Este trabalho foi financiado por subvenções dos Institutos Nacionais de Saúde ea Fundação de Fibrose Cística.

1. Preparação de bactérias para Extração de LPS <ol><li> Iniciar uma cultura durante a noite em 5 mL de caldo de Luria (LB) suplementado com antibióticos, se necessário. Crescer a cultura durante a noite (12-18 horas) em uma agitação incubadora a 37 ° C e 200 rpm. </li><li> Diluir a 1:10 com cultura LB e tomar uma OD 600 leitura em espectrofotômetro. Com base na OD 600 leitura, fazer uma suspensão de 1,5 mL dos seus bactérias para uma DO600 de 0,5. </li><li> Sedimentar as bactérias numa microcentrífuga a 10.600 x g durante 10 minutos. Remova e descarte o sobrenadante. O sedimento pode ser armazenada a -20 ° C, se LPS não vai ser extraído imediatamente. </li></ol> 2. Extracção de LPS <ol><li> Primeiro, prepara 2x tampão de SDS. Fazer uma solução de 50 mL de 4% β-mercaptoetanol (BME), SDS 4% e glicerol a 20% em 0,1 M de Tris-HCl, pH 6,8. Adicionar uma pitada de azul de bromofenol para tingir a solução. Faça um estoque 1x SDS-tampão diluindo 2X stac 1:1 em destilada estéril H 2 O. Isto pode ser armazenado à temperatura ambiente. </li><li> Faça três separadas 10 mg / mL de soluções de DNase I, RNase, e proteinase K em destilada estéril H 2 O. </li><li> Ressuspender as bactérias peletizadas a partir do passo de 1,3 em 200 ul de SDS-1x buffer. Assegurar que o pelete é ressuspenso completamente por pipetagem a solução cima e para baixo lentamente. Não vórtice. </li><li> Ferver as bactérias em suspensão em um banho de água durante 15 minutos. Permitir que a solução a arrefecer à temperatura ambiente durante 15 minutos. </li><li> Adicionar 5 uL de ambos DNase I e soluções RNase preparado em 2,2. Incubar as amostras a 37 ° C durante 30 minutos. * Este passo é opcional, não há diferença mínima na qualidade de LPS entre as amostras de nuclease-tratados e não tratados. </li><li> Adicionar 10 ul da solução de proteinase K preparado em 2,2. Incubar as amostras a 59 ° C durante 3 horas. Esta etapa pode ser realizada durante a noite, se existem restrições de tempo. </li><li> Para cada amostra de anúncio,d uL 200 de gelo-frio de Tris-fenol saturado (saturado de água fenol pode ser utilizado como um substituto se Tris-fenol saturado não está disponível). Garantir as tampas nos tubos são fechados hermeticamente, e cada amostra de vórtice durante cerca de 5 a 10 segundos. </li><li> Incubar as amostras a 65 ° C durante 15 minutos, vortex ocasionalmente. Após incubação arrefecer à temperatura ambiente, em seguida, adicionar 1 mL de temperatura ambiente éter dietílico para cada amostra e vortex durante 5 a 10 segundos. Certifique-se de realizar éter pega em um exaustor, como ele é volátil. </li><li> Centrifugar as amostras a 20.600 X g durante 10 minutos. Remover cuidadosamente as amostras da centrífuga e extrair a camada de fundo azul. Certifique-se de evitar a camada superior, claro. Deixando para trás uma pequena quantidade da camada de azul é preferível a contaminação com a camada superior. </li><li> Re-extrair as amostras, repetindo os passos 2,7-2,9. Duas extracções são normalmente suficientes. Se as amostras de aspecto turvo, extrações mais pode ser performed. Adicionar 200 ul de 2x tampão SDS-a cada uma das amostras extraídas antes de separar por SDS-PAGE. As amostras podem ser executados em 8% -15% de poliacrilamida SDS-géis. Cinco a 15 ul de LPS preparados usando este método é geralmente suficiente para visualização. </li></ol> 3. Os resultados representativos As amostras de LPS preparadas como acima pode ser visualizada por coloração directa após a separação por SDS-PAGE utilizando coloração de prata de um protocolo padrão ou um kit de coloração comercialmente disponível LPS. Alternativamente, o LPS separados num gel de poliacrilamida pode ser transferida para uma membrana de nitrocelulose e sujeitas a Western immunoblotting utilizando LPS-específico anti-soros. Para este protocolo, foi utilizado o Pro-Q Emerald 300 Kit Gel Stain lipopolissacarídeo (Molecular Probes), e seguiu as instruções do fabricante. Mostrada na Figura 1 é um Pro-Q Emerald 300 manchado 12% de gel de SDS-poliacrilamida. Cada pista contém 15 uL de LPS preparados a partir de dicepas diferentes de Burkholderia dolosa isolado de amostras de escarro de pacientes com fibrose cística. LPS diferentes padrões de bandas de escada, reflectoras de números diferentes de antigénios S-unidades de repetição ligados ao núcleo oligossacárido, são evidentes utilizando este método, por exemplo, as amostras em pista 1 e 6 têm padrões de bandas semelhantes um ao outro (disponível comercialmente em vermelho). <img alt="A Figura 1" src="/files/ftp_upload/3916/3916fig1.jpg" /> Figura 1. Pro-Q Esmeralda 300 LPS manchadas de isolados de Burkholderia dolosa clínicos. LPS de B. sete cepas dolosa de um surto em pacientes com fibrose cística foram isoladas como descrito neste protocolo. Quinze uL foram separados num gel de 12% SDS-poliacrilamida, e coradas com Pro-Q Emerald 300, segundo as instruções do fabricante. LPS núcleo é indicado uma flecha, e LPS que mostram padrões similares de bandas de O-antígeno repete são embalados em vermelho. M = marcador de peso molecular.

