Nous sommes particulièrement reconnaissants à S. et V. Graewe Heussler pour la formation initiale et continue en entrée microscopie intravitale des parasites du paludisme, de J. Burns pour le don de la GFP parasites transgéniques, à A. Bosch (Unité confocale, CCIT-UB, IDIBAPS) d&#39;assistance dans l&#39;analyse d&#39;image et de la quantification et à P. Astola d&#39;assistance technique. Nous remercions Tous R. et I. Caralt pour la production vidéo. MF est un bénéficiaire d&#39;une bourse d&#39;études supérieures de la Généralité de Catalogne. HAP est un professeur de recherche ICREA. Le travail dans le laboratoire de HAP est financé par le Programme de la Communauté européenne septième programme-cadre (FP7/2007-2013) sous convention de subvention n ° 242095, par le privé CELLEX Foundation (Catalogne, Espagne), et par le ministère espagnol de la science et l&#39;innovation ( SAF2009-07760).

<ol>
	<li>Amino, R., Menard, R., Frischknecht, F. <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+imaging+of+malaria+parasites--recent+advances+and+future+directions.">In vivo imaging of malaria parasites--recent advances and future directions.</a> Curr. Opin. Microbiol. 8, 407-414 (2005).</li><li>Heussler, V., Doerig, C. <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+imaging+enters+parasitology.">In vivo imaging enters parasitology.</a> Trends. Parasitol. 22, 192-195 (2006).</li><li>Amino, R., Thiberge, S., Blazquez, S., Baldacci, P., Renaud, O., Shorte, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+malaria+sporozoites.">Imaging malaria sporozoites.</a> in the dermis of the mammalian. 2, 1705-1712 (2007).</li><li>Gueirard, P., Tavares, J., Thiberge, S., Bernex, F., Ishino, T., Milon, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+the+malaria+parasite+in+the+skin+of+the+mammalian+host.">Development of the malaria parasite in the skin of the mammalian host.</a> Proc. Natl. Acad. Sci. U. S. A. 107, 18640-18645 (2010).</li><li>Sturm, A., Amino, R., van de Sand, C., Regen, T., Retzlaff, S., Rennenberg, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Manipulation+of+host+hepatocytes+by+the+malaria+parasite+for+delivery+into+liver+sinusoids.">Manipulation of host hepatocytes by the malaria parasite for delivery into liver sinusoids.</a> Science. 313, 1287-1290 (2006).</li><li>Gruring, C., Heiber, A., Kruse, F., Ungefehr, J., Gilberger, T. W., Spielmann, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+and+host+cell+modifications+of+Plasmodium+falciparum+blood+stages+in+four+dimensions.">Development and host cell modifications of Plasmodium falciparum blood stages in four dimensions.</a> Nat. Commun. 2, 165-165 (2011).</li><li>Martin-Jaular, L., Ferrer, M., Calvo, M., Rosanas-Urgell, A., Kalko, S., Graewe, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strain-specific+spleen+remodelling+in+Plasmodium+yoelii+infections+in+Balb/c+mice+facilitates+adherence+and+spleen+macrophage-clearance+escape.">Strain-specific spleen remodelling in Plasmodium yoelii infections in Balb/c mice facilitates adherence and spleen macrophage-clearance escape.</a> Cell. Microbiol. 13, 109-122 (2011).</li><li>Linden, M. v. a. n. d. e. r., R, . <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Plasmodium+berghei+reference+line+that+constitutively+expresses+GFP+at+a+high+level+throughout+the+complete+life+cycle.">A Plasmodium berghei reference line that constitutively expresses GFP at a high level throughout the complete life cycle.</a> Mol. Biochem. Parasitol. 137, 23-33 (2004).</li><li>Cormack, B. P., Valdivia, R. H., Falkow, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=FACS-optimized+mutants+of+the+green+fluorescent+protein.">FACS-optimized mutants of the green fluorescent protein.</a> 173, 33-38 (1996).</li><li>Dunn, K. W., Sandoval, R. M., Kelly, K. J., Dagher, P. C., Tanner, G. A., Atkinson, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+studies+of+the+kidney+of+living+animals+using+multicolor+two-photon+microscopy.">Functional studies of the kidney of living animals using multicolor two-photon microscopy.</a> Am. J. Physiol. Cell. Physiol. 283, C905-C916 (2002).</li><li>Zhong, Z., Petrig, B. L., Qi, X., Burns, 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=In+vivo+measurement+of+erythrocyte+velocity+and+retinal+blood+flow+using+adaptive+optics+scanning+laser+ophthalmoscopy.">In vivo measurement of erythrocyte velocity and retinal blood flow using adaptive optics scanning laser ophthalmoscopy.</a> Opt. Express. 16, 12746-12756 (2008).</li><li>Miller, M. J., Wei, S. H., Parker, I., Cahalan, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-photon+imaging+of+lymphocyte+motility+and+antigen+response+in+intact+lymph+node.">Two-photon imaging of lymphocyte motility and antigen response in intact lymph node.</a> Science. 296, 1869-1873 (2002).</li><li>Bowdler, A. J. <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 complete spleen. , (2002).</li><li>Grayson, M. H., Hotchkiss, R. S., Karl, I. E., Holtzman, M. J., Chaplin, D. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intravital+microscopy+comparing+T+lymphocyte+trafficking+to+the+spleen+and+the+mesenteric+lymph+node.">Intravital microscopy comparing T lymphocyte trafficking to the spleen and the mesenteric lymph node.</a> Am. J. Physiol. Heart. Circ. Physiol. 284, H2213-H2226 (2003).</li><li>Khandoga, A. G., Khandoga, A., Reichel, C. A., Bihari, P., Rehberg, M., Krombach, F. <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+imaging+and+quantitative+analysis+of+leukocyte+directional+migration+and+polarization+in+inflamed+tissue.">In vivo imaging and quantitative analysis of leukocyte directional migration and polarization in inflamed tissue.</a> PLoS. One. 4, 4693-4693 (2009).</li><li>Weiss, L., Geduldig, U., Weidanz, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+splenic+control+of+murine+malaria:+reticular+cell+activation+and+the+development+of+a+blood-spleen+barrier.">Mechanisms of splenic control of murine malaria: reticular cell activation and the development of a blood-spleen barrier.</a> Am. J. Anat. 176, 251-285 (1986).</li><li>Swirski, F. K., Nahrendorf, M., Etzrodt, M., Wildgruber, M., Cortez-Retamozo, V., Panizzi, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+splenic+reservoir+monocytes+and+their+deployment+to+inflammatory+sites.">Identification of splenic reservoir monocytes and their deployment to inflammatory sites.</a> Science. 325, 612-616 (2009).</li><li>Grayson, M. H., Chaplin, D. D., Karl, I. E., Hotchkiss, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Confocal+fluorescent+intravital+microscopy+of+the+murine+spleen.">Confocal fluorescent intravital microscopy of the murine spleen.</a> J. Immunol. Methods. 256, 55-63 (2001).</li><li>Bajenoff, M., Glaichenhaus, N., Germain, R. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fibroblastic+reticular+cells+guide+T+lymphocyte+entry+into+and+migration+within+the+splenic+T+cell+zone.">Fibroblastic reticular cells guide T lymphocyte entry into and migration within the splenic T cell zone.</a> J. Immunol. 181, 3947-3954 (2008).</li></ol>

Pas de conflits d&#39;intérêt déclarés.

La mise en œuvre de la microscopie intravitale de la rate dans ce modèle du paludisme des rongeurs a ouvert la possibilité d&#39;enquêter sur le passage dynamique des parasites par cet organe qui a été jusqu&#39;à présent considéré comme une «boîte noire» en raison de considérations techniques. Ici, un effort majeur a été mis à adapter une méthode quantitative qui permet une analyse comparative des lignes parasites différents niveaux unique et de la population. Contrairement à d&#39;autres tissus et ...

<table border="1"><tbody><tr><td> Nom du réactif </td><td> Société </td><td> Numéro de catalogue </td><td> Commentaires </td></tr><tr><td> Leica TCS SP5-microscope confocal </td><td> Leica Microsystems, Heidelberg, Allemagne </td><td> TCS-SP5 N ° de série. 5100000419 </td><td></td></tr><tr><td> La kétamine (Ketolar 50 mg / ml) </td><td> Pfizer </td><td> 631028 </td><td></td></tr><tr><td> Le midazolam 15 mg / 3 ml </td><td> Normon </td><td> 838193 </td><td></td></tr><tr><td> 70000 MW Dextran, conjugué au Texas Red </td><td> Molecular Probes </td><td> D1830 </td><td></td></tr><tr><td> Isothiocyanate de fluorescéine, l&#39;isomère I (FITC) </td><td> Sigma </td><td> F7250 </td><td></td></tr><tr><td> Hoechst 33342 </td><td> Sigma </td><td> H1399 </td><td></td></tr><tr><td> Giemsa </td><td> Sigma </td><td> GS1 </td><td> Solution de travail est à 10% dans de l&#39;eau distillée </td></tr><tr><td> Super Glue-3 Loctite </td><td> Loctite </td><td> 9975-0880 </td><td></td></tr></tbody></table>

intravital microscopy of the spleen: quantitative analysis of parasite mobility and blood flow

L&#39;avènement de la microscopie intravitale dans des modèles expérimentaux de paludisme des rongeurs a permis des avancées majeures à la connaissance de parasite-hôte 1,2 interactions. Ainsi, l&#39;imagerie in vivo des parasites du paludisme au cours stades pré-érythrocytaires ont révélé l&#39;entrée active de parasites dans les ganglions lymphatiques peau 3, le développement complet du parasite dans la peau 4, et la formation d&#39;un merosome hépatocytes dérivés pour assurer la migration et libération de mérozoïtes dans la circulation sanguine 5. Par ailleurs, le développement de parasites individuels dans les érythrocytes a été récemment documenté en utilisant l&#39;imagerie 4D et a contesté notre point de vue actuel sur l&#39;exportation de protéines dans le paludisme 6. Ainsi, l&#39;imagerie intravitale a radicalement changé notre vision sur les événements clés dans le développement de Plasmodium. Malheureusement, les études sur le passage dynamique des parasites du paludisme à travers la rate, un organe majeur lymphoïdes délicieusement adapté à claire rouge infecté bcellules lood manquent en raison de contraintes techniques. En utilisant le modèle murin de paludisme à Plasmodium yoelii de souris Balb / c, nous avons mis en imagerie intravitale de la rate et rapporté un remodelage différentiel de lui et l&#39;adhérence des globules rouges parasités (culot globulaire) à des cellules d&#39;origine fibroblastique barrière dans la pulpe rouge pendant l&#39;infection par le parasite du non-létales ligne 17X P.yoelii par opposition aux infections à la ligne P.yoelii 17XL mortelle du parasite 7. Pour arriver à ces conclusions, une méthodologie spécifique en utilisant le logiciel libre ImageJ a été développé pour permettre la caractérisation de la vitesse en trois dimensions des mouvements mono-culot globulaire. Les résultats obtenus avec ce protocole permettra de déterminer le temps de vitesse, la directivité et de séjour des parasites dans la rate, tous les paramètres d&#39;adressage adhésion in vivo. En outre, nous présentons la méthodologie pour la quantification du flux sanguin en utilisant la microscopie intravitale et l&#39;utilisation de DIFdifférents agents colorants pour mieux comprendre la structure complexe de la microcirculation de la rate. Déclaration d&#39;éthique Toutes les études animales ont été effectuées dans les installations animales de l&#39;Université de Barcelone, en conformité avec les directives et protocoles approuvés par le comité d&#39;éthique pour l&#39;expérimentation animale de l&#39;Université de Barcelone CEEA-UB (Protocole n ° DMAH: 5429). Femme souris Balb / c de 6-8 semaines d&#39;âge ont été obtenues de Charles River Laboratories.

Watch this Scientific Journal Video about Intravital Microscopy of the Spleen: Quantitative Analysis of Parasite Mobility and Blood Flow at JoVE.com

Intravital Microscopy of the Spleen: Quantitative Analysis of Parasite Mobility and Blood Flow

Nous montrons la méthode pour effectuer la microscopie intravitale de la rate à l&#39;aide des parasites du paludisme transgéniques GFP et la quantification de la mobilité et la circulation sanguine du parasite au sein de cet organe.

Microscopie intravitale de la rate: Analyse quantitative de la mobilité des parasites et la circulation sanguine

The advent of intravital microscopy in experimental rodent malaria models has allowed major advances to the knowledge of parasite-host interactions 1,2. ...

intravital-microscopy-spleen-quantitative-analysis-parasite-mobility

Research

JoVE Journal

Immunology and Infection

18.1K vues.  Barcelona Centre for International Health Research. Nous montrons la méthode pour effectuer la microscopie intravitale de la rate à l'aide des parasites du paludisme transgéniques GFP et la quantification de la mobilité et la circulation sanguine du parasite au sein de cet organe.

Vidéo: Intravital Microscopy of the Spleen: Quantitative Analysis of Parasite Mobility and Blood Flow

Intravital Microscopy of the Inguinal Lymph Node

Lymph nodes (LN's), located throughout the body, are an integral component of the immune system. They serve as a site for induction of adaptive immune response and therefore, the development of effector cells. As such, LNs are key to fighting invading pathogens and maintaining health. The choice of LN to study is dictated by accessibility and the desired model; the inguinal lymph node is well situated and easily supports studies of biologically relevant models of skin and genital mucosal infection.
The inguinal LN, like all LNs, has an extensive microvascular network supplying it with blood. In general, this microvascular network includes the main feed arteriole of the LN that subsequently branches and feeds high endothelial venules (HEVs). HEVs are specialized for facilitating the trafficking of immune cells into the LN during both homeostasis and infection. How HEVs regulate trafficking into the LN under both of these circumstances is an area of intense exploration. The LN feed arteriole, has direct upstream influence on the HEVs and is the main supply of nutrients and cell rich blood into the LN. Furthermore, changes in the feed arteriole are implicated in facilitating induction of adaptive immune response. The LN microvasculature has obvious importance in maintaining an optimal blood supply to the LN and regulating immune cell influx into the LN, which are crucial elements in proper LN function and subsequently immune response. 
The ability to study the LN microvasculature in vivo is key to elucidating how the immune system and the microvasculature interact and influence one another within the LN. Here, we present a method for in vivo imaging of the inguinal lymph node. We focus on imaging of the microvasculature of the LN, paying particular attention to methods that ensure the study of healthy vessels, the ability to maintain imaging of viable vessels over a number of hours, and quantification of vessel magnitude. Methods for perfusion of the microvasculature with vasoactive drugs as well as the potential to trace and quantify cellular traffic are also presented. 
Intravital microscopy of the inguinal LN allows direct evaluation of microvascular functionality and real-time interface of the direct interface between immune cells, the LN, and the microcirculation. This technique potential to be combined with many immunological techniques and fluorescent cell labelling as well as manipulated to study vasculature of other LNs.

A technique for performing intravital microscopy of the inguinal lymph node (LN) is outlined. Such technique allows for real-time, in vivo study of the lymph node microvasculature and structure both during homeostasis and infection. This technique can be adapted to cell trafficking studies and to other lymph node sites.

Microscopie intravitale du ganglion lymphatique inguinal

Lymph nodes (LN's), located throughout the body, are an integral component of the immune system. They serve as a site for induction of adaptive immune ...

Recherche

Immunologie et infection

Intravital Imaging of the Mouse Thymus using 2-Photon Microscopy

Two-photon Microscopy (TPM) provides image acquisition in deep areas inside tissues and organs. In combination with the development of new stereotactic tools and surgical procedures, TPM becomes a powerful technique to identify "niches" inside organs and to document cellular "behaviors" in live animals. While intravital imaging provides information that best resembles the real cellular behavior inside the organ, it is both more laborious and technically demanding in terms of required equipment/procedures than alternative ex vivo imaging acquisition. Thus, we describe a surgical procedure and novel "stereotactic" organ holder that allows us to follow the movements of Foxp3+ cells within the thymus.
Foxp3 is the master regulator for the generation of regulatory T cells (Tregs). Moreover, these cells can be classified according to their origin: ie. thymus-differentiated Tregs are called "naturally-occurring Tregs" (nTregs), as opposed to peripherally-converted Tregs (pTregs). Although significant amount of research has been reported in the literature concerning the phenotype and physiology of these T cells, very little is known about their in vivo interactions with other cells. This deficiency may be due to the absence of techniques that would permit such observations. The protocol described in this paper provides a remedy for this situation.
Our protocol consists of using nude mice that lack an endogenous thymus since they have a punctual mutation in the DNA sequence that compromises the differentiation of some epithelial cells, including thymic epithelial cells. Nude mice were gamma-irradiated and reconstituted with bone marrows (BM) from Foxp3-KIgfp/gfp mice. After BM recovery (6 weeks), each animal received embryonic thymus transplantation inside the kidney capsule. After thymus acceptance (6 weeks), the animals were anesthetized; the kidney containing the transplanted thymus was exposed, fixed in our organ holder, and kept under physiological conditions for in vivo imaging by TPM. We have been using this approach to study the influence of drugs in the generation of regulatory T cells.

We have developed novel laboratory tools and protocols for intravital imaging acquisition of the thymus. Our technique should help in the identification of &#x201C;niches&#x201D; within the thymus where T cell development occurs.

Imagerie intravitale du Thymus souris utilisant la 2-microscopie biphotonique

Two-photon Microscopy (TPM) provides image acquisition in deep areas inside tissues and organs. In combination with the development of new stereotactic ...

Single-cell Analysis of Bacillus subtilis Biofilms Using Fluorescence Microscopy and Flow Cytometry

Biofilm formation is a general attribute to almost all bacteria 1-6. When bacteria form biofilms, cells are encased in extracellular matrix that is mostly constituted by proteins and exopolysaccharides, among other factors 7-10. The microbial community encased within the biofilm often shows the differentiation of distinct subpopulation of specialized cells 11-17. These subpopulations coexist and often show spatial and temporal organization within the biofilm 18-21.
Biofilm formation in the model organism Bacillus subtilis requires the differentiation of distinct subpopulations of specialized cells. Among them, the subpopulation of matrix producers, responsible to produce and secrete the extracellular matrix of the biofilm is essential for biofilm formation 11,19. Hence, differentiation of matrix producers is a hallmark of biofilm formation in B. subtilis.
We have used fluorescent reporters to visualize and quantify the subpopulation of matrix producers in biofilms of B. subtilis 15,19,22-24. Concretely, we have observed that the subpopulation of matrix producers differentiates in response to the presence of self-produced extracellular signal surfactin 25. Interestingly, surfactin is produced by a subpopulation of specialized cells different from the subpopulation of matrix producers 15.
We have detailed in this report the technical approach necessary to visualize and quantify the subpopulation of matrix producers and surfactin producers within the biofilms of B. subtilis. To do this, fluorescent reporters of genes required for matrix production and surfactin production are inserted into the chromosome of B. subtilis. Reporters are expressed only in a subpopulation of specialized cells. Then, the subpopulations can be monitored using fluorescence microscopy and flow cytometry (See Fig 1).
The fact that different subpopulations of specialized cells coexist within multicellular communities of bacteria gives us a different perspective about the regulation of gene expression in prokaryotes. This protocol addresses this phenomenon experimentally and it can be easily adapted to any other working model, to elucidate the molecular mechanisms underlying phenotypic heterogeneity within a microbial community.

Single-cell Analysis of Bacillus subtilis Biofilms Using Fluorescence Microscopy and Flow Cytometry

Microbial biofilms are generally constituted by distinct subpopulations of specialized cells. Single-cell analysis of these subpopulations requires the use of fluorescent reporters. Here we describe a protocol to visualize and monitor several subpopulationswithin B. subtilis biofilms using fluorescence microscopy and flow cytometry.

Analyse unicellulaire des<emBacillus subtilis> Les biofilms par microscopie à fluorescence et cytométrie de flux

Biofilm formation is a general attribute to almost all bacteria 1-6. When bacteria form biofilms, cells are encased in extracellular matrix that is mostly ...

Highly Resolved Intravital Striped-illumination Microscopy of Germinal Centers

Monitoring cellular communication by intravital deep-tissue multi-photon microscopy is the key for understanding the fate of immune cells within thick tissue samples and organs in health and disease. By controlling the scanning pattern in multi-photon microscopy and applying appropriate numerical algorithms, we developed a striped-illumination approach, which enabled us to achieve 3-fold better axial resolution and improved signal-to-noise ratio, i.e. contrast, in more than 100 &#181;m tissue depth within highly scattering tissue of lymphoid organs as compared to standard multi-photon microscopy. The acquisition speed as well as photobleaching and photodamage effects were similar to standard photo-multiplier-based technique, whereas the imaging depth was slightly lower due to the use of field detectors. By using the striped-illumination approach, we are able to observe the dynamics of immune complex deposits on secondary follicular dendritic cells &#8211; on the level of a few protein molecules in germinal centers.

High-resolution intravital imaging with enhanced contrast up to 120 &#181;m depth in lymph nodes of adult mice is achieved by spatially modulating the excitation pattern of a multi-focal two-photon microscope. In 100 &#181;m depth we measured resolutions of 487 nm (lateral) and 551 nm (axial), thus circumventing scattering and diffraction limits.

Très Résolu microscopie intravitale Striped-éclairage de centres germinaux

Monitoring cellular communication by intravital deep-tissue multi-photon microscopy is the key for understanding the fate of immune cells within thick ...

Intravital Microscopy Imaging of the Liver following Leishmania Infection: An Assessment of Hepatic Hemodynamics

Intravital microscopy (IVM) is a powerful optical imaging technique that has made possible the visualization, monitoring and quantification of various biological events in real time and in live animals. This technology has greatly advanced our understanding of physiological processes and pathogen-mediated phenomena in specific organs.
In this study, IVM is applied to the mouse liver and protocols are designed to image in vivo the circulatory system of the liver and measure red blood cell (RBC) velocity in individual hepatic vessels. To visualize the different vessel subtypes that characterize the hepatic organ and perform blood flow speed measurements, C57Bl/6 mice are intravenously injected with a fluorescent plasma reagent that labels the liver-associated vasculature. IVM enables in vivo, real time, measurement of RBC velocity in a specific vessel of interest. Establishing this methodology will make it possible to investigate liver hemodynamics under physiological and pathological conditions. Ultimately, this imaging-based methodology will be important for studying the influence of L. donovani infection&#160;on hepatic hemodynamics.
This method can be applied to other infectious models and mouse organs and might be further extended to pre-clinical testing of a drug&#8217;s effect on inflammation by quantifying its effect on blood flow.

Intravital Microscopy Imaging of the Liver following Leishmania Infection: An Assessment of Hepatic Hemodynamics

This article reports on a detailed method for the dynamic measurement and quantification of blood flow velocity within individual blood vessels of the mouse liver vasculature using intravital microscopy imaging in combination with a specific methodology for image acquisition and analysis.

Microscopie intravitale imagerie du foie suivante<em&gt; Leishmania</em&gt; Infection: Une évaluation de l&#39;hémodynamique hépatiques

Intravital microscopy (IVM) is a powerful optical imaging technique that has made possible the visualization, monitoring and quantification of various ...

Isolation and Flow Cytometric Analysis of Glioma-infiltrating Peripheral Blood Mononuclear Cells

Our laboratory has recently demonstrated that natural killer (NK) cells are capable of eradicating orthotopically implanted mouse GL26 and rat CNS-1 malignant gliomas soon after intracranial engraftment if the cancer cells are rendered deficient in their expression of the &#946;-galactoside-binding lectin galectin-1 (gal-1). More recent work now shows that a population of Gr-1+/CD11b+ myeloid cells is critical to this effect. To better understand the mechanisms by which NK and myeloid cells cooperate to confer gal-1-deficient tumor rejection we have developed a comprehensive protocol for the isolation and analysis of glioma-infiltrating peripheral blood mononuclear cells (PBMC). The method is demonstrated here by comparing PBMC infiltration into the tumor microenvironment of gal-1-expressing GL26 gliomas with those rendered gal-1-deficient via shRNA knockdown. The protocol begins with a description of&#160;how to culture and prepare GL26 cells for inoculation into the syngeneic C57BL/6J mouse brain. It then explains the steps involved in the isolation and flow cytometric analysis of glioma-infiltrating PBMCs from the early brain tumor microenvironment. The method is adaptable to a number of in vivo experimental designs in which temporal data on immune infiltration into the brain is required. The method is sensitive and highly reproducible, as glioma-infiltrating PBMCs can be isolated from intracranial tumors as soon as 24 hr post-tumor engraftment with similar cell counts observed from time point matched tumors throughout independent experiments. A single experimentalist can perform the method from brain harvesting to flow cytometric analysis of glioma-infiltrating PBMCs in roughly 4-6 hr depending on the number of samples to be analyzed. Alternative glioma models and/or cell-specific detection antibodies may also be used at the experimentalists&#8217; discretion to assess the infiltration of several other immune cell types of interest without the need for alterations to the overall procedure.

Presented here is a straightforward method for the isolation and flow cytometric analysis of glioma-infiltrating peripheral blood mononuclear cells that yields time-dependent quantitative data on the number and activation status of immune cells entering the early brain tumor microenvironment.

L&#39;isolement et la cytométrie en flux analyse des cellules mononucléaires du sang périphérique gliome infiltrant

Our laboratory has recently demonstrated that natural killer (NK) cells are capable of eradicating orthotopically implanted mouse GL26 and rat CNS-1 ...

Flow Cytometric Analysis of Natural Killer Cell Lytic Activity in Human Whole Blood

NK cell cytotoxicity is a widely used measure to determine the effect of outside intervention on NK cell function. However, the accuracy and reproducibility of this assay can be considered unstable, either because of user&#39;s errors or because of the sensitivity of NK cells to experimental manipulation. To eliminate these issues, a workflow that reduces them to a minimum was established and is presented here. To illustrate, we obtained blood samples, at various time points, from runners (n = 4) that were submitted to an intense bout of exercise. First, NK cells are simultaneously identified and isolated through CD56 tagging and magnetic-based sorting, directly from whole blood and from as little as one milliliter. The sorted NK cells are removed of any reagent or capping antibodies. They can be counted in order to establish an accurate NK cell count per milliliter of blood. Secondly, the sorted NK cells (effectors cells or E) can be mixed with 3,3&#39;-Diotadecyloxacarbocyanine Perchlorate (DiO) tagged K562 cells (target cells or T) at an assay-optimal 1:5 T:E ratio, and analyzed using an imaging flow-cytometer that allows for the visualization of each event and the elimination of any false positive or false negatives (such as doublets or effector cells). This workflow can be completed in about 4 h, and allows for very stable results even when working with human samples. When available, research teams can test several experimental interventions in human subjects, and compare measurements across several time points without compromising the data&#39;s integrity.

This work describes an advanced workflow for the accurate and fast determination of NK (Natural Killer) cell count and NK cell cytotoxicity in human blood samples.

Cytométrie en flux Analyse des cellules tueuses naturelles lytique Activité dans le sang humain

NK cell cytotoxicity is a widely used measure to determine the effect of outside intervention on NK cell function. However, the accuracy and ...

Dextran Enhances the Lentiviral Transduction Efficiency of Murine and Human Primary NK Cells

The efficient transduction of specific genes into natural killer (NK) cells has been a major challenge. Successful transductions are critical to defining the role of the gene of interest in the development, differentiation, and function of NK cells. Recent advances related to chimeric antigen receptors (CARs) in cancer immunotherapy accentuate the need for an efficient method to deliver exogenous genes to effector lymphocytes. The efficiencies of lentiviral-mediated gene transductions into primary human or mouse NK cells remain significantly low, which is a major limiting factor. Recent advances using cationic polymers, such as polybrene, show an improved gene transduction efficiency in T cells. However, these products failed to improve the transduction efficiencies of NK cells. This work shows that dextran, a branched glucan polysaccharide, significantly improves the transduction efficiency of human and mouse primary NK cells. This highly reproducible transduction methodology provides a competent tool for transducing human primary NK cells, which can vastly improve clinical gene delivery applications and thus NK cell-based cancer immunotherapy.

The goal of this study was to formulate technologies that allow for successful gene transduction in primary natural killer (NK) cells. The dextran-mediated lentiviral transduction of human or mouse primary NK cells results in higher gene expression efficiencies. This method of gene transduction will vastly improve NK cell genetic manipulation.

Dextrane augmente l’efficacité de la Transduction des gènes des cellules NK primaires murines et humaines

The efficient transduction of specific genes into natural killer (NK) cells has been a major challenge. Successful transductions are critical to defining ...

Qualitative and Quantitative Analysis of the Immune Synapse in the Human System Using Imaging Flow Cytometry

The immune synapse is the area of communication between T cells and antigen-presenting cells (APCs). T cells polarize surface receptors and proteins towards the immune synapse to assure a stable binding and signal exchange. Classical confocal, TIRF, or super-resolution microscopy have been used to study the immune synapse. Since these methods require manual image acquisition and time-consuming quantification, the imaging of rare events is challenging. Here, we describe a workflow that enables the morphological analysis of tens of thousands of cells. Immune synapses are induced between primary human T cells in pan-leukocyte preparations and Staphylococcus aureus enterotoxin B (SEB)-loaded Raji cells as APCs. Image acquisition is performed with imaging flow cytometry, also called In-Flow microscopy, which combines features of a flow cytometer and a fluorescence microscope. A complete gating strategy for identifying T cell/APC couples and analyzing the immune synapses is provided. As this workflow allows the analysis of immune synapses in unpurified pan-leukocyte preparations and hence requires only a small volume of blood (i.e., 1 mL), it can be applied to samples from patients. Importantly, several samples can be prepared, measured, and analyzed in parallel.

Here, we describe a complete workflow for the qualitative and quantitative analysis of immune synapses between primary human T cells and antigen-presenting cells. The method is based on imaging flow cytometry, which allows the acquisition and evaluation of several thousand cell images within a relatively short period of time.

Analyse qualitative et Quantitative de la Synapse immunitaire dans le système humain à l’aide d’imagerie de cytométrie en flux

The immune synapse is the area of communication between T cells and antigen-presenting cells (APCs). T cells polarize surface receptors and proteins ...

Phenotypic Analysis of Rodent Malaria Parasite Asexual and Sexual Blood Stages and Mosquito Stages

Recent advances in genetics and systems biology technologies have promoted our understanding of the biology of malaria parasites on the molecular level. However, effective malaria parasite targets for vaccine and chemotherapy development are still limited. This is largely due to the unavailability of relevant and practical in vivo infection models for human Plasmodium species, most notably for P.&#160;falciparum and P. vivax. Therefore, rodent malaria species have been extensively used as practical alternative in vivo models for malaria vaccine, drug targeting, immune response, and functional characterization studies of conserved Plasmodiumspp. genes. Indeed, rodent malaria models have proven to be invaluable, especially for exploring mosquito transmission and liver stage biology, and were indispensable for immunological studies. However, there are discrepancies in the methods used to evaluate the phenotypes of transgenic and wild-type asexual and sexual blood-stage parasites.&#160;Examples of these discrepancies are the choice of an intravenous vs. intraperitoneal infection of rodents with blood-stage parasites and the evaluation of male gamete exflagellation. Herein, we detail standardized experimental methods to evaluate the phenotypes of asexual and sexual blood stages in transgenic parasites expressing reporter-gene or wild-type rodent malaria parasite species. We also detail the methods to evaluate the phenotypes of malaria parasite mosquito stages (gametes, ookinetes, oocysts, and sporozoites) inside Anopheles mosquