I. Décongeler les cellules Prenez le flacon congelé des cellules TN5, et le placer dans un bain d&#39;eau à 37 ° C. Ajouter 5 ml d&#39;insectes express moyennes (Invitrogen, numéro de catalogue 10486-) dans 25cm 2 flacon de CT. Notez que cinq express vient sans glutamine; besoin d&#39;ajouter 10ml de streptocoque stylo 100X glutamine ou glutamine seule à une des médias lt. Ajouter TN5 cellules en elle et incuber pendant 30 minutes dans un incubateur à 27 ° C. Ensuite, aspirer le milieu avec du DMSO en douceur sans perturber les cellules attachées au fond du flacon. Ajouter 5 ml de milieu frais. II. Croissance et l&#39;expansion des cellules Surveiller les cellules chaque jour. Lorsque flacon est près de 70% de confluence, mettre les cellules en suspension en tapant dans le ballon des deux côtés et le transfert aux cellules de 175cm 2 flacon en ajoutant 21 ml d&#39;exprimer moyennes insectes et 5ml de culture cellulaire. Chaque flacon T175 devrait avoir autour de 25-30ml médium comme un volume final. Fractionner flacon confluence (environ 1 million / ml conc.) 1 / 4 ou 1 / 5 des besoins. Ne laissez pas envahir les cellules. Comptez le nombre de passages que vous avez fractionner les cellules. Ne pas pousser plus de 30 le nombre de passages, car il peut causer le vieillissement des cellules résultant lyse cellulaire. Lorsque vous atteignez le volume souhaité à la concentration de 1 million / ml, infectent les cellules. J&#39;ai généralement une croissance de 2 à 2,5 litres, ce qui équivaut généralement à soixante-dix 175cm 2 flacons et env. 25 à 30ml flacon / ou de cinq litres 1 erlenmeyers et env. 400ml à 500 ml dans chaque flacon Note: Vous pouvez soit cultiver des cellules de T-175 flacon joint fiche ou Corning Erlenmeyer. Des cellules en croissance dans des erlenmeyers est plus rapide et plus facile. III. Titrage du virus par la méthode de dilution End Point <ol><li> Assiette 3000-5000 cellules par puits dans le fond 96 plaque plane bien dans 200ul de milieu express GDF cinq. Laissez les cellules s&#39;établir à 27 ° C pendant au moins 30 minutes. </li><li> Faire de dilution en série de stock de baculovirus. On devrait faire de dilution 1 / 10 dans une ligne de 96 puits plaque de fond en U, en utilisant 250ul par puits. Les dilutions sont faites en milieu express GDF Cinq. </li><li> En utilisant une pipette multicanaux, le transfert d&#39;un montant fixe (généralement 20 ul) de différentes dilutions pour les cellules. </li><li> Culture à 27 ° C pendant 7 jours. Pour éviter l&#39;évaporation à partir des lignes de pointe, envelopper les bords de la plaque avec du parafilm. </li><li> Après 7 jours, vérifier la plaque et de déterminer ce qui donne de dilution du virus d&#39;une infection de 50% - la moitié du puits à cette concentration de virus sont infectés). Ensuite, utilisez une formule pour calculer le titre, ce qui est exprimé en pfu / ml (UFP-unités formant la plaque). La formule se trouve dans la plupart des manuels de baculovirus. </li></ol> IV. Infectant les cellules Il est très important de connaître le titre exact du virus. Ajoutez la quantité requise de virus. Pour la préparation de stock viral des cellules infectées doivent être à une multiplicité d&#39;infection (MOI) de pas plus de 1 (1pfu d&#39;1High Cinq cellulaire) supérieur MOI mène à la production de mutations virales. Pour la production de protéines, la quantité habituelle est MO1 5-10. Exemple: Le titre de baculovirus mCD1d = 1X108 pfu / ml Ajouter MOI = 1 (pour amplifier le virus) = 20X10 ^ 6 cellules / flacon / 1x10 ^ 8 pfu / ml = 200 ul / flacon MOI = 5 à 10 (pour la production de protéines) = 1 ml à 2 ml Pour 20x10 ^ 6 cellules / flacon Au jour 4, après l&#39;infection, regarder les cellules infectées. Ils devraient être détachée, flottante, saucisses gonflées et formant. Surnageants V. Récupération Prenez la moyenne des flacons infectés, et transfert à 250ml bouteilles bouchon bleu Falcon Spinning. Ils peuvent être autoclavés et réutilisés. Remplissez les bouteilles de façon égale et centrifuger les cellules Sorvall GSA rotor à 200rpm, 20 minutes, 4 ° C. Recueillir le surnageant et procéder d&#39;une purification supplémentaire. VI. Purification de recombinaison mCD1d <ol><li> La dialyse et la concentration dans tampon phosphate de sodium 150 mM (pH 7,4) </li><li> Par Ni-NTA agarose chromatographie, éluer la protéine mCD1d + B2M avec 150 mM de phosphate de sodium 200 mM Immidazole </li><li> Exécuter colonne de dessalage en utilisant 20 mM Tris HCl pH8 tampon pour se débarrasser des Immidazole </li><li> Exécuter chromatographie échangeuse d&#39;anions en utilisant la colonne MonoQ pour éliminer les contaminants restants. </li><li> Concentré à 1mg/ml utilisant YM 30 concentrateur (Millipore) </li><li> BirA biotynlation enzymatique de mCD1d selon le protocole du fabricant (avidité) </li><li> La biotine libre est éliminé par S200 colonne (Chromatographie d&#39;exclusion stérique) à l&#39;aide du tampon phosphate salin (PBS), pH 7,4. Une moyenne de 2 à 3 mg de protéine biotynlated pourrait être obtenu à partir de 2 litre de surnageant </li><li> Production d&#39;un tétramère-GalCer CD1d. </li></ol> Afin de charger molécule CD1d avec un GalCer-, soluble biotynlated CD1d-b2m est incubé une nuit à température ambiante avec trois fois excès molaire d&#39;un GalCer-, dissous dans 0,5% de Tween -20 en PBS, chlorure de sodium O.9%. Tétramères sont générées par le mélange d&#39;un-GalCer monomères chargés CD1d avec 4 excès molaire pli du PE - streptavidine conjuguée et incubation pendant 4 heures à température ambiante. Entreposer à 48 ° C.