<ol>
	<li>Raetz, C. R., Whitfield, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lipopolysaccharide+endotoxins.">Lipopolysaccharide endotoxins.</a> Annu. Rev. Biochem. 71, 635-700 (2002).</li><li>Valvano, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Export+of+O-specific+lipopolysaccharide.">Export of O-specific lipopolysaccharide.</a> Front. Biosci. 8, 452-471 (2003).</li><li>Pier, G. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pseudomonas+aeruginosa+lipopolysaccharide:+a+major+virulence+factor,+initiator+of+inflammation+and+target+for+effective+immunity.">Pseudomonas aeruginosa lipopolysaccharide: a major virulence factor, initiator of inflammation and target for effective immunity.</a> Int. J. Med. Microbiol. 297, 277-295 (2007).</li><li>Freudenberg, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+lipopolysaccharide+susceptibility+in+the+innate+immune+response+to+Salmonella+typhimurium+infection:+LPS,+a+primary+target+for+recognition+of+Gram-negative+bacteria.">Role of lipopolysaccharide susceptibility in the innate immune response to Salmonella typhimurium infection: LPS, a primary target for recognition of Gram-negative bacteria.</a> Microbes Infect. 3, 1213-1222 (2001).</li><li>Jann, K., Jann, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polysaccharide+antigens+of+Escherichia+coli.">Polysaccharide antigens of Escherichia coli.</a> Rev. Infect. Dis. 9, S517-S526 (1987).</li><li>McCallum, K. L., Schoenhals, G., Laakso, D., Clarke, B., Whitfield, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+high-molecular-weight+fraction+of+smooth+lipopolysaccharide+in+Klebsiella+serotype+O1:K20+contains+a+unique+O-antigen+epitope+and+determines+resistance+to+nonspecific+serum+killing.">A high-molecular-weight fraction of smooth lipopolysaccharide in Klebsiella serotype O1:K20 contains a unique O-antigen epitope and determines resistance to nonspecific serum killing.</a> Infect. Immun. 57, 3816-3822 (1989).</li><li>Hancock, 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=Pseudomonas+aeruginosa+isolates+from+patients+with+cystic+fibrosis:+a+class+of+serum-sensitive,+nontypable+strains+deficient+in+lipopolysaccharide+O+side+chains.">Pseudomonas aeruginosa isolates from patients with cystic fibrosis: a class of serum-sensitive, nontypable strains deficient in lipopolysaccharide O side chains.</a> Infect. Immun. 42, 170-177 (1983).</li><li>Gupta, S. K., Masinick, S., Garrett, M., Hazlett, L. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pseudomonas+aeruginosa+lipopolysaccharide+binds+galectin-3+and+other+human+corneal+epithelial+proteins.">Pseudomonas aeruginosa lipopolysaccharide binds galectin-3 and other human corneal epithelial proteins.</a> Infect. Immun. 65, 2747-2753 (1997).</li><li>Hitchcock, P. J., Brown, T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphological+heterogeneity+among+Salmonella+lipopolysaccharide+chemotypes+in+silver-stained+polyacrylamide+gels.">Morphological heterogeneity among Salmonella lipopolysaccharide chemotypes in silver-stained polyacrylamide gels.</a> J. Bacteriol. 154, 269-277 (1983).</li><li>Westphal, O., Jann, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bacterial+lipopolysaccharides.">Bacterial lipopolysaccharides.</a> Methods Carbohyr. Chem. 5, 83 (1965).</li><li>Lieberman, T. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Parallel+bacterial+evolution+within+multiple+patients+ties+novel+genes+to+pathogenesis.">Parallel bacterial evolution within multiple patients ties novel genes to pathogenesis.</a> Nat Genet. , (2011).</li></ol>

