenadante a un nuevo 1.5 limpio. tubo mL. Se trata de la fracción nuclear.</li>
</ol>6. cuantificación de proteínas
Nota: Cuantificar las proteínas bicinchoninic ácido (BCA) proteína análisis kit. La concentración de proteínas en las fracciones que van entre 0.5 y 5 μg/μl, siendo menor en la fracción nuclear (ver tabla 2 para las concentraciones de la proteína resultantes de las biopsias de 2 mg).
<ol><li>Preparar una curva estándar con los siguientes albúmina de suero bovino (BSA) cantidad (μg)12: 0-0.5-1-2-3-4-5-6.</li>
	<li>Preparar los reactivos necesarios para utilizar 100 μl de la mezcla final de BCA por muestra.</li>
	<li>Pipetear 2 μl de cada fracción de proteína en un plato bien 96, añadir la mezcla BCA y siga las instrucciones del fabricante para la lectura.</li>
</ol>

<ol>
	<li>Cox, B., Emili, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue+subcellular+fractionation+and+protein+extraction+for+use+in+mass-spectrometry-based+proteomics.">Tissue subcellular fractionation and protein extraction for use in mass-spectrometry-based proteomics.</a> Nature Protocols. 1 (4), 1872-1878 (2006).</li><li>Itzhak, D. N., Tyanova, S., Cox, J., Borner, G. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Global,+quantitative+and+dynamic+mapping+of+protein+subcellular+localization.">Global, quantitative and dynamic mapping of protein subcellular localization.</a> eLife. 5, (2016).</li><li>Preedy, V. R., Watson, R. R., Ronald, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Methods in disease investigating the gastrointestinal tract. , (1998).</li><li>Alex, P., Gucek, M., Li, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Applications+of+proteomics+in+the+study+of+inflammatory+bowel+diseases:+Current+status+and+future+directions+with+available+technologies.">Applications of proteomics in the study of inflammatory bowel diseases: Current status and future directions with available technologies.</a> Inflammatory bowel diseases. 15 (4), 616-629 (2009).</li><li>Ericsson, C., Franz&#233;n, B., Nist&#233;r, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Frozen+tissue+biobanks.+Tissue+handling,+cryopreservation,+extraction,+and+use+for+proteomic+analysis.">Frozen tissue biobanks. Tissue handling, cryopreservation, extraction, and use for proteomic analysis.</a> Acta oncologica (Stockholm, Sweden). 45 (6), 643-661 (2006).</li><li>Hoffmann, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+application+of+a+subcellular+fractionation+method+to+kidney+and+testis+for+the+determination+of+conjugated+linoleic+acid+in+selected+cell+organelles+of+healthy+and+cancerous+human+tissues.">New application of a subcellular fractionation method to kidney and testis for the determination of conjugated linoleic acid in selected cell organelles of healthy and cancerous human tissues.</a> Analytical and Bioanalytical Chemistry. 381 (6), 1138-1144 (2005).</li><li>Foster, L. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Mammalian+Organelle+Map+by+Protein+Correlation+Profiling.">A Mammalian Organelle Map by Protein Correlation Profiling.</a> Cell. 125 (1), 187-199 (2006).</li><li>Baghirova, S., Hughes, B. G., Hendzel, M. J., Schulz, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sequential+fractionation+and+isolation+of+subcellular+proteins+from+tissue+or+cultured+cells.">Sequential fractionation and isolation of subcellular proteins from tissue or cultured cells.</a> MethodsX. 2, e440-e445 (2015).</li><li>B&#246;rner, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subcellular+protein+extraction+from+human+pancreatic+cancer+tissues.">Subcellular protein extraction from human pancreatic cancer tissues.</a> BioTechniques. 46 (4), 297-304 (2009).</li><li>Antalis, T. M., Shea-Donohue, T., Vogel, S. 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Los autores no tienen nada que revelar.

