Instituto de Ciencias de la UTMB traslacional-NIH subvención 1UL1RR029876-01 y Prather Alisha por su ayuda con la edición de vídeo de este manuscrito.

1. Preparación Animal <ol><li> Llegada Animal: Al llegar al nivel de Bioseguridad Animal 2 (ABSL2) instalaciones, permiten a los animales un mínimo de 2 días para aclimatarse a su nuevo entorno. Tras este período de descanso, inspeccionar a los animales para evaluar su salud y apariencia física en general. <ol><li> Cuando se utilizan los reporteros fluorescentes es importante para situar todos los sujetos animales con una dieta libre de alfalfa para limitar la cantidad de autofluorescencia GI y la señal de fondo. </li></ol></li><li> Afeitado animales: Para mejorar la señal bioluminiscente detectado desde la región craneal durante la exploración; afeitarse las cabezas de todos los animales. Anestesiar a los animales con una mezcla de oxígeno y gas vaporizado isoflurano. Una vez que los animales son completamente anestesiado, usar maquinillas eléctricas de afeitar sus cabezas. Una vez finalizado el afeitado, devolver los animales a sus jaulas y observar para la recuperación completa de los efectos de la anestesia. </li><li> Bio Medic DataSystems (CMBD) de transpondedor de inserción (que tendrá lugar tras el afeitado de los ratones, mientras que los animales están completamente anestesiados): Para un medio menos invasivos para el seguimiento de un implante temperatura preprogramada BMDS transponder inalámbrica vía subcutánea en la región dorsal de cada ratón. Estos transpondedores permiten la identificación inalámbrica y registro de la temperatura. Tras la implantación del transpondedor, aplicar un adhesivo de tejido veterinario de grado a la herida. </li><li> Colección de referencia: Antes de la infección, registre una temperatura de referencia y el peso de todos los animales. Recoger la sangre por neutralización por reducción de placas de prueba (PRNT) el análisis a través de retro-orbitales (RO) de purga mientras que los ratones están bajo anestesia. Tras la extracción de sangre, aplique ungüento antibiótico veterinario ojo para reducir el potencial de infección bacteriana secundaria. Esta colección de línea de base debe ser completada con consideración a la cantidad de veces que los animales se colocaron bajo anestesia debido a la tensión en los ratones. Las futuras colecciones ro should ser completada después de formación de imágenes, mientras que el ratón está todavía bajo anestesia. La sangre obtenida de un máximo RO debe estar alrededor de 200 l. </li><li> Infección: ratones a cabo bajo anestesia como se describe anteriormente. Inocular a través de la vía intranasal con una dosis de 5x10 a 5x10 6 7 ufp TC83-luciferasa en un volumen total de 40 l diluido por Tampón fosfato salino (PBS) a través de la infección intranasal. Después de la infección, los ratones colocar dentro de su jaula de alojamiento y observar la recuperación. </li></ol> 2. Animal de imágenes Descargo de responsabilidad: mantener a los ratones dentro de su unidad de vivienda, el gabinete de seguridad biológica (BSC) o el cuadro de contención XIC en todo momento. El BSC aprobados para este protocolo son una clase B1 o B2 Tipo II. <ol><li> Inyectar todos los animales con 10 l por gramo de peso corporal de intraperitoneal (IP) luciferina en una concentración de 15 mg / ml. <ol><li> Los ratones que recibieron Ampligen son para ser injected IP a una dosis de 12,5 mg de peso corporal / kg a -4 h después de la infección o 48 h después de la infección en base a su grupo. </li></ol></li><li> Antes de la inyección con luciferina, separar los ratones en grupos de tres a asegurar un ajuste apropiado dentro de la caja de contención XIC-3. <ol><li> Para todos obtención de imágenes, utilizar pomada ocular / lubricante para evitar el secado de la córnea durante todo el procedimiento. </li></ol></li><li> Abra el software LivingImage y pulse Iniciar para preparar el cuadro de imagen, ahorro de ajuste automático, el tiempo de exposición en automático (tiempo de exposición de automóviles es una nueva característica del software LivingImage 3.2 y posteriores), ver el campo a C, y el filtro para abrir; campo de vista se basa en el número de ratones que son imágenes; filtro y se puede optimizar según sea necesario para los proyectos de diagnóstico por imágenes. </li><li> Asegúrese de que los filtros de carbón del aire no han expirado, el tanque de oxígeno está llena, y el depósito lleno se isoflurano. Coloque pequeñas tiras de cinta aislante en la XIC-3 