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Nós descrevemos um método de purificação de LPS de distância a partir de outros componentes celulares, incluindo ácidos nucleicos e proteínas. Este método proporciona alta qualidade LPS que podem ser utilizados num certo número de métodos de visualização diferentes, incluindo coloração de hidratos de carbono géis de SDS-PAGE, como mostrado na Figura 1. Este método pode ser usado para serotipar LPS a partir de uma variedade de estirpes, utilizando anticorpos específicos anti-soros, ou para mostrar parent...

<table border="1"><tbody><tr><td> Nome do reagente </td><td> Companhia </td><td> Número de catálogo </td></tr><tr><td> DNase I recombinante, livre de RNase </td><td> Roche </td><td> 04716728001 </td></tr><tr><td> RNase A </td><td> Roche </td><td> 10109169001 </td></tr><tr><td> Proteinase K </td><td> Pescador </td><td> BP1700 </td></tr><tr><td> Tris-fenol saturado </td><td> Pescador </td><td> BP1750-100 </td></tr><tr><td> Éter dietílico </td><td> Thomas Scientific </td><td> C313K31 </td></tr><tr><td> Pro-Q Emerald 300 Kit Gel lipopolissacárido Stain </td><td> Molecular Probes </td><td> P20495 </td></tr></tbody></table>

purification and visualization of lipopolysaccharide from gram-negative bacteria by hot aqueous-phenol extraction

Lipopolissacarídeo (LPS) é um componente importante da bacteriana gram-negativa membranas externas. É uma molécula tripartido consistindo de lípido A, que é incorporado na membrana externa, um núcleo de oligossacáridos e repetindo O-antigénio unidades que se estendem para fora a partir da superfície da célula 1, 2. LPS é uma molécula imunodominante que é importante para a virulência e patogénese de muitas espécies bacterianas, incluindo Pseudomonas aeruginosa, espécies de Salmonella e Escherichia coli 3-5, e as diferenças na forma de composição LPS O-antigénio a base para serotipagem de estirpes. LPS está envolvido na ligação a células hospedeiras no momento do início da infecção e fornece protecção contra a morte mediada pelo complemento; estirpes que carecem de LPS pode ser atenuado para a virulência 6-8. Por estas razões, é importante para a visualização de LPS, particularmente a partir de isolados clínicos. LPS Visualizing bandas padrões e reconhecimento por um específicontibodies podem ser ferramentas úteis para identificar linhagens de deformação e caracterizar vários mutantes. Neste relatório, nós descrevemos um método aquosa-fenol quente para o isolamento e purificação de LPS de bactérias Gram-negativas células bacterianas. Este protocolo permite a extracção de LPS de distância a partir de ácidos nucleicos e proteínas que podem interferir com a visualização do LPS, que ocorre com mais curtos, métodos de extracção menos intensivos 9. LPS preparados desta maneira podem ser separados por dodecilsulfato de sódio (SDS)-poliacrilamida electroforese em gel (PAGE) e directamente corado usando hidrato de carbono / glicoproteína manchas ou métodos de coloração padrão de prata. Muitos anti-soros para LPS conter anticorpos que reagem de forma cruzada com as proteínas da membrana externa ou alvos antigénicos outros que podem dificultar a reactividade observados após immunoblot ocidental de SDS-PAGE separados lisados ​​celulares brutos. Tratamento com protease de lisados ​​celulares brutos por si só não é sempre uma forma eficaz de remoção destafundo de usar este ou outros métodos de visualização. Além disso, o tratamento da protease extensa, numa tentativa de remover este pano de fundo pode levar a LPS de baixa qualidade que não é bem resolvidos por qualquer um dos métodos acima mencionados. Por estas razões, acreditamos que o protocolo seguinte, adaptado de Westpahl e Jann 10, é ideal para a extracção de LPS.

Watch this Scientific Journal Video about Purification and Visualization of Lipopolysaccharide from Gram-negative Bacteria by Hot Aqueous-phenol Extraction at JoVE.com

Purification and Visualization of Lipopolysaccharide from Gram-negative Bacteria by Hot Aqueous-phenol Extraction

Nós descrevemos um método modificado de extracção a quente aquoso-fenol para a purificação de lipopolissacarídeo (LPS) de bactérias Gram-negativas. Uma vez extraído, os LPS pode ser subsequentemente analisadas por SDS-PAGE e visualizados por coloração directa ou imunotransferência Western.

Purificação e visualização de lipopolissacarídeo de bactérias Gram-negativas por extracção aquosa de fenol-Hot

Lipopolysaccharide (LPS)  is a major component of Gram-negative bacterial outer membranes. It is a tripartite molecule consisting of  lipid A, which is ...

purification-visualization-lipopolysaccharide-from-gram-negative

Research

JoVE Journal

Immunology and Infection

34.7K visualizações.  University of Virginia Health System. Nós descrevemos um método modificado de extracção a quente aquoso-fenol para a purificação de lipopolissacarídeo (LPS) de bactérias Gram-negativas. Uma vez extraído, os LPS pode ser subsequentemente analisadas por SDS-PAGE e visualizados por coloração directa ou imunotransferência Western.

Vídeo: Purification and Visualization of Lipopolysaccharide from Gram-negative Bacteria by Hot Aqueous-phenol Extraction

Purification of Specific Cell Population by Fluorescence Activated Cell Sorting (FACS)

Experimental and clinical studies often require highly purified cell populations.  FACS is a technique of choice to purify cell populations of known phenotype.  Other bulk methods of purification include panning, complement depletion and magnetic bead separation.  However, FACS has several advantages over other available methods.  FACS is the preferred method when very high purity of the desired population is required, when the target cell population expresses a very low level of the identifying marker or when cell populations require separation based on differential marker density.  In addition, FACS is the only available purification technique to isolate cells based on internal staining or intracellular protein expression, such as a genetically modified fluorescent protein marker.  FACS allows the purification of individual cells based on size, granularity and fluorescence.  In order to purify cells of interest, they are first stained with fluorescently-tagged monoclonal antibodies (mAb), which recognize specific surface markers on the desired cell population (1).  Negative selection of unstained cells is also possible.  FACS purification requires a flow cytometer with sorting capacity and the appropriate software.  For FACS, cells in suspension are passed as a stream in droplets with each containing a single cell in front of a laser.  The fluorescence detection system detects cells of interest based on predetermined fluorescent parameters of the cells.  The instrument applies a charge to the droplet containing a cell of interest and an electrostatic deflection system facilitates collection of the charged droplets into appropriate collection tubes (2).  The success of staining and thereby sorting depends largely on the selection of the identifying markers and the choice of mAb.  Sorting parameters can be adjusted depending on the requirement of purity and yield.  Although FACS requires specialized equipment and personnel training, it is the method of choice for isolation of highly purified cell populations.

Purification of Specific Cell Population by Fluorescence Activated Cell Sorting FACS

For many scientific studies requiring a biological and chemical analysis of cell populations the cells must be in a high state of purity. Fluorescence activated cell sorting (FACS) is a superior method in which to obtain pure cell populations.

Purificação da população de células específicas de separação de células de fluorescência Ativado (FACS)

Experimental and clinical studies often require highly purified cell populations.  FACS is a technique of choice to purify cell populations of known ...

Imunologia e Infecção

IgY Technology: Extraction of Chicken Antibodies from Egg Yolk by Polyethylene Glycol (PEG) Precipitation

Hens can be immunized by means of i.m. vaccination (Musculus pectoralis, left and right, injection volume 0.5-1.0 ml) or by means of Gene-Gun plasmid-immunization. Dependent on the immunogenicity of the antigen, high antibody-titres (up to 1:100,000 - 1:1,000,000) can be achieved after only one or 3 - 4 boost immunizations. Normally, a hen lays eggs continuously for about 72 weeks, thereafter the laying capacity decreases. This protocol describes the extraction of total IgY from egg yolk by means of a precipitation procedure (PEG. Polson et al. 1980). The method involves two important steps. The first one is the removal of lipids and the second is the precipitation of total IgY from the supernatant of step one. After dialysis against a buffer (normally PBS) the IgY-extract can be stored at -20&deg;C for more than a year. The purity of the extract is around 80 %, the total IgY per egg varies from 40-80 mg, dependent on the age of the laying hen. The total IgY content increases with the age of the hen from around 40 mg/egg up to 80 mg/egg (concerning PEG precipitation). The laying capacity of a hen per year is around 325 eggs. That means a total potential harvest of 20 g total IgY/year based on a mean IgY content of 60 mg total IgY/egg (see Table 1).

IgY Technology: Extraction of Chicken Antibodies from Egg Yolk by Polyethylene Glycol PEG Precipitation

This protocol describes in particular the extraction of total IgY from egg yolk by means of polyethylene glycol precipitation and gives general information about IgY technology.

Tecnologia IgY: Extração de anticorpos de gema de ovo de galinha por polietileno glicol (PEG) Precipitação

Hens can be immunized by means of  i.m. vaccination (Musculus pectoralis, left and right, injection volume  0.5-1.0 ml) or by means of Gene-Gun ...

Purification of Pathogen Vacuoles from Legionella-infected Phagocytes

The opportunistic pathogen Legionella pneumophila is an amoeba-resistant bacterium, which also replicates in alveolar macrophages thus causing the severe pneumonia "Legionnaires' disease"1. In protozoan and mammalian phagocytes, L. pneumophila employs a conserved mechanism to form a specific, replication-permissive compartment, the "Legionella-containing vacuole" (LCV). LCV formation requires the bacterial Icm/Dot type IV secretion system (T4SS), which translocates as many as 275 "effector" proteins into host cells. The effectors manipulate host proteins as well as lipids and communicate with secretory, endosomal and mitochondrial organelles2-4.
The formation of LCVs represents a complex, robust and redundant process, which is difficult to grasp in a reductionist manner. An integrative approach is required to comprehensively understand LCV formation, including a global analysis of pathogen-host factor interactions and their temporal and spatial dynamics. As a first step towards this goal, intact LCVs are purified and analyzed by proteomics and lipidomics.
The composition and formation of pathogen-containing vacuoles has been investigated by proteomic analysis using liquid chromatography or 2-D gel electrophoresis coupled to mass-spectrometry. Vacuoles isolated from either the social soil amoeba Dictyostelium discoideum or mammalian phagocytes harboured Leishmania5, Listeria6, Mycobacterium7, Rhodococcus8, Salmonella9 or Legionella spp.10. However, the purification protocols employed in these studies are time-consuming and tedious, as they require e.g. electron microscopy to analyse LCV morphology, integrity and purity. Additionally, these protocols do not exploit specific features of the pathogen vacuole for enrichment.
The method presented here overcomes these limitations by employing D. discoideum producing a fluorescent LCV marker and by targeting the bacterial effector protein SidC, which selectively anchors to the LCV membrane by binding to phosphatidylinositol 4-phosphate (PtdIns(4)P)3,11 . LCVs are enriched in a first step by immuno-magnetic separation using an affinity-purified primary antibody against SidC and a secondary antibody coupled to magnetic beads, followed in a second step by a classical Histodenz density gradient centrifugation12,13 (Fig. 1).
A proteome study of isolated LCVs from D. discoideum revealed more than 560 host cell proteins, including proteins associated with phagocytic vesicles, mitochondria, ER and Golgi, as well as several GTPases, which have not been implicated in LCV formation before13. LCVs enriched and purified with the protocol outlined here can be further analyzed by microscopy (immunofluorescence, electron microscopy), biochemical methods (Western blot) and proteomic or lipidomic approaches.