El protocolo aquí descrito se utiliza para el fraccionamiento citoplasmático y nuclear de las biopsias intestinales. Las proteínas purificadas no son desnaturalizadas y puede ser utilizadas no sólo en el análisis de western blot como se muestra en la figura 2 y 3 y también en ensayos que requieren proteínas doblado nativo como inmunoprecipitación, análisis de cambio de movilidad electroforética (EMSA) o electroforesis en gel de poliacrilamida nativo (página).
...

Las proteínas participan en casi todas las funciones biológicas dentro de una célula y cualquier variación en su estructura, la cantidad o la ubicación puede conducir a un escenario de patógeno. Métodos de fraccionamiento de muestras de tejido son un método útil para reducir la complejidad de la enfermedad relacionados con el análisis de la proteína. Algunos estudios utilizan información de localización de la proteína o enriquecen una proteína de un compartimento celular específico, por lo que un protocolo reproducible fraccionamiento de proteínas intactas es útil para responder a ciertas cuestiones biológicas. Determinación de la localización subcelular de las proteínas y vigilar su redistribución compartimentación o interacciones en basal y las condiciones de la enfermedad ayudará a identificar la enfermedad relacionada con las diferencias funcionales1,2. Así, este método pretende fraccionar reproducible las biopsias de tejido intestinal, frescas y congeladas, en compartimentos subcelulares citoplásmicas y nucleares.
Las muestras de biopsia intestinal habitualmente se obtienen durante la endoscopia procedimientos3 (figura 1) y pueden ser utilizadas eficazmente para la cuantificación de la proteína o los estudios de inmunoprecipitación. Puesto que las muestras de tejido del intestinal epitelios contiene proteínas que pueden estar directamente involucradas en la patogénesis de la enfermedad4, las muestras de biopsia intestinal son una fuente muy valiosa para la identificación exitosa de específicos de la enfermedad intestinal proteínas. Muestras de tejido congelado, paciente almacenados junto con la información clínica son recursos útiles para el análisis de la proteína, y una preparación simple y reproducible es una cuestión clave para proporcionar información de compartimentación celular utilizando cantidades limitantes de congelados tejido5.
Hay varios kits disponibles en el mercado para la separación de fracciones celulares, pero son más caras y generalmente más lento que el protocolo presentado aquí. Protocolos basados en varios pasos centrifugación degradado y gradientes continuos también se han utilizado previamente para el fraccionamiento de los diversos compartimentos celulares en diferentes tejidos6,7. Sin embargo, mantener la consistencia de gradientes continuos suele ser una tarea difícil. Similares protocolos basados en la secuencial lisis de las membranas se han descrito anteriormente pero generalmente necesitan más de dos tampones y las manos el tiempo es más largo8 .
Fraccionamiento de muestras de tejido, tener en cuenta ese tejido muestras presentes célula-célula y célula-matriz de interacciones que son no presentes en células cultivadas e importantes cuando proceder a la extracción de proteínas. El adecuado desglose entre células y matriz extracelular sin afectar la calidad de la proteína será un factor crítico en el tejido intestinal proteínas aislamiento9. En este protocolo, contactos célula-célula y célula matriz primero se rompen, liberando las células y permitiendo que el búfer llegar a las células individuales. Para evitar la proteína-compartimiento de mezcla antes del fraccionamiento, la ruptura de los contactos debe ocurrir sin alterar la integridad de las células o las membranas nucleares.
Por el enriquecimiento de distintas proteasas en la mucosa intestinal10, es importante para el control de la degradación de la proteína durante la extracción. Para minimizar la potencial degradación de las proteínas, múltiples inhibidores de proteasa deben incluirse en los buffers de extracción de proteína. Además, si extractos van a utilizarse para el análisis funcionales, es esencial para evitar la desnaturalización de las proteínas o la proteólisis, pues esto ocasionará una pérdida de proteína actividad11. Para ello, el protocolo se lleva a cabo a 4 ° C y fresco phenylmethylsulfonyl fluoruro (PMSF) se añade a los buffers en una concentración final de 0,1 mM justo antes de usar además inhibir la proteólisis.
El primer paso en el fraccionamiento celular es interrupción de tejido y lisis celular. Como se mencionó anteriormente, el objetivo es separar las células y les abren con mínimo daño de rotura. Las muestras de tejido intestinal deben ser homogeneizadas y lisis de las células para lograr máxima rotura de la membrana celular. En este protocolo, utilizamos una batidora de mano motorizado para romper el tejido intestinal que se homogeneiza dentro de segundos por medio de la acción de Vortex de alta velocidad. Después de la homogeneización, se incuban las células del tejido en un tampón hipotónico que estallará la membrana de la célula pero mantendrá los núcleos intactos, seguido por la adición de un detergente no desnaturalizantes (nonil phenoxypolyethoxylethanol) y un vortex corto para separar los núcleos de la fracción citoplasmática. Después de la separación del citoplasma, la membrana celular de los núcleos es irrumpió en un buffer hipertónico con agitación.
El método presentado aquí es un método adecuado para el fraccionamiento subcelular de las biopsias intestinales frescos y congelados que se han obtenido durante procedimientos endoscópicos y oscilan entre los 2 y 10 mg de peso. El protocolo es fácil y reproducible y se podría realizar utilizando equipos de laboratorio básicos y reactivos en menos de una hora.