icaja solation que ayuda a reducir el movimiento de animales durante la exploración. </li><li> Inyectar a los ratones con IP luciferina como se describe en la sección 2.1 y el lugar dentro de la cámara de inducción isoflurano (con la tapa abierta) durante 3-5 min. </li><li> Después de 5 min, cerrar la tapa de la cámara de inducción e iniciar el flujo de isoflurano. El anestésico se hace funcionar a aproximadamente 3-5% de oxígeno con el conjunto de velocidad de flujo de aproximadamente 2,0 L / min. Una vez completamente inconsciente esperar otros 30 segundos y la transferencia de los ratones a la caja de aislamiento XIC-3. Asegúrese de que el gabinete de bioseguridad que se utilizan para el seguro permite la compactación de isoflurano ya que este procedimiento implicará la pérdida de isoflurano de la cámara de inducción (la unidad IVIS contiene sus propios recipientes pasivos Justo y la caja de contención XIC-3 se conecta directamente a la entrada / salida de sockets para asegurar contenida flujo anestésico). <ol><li> Transfiera los ratones en base a número de chip / grupo en el cuadro de aislamiento XIC-3 con el conector conectado un isofluranod abrir. Coloque los ratones para que ellos se ponen en decúbito esternal con la cabeza suavemente descansando sobre las tiras de cinta. </li></ol></li><li> Limpie la caja de contención XIC con las manos etanol spray, y el fondo del XIC-3 con Cavicide, y transferir a la cámara de imágenes IVIS. Vuelva a conectar la anestesia a la caja de contención una vez dentro de la unidad de imagen. </li><li> Después de 10 min después de la inyección de luciferina, la imagen de los ratones a través del software de imagen viva. </li><li> Siguiendo imagen inicial con un filtro abierto, iniciar un dlit 3-Dimensional imágenes usando el análisis de la secuencia y la configuración de imagen Asistente para bioluminiscente luciferasa de luciérnaga. Este proceso de formación de imágenes se llevará a 4-5 min y se debe completar en un campo de vista relevantes para el número de ratones deseados. <ol><li> Ex-vivo análisis es posible siguiente necropsia y recolección del cerebro. Coloque el cerebro en una placa de Petri estéril, goteo 50-100 l de acciones luciferina en la parte superior, y el lugar dentro de la imaging caja. </li></ol></li><li> Finalizar un segundo filtro de imagen abierto en 15-17 min después de la infección sobre la terminación de la imagen dlit. Asegúrese de análisis de la secuencia está apagado y el campo de visión y la configuración de los filtros se devuelven a la configuración anterior. </li></ol> 3. Ratones retorno y Análisis de Datos <ol><li> Apague el vaporizador de isoflurano y transferir la caja de contención XIC de nuevo a la cabina de bioseguridad. </li><li> Coloque los ratones de vuelta dentro de su vivienda, cierre la tapa, rocíe el exterior con un desinfectante apropiado y vuelva a colocarlo en el estante de la vivienda. <ol><li> Asegurar que los ratones se haya recuperado de la anestesia. </li></ol></li><li> Repita el procedimiento anterior según el experimento requiere hasta que imagen se ha completado. </li><li> Desinfectar el BSC, apagar el equipo, y transferir todos los datos a una ubicación fuera de laboratorio para un análisis adicional. </li><li> Analizar los datos y generar imágenes en 3 dimensiones sobre la base de los resultados de IVIS utiLizing el software LivingImage. <ol><li> Asegúrese de que la imagen está correctamente orientada y la iluminación / balance de color se establece. Dentro de la paleta de herramientas las opciones incluyen ajuste de imagen, correcciones, datos de imagen y herramientas de ROI. </li><li> Utilizar las formas de ROI para identificar los puntos fuertes específicos de señales basados ​​en ubicación. </li><li> Reconstruir la topografía de la superficie para resaltar el cuerpo del ratón, inicializar reconstrucción 3D dlit, y utilizar en forma lineal para ajustar el mapa órgano para la reconstrucción topográfica. </li></ol></li><li> Un análisis más detallado de titulación viral se puede completar mediante la recogida de sangre y órganos. Titulación en este estudio se completó mediante la homogeneización de tejido cerebral en medio de Eagle modificado (MEM). El homogeneizado se diluyó en serie y se infectaron una placa de 6 pocillos de células Vero durante 1 hr. Las células se cubrieron con una capa de agarose/2xMEM 1,5% y se incubaron durante 2 días a 37 grados. Las células fueron fijadas con 10% de formalina durante 30 min y se tiñeron concristal violeta. </li></ol>

<ol>
	<li>Steele, K. E., 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=Comparative+Neurovirulence+and+Tissue+Tropism+of+Wild-type+and+Attenuated+Strains+of+Venezuelan+Equine+Encephalitis+Virus+Administered+by+Aerosol+in+C3H/HeN+and+BALB/c+Mice.">Comparative Neurovirulence and Tissue Tropism of Wild-type and Attenuated Strains of Venezuelan Equine Encephalitis Virus Administered by Aerosol in C3H/HeN and BALB/c Mice.</a> Veterinary Pathology Online. 35, 386-397 (1998).</li><li>Ludwig, G. V., 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=Comparative+neurovirulence+of+attenuated+and+non-attenuated+strains+of+Venezuelan+equine+encephalitis+virus+in+mice.">Comparative neurovirulence of attenuated and non-attenuated strains of Venezuelan equine encephalitis virus in mice.</a> Am. J. Trop. Med. Hyg. 64, 49-55 (2001).</li><li>Charles, P. C., Walters, E., Margolis, F., Johnston, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanism+of+Neuroinvasion+of+Venezuelan+Equine+Encephalitis+Virus+in+the+Mouse.">Mechanism of Neuroinvasion of Venezuelan Equine Encephalitis Virus in the Mouse.</a> Virology. , 208-662 (1995).</li><li>Volkova, E., Gorchakov, R., Frolov, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+efficient+packaging+of+Venezuelan+equine+encephalitis+virus-specific+RNAs+into+viral+particles+is+determined+by+nsP1-3+synthesis.">The efficient packaging of Venezuelan equine encephalitis virus-specific RNAs into viral particles is determined by nsP1-3 synthesis.</a> Virology. 344, 315-327 (2006).</li><li>Patterson, M., 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=Rapid,+non-invasive+imaging+of+alphaviral+brain+infection:+Reducing+animal+numbers+and+morbidity+to+identify+efficacy+of+potential+vaccines+and+antivirals.">Rapid, non-invasive imaging of alphaviral brain infection: Reducing animal numbers and morbidity to identify efficacy of potential vaccines and antivirals.</a> Vaccine. 29, 9345-9351 (2011).</li><li>Cook, S. H., Griffin, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Luciferase+Imaging+of+a+Neurotropic+Viral+Infection+in+Intact+Animals.">Luciferase Imaging of a Neurotropic Viral Infection in Intact Animals.</a> J. Virol. 77, 5333-5338 (2003).</li><li>Contag, P. R., Olomu, I. N., Stevenson, D. K., Contag, C. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioluminescent+indicators+in+living+mammals.">Bioluminescent indicators in living mammals.</a> Nat. Med. 4, 245-247 (1998).</li><li>Osorio, J. E., Iams, K. P., Meteyer, C. U., Rocke, T. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+Monkeypox+Viruses+Pathogenesis+in+Mice+by+In+Vivo+Imaging.">Comparison of Monkeypox Viruses Pathogenesis in Mice by In Vivo Imaging.</a> PLoS ONE. 4, e6592 (2009).</li><li>Luker, G. D., Prior, J. L., Song, J., Pica, C. M., Leib, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioluminescence+Imaging+Reveals+Systemic+Dissemination+of+Herpes+Simplex+Virus+Type+1+in+the+Absence+of+Interferon+Receptors.">Bioluminescence Imaging Reveals Systemic Dissemination of Herpes Simplex Virus Type 1 in the Absence of Interferon Receptors.</a> J. Virol. 77, 11082-11093 (2003).</li><li>Russell, W. M. S., Burch, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Principles of Humane Experimental Technique. , (1959).</li><li>Kuehne, R. W., Pannier, W. L., Stephen, E. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Indirect+mouse+model+for+the+evaluation+of+potential+antiviral+compounds:+results+with+Venezuelan+equine+encephalomyelitis+virus.">Indirect mouse model for the evaluation of potential antiviral compounds: results with Venezuelan equine encephalomyelitis virus.</a> Antimicrob. Agents Chemother. 11, (1977).</li><li>Lukaszewski, R. A., Brooks, T. J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pegylated+Alpha+Interferon+Is+an+Effective+Treatment+for+Virulent+Venezuelan+Equine+Encephalitis+Virus+and+Has+Profound+Effects+on+the+Host+Immune+Response+to+Infection.">Pegylated Alpha Interferon Is an Effective Treatment for Virulent Venezuelan Equine Encephalitis Virus and Has Profound Effects on the Host Immune Response to Infection.</a> J. Virol. 74, 5006-5015 (2000).</li></ol>

No hay conflictos de interés declarado.

Si bien este protocolo cubre los aspectos de formación de imágenes para el análisis in vivo, es importante reconocer el vector bioluminiscente como un factor clave para futuros estudios. Nuestra utilización de TC83, una cepa de vacuna atenuada de VEEV, como un vector para la expresión de la luciferasa asegura que grandes cantidades de la enzima se producen debido a la alta tasa de replicación del virus en el SNC como se describió previamente 1-4. Mientras que la adición de un promoto...

<table border="1"><tbody><tr><td> Nombre del reactivo </td><td> Empresa </td><td> Número de catálogo </td><td> Comentarios (opcional) </td></tr><tr><td> D-luciferina </td><td></td><td></td><td></td></tr><tr><td> El isoflurano </td><td></td><td></td><td></td></tr><tr><td> Xenogen IVIS System (Spectrum) </td><td> Caliper Life Sciences </td><td></td><td></td></tr><tr><td> XGI-8-gas Anestesia Sistema </td><td> Caliper Life Sciences </td><td></td><td></td></tr><tr><td> XIC-3 Caja de Contención </td><td> Caliper Life Sciences </td><td></td><td></td></tr><tr><td> LivingImage 4.0 Software </td><td> Caliper Life Sciences </td><td></td><td></td></tr><tr><td> Telemetría / identificación fichas </td><td> Bio Medic Data Systems </td><td> IPTT-300 </td><td> Identificación Animal y TemperATURALEZA </td></tr><tr><td> BD Integra jeringa de 1 ml con 26 TB gx 3/8 &quot;aguja </td><td> Fisher Scientific </td><td> 305279 </td><td></td></tr><tr><td> Bond Vet tejido adhesivo </td><td> Fisher Scientific </td><td> NC9259532 </td><td></td></tr><tr><td> Vetropolycin Ungüento Oftálmico </td><td> Webster veterinarios </td><td> 78444656 </td><td></td></tr><tr><td> Fosfato de Dulbecco 1X solución salina tamponada </td><td> Invitrogen </td><td> 14190-144 </td><td></td></tr><tr><td> BMDS chip lector </td><td> Bio Medic Data Systems </td><td> DAS-7007S </td><td></td></tr><tr><td> DAS-HOST Software </td><td> Bio Medic Data Systems </td><td></td><td> Se utiliza para descargar información de la sonda </td></tr></tbody></table>

in vivo imaging systems (ivis) detection of a neuro-invasive encephalitic virus

Los avances modernos en tecnología de imagen fomenten el desarrollo y refinamiento en la forma en que se realiza la investigación viral. Inicialmente propuesto por Russel y Burch en 3Rs Hume (reemplazo, reducción, refinamiento), la utilización de modelos animales en la investigación científica está bajo presión constante para identificar nuevas metodologías para reducir el uso de animales al tiempo que mejora la precisión científica y la velocidad. Un reto importante para los directores de Hume sin embargo, es cómo asegurar que los estudios son estadísticamente precisos y reducir la morbilidad de las enfermedades animales y los números totales. Estudios de eficacia de las vacunas actualmente se requiere un gran número de animales con el fin de ser considerado estadísticamente significativo y a menudo resultan en una alta morbilidad y mortalidad de los puntos finales para la identificación de la protección inmune. Hemos utilizado los sistemas de formación de imágenes in vivo (IVIS) en conjunción con una enzima de luciérnaga bioluminiscente para rastrear progresivamente la invasión del sistema nervioso central (SNC) por un renciavirus phalitic en un modelo murino. Típicamente, la enfermedad avanza de forma relativamente lenta, pero, la replicación del virus es rápida, especialmente en el SNC, y puede conducir a una frecuencia, resultado letal. Después de la infección intranasal de los ratones con TC83-Luc, una cepa atenuada venezolana virus de la encefalitis equina modificado para expresa un gen de la luciferasa, somos capaces de visualizar la replicación del virus dentro del cerebro por lo menos tres días antes de la aparición de síntomas clínicos de la enfermedad. Utilizando invasión del SNC como una clave de punto final encefalítica desarrollo de la enfermedad que son capaces de identificar rápidamente terapéutico y protección de la vacuna contra TC83-Luc infección antes de desarrollar los síntomas clínicos. Con la tecnología IVIS somos capaces de demostrar la prueba rápida y precisa de la terapéutica de fármacos y vacunas al tiempo que reduce el número de animales y la morbilidad.

Con un virus genéticamente modificado, TC83-luciferasa, hemos visto un aumento en la intensidad de la señal bioluminiscente como la replicación del virus se mueve desde la región nasal en el SNC centrales (Figura 1). Debido a la tasa de replicación viral alta, esperamos que los niveles altos de señal bioluminiscente (Figura 2A) que dependen del vector y la respuesta del animal inmune contra el vector. Esperamos que este aumento de la señal de seguir un pico, entre la infección d...

Watch this Scientific Journal Video about In Vivo Imaging Systems IVIS Detection of a Neuro-Invasive Encephalitic Virus at JoVE.com

In Vivo Imaging Systems IVIS Detection of a Neuro-Invasive Encephalitic Virus

Utilizando luciferasa y los sistemas de formación de imágenes in vivo (IVIS) como un nuevo medio para identificar las variables de enfermedad antes de los desarrollos clínicos ocurrir. IVIS nos ha permitido visualizar en tiempo real la invasión de los virus de encefalitis durante varios días, ofreciendo un modelo de enfermedad más preciso para el estudio futuro. También ha permitido identificar las características potenciales de protección de antivirales y vacunas más rápido que los modelos animales utilizados actualmente. La capacidad de utilizar animales individuales a través de múltiples puntos de tiempo asegura la reducción de las condiciones de policía, los costos y la morbilidad global a los animales utilizados garantizar un medio más humano y más científico de estudio de la enfermedad.

En Vivo Imaging Systems (IVIS) La detección de un virus invasor Neuro-encefálico

Modern advancements in imaging technology encourage further development and refinement in the way viral research is accomplished. Initially proposed by ...

in-vivo-imaging-systems-ivis-detection-neuro-invasive-encephalitic

Research

JoVE Journal

Immunology and Infection

In Vivo Imaging Systems (IVIS) Detection of a Neuro-Invasive Encephalitic Virus

20.5K vistas.  University of Texas Medical Branch. Utilizando luciferasa y los sistemas de formación de imágenes in vivo (IVIS) como un nuevo medio para identificar las variables de enfermedad antes de los desarrollos clínicos ocurrir. IVIS nos ha permitido visualizar en tiempo real la invasión de los virus de encefalitis durante varios días, ofreciendo un modelo de enfermedad más preciso para el estudio futuro. También ha permitido identificar las características potenciales de protección de antivirales y vacuna...

Video: In Vivo Imaging Systems IVIS Detection of a Neuro-Invasive Encephalitic Virus

In vivo Imaging of Transgenic Leishmania Parasites in a Live Host

Distinct species of Leishmania, a protozoan parasite of the family Trypanosomatidae, typically cause different human disease manifestations. The most common forms of disease are visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL). Mouse models of leishmaniasis are widely used, but quantification of parasite burdens during murine disease requires mice to be euthanized at various times after infection. Parasite loads are then measured either by microscopy, limiting dilution assay, or qPCR amplification of parasite DNA. The in vivo imaging system (IVIS) has an integrated software package that allows the detection of a bioluminescent signal associated with cells in living organisms. Both to minimize animal usage and to follow infection longitudinally in individuals, in vivo models for imaging Leishmania spp. causing VL or CL were established. Parasites were engineered to express luciferase, and these were introduced into mice either intradermally or intravenously. Quantitative measurements of the luciferase driving bioluminescence of the transgenic Leishmania parasites within the mouse were made using IVIS. Individual mice can be imaged multiple times during longitudinal studies, allowing us to assess the inter-animal variation in the initial experimental parasite inocula, and to assess the multiplication of parasites in mouse tissues. Parasites are detected with high sensitivity in cutaneous locations. Although it is very likely that the signal (photons/second/parasite) is lower in deeper visceral organs than the skin, but quantitative comparisons of signals in superficial versus deep sites have not been done. It is possible that parasite numbers between body sites cannot be directly compared, although parasite loads in the same tissues can be compared between mice. Examples of one visceralizing species (L. infantum chagasi) and one species causing cutaneous leishmaniasis (L. mexicana) are shown. The IVIS procedure can be used for monitoring and analyzing small animal models of a wide variety of Leishmania species causing the different forms of human leishmaniasis.

In vivo Imaging of Transgenic Leishmania Parasites in a Live Host

An in vivo imaging system is used to generate quantitative measurements of murine infection with the Trypanosomatid protozoan Leishmania. This is a non-invasive and non-lethal method for detecting parasites expressing luciferase within many tissues throughout the course of chronic Leishmania spp. infection.

Imágenes in vivo de los cultivos transgénicos parásitos Leishmania en un host en vivo

Distinct species of Leishmania, a protozoan parasite of the family Trypanosomatidae, typically cause different human disease manifestations. The most ...

Investigación

Inmunología e Infección

Non-invasive Imaging of Leukocyte Homing and Migration in vivo

Two-photon (2P) microscopy is a high resolution imaging technique that has been broadly adapted by biologists. The value of 2P microscopy is that it provides rich spatiotemporal information regarding cell behaviors within intact tissues and in live mice. Leukocyte recruitment plays a significant role in host defense against infection and when unchecked, can contribute to inflammatory and autoimmune diseases. Studying leukocyte recruitment in vivo is technically challenging since cells are moving rapidly within vessels located deep within light scattering tissues. To date, most intravital imaging studies require surgical preparation to expose the blood vessels and tissues. To avoid the tissue damage and inflammation induced by surgery itself, here, we describe a non-invasive single-cell imaging approach that can be used to study leukocyte trafficking in the mouse footpad and phalanges. We discuss the technical aspects of our 2P imaging preparation and walk the reader through a typical experiment from initial set up to execution and data collection.

Non-invasive Imaging of Leukocyte Homing and Migration in vivo

Here, we describe a non-invasive two-photon (2P) microscopy approach to study leukocyte homing in the mouse footpad. We discuss the technical aspects of our tissue imaging preparation and walk the reader through a typical experiment from initial set up to execution and data collection.

De imagen no invasivas de Homing leucocitos y Migración In vivo</em

Two-photon (2P) microscopy is a high resolution imaging technique that has been broadly adapted by biologists.  The value of 2P microscopy is that it ...

Estimating Virus Production Rates in Aquatic Systems

Viruses are pervasive components of marine and freshwater systems, and are known to be significant agents of microbial mortality. Developing quantitative estimates of this process is critical as we can then develop better models of microbial community structure and function as well as advance our understanding of how viruses work to alter aquatic biogeochemical cycles. The virus reduction technique allows researchers to estimate the rate at which virus particles are released from the endemic microbial community. In brief, the abundance of free (extracellular) viruses is reduced in a sample while the microbial community is maintained at near ambient concentration. The microbial community is then incubated in the absence of free viruses and the rate at which viruses reoccur in the sample (through the lysis of already infected members of the community) can be quantified by epifluorescence microscopy or, in the case of specific viruses, quantitative PCR. These rates can then be used to estimate the rate of microbial mortality due to virus-mediated cell lysis.

The turnover rate of viruses in marine and freshwater systems can be estimated by a reduction and reoccurrence technique. The data allow researchers to infer rates of virus-mediated microbial mortality in aquatic systems.

Estimación de las tasas de producción de virus en los sistemas acuáticos

Viruses are pervasive components of marine and freshwater systems, and are known to be significant agents of microbial mortality. Developing quantitative ...

Using Bioluminescent Imaging to Investigate Synergism Between Streptococcus pneumoniae and Influenza A Virus in Infant Mice

During the 1918 influenza virus pandemic, which killed approximately 50 million people worldwide, the majority of fatalities were not the result of infection with influenza virus alone. Instead, most individuals are thought to have succumbed to a secondary bacterial infection, predominately caused by the bacterium Streptococcus pneumoniae (the pneumococcus). The synergistic relationship between infections caused by influenza virus and the pneumococcus has subsequently been observed during the 1957 Asian influenza virus pandemic, as well as during seasonal outbreaks of the virus (reviewed in 1, 2). Here, we describe a protocol used to investigate the mechanism(s) that may be involved in increased morbidity as a result of concurrent influenza A virus and S. pneumoniae infection. We have developed an infant murine model to reliably and reproducibly demonstrate the effects of influenza virus infection of mice colonised with S. pneumoniae. Using this protocol, we have provided the first insight into the kinetics of pneumococcal transmission between co-housed, neonatal mice using in vivo imaging 3.

Using Bioluminescent Imaging to Investigate Synergism Between Streptococcus pneumoniae and Influenza A Virus in Infant Mice

A concurrent infection with influenza A virus is one of the factors implicated in the induction of invasive pneumococcal disease during asymptomatic Streptococcus pneumoniae carriage. Here we describe a mixed infection method using infant mice to investigate the synergism between these two respiratory pathogens.

Utilizando imágenes bioluminiscentes encargado de investigar la sinergia entre Streptococcus pneumoniae Y el Virus de la Influenza en ratones lactantes

During the 1918 influenza virus pandemic, which killed approximately 50 million people worldwide, the majority of fatalities were not the result of ...