Purification of Pathogen Vacuoles from Legionella-infected Phagocytes

This article describes a method for the isolation and purification of intact Legionella-containing vacuoles (LCVs) from amoeba and macrophages. The two-step protocol comprises LCV enrichment by immuno-magnetic separation using an antibody against a bacterial LCV marker and further purification by density gradient centrifugation.

Purificação de vacúolos patógeno de<em&gt; Legionella</em&gt; Infectados Fagócitos

The opportunistic pathogen Legionella pneumophila is an amoeba-resistant bacterium, which also replicates in alveolar macrophages thus causing the severe ...

A Method for Generating Pulmonary Neutrophilia Using Aerosolized Lipopolysaccharide

Acute lung injury (ALI) is a severe disease characterized by alveolar neutrophilia, with limited treatment options and high mortality. Experimental models of ALI are key in enhancing our understanding of disease pathogenesis. Lipopolysaccharide (LPS) derived from gram positive bacteria induces neutrophilic inflammation in the airways and lung parenchyma of mice. Efficient pulmonary delivery of compounds such as LPS is, however, difficult to achieve. In the approach described here, pulmonary delivery in mice is achieved by challenge to aerosolized Pseudomonas aeruginosa LPS. Dissolved LPS was aerosolized by a nebulizer connected to compressed air. Mice were exposed to a continuous flow of LPS aerosol in a Plexiglas box for 10 min, followed by 2 min conditioning after the aerosol was discontinued. Tracheal intubation and subsequent bronchoalveolar lavage, followed by formalin perfusion was next performed, which allows for characterization of the sterile pulmonary inflammation. Aerosolized LPS generates a pulmonary inflammation characterized by alveolar neutrophilia, detected in bronchoalveolar lavage and by histological assessment. This technique can be set up at a small cost with few appliances, and requires minimal training and expertise. The exposure system can thus be routinely performed at any laboratory, with the potential to enhance our understanding of lung pathology.

We describe a method for inducing neutrophilic pulmonary inflammation by challenge to aerosolized lipopolysaccharide by nebulization, to model acute lung injury. In addition, basic surgical techniques for lung isolation, tracheal intubation and bronchoalveolar lavage are also described.

Um método para gerar Pulmonar Neutrofilia Usando Aerosolized Lipopolysaccharide

Acute lung injury (ALI) is a severe disease characterized by alveolar neutrophilia, with limited treatment options and high mortality. Experimental models ...

Rapid Identification of Gram Negative Bacteria from Blood Culture Broth Using MALDI-TOF Mass Spectrometry

An important role of the clinical microbiology laboratory is to provide rapid identification of bacteria causing bloodstream infection. Traditional identification requires the sub-culture of signaled blood culture broth with identification available only after colonies on solid agar have matured. MALDI-TOF MS is a reliable, rapid method for identification of the majority of clinically relevant bacteria when applied to colonies on solid media. The application of MALDI-TOF MS directly to blood culture broth is an attractive approach as it has potential to accelerate species identification of bacteria and improve clinical management. However, an important problem to overcome is the pre-analysis removal of interfering resins, proteins and hemoglobin&#160;contained in blood culture specimens which, if not removed, interfere with the MS spectra and can result in insufficient or low discrimination identification scores. In addition it is necessary to concentrate bacteria to develop spectra of sufficient quality. The presented method describes the concentration, purification, and extraction of Gram negative bacteria allowing for the early identification of bacteria from a signaled blood culture broth.

The application of matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (MS) directly to blood culture broth expedites the identification of bacteria. The presented method is a rapid and reliable method for identification of Gram negative bacteria directly from blood culture broth.

Rápida identificação de bactérias gram-negativas de Sangue Cultura Caldo Usando MALDI-TOF Espectrometria de Massa

An important role of the clinical microbiology laboratory is to provide rapid identification of bacteria causing bloodstream infection. Traditional ...

Application of Fluorescent Nanoparticles to Study Remodeling of the Endo-lysosomal System by Intracellular Bacteria

Fluorescent nanoparticles (NPs) with desirable chemical, optical and mechanical properties are promising tools to label intracellular organelles. Here, we introduce a method using gold-BSA-rhodamine NPs to label the endo-lysosomal system of eukaryotic cells and monitor manipulations of host cellular pathways by the intracellular pathogen Salmonella enterica. The NPs were readily internalized by HeLa cells and localized in late endosomes/lysosomes. Salmonella infection induced rearrangement of the vesicles and accumulation of NPs in Salmonella-induced membrane structures. We deployed the Imaris software package for quantitative analyses of confocal microscopy images. The number of objects and their size distribution in non-infected cells were distinct from the ones in Salmonella-infected cells, indicating extremely remodeling of the endo-lysosomal system by WT Salmonella.

This article describes methods for the synthesis and fluorescent labeling of nanoparticles (NPs). The NPs were applied in pulse-chase experiments to label the endo-lysosomal system of eukaryotic cells. Manipulation of the endo-lysosomal system by activities of the intracellular pathogen Salmonella enterica were followed by live cell imaging and quantified.

Aplicação de nanopartículas fluorescentes para estudar Reformas do Sistema Endo-lysosomal por bactérias intracelulares

Fluorescent nanoparticles (NPs) with desirable chemical, optical and mechanical properties are promising tools to label intracellular organelles. Here, we ...

T Cells Capture Bacteria by Transinfection from Dendritic Cells

Recently, we have shown, contrary to what is described, that CD4+ T cells, the paradigm of adaptive immune cells, capture bacteria from infected dendritic cells (DCs) by a process called transinfection. Here, we describe the analysis of the transinfection process, which occurs during the course of antigen presentation. This process was unveiled by using CD4+ T cells from transgenic OTII mice, which bear a T cell receptor (TCR) specific for a peptide of ovoalbumin (OVAp), which therefore can form stable immune complexes with infected dendritic cells loaded with this specific OVAp. The dynamics of green fluorescent protein (GFP)-expressing bacteria during DC-T cell transmission can be monitored by live-cell imaging and the quantification of bacterial transinfection can be performed by flow cytometry. In addition, transinfection can be quantified by a more sensitive method based in the use of gentamicin, a non-permeable aminoglycoside antibiotic killing extracellular bacteria but not intracellular ones. This classical method has been used previously in microbiology to study the efficiency of bacterial infections. We hereby explain the protocol of the complete process, from the isolation of the primary cells to the quantification of transinfection.

Here a protocol is presented to measure bacterial capture by CD4+ T cells which occurs during antigen presentation via transinfection from pre-infected dendritic cells (DC). We show how to perform the necessary steps: isolation of primary cells, infection of DC, DC/T cell conjugate formation, and measurement of bacterial T cell transfection.

As células T Capturar Bactérias por Transinfection das dendríticas

Recently, we have shown, contrary to what is described, that CD4+ T cells, the paradigm of adaptive immune cells, capture bacteria from infected dendritic ...

Determination of Biofilm Initiation on Virus-infected Cells by Bacteria and Fungi

The study of polymicrobial interactions across the taxonomic kingdoms that include fungi, bacteria and virus have not been previously examined with respect to how viral members of the microbiome affect subsequent microbe interactions with these virus-infected host cells. The co-habitation of virus with bacteria and fungi is principally present on the mucosal surfaces of the oral cavity and genital tract. Mucosal cells, particularly those with persistent chronic or persistent latent viral infections, could have a significant impact on members of the microbiome through virus alteration in number and type of receptors expressed. Modification in host cell membrane architecture would result in altered ability of subsequent members of the normal flora and opportunistic pathogens to initiate the first step in biofilm formation, i.e., adherence. This study describes a method for quantitation and visual examination of HSV&#39;s effect on the initiation of biofilm formation (adherence) of S. aureus and C. albicans.

A method is described herein for the determination of inter-Kingdom association and competition (bacterial and fungal) for adherence to virus-infected HeLa cell monolayers. This protocol can be extended to multiple combinations of prokaryotes, eukaryotes, and viruses.

Determinação do biofilme Iniciação em células infectadas por vírus por bactérias e fungos

The study of polymicrobial interactions across the taxonomic kingdoms that include fungi, bacteria and virus have not been previously examined with ...

Isolation, Characterization, and Purification of Macrophages from Tissues Affected by Obesity-related Inflammation

Obesity promotes a chronic inflammatory state that is largely mediated by tissue-resident macrophages as well as monocyte-derived macrophages. Diet-induced obesity (DIO) is a valuable model in studying the role of macrophage heterogeneity; however, adequate macrophage isolations are difficult to acquire from inflamed tissues. In this protocol, we outline the isolation steps and necessary troubleshooting guidelines derived from our studies for obtaining a suitable population of tissue-resident macrophages from mice following 18 weeks of high-fat (HFD) or high-fat/high-cholesterol (HFHCD) diet intervention. This protocol focuses on three hallmark tissues studied in obesity and atherosclerosis including the liver, white adipose tissues (WAT), and the aorta. We highlight how dualistic usage of flow cytometry can achieve a new dimension of isolation and characterization of tissue-resident macrophages. A fundamental section of this protocol addresses the intricacies underlying tissue-specific enzymatic digestions and macrophage isolation, and subsequent cell-surface antibody staining for flow cytometric analysis. This protocol addresses existing complexities underlying fluorescent-activated cell sorting (FACS) and presents clarifications to these complexities so as to obtain broad range characterization from adequately sorted cell populations. Alternate enrichment methods are included for sorting cells, such as the dense liver, allowing for flexibility and time management when working with FACS. In brief, this protocol aids the researcher to evaluate macrophage heterogeneity from a multitude of inflamed tissues in a given study and provides insightful troubleshooting tips that have been successful for favorable cellular isolation and characterization of immune cells in DIO-mediated inflammation.

This protocol allows a researcher to isolate and characterize tissue-resident macrophages in various hallmark inflamed tissues extracted from diet-induced models of metabolic disorders.

Isolamento, caracterização e purificação dos macrófagos dos tecidos afetados pela inflamação obesidade

Obesity promotes a chronic inflammatory state that is largely mediated by tissue-resident macrophages as well as monocyte-derived macrophages. ...

Dissecting Multi-protein Signaling Complexes by Bimolecular Complementation Affinity Purification (BiCAP)

The assembly of protein complexes is a central mechanism underlying the regulation of many cell signaling pathways. A major focus of biomedical research is deciphering how these dynamic protein complexes act to integrate signals from multiple sources in order to direct a specific biological response, and how this becomes deregulated in many disease settings. Despite the importance of this key biochemical mechanism, there is a lack of experimental techniques that can facilitate the specific and sensitive deconvolution of these multi-molecular signaling complexes.
Here this shortcoming is addressed through the combination of a protein complementation assay with a conformation-specific nanobody, which we have termed Bimolecular Complementation Affinity Purification (BiCAP). This novel technique facilitates the specific isolation and downstream proteomic characterization of any pair of interacting proteins, to the exclusion of un-complexed individual proteins and complexes formed with competing binding partners. 
The BiCAP technique is adaptable to a wide array of downstream experimental assays, and the high degree of specificity afforded by this technique allows more nuanced investigations into the mechanics of protein complex assembly than is currently possible using standard affinity purification techniques.

Dissecting Multi-protein Signaling Complexes by Bimolecular Complementation Affinity Purification BiCAP

This manuscript describes the protocol for Bimolecular Complementation Affinity Purification (BiCAP). This novel method facilitates the specific isolation and downstream proteomic characterization of any two interacting proteins, while excluding un-complexed individual proteins as well as complexes formed with competing binding partners.

Dissecando a proteínas multi sinalização complexos pela purificação da afinidade de complementação Bimolecular (BiCAP)

The assembly of protein complexes is a central mechanism underlying the regulation of many cell signaling pathways. A major focus of biomedical research ...