<table border="0" cellpadding="0" cellspacing="0" style="width:657px;" width="658">
	<tbody>
		<tr height="22">
			<td height="22" style="height:23px;width:244px;">HEPES</td>
			<td style="width:128px;">Sigma Aldrich</td>
			<td style="width:119px;">H4034-1kg</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:23px;width:244px;">KCl</td>
			<td style="width:128px;">Sigma Aldrich</td>
			<td style="width:119px;">P9333-1kg</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:23px;width:244px;">EDTA</td>
			<td style="width:128px;">Sigma Aldrich</td>
			<td style="width:119px;">E9884-100G</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:23px;width:244px;">NaCl</td>
			<td style="width:128px;">Sigma Aldrich</td>
			<td style="width:119px;">5588886-1kg</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:23px;width:244px;">DTT</td>
			<td style="width:128px;">Sigma Aldrich</td>
			<td style="width:119px;">10197777001</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:23px;width:244px;">PMSF</td>
			<td style="width:128px;">Thermo Scientific</td>
			<td style="width:119px;">36978</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:23px;width:244px;">Proteinase and phosphatase inhibitors</td>
			<td style="width:128px;">Thermo Scientific</td>
			<td style="width:119px;">A32959</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:23px;width:244px;">NP-40&#160;</td>
			<td style="width:128px;">Sigma Aldrich</td>
			<td style="width:119px;">CA-630</td>
			<td>Detergent</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:23px;width:244px;">BCA assay</td>
			<td style="width:128px;">Thermo Scientific</td>
			<td style="width:119px;">23227</td>
			<td>Protein quantification kit</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:23px;width:244px;">Disposable plastic pestles</td>
			<td style="width:128px;">Sigma Aldrich</td>
			<td style="width:119px;">Z359947-100EA</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:23px;width:244px;">Dounce homogeneizer</td>
			<td style="width:128px;">VWR</td>
			<td style="width:119px;">431-0100</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:23px;width:244px;">Microcentrifuge</td>
			<td style="width:128px;">Eppendorf</td>
			<td style="width:119px;">5415-R</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:23px;width:244px;">Shacker</td>
			<td style="width:128px;">IKA</td>
			<td style="width:119px;">MS3 basic</td>
			<td></td>
		</tr>
	</tbody>
</table>

subcellular fractionation from fresh and frozen gastrointestinal specimens

El propósito de este protocolo es fraccionar tejido intestinal humano obtenido por endoscopia en compartimentos citoplásmicos y nucleares para el análisis de localización de proteínas específicas o complejos de proteína en Estados diferentes del tejido (es decir, saludable frente a la enfermedad). Este método es útil para el fraccionamiento de ambas muestras de tejido intestinal frescos y congelados; es fácilmente accesible para todos los laboratorios y no requiere mucho tiempo.

La figura 1 muestra una hematoxilina eosina de una sección de la biopsia intestinal con las vellosidades intactas y las estructuras de la cripta.
Resultados representativos de fraccionamiento citoplasmática y nuclear mediante este protocolo se muestran en las figuras 2 y 3. En el experimento se muestra en la figura 2, un fresco (Fh) y...

Watch this Scientific Journal Video about Subcellular Fractionation from Fresh and Frozen Gastrointestinal Specimens at JoVE.com

Subcellular Fractionation from Fresh and Frozen Gastrointestinal Specimens

Aquí, presentamos un protocolo para realizar un fraccionamiento celular simple para la separación subcelular de proteínas citoplásmicas y nucleares en biopsias intestinales humanas frescas y congeladas.

Fraccionamiento subcelular de especímenes gastrointestinales frescos y congelados

The purpose of this protocol is to fractionate human intestinal tissue obtained by endoscopy into nuclear and cytoplasmic compartments for the ...

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9.6K vistas.  University of the Basque Country (UPV-EHU), Biocruces Health Research Institute. Aquí, presentamos un protocolo para realizar un fraccionamiento celular simple para la separación subcelular de proteínas citoplásmicas y nucleares en biopsias intestinales humanas frescas y congeladas.

Video: Subcellular Fractionation from Fresh and Frozen Gastrointestinal Specimens

Combination of Adhesive-tape-based Sampling and Fluorescence in situ Hybridization for Rapid Detection of Salmonella on Fresh Produce

This protocol describes a simple approach for adhesive-tape-based sampling of tomato and other fresh produce surfaces, followed by on-tape fluorescence in situ hybridization (FISH) for rapid culture-independent detection of Salmonella spp. Cell-charged tapes can also be placed face-down on selective agar for solid-phase enrichment prior to detection. Alternatively, low-volume liquid enrichments (liquid surface miniculture) can be performed on the surface of the tape in non-selective broth, followed by FISH and analysis via flow cytometry. To begin, sterile adhesive tape is brought into contact with fresh produce, gentle pressure is applied, and the tape is removed, physically extracting microbes present on these surfaces. Tapes are mounted sticky-side up onto glass microscope slides and the sampled cells are fixed with 10% formalin (30 min) and dehydrated using a graded ethanol series (50, 80, and 95%; 3 min each concentration). Next, cell-charged tapes are spotted with buffer containing a Salmonella-targeted DNA probe cocktail and hybridized for 15 - 30 min at 55&deg;C, followed by a brief rinse in a washing buffer to remove unbound probe. Adherent, FISH-labeled cells are then counterstained with the DNA dye 4',6-diamidino-2-phenylindole (DAPI) and results are viewed using fluorescence microscopy. For solid-phase enrichment, cell-charged tapes are placed face-down on a suitable selective agar surface and incubated to allow in situ growth of Salmonella microcolonies, followed by FISH and microscopy as described above. For liquid surface miniculture, cell-charged tapes are placed sticky side up and a silicone perfusion chamber is applied so that the tape and microscope slide form the bottom of a water-tight chamber into which a small volume (&le; 500 &mu;L) of Trypticase Soy Broth (TSB) is introduced. The inlet ports are sealed and the chambers are incubated at 35 - 37&deg;C, allowing growth-based amplification of tape-extracted microbes. Following incubation, inlet ports are unsealed, cells are detached and mixed with vigorous back and forth pipetting, harvested via centrifugation and fixed in 10% neutral buffered formalin. Finally, samples are hybridized and examined via flow cytometry to reveal the presence of Salmonella spp. As described here, our "tape-FISH" approach can provide simple and rapid sampling and detection of Salmonella on tomato surfaces. We have also used this approach for sampling other types of fresh produce, including spinach and jalape&ntilde;o peppers.

Combination of Adhesive-tape-based Sampling and Fluorescence in situ Hybridization for Rapid Detection of Salmonella on Fresh Produce

This protocol describes a simple adhesive-tape-based approach for sampling of tomato and other fresh produce surfaces, followed by rapid whole cell detection of Salmonella using fluorescence in situ hybridization (FISH).

Combinación de adhesivo basado en cinta de muestreo y de fluorescencia In situ La hibridación para la detección rápida de Salmonella En los productos frescos

This protocol describes a simple approach for adhesive-tape-based sampling of tomato and other fresh produce surfaces, followed by on-tape fluorescence in ...

Investigación

Inmunología e Infección

Competitive Homing Assays to Study Gut-tropic T Cell Migration

In order to exert their function lymphocytes need to leave the blood and migrate into different tissues in the body. Lymphocyte adhesion to endothelial cells and tissue extravasation is a multistep process controlled by different adhesion molecules (homing receptors) expressed on lymphocytes and their respective ligands (addressins) displayed on endothelial cells 1 2. Even though the function of these adhesion receptors can be partially studied ex vivo, the ultimate test for their physiological relevance is to assess their role during in vivo lymphocyte adhesion and migration. Two complementary strategies have been used for this purpose: intravital microscopy (IVM) and homing experiments. Although IVM has been essential to define the precise contribution of specific adhesion receptors during the adhesion cascade in real time and in different tissues, IVM is time consuming and labor intensive, it often requires the development of sophisticated surgical techniques, it needs prior isolation of homogeneous cell populations and it permits the analysis of only one tissue/organ at any given time. By contrast, competitive homing experiments allow the direct and simultaneous comparison in the migration of two (or even more) cell subsets in the same mouse and they also permit the analysis of many tissues and of a high number of cells in the same experiment.
Here we describe the classical competitive homing protocol used to determine the advantage/disadvantage of a given cell type to home to specific tissues as compared to a control cell population. We chose to illustrate the migratory properties of gut-tropic versus non gut-tropic T cells, because the intestinal mucosa is the largest body surface in contact with the external environment and it is also the extra-lymphoid tissue with the best-defined migratory requirements. Moreover, recent work has determined that the vitamin A metabolite all-trans retinoic acid (RA) is the main molecular mechanism responsible for inducing gut-specific adhesion receptors (integrin a4b7and chemokine receptor CCR9) on lymphocytes. Thus, we can readily generate large numbers of gut-tropic and non gut-tropic lymphocytes ex vivoby activating T cells in the presence or absence of RA, respectively, which can be finally used in the competitive homing experiments described here.

Competitive homing experiments allow to directly assessing the migratory properties of two different cell populations in a single mouse. Here we illustrate this procedure by comparing the migration of ex vivo-generated gut-tropic versus non-gut tropic T cells.

Los análisis competitivos de Homing para el Estudio de la tripa-trópico migración de células T

In order to exert their function lymphocytes need to leave the blood and migrate into different tissues in the body. Lymphocyte adhesion to endothelial ...

RNA Isolation of Pseudomonas aeruginosa Colonizing the Murine Gastrointestinal Tract

Pseudomonas aeruginosa (PA) infections result in significant morbidity and mortality in hosts with compromised immune systems, such as patients with leukemia, severe burn wounds, or organ transplants1. In patients at high-risk for developing PA bloodstream infections, the gastrointestinal (GI) tract is the main reservoir for colonization2, but the mechanisms by which PA transitions from an asymptomatic colonizing microbe to an invasive, and often deadly, pathogen are unclear. Previously, we performed in vivo transcription profiling experiments by recovering PA mRNA from bacterial cells residing in the cecums of colonized mice 3 in order to identify changes in bacterial gene expression during alterations to the host&#x2019;s immune status.
As with any transcription profiling experiment, the rate-limiting step is in the isolation of sufficient amounts of high quality mRNA. Given the abundance of enzymes, debris, food residues, and particulate matter in the GI tract, the challenge of RNA isolation is daunting. Here, we present a method for reliable and reproducible isolation of bacterial RNA recovered from the murine GI tract. This method utilizes a well-established murine model of PA GI colonization and neutropenia-induced dissemination4. Once GI colonization with PA is confirmed, mice are euthanized and cecal contents are recovered and flash frozen. RNA is then extracted using a combination of mechanical disruption, boiling, phenol/chloroform extractions, DNase treatment, and affinity chromatography. Quantity and purity are confirmed by spectrophotometry (Nanodrop Technologies) and bioanalyzer (Agilent Technologies) (Fig 1). This method of GI microbial RNA isolation can easily be adapted to other bacteria and fungi as well.

RNA Isolation of Pseudomonas aeruginosa Colonizing the Murine Gastrointestinal Tract

A reliable method for the RNA isolation of Pseudomonas aeruginosa recovered from murine cecums is described. The RNA recovered is of sufficient quantity and quality for subsequent qPCR, transcription profiling, and RNA Seq experiments. This technique can be adapted for RNA isolation of other intestinal microbes.

El aislamiento de ARN Pseudomonas aeruginosa Que colonizan el tracto gastrointestinal murino

Pseudomonas aeruginosa (PA) infections result in significant morbidity and mortality in hosts with compromised immune systems, such as patients with ...

Optimized Protocols for Mycobacterium leprae Strain Management: Frozen Stock Preservation and Maintenance in Athymic Nude Mice

Leprosy, caused by Mycobacterium leprae, is an important infectious disease that is still endemic in many countries around the world, including Brazil. There are currently no known methods for growing M. leprae in vitro, presenting a major obstacle in the study of this pathogen in the laboratory. Therefore, the maintenance and growth of M. leprae strains are preferably performed in athymic nude mice (NU-Foxn1nu). The laboratory conditions for using mice are readily available, easy to perform, and allow standardization and development of protocols for achieving reproducible results. In the present report, we describe a simple protocol for purification of bacilli from nude mouse footpads using trypsin, which yields a suspension with minimum cell debris and with high bacterial viability index, as determined by fluorescent microscopy. A modification to the standard method for bacillary counting by Ziehl-Neelsen staining and light microscopy is also demonstrated. Additionally, we describe a protocol for freezing and thawing bacillary stocks as an alternative protocol for maintenance and storage of M. leprae strains.

Optimized Protocols for Mycobacterium leprae Strain Management: Frozen Stock Preservation and Maintenance in Athymic Nude Mice

Mycobacterium leprae, the causative agent of leprosy, does not grow in vitro. We describe an easy to follow protocol to prepare a bacillary suspension to ensure the maintenance of large quantities of M. leprae for a variety of applications. Protocols for propagation by mouse footpad inoculation, evaluation of viability, freezing and thawing bacillary stock are described in detail.

Protocolos optimizados para<em&gt; Mycobacterium leprae</em&gt; Gestión Strain: Congelado Stock Conservación y Mantenimiento en ratones desnudos atímicos

Leprosy, caused by Mycobacterium leprae, is an important infectious disease that is still endemic in many countries around the world, including Brazil. ...

A Simple and Rapid Protocol to Non-enzymatically Dissociate Fresh Human Tissues for the Analysis of Infiltrating Lymphocytes

The ability of malignant cells to evade the immune system, characterized by tumor escape from both innate and adaptive immune responses, is now accepted as an important hallmark of cancer. Our research on breast cancer focuses on the active role that tumor infiltrating lymphocytes play in tumor progression and patient outcome. Toward this goal, we developed a methodology for the rapid isolation of intact lymphoid cells from normal and abnormal tissues in an effort to evaluate them proximate to their native state. Homogenates prepared using a mechanical dissociator show both increased viability and cell recovery while preserving surface receptor expression compared to enzyme-digested tissues. Furthermore, enzymatic digestion of the remaining insoluble material did not recover additional CD45+ cells indicating that quantitative and qualitative measurements in the primary homogenate likely genuinely reflect infiltrating subpopulations in the tissue fragment. The lymphoid cells in these homogenates can be easily characterized using immunological (phenotype, proliferation, etc.) or molecular (DNA, RNA and/or protein) approaches. CD45+ cells can also be used for subpopulation purification, in vitro expansion or cryopreservation. An additional benefit of this approach is that the primary tissue supernatant from the homogenates can be used to characterize and compare cytokines, chemokines, immunoglobulins and antigens present in normal and malignant tissues. This protocol functions extremely well for human breast tissues and should be applicable to a wide variety of normal and abnormal tissues.

This protocol describes the rapid non-enzymatic dissociation of fresh human tissue fragments for qualitative and quantitative assessment of CD45+ cells (lymphocytes/leukocytes) present in various normal and malignant human tissues. Additionally, the supernatant obtained from the primary tissue homogenate can be collected and stored for further analysis or experimentation.

Un protocolo simple y rápida para no enzimáticamente disociarse Tejidos Humanos frescas para el Análisis de los linfocitos infiltrantes

The ability of malignant cells to evade the immune system, characterized by tumor escape from both innate and adaptive immune responses, is now accepted ...

Induction of Murine Intestinal Inflammation by Adoptive Transfer of Effector CD4+CD45RBhigh T Cells into Immunodeficient Mice

There are many different animal models available for studying the pathogenesis of human inflammatory bowel diseases (IBD), each with its own advantages and disadvantages. We describe here an experimental colitis model that is initiated by adoptive transfer of syngeneic splenic CD4+CD45RBhigh T cells into T and B cell deficient recipient mice. The CD4+CD45RBhigh T cell population that largely consists of na&#239;ve effector cells is capable of inducing chronic intestinal inflammation, closely resembling key aspects of human IBD. This method can be manipulated to study aspects of disease onset and progression. Additionally it can be used to study the function of innate, adaptive, and regulatory immune cell populations, and the role of environmental exposures, i.e., the microbiota, in intestinal inflammation. In this article we illustrate the methodology for inducing colitis with a step-by-step protocol. This includes a video demonstration of key technical aspects required to successfully develop this murine model of experimental colitis for research purposes.

Induction of Murine Intestinal Inflammation by Adoptive Transfer of Effector CD4+CD45RBhigh T Cells into Immunodeficient Mice

Here, we present a protocol to induce colonic inflammation in mice by adoptive transfer of syngeneic CD4+CD45RBhigh T cells into T and B cell deficient recipients. Clinical and histopathological features mimic human inflammatory bowel diseases. This method allows the study of the initiation of colonic inflammation and progression of disease.

La inducción de la inflamación intestinal murino por transferencia adoptiva de Efector CD4<sup&gt; +</sup&gt; CD45RB<sup&gt; Alta</sup&gt; T células en ratones inmunodeficientes

There are many different animal models available for studying the pathogenesis of human inflammatory bowel diseases (IBD), each with its own advantages ...

Transformation of Probiotic Yeast and Their Recovery from Gastrointestinal Immune Tissues Following Oral Gavage in Mice

Development of recombinant oral therapy would allow for more direct targeting of the mucosal immune system and improve the ability to combat gastrointestinal disorders. Adapting probiotic yeast in particular for this approach carries several advantages. These strains have not only the potential to synthesize a wide variety of complex heterologous proteins but are also capable of surviving and protecting those proteins during transit through the intestine. Critically, however, this approach requires expertise in many diverse laboratory techniques not typically used in tandem. Furthermore, although individual protocols for yeast transformation are well characterized for commonly used laboratory strains, emphasis is placed here on alternative approaches and the importance of optimizing transformation for less well characterized probiotic strains. Detailing these methods will help facilitate discussion as to the best approaches for testing probiotic yeast as oral drug delivery vehicles and indeed serve to advance the development of this novel strategy for gastrointestinal therapy.

Presented here is a unified description of techniques that can be used to develop, transform, administer, and test heterologous protein expression of the probiotic yeast Saccharomyces boulardii.

Transformación de la levadura probiótica y su recuperación de tejidos gastrointestinales inmune después de alimentación forzada oral en ratones

Development of recombinant oral therapy would allow for more direct targeting of the mucosal immune system and improve the ability to combat ...

High-throughput Detection of Respiratory Pathogens in Animal Specimens by Nanoscale PCR

Nanoliter scale real-time PCR uses spatial multiplexing to allow multiple assays to be run in parallel on a single plate without the typical drawbacks of combining reactions together. We designed and evaluated a panel based on this principle to rapidly identify the presence of common disease agents in dogs and horses with acute respiratory illness. This manuscript describes a nanoscale diagnostic PCR workflow for sample preparation, amplification, and analysis of target pathogen sequences, focusing on procedures that are different from microliter scale reactions. In the respiratory panel presented, 18 assays were each set up in triplicate, accommodating up to 48 samples per plate. A universal extraction and pre-amplification workflow was optimized for high-throughput sample preparation to accommodate multiple matrices and DNA and RNA based pathogens. Representative data are presented for one RNA target (influenza A matrix) and one DNA target (equine herpesvirus 1). The ability to quickly and accurately test for a comprehensive, syndrome-based group of pathogens is a valuable tool for improving efficiency and ergonomics of diagnostic testing and for acute respiratory disease diagnosis and management.

High-throughput testing of DNA and RNA based pathogens by nanoscale PCR is described using a syndromic canine and equine respiratory PCR panel.

La detección de alto rendimiento de los patógenos respiratorios de especímenes animales por PCR nanoescala

Nanoliter scale real-time PCR uses spatial multiplexing to allow multiple assays to be run in parallel on a single plate without the typical drawbacks of ...

Live-Cell Fluorescence Microscopy to Investigate Subcellular Protein Localization and Cell Morphology Changes in Bacteria

Investigations of factors influencing cell division and cell shape in bacteria are commonly performed in conjunction with high-resolution fluorescence microscopy as observations made at a population level may not truly reflect what occurs at a single cell level. Live-cell timelapse microscopy allows investigators to monitor the changes in cell division or cell morphology which provide valuable insights regarding subcellular localization of proteins and timing of gene expression, as it happens, to potentially aid in answering important biological questions. Here, we describe our protocol to monitor phenotypic changes in Bacillus subtilis and Staphylococcus aureus using a high-resolution deconvolution microscope. The objective of this report is to provide a simple and clear protocol that can be adopted by other investigators interested in conducting fluorescence microscopy experiments to study different biological processes in bacteria as well as other organisms.

This article provides a step-by-step guide to investigate protein subcellular localization dynamics and to monitor morphological changes using high-resolution fluorescence microscopy in Bacillus subtilis and Staphylococcus aureus.

Microscopía de Fluorescencia de Células Vivas para Investigar la Localización de Proteínas Subcelulares y Cambios de Morfología Celular en Bacterias

Investigations of factors influencing cell division and cell shape in bacteria are commonly performed in conjunction with high-resolution fluorescence ...

Isolation of Macrophage Subsets and Stromal Cells from Human and Mouse Myocardial Specimens

Macrophages represent the most heterogeneous and abundant immune cell populations in the heart and are central in driving inflammation and reparative responses after cardiac injury. How various subsets of macrophages orchestrate the immune responses after cardiac injury is an active area of research. Presented here is a simple protocol that our lab performs routinely, for the extraction of macrophages from mouse and human myocardium specimens obtained from healthy and diseased individuals. Briefly, this protocol involves enzymatic digestion of cardiac tissue to generate a single cell suspension, followed by antibody staining, and flow cytometry. This technique is suitable for functional assays performed on sorted cells as well as bulk and single cell RNA sequencing. A major advantage of this protocol is its simplicity, minimal day to day variation and wide applicability allowing investigation of macrophage heterogeneity across various mouse models and human disease entities.

Presented here is a protocol to isolate various subsets of macrophages and other non-immune cells from human and mouse myocardium by preparing a single cell suspension through enzymatic digestion. Gating schemes for flow cytometry based identification and characterization of isolated macrophages are also presented.

Aislamiento de subconjuntos de macrófagos y células estromas de especímenes miocárgonos humanos y de ratón

Macrophages represent the most heterogeneous and abundant immune cell populations in the heart and are central in driving inflammation and reparative ...