High-throughput Detection Method for Influenza Virus

Influenza virus is a respiratory pathogen that causes a high degree of morbidity and mortality every year in multiple parts of the world. Therefore, precise diagnosis of the infecting strain and rapid high-throughput screening of vast numbers of clinical samples is paramount to control the spread of pandemic infections. Current clinical diagnoses of influenza infections are based on serologic testing, polymerase chain reaction, direct specimen immunofluorescence and cell culture 1,2.
Here, we report the development of a novel diagnostic technique used to detect live influenza viruses. We used the mouse-adapted human A/PR/8/34 (PR8, H1N1) virus 3 to test the efficacy of this technique using MDCK cells 4. MDCK cells (104 or 5 x 103 per well) were cultured in 96- or 384-well plates, infected with PR8 and viral proteins were detected using anti-M2 followed by an IR dye-conjugated secondary antibody. M2 5 and hemagglutinin 1 are two major marker proteins used in many different diagnostic assays. Employing IR-dye-conjugated secondary antibodies minimized the autofluorescence associated with other fluorescent dyes. The use of anti-M2 antibody allowed us to use the antigen-specific fluorescence intensity as a direct metric of viral quantity. To enumerate the fluorescence intensity, we used the LI-COR Odyssey-based IR scanner. This system uses two channel laser-based IR detections to identify fluorophores and differentiate them from background noise. The first channel excites at 680 nm and emits at 700 nm to help quantify the background. The second channel detects fluorophores that excite at 780 nm and emit at 800 nm. Scanning of PR8-infected MDCK cells in the IR scanner indicated a viral titer-dependent bright fluorescence. A positive correlation of fluorescence intensity to virus titer starting from 102-105 PFU could be consistently observed. Minimal but detectable positivity consistently seen with 102-103 PFU PR8 viral titers demonstrated the high sensitivity of the near-IR dyes. The signal-to-noise ratio was determined by comparing the mock-infected or isotype antibody-treated MDCK cells.
Using the fluorescence intensities from 96- or 384-well plate formats, we constructed standard titration curves. In these calculations, the first variable is the viral titer while the second variable is the fluorescence intensity. Therefore, we used the exponential distribution to generate a curve-fit to determine the polynomial relationship between the viral titers and fluorescence intensities. Collectively, we conclude that IR dye-based protein detection system can help diagnose infecting viral strains and precisely enumerate the titer of the infecting pathogens.

This method describes the use of Infrared dye based imaging system for detection of H1N1 in bronchioalveolar lavage (BAL) fluid of infected mice at a high sensitivity. This methodology can be performed in a 96- or 384-well plate, requires &lt;10 &mu;l volume of test material and has the potential for concurrent screening of multiple pathogens.

De alto rendimiento Método de detección de virus de la influenza

Influenza virus is a respiratory pathogen that causes a high degree of morbidity and mortality every year in multiple parts of the world. Therefore, ...

Nasal Wipes for Influenza A Virus Detection and Isolation from Swine

Surveillance for influenza A viruses in swine is critical to human and animal health because influenza A virus rapidly evolves in swine populations and new strains are continually emerging. Swine are able to be infected by diverse lineages of influenza A virus making them important hosts for the emergence and maintenance of novel influenza A virus strains. Sampling pigs in diverse settings such as commercial swine farms, agricultural fairs, and live animal markets is important to provide a comprehensive view of currently circulating IAV strains. The current gold-standard ante-mortem sampling technique (i.e. collection of nasal swabs) is labor intensive because it requires physical restraint of the pigs. Nasal wipes involve rubbing a piece of fabric across the snout of the pig with minimal to no restraint of the animal. The nasal wipe procedure is simple to perform and does not require personnel with professional veterinary or animal handling training. While slightly less sensitive than nasal swabs, virus detection and isolation rates are adequate to make nasal wipes a viable alternative for sampling individual pigs when low stress sampling methods are required. The proceeding protocol outlines the steps needed to collect a viable nasal wipe from an individual pig.

The authors present a protocol to collect swine nasal wipes to detect and isolate influenza A viruses.

Nasal Toallitas para Influenza A Detección de Virus y aislamiento de los cerdos

Surveillance for influenza A viruses in swine is critical to human and animal health because influenza A virus rapidly evolves in swine populations and ...

Neutrophil Isolation and Analysis to Determine their Role in Lymphoma Cell Sensitivity to Therapeutic Agents

Neutrophils are the most abundant (40% to 75%) type of white blood cells and among the first inflammatory cells to migrate towards the site of inflammation. They are key players in the innate immune system and play major roles in cancer biology. Neutrophils have been proposed as key mediators of malignant transformation, tumor progression, angiogenesis and in the modulation of the antitumor immunity; through their release of soluble factors or their interaction with tumor cells. To characterize the specific functions of neutrophils, a fast and reliable method is coveted for in vitro isolation of neutrophils from human blood. Here, a density gradient separation method is demonstrated to isolate neutrophils as well as mononuclear cells from the blood. The procedure consists of layering the density gradient solution such as Ficoll carefully above the diluted blood obtained from patients diagnosed with chronic lymphocytic leukemia (CLL), followed by centrifugation, isolation of mononuclear layer, separation of neutrophils from RBCsby dextran then lysis of residual erythrocytes. This method has been shown to isolate neutrophils &#8805; 90 % pure. To mimic the tumor microenvironment, 3-dimensional (3D) experiments were performed using basement membrane matrix such as Matrigel. Given the short half-life of neutrophils in vitro, 3D experiments with fresh human neutrophils cannot be performed. For this reason promyelocytic HL60 cells are differentiated along the granulocytic pathway using the differentiation inducers dimethyl sulfoxide (DMSO) and retinoic acid (RA). The aim of our experiments is to study the role of neutrophils on the sensitivity of lymphoma cells to anti-lymphoma agents. However these methods can be generalized to study the interactions of neutrophils or neutrophil-like cells with a large range of cell types in different situations.

Neutrophils are the most abundant type of white blood cells. The isolation of neutrophils from human blood by density gradient separation method and the differentiation of human promyelocytic (HL60) cells along the granulocytic pathway are described here; to test their role on sensitivity of lymphoma cells to anti-lymphoma agents.

Aislamiento de neutrófilos y análisis para determinar su papel en el linfoma de células sensibles a los agentes terapéuticos

Neutrophils are the most abundant (40% to 75%) type of white blood cells and among the first inflammatory cells to migrate towards the site of ...

Detection and Removal of Nuclease Contamination During Purification of Recombinant Prototype Foamy Virus Integrase

The integrase (IN) protein of the retrovirus prototype foamy virus (PFV) is a model enzyme for studying the mechanism of retroviral integration. Compared to IN from other retroviruses, PFV IN is more soluble and more amenable to experimental manipulation. Additionally, it is sensitive to clinically relevant human immunodeficiency virus (HIV-1) IN inhibitors, suggesting that the catalytic mechanism of PFV IN is similar to that of HIV-1 IN. IN catalyzes the covalent joining of viral complementary DNA (cDNA) to target DNA in a process called strand transfer. This strand transfer reaction introduces nicks to the target DNA. Analysis of integration reaction products can be confounded by the presence of nucleases that similarly nick DNA. A bacterial nuclease has been shown to co-purify with recombinant PFV IN expressed in Escherichia coli (E. coli). Here we describe a method to isolate PFV IN from the contaminating nuclease by heparin affinity chromatography. Fractions are easily screened for nuclease contamination with a supercoiled plasmid and agarose gel electrophoresis. PFV IN and the contaminating nuclease display alternative affinities for heparin sepharose allowing a nuclease-free preparation of recombinant PFV IN suitable for bulk biochemical or single molecule analysis of integration.

Recombinant prototype foamy virus integrase protein is often contaminated with a bacterial nuclease during purification. This method identifies nuclease contamination and removes it from the final preparation of the enzyme.

Detección y eliminación de nucleasa contaminación durante la purificación de prototipo recombinante Virus Espumoso integrasa

The integrase (IN) protein of the retrovirus prototype foamy virus (PFV) is a model enzyme for studying the mechanism of retroviral integration. Compared ...

Rapid, Safe, and Simple Manual Bedside Nucleic Acid Extraction for the Detection of Virus in Whole Blood Samples

The rapid diagnosis of an infection is essential for the outbreak management, risk containment, and patient care. We have previously shown a method for the rapid bedside inactivation of the Ebola virus during blood sampling for safe nucleic acid (NA) tests by adding a commercial lysis/binding buffer directly into the vacuum blood collection tubes. Using this bedside inactivation approach, we have developed a safe, rapid, and simplified bedside NA extraction method for the subsequent detection of a virus in lysis/binding buffer-inactivated whole blood. The NA extraction is directly performed in the blood collection tubes and requires no equipment or electricity. 
After the blood is collected into the lysis/binding buffer, the contents are mixed by flipping the tube by hand, and the mixture is incubated for 20 min at room temperature. Magnetic glass particles (MGPs) are added to the tube, and the contents are mixed by flipping the collection tube by hand. The MGPs are then collected on the side of the blood collection tube using a magnetic holder or a magnet and a rubber band. The MGPs are washed three times, and after the addition of elution buffer directly into the collection tube, the NAs are ready for NA tests, such as qPCR or isothermal loop amplification (LAMP), without the removal of the MGPs from the reaction. The NA extraction method is not dependent on any laboratory facilities and can easily be used anywhere (e.g., in field hospitals and hospital isolation wards). When this NA extraction method is combined with LAMP and a portable instrument, a diagnosis can be obtained within 40 min of the blood collection.

Here, we present a protocol for the rapid virus nucleic acid extraction from the virus-inactivated whole blood. The extraction is performed directly in the blood collection tubes and requires no equipment or electricity. The method is not dependent on laboratory facilities and can be used anywhere (e.g., in field hospitals).

Extracción rápido, seguro y sencillo Manual cabecera de ácido nucleico para la detección del Virus en muestras de sangre entera

The rapid diagnosis of an infection is essential for the outbreak management, risk containment, and patient care. We have previously shown a method for ...

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.

Una plataforma de alto rendimiento para la detección de 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 ...