<ol>
	<li>Benlagha, K., Weiss, A., Beavis, A., Teyton, L., Bendelac, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+identification+of+glycolipipd+antigen-specific+T+cells+using+fluorecent+CD1d+tetramers.">In vivo identification of glycolipipd antigen-specific T cells using fluorecent CD1d tetramers.</a> J. Exp. Med. 191, 1895-1903 (2000).</li><li>Kinjo, Y., Wu, D., Kim, G., Xing, G. W., Poles, M. A., Ho, D. D., Tsuji, M., Kawahara, K., Wong, C. H., Kronenberg, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recognition+of+bacterial+glycosphingolipids+by+natural+killer+T+cells.">Recognition of bacterial glycosphingolipids by natural killer T cells.</a> Nature. 434, 520-525 (2005).</li><li>Naidenko, O. V., Maher, J. K., Ernst, W. A., Sakai, T., Modlin, R. L., Kronenberg, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Binding+and+antigen+presentation+of+ceramide-containing+glycolipids+by+soluble+mouse+and+human+CD1d+molecules.">Binding and antigen presentation of ceramide-containing glycolipids by soluble mouse and human CD1d molecules.</a> J. Exp. Med. 190, 1069-1080 (1999).</li><li>Porcelli, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+CD1+family:+A+third+lineage+of+antigen-+presenting+molecules.">The CD1 family: A third lineage of antigen- presenting molecules.</a> Adv. Immunol. 59, 1-98 (1995).</li><li>Sidobre, S., Kronemberg, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CD1+tetramers:+A+powerful+tool+for+the+analysis+of+glycolipid-reactive+T+cells.">CD1 tetramers: A powerful tool for the analysis of glycolipid-reactive T cells.</a> J. Immunol. 169, 1340-1348 (2002).</li></ol>

Dans cette procédure, il est montré comment initier, grandir, infecter les cellules d&#39;insectes et la façon de titrer la baculovirus utilisation de ces cellules. Les aspects les plus importants de cette procédure sont la maintenance des cellules et de connaître le titre exact de baculovirus. Une fois que vous avez généré CD1 tétramères, ils peuvent être utilisés comme un outil puissant pour l&#39;analyse des glycolipides des cellules T réactives. Systèmes baculovirus sont également largement utilisées pour produire des pr...

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Express Five SFM</td>
<td> Serum Free Medium</td>
<td>Invitrogen</td>
<td>10486025</td>
<td>&nbsp;</td>
<tr>
<td>High Five TM</td>
<td> Insect Cells</td>
<td>Invitrogen</td>
<td>B855-02</td>
<td>&nbsp;</td>
<tr>
<td>Glutamine Pen strep</td>
<td>Antibiotics</td>
<td>Invitrogen</td>
<td>10378-016</td>
<td>&nbsp;</td>
<tr>
<td>25cm2 TC Flask</td>
<td> Plastic</td>
<td>Fisher</td>
<td>10-126-28</td>
<td>&nbsp;</td>
<tr>
<td>175 cm2 TC Flask</td>
<td> Plug seal flask</td>
<td>Fisher</td>
<td>10-126-8</td>
<td>&nbsp;</td>
<tr>
<td>Erlenmeyer Flask</td>
<td> Cell Culture Flask</td>
<td>Fisher</td>
<td>07 200 672</td>
<td>&nbsp;</td>
<tr>
<td>YM 30 Concenterator</td>
<td>30,000 MWCO</td>
<td>Millipore</td>
<td>UFC 903096</td>
<td>&nbsp;</td>
<tr>
<td>FPLC equipment</td>
<td>&nbsp;</td>
<td>GE Healthcare</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>BrA Enzyme and Buffer</td>
<td> Biotinylation Kit</td>
<td>Avidity</td>
<td>BIRA500</td>
<td>&nbsp;</td>
<tr>
<td>Ni-NTA Agarose Column</td>
<td>His Tag Protein Purification Column</td>
<td>GE Healthcare</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Desalting column</td>
<td> To get Rod of Salt from Protein</td>
<td>GE Healthcare</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>MonoQ Column</td>
<td>Anion Exchange Chromatgraphy</td>
<td>GE Healthcare</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>S200 Column</td>
<td> Size Exclusion Chromatography</td>
<td>GE Healthcare</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>alpha-Galcer</td>
<td> Glycolipid</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>PE- Streptavidin</td>
<td> For conjugating Protein</td>
<td>Molecular Probe</td>
<td> S-866</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

a method for production of recombinant mcd1d protein in insect cells.

CD1 protéines constituent une troisième classe de molécules présentatrices d&#39;antigène. Ils sont des glycoprotéines de surface cellulaire, exprimée en environ 50 kDa glycosylée lourdes chaînes qui sont non covalente associée à béta2-microglobuline. Ils se lier aux lipides plutôt que les peptides. Bien que leur structure confirme la similitude des protéines CD1 du CMH de classe I et molécules de classe II présentant l&#39;antigène, la rainure mCD1d est relativement étroite, profonde et hautement hydrophobe et il a deux poches de liaison au lieu de la faible profondeur des poches de plusieurs classiques décrites pour la MHC- codée molécules présentatrices d&#39;antigène. Sur la base de leurs séquences d&#39;acides aminés, une telle rainure hydrobphobic fournit un environnement idéal pour la fixation des antigènes lipidiques. Le Natural Killer T (NKT), les cellules utilisent leur TCR à reconnaître glycolipides liés à ou présentés par CD1d. Les cellules T réactives aux lipides présentés par CD1 ont été impliqués dans la protection contre les maladies auto-immunes et infectieuses et dans le rejet de la tumeur. Ainsi, la capacité d&#39;identifier, purifier, et de suivre la réponse du CD1-réactive cellules NKT est de grande importance. La génération de tétramères d&#39;alpha galactosyl céramide (une-GalCer) avec CD1d a aperçu significatif de la biologie des cellules NKT. Tétramères construits à partir d&#39;autres molécules CD1 ont aussi été générés et ces nouveaux réactifs ont considérablement élargi les connaissances sur les fonctions des cellules T réactives de lipides, avec une utilisation potentielle dans le suivi de la réponse aux vaccins à base de lipides et dans le diagnostic des maladies auto-immunes et d&#39;autres traitements.

Watch this Scientific Journal Video about A Method For Production of Recombinant mCD1d Protein in Insect Cells. at JoVE.com

A Method For Production of Recombinant mCD1d Protein in Insect Cells.

Une méthode pour préparer les cellules d&#39;insectes et de les infecter avec le baculovirus à des fins de production de l&#39;recombinante proteinand mCD1d générant tétramères mCD1d.

Un procédé de production de protéine recombinante mCD1d en cellules d&#39;insectes.

CD1 proteins constitute a third class of antigen-presenting molecules. They are cell surface glycoproteins, expressed as approximately 50-kDa glycosylated ...

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Research

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Biology

10.6K vues.  La Jolla Institute for Allergy and Immunology. Une méthode pour préparer les cellules d'insectes et de les infecter avec le baculovirus à des fins de production de l'recombinante proteinand mCD1d générant tétramères mCD1d.

Vidéo: A Method For Production of Recombinant mCD1d Protein in Insect Cells.

A Protocol for Phage Display and Affinity Selection Using Recombinant Protein Baits

Using recombinant phage as a scaffold to present various protein portions encoded by a directionally cloned cDNA library to immobilized bait molecules is an efficient means to discover interactions. The technique has largely been used to discover protein-protein interactions but the bait molecule to be challenged need not be restricted to proteins. The protocol presented here has been optimized to allow a modest number of baits to be screened in replicates to maximize the identification of independent clones presenting the same protein. This permits greater confidence that interacting proteins identified are legitimate interactors of the bait molecule. Monitoring the phage titer after each affinity selection round provides information on how the affinity selection is progressing as well as on the efficacy of negative controls. One means of titering the phage, and how and what to prepare in advance to allow this process to progress as efficiently as possible, is presented. Attributes of amplicons retrieved following isolation of independent plaque are highlighted that can be used to ascertain how well the affinity selection has progressed. Trouble shooting techniques to minimize false positives or to bypass persistently recovered phage are explained. Means of reducing viral contamination flare up are discussed.

Phage display is a powerful technique to capture proteins or protein moieties that interact with an immobilized molecule of interest. Once a decision of the type of phage cDNA library to create and screen has been made, the protocol described here permits efficient affinity selection leading to identification of interactors.

Un protocole pour Phage Display et Affinity sélection en utilisant appâts protéine recombinante

Using  recombinant phage as a scaffold to present various protein portions encoded by  a directionally cloned cDNA library to immobilized bait molecules ...

Recherche

Biologie

Efficient Production and Purification of Recombinant Murine Kindlin-3 from Insect Cells for Biophysical Studies

Kindlins are essential coactivators, with talin, of the cell surface receptors&#160;integrins and also participate in integrin outside-in signalling, and the control of gene transcription in the cell nucleus. The kindlins are ~75 kDa multidomain proteins and bind to an NPxY motif and upstream T/S cluster of the integrin &#946;-subunit cytoplasmic tail. The hematopoietically-important kindlin isoform, kindlin-3, is critical for platelet aggregation during thrombus formation, leukocyte rolling in response to infection and inflammation and osteoclast podocyte formation in bone resorption. Kindlin-3&#39;s role in these processes has resulted in extensive cellular and physiological studies. However, there is a need for an efficient method of acquiring high quality milligram quantities of the protein for further studies. We have developed a protocol, here described, for the efficient expression and purification of recombinant murine kindlin-3 by use of a baculovirus-driven expression system in Sf9 cells yielding sufficient amounts of high purity full-length protein to allow its biophysical characterization. The same approach could be taken in the study of the other mammalian kindlin isoforms.

Kindlins are fundamental to cell adhesion through integrins but studies of them have been hampered by the difficulty encountered in expressing them recombinantly in bacterial hosts. We describe here methods for their efficient production in baculovirus-infected insect cells.

La production efficace et purification de recombinant murin Kindlin-3 à partir de cellules d&#39;insectes pour les études biophysiques

Kindlins are essential coactivators, with talin, of the cell surface receptors&#160;integrins and also participate in integrin outside-in signalling, and ...

Investigating Protein-protein Interactions in Live Cells Using Bioluminescence Resonance Energy Transfer

Assays based on Bioluminescence Resonance Energy Transfer (BRET) provide a sensitive and reliable means to monitor protein-protein interactions in live cells. BRET is the non-radiative transfer of energy from a 'donor' luciferase enzyme to an 'acceptor' fluorescent protein. In the most common configuration of this assay, the donor is Renilla reniformis luciferase and the acceptor is Yellow Fluorescent Protein (YFP). Because the efficiency of energy transfer is strongly distance-dependent, observation of the BRET phenomenon requires that the donor and acceptor be in close proximity. To test for an interaction between two proteins of interest in cultured mammalian cells, one protein is expressed as a fusion with luciferase and the second as a fusion with YFP. An interaction between the two proteins of interest may bring the donor and acceptor sufficiently close for energy transfer to occur. Compared to other techniques for investigating protein-protein interactions, the BRET assay is sensitive, requires little hands-on time and few reagents, and is able to detect interactions which are weak, transient, or dependent on the biochemical environment found within a live cell. It is therefore an ideal approach for confirming putative interactions suggested by yeast two-hybrid or mass spectrometry proteomics studies, and in addition it is well-suited for mapping interacting regions, assessing the effect of post-translational modifications on protein-protein interactions, and evaluating the impact of mutations identified in patient DNA.

Interactions between proteins are fundamental to all cellular processes. Using Bioluminescence Resonance Energy Transfer, the interaction between a pair of proteins can be monitored in live cells and in real time. Furthermore, the effects of potentially pathogenic mutations can be assessed.

Étudier les interactions protéine-protéine dans les cellules vivantes en utilisant le transfert d&#39;énergie de résonance de bioluminescence

Assays based on Bioluminescence Resonance Energy Transfer (BRET) provide a sensitive and reliable means to monitor protein-protein interactions in live ...

Recombinant Protein Expression for Structural Biology in HEK 293F Suspension Cells: A Novel and Accessible Approach

The expression and purification of large amounts of recombinant protein complexes is an essential requirement for structural biology studies. For over two decades, prokaryotic expression systems such as E. coli have dominated the scientific literature over costly and less efficient eukaryotic cell lines. Despite the clear advantage in terms of yields and costs of expressing recombinant proteins in bacteria, the absence of specific co-factors, chaperones and post-translational modifications may cause loss of function, mis-folding and can disrupt protein-protein interactions of certain eukaryotic multi-subunit complexes, surface receptors and secreted proteins. The use of mammalian cell expression systems can address these drawbacks since they provide a eukaryotic expression environment. However, low protein yields and high costs of such methods have until recently limited their use for structural biology. Here we describe a simple and accessible method for expressing and purifying milligram quantities of protein by performing transient transfections of suspension grown HEK (Human Embryonic Kidney) 293F cells.

The expression of recombinant proteins by mammalian systems is becoming an attractive method for producing protein complexes for structural biology. Here we present a simple yet highly efficient expression system using suspension grown mammalian cells to purify protein complexes for structural studies.

Expression de protéines recombinantes pour la Biologie Structurale HEK 293F cellules en suspension: une approche nouvelle et accessible

The expression and purification of large amounts of recombinant protein complexes is an essential requirement for structural biology studies. For over two ...

Green Fluorescent Protein-based Expression Screening of Membrane Proteins in Escherichia coli

The production of recombinant membrane proteins for structural and functional studies remains technically challenging due to low levels of expression and the inherent instability of many membrane proteins once solubilized in detergents. A protocol is described that combines ligation independent cloning of membrane proteins as GFP fusions with expression in Escherichia coli detected by GFP fluorescence. This enables the construction and expression screening of multiple membrane protein/variants to identify candidates suitable for further investment of time and effort. The GFP reporter is used in a primary screen of expression by visualizing GFP fluorescence following SDS polyacrylamide gel electrophoresis (SDS-PAGE). Membrane proteins that show both a high expression level with minimum degradation as indicated by the absence of free GFP, are selected for a secondary screen. These constructs are scaled and a total membrane fraction prepared and solubilized in four different detergents. Following ultracentrifugation to remove detergent-insoluble material, lysates are analyzed by fluorescence detection size exclusion chromatography (FSEC). Monitoring the size exclusion profile by GFP fluorescence provides information about the mono-dispersity and integrity of the membrane proteins in different detergents. Protein: detergent combinations that elute with a symmetrical peak with little or no free GFP and minimum aggregation are candidates for subsequent purification. Using the above methodology, the heterologous expression in E. coli of SED (shape, elongation, division, and sporulation) proteins from 47 different species of bacteria was analyzed. These proteins typically have ten transmembrane domains and are essential for cell division. The results show that the production of the SEDs orthologues in E. coli was highly variable with respect to the expression levels and integrity of the GFP fusion proteins. The experiment identified a subset for further investigation.

Green Fluorescent Protein-based Expression Screening of Membrane Proteins in Escherichia coli

A streamlined approach to screening for the expression of recombinant membrane proteins in Escherichia coli based on fusion to green fluorescent protein is presented.

Green Fluorescent Protein base Expression dépistage des protéines membranaires dans<em&gt; Escherichia coli</em

The production of recombinant membrane proteins for structural and functional studies remains technically challenging due to low levels of expression and ...

A Comparative Analysis of Recombinant Protein Expression in Different Biofactories: Bacteria, Insect Cells and Plant Systems

Plant-based systems are considered a valuable platform for the production of recombinant proteins as a result of their well-documented potential for the flexible, low-cost production of high-quality, bioactive products.
In this study, we compared the expression of a target human recombinant protein in traditional fermenter-based cell cultures (bacterial and insect) with plant-based expression systems, both transient and stable.
For each platform, we described the set-up, optimization and length of the production process, the final product quality and the yields and we evaluated provisional production costs, specific for the selected target recombinant protein.
Overall, our results indicate that bacteria are unsuitable for the production of the target protein due to its accumulation within insoluble inclusion bodies. On the other hand, plant-based systems are versatile platforms that allow the production of the selected protein at lower-costs than Baculovirus/insect cell system. In particular, stable transgenic lines displayed the highest-yield of the final product and transient expressing plants the fastest process development. However, not all recombinant proteins may benefit from plant-based systems but the best production platform should be determined empirically with a case-by-case approach, as described here.

In this study the expression of a target human recombinant protein in different production platforms was compared. We focused on traditional fermenter-based cultures and on plants, describing the set-up of each system and highlighting, on the basis of the reported results, the inherent limits and advantages for each platform.

Une analyse comparative des recombinant expression des protéines dans différents bio-usines: bactéries, cellules d&#39;insectes et Plant Systems

Plant-based systems are considered a valuable platform for the production of recombinant proteins as a result of their well-documented potential for the ...

Nephrotoxin Microinjection in Zebrafish to Model Acute Kidney Injury

The kidneys are susceptible to harm from exposure to chemicals they filter from the bloodstream. This can lead to organ injury associated with a rapid decline in renal function and development of the clinical syndrome known as acute kidney injury (AKI). Pharmacological agents used to treat medical circumstances ranging from bacterial infection to cancer, when administered individually or in combination with other drugs, can initiate AKI. Zebrafish are a useful animal model to study the chemical effects on renal function in vivo, as they form an embryonic kidney comprised of nephron functional units that are conserved with higher vertebrates, including humans. Further, zebrafish can be utilized to perform genetic and chemical screens, which provide opportunities to elucidate the cellular and molecular facets of AKI and develop therapeutic strategies such as the identification of nephroprotective molecules. Here, we demonstrate how microinjection into the zebrafish embryo can be utilized as a paradigm for nephrotoxin studies.

Renal injuries incurred from nephrotoxins, which include drugs ranging from antibiotics to chemotherapeutics, can result in complex disorders whose pathogenesis remains incompletely understood. This protocol demonstrates how zebrafish can be used for disease modeling of these conditions, which can be applied to the identification of renoprotective measures.

Néphrotoxine microinjection dans Zebrafish au Modèle lésion rénale aiguë

The kidneys are susceptible to harm from exposure to chemicals they filter from the bloodstream. This can lead to organ injury associated with a rapid ...

A Graphical User Interface for Software-assisted Tracking of Protein Concentration in Dynamic Cellular Protrusions

Filopodia are dynamic, finger-like cellular protrusions associated with migration and cell-cell communication. In order to better understand the complex signaling mechanisms underlying filopodial initiation, elongation and subsequent stabilization or retraction, it is crucial to determine the spatio-temporal protein activity in these dynamic structures. To analyze protein function in filopodia, we recently developed a semi-automated tracking algorithm that adapts to filopodial shape-changes, thus allowing parallel analysis of protrusion dynamics and relative protein concentration along the whole filopodial length. Here, we present a detailed step-by-step protocol for optimized cell handling, image acquisition and software analysis. We further provide instructions for the use of optional features during image analysis and data representation, as well as troubleshooting guidelines for all critical steps along the way. Finally, we also include a comparison of the described image analysis software with other programs available for filopodia quantification. Together, the presented protocol provides a framework for accurate analysis of protein dynamics in filopodial protrusions using image analysis software.

We present a software solution for semi-automated tracking of relative protein concentration along the length of dynamic cellular protrusions.

Une interface utilisateur graphique pour le suivi assisté par logiciel de la concentration de protéines dans les protrusions cellulaires dynamiques

Filopodia are dynamic, finger-like cellular protrusions associated with migration and cell-cell communication. In order to better understand the complex ...

Transient Expression and Cellular Localization of Recombinant Proteins in Cultured Insect Cells

Heterologous protein expression systems are used for the production of recombinant proteins, the interpretation of cellular trafficking/localization, and the determination of the biochemical function of proteins at the sub-organismal level. Although baculovirus expression systems are increasingly used for protein production in numerous biotechnological, pharmaceutical, and industrial applications, nonlytic systems that do not involve viral infection have clear benefits but are often overlooked and underutilized. Here, we describe a method for generating nonlytic expression vectors and transient recombinant protein expression. This protocol allows for the efficient cellular localization of recombinant proteins and can be used to rapidly discern protein trafficking within the cell. We show the expression of four&#160;recombinant proteins in a commercially available insect cell line, including two aquaporin proteins from the insect Bemisia tabaci, as well as subcellular marker proteins specific for the cell plasma membrane and for intracellular lysosomes. All recombinant proteins were produced as chimeras with fluorescent protein markers at their carboxyl termini, which allows for the direct detection of the recombinant proteins. The double transfection of cells with plasmids harboring constructs for the genes of interest and a known subcellular marker allows for live cell imaging and improved validation of cellular protein localization.

Nonlytic insect cell expression systems are underutilized for production, cellular trafficking/localization, and recombinant protein functional analysis. Here, we describe methods to generate expression vectors and subsequent transient protein expression in commercially available lepidopteran cell lines. The co-localization of Bemisia tabaci aquaporins with subcellular fluorescent marker proteins is also presented.

Expression transitoire et localisation cellulaire des protéines recombinantes dans les cellules d&#39;insectes Cultured

Heterologous protein expression systems are used for the production of recombinant proteins, the interpretation of cellular trafficking/localization, and ...

Production et imagerie de vésicules remplies de protéines recombinantes à partir d’E. coli

Optimized Production and Analysis of Recombinant Protein-Filled Vesicles from E. coli

This innovative system, using a short peptide tag, that exports multiple recombinant proteins in membrane bound vesicles from E. coli, provides an effective solution to a range of problems associated with bacterial recombinant protein expression. These recombinant vesicles compartmentalise proteins within a micro-environment that facilitates the production of otherwise challenging, toxic, insoluble, or disulfide-bond containing proteins from bacteria. Protein yield is increased considerably when compared to typical bacterial expression in the absence of the vesicle-nucleating peptide tag. The release of vesicle-packaged proteins supports isolation from the culture medium&#160;and permits long-term active protein storage. This technology gives rise to increased yields of vesicle-packaged, functional proteins for simplified downstream processing for a diverse range of applications from applied biotechnology to discovery science and medicine. In the present article and the associated video, a detailed protocol of the method is provided, which highlights key steps in the methodology to maximize recombinant protein-filled vesicle production.

Pleins feux sur l’auteur : La production de protéines recombinantes 

The present protocol describes a detailed method for the bacterial production of recombinant proteins, including typically insoluble or disulfide-bond containing proteins, packaged inside extracellular membrane-bound vesicles. This has the potential to be applied to versatile areas of scientific research, including applied biotechnology and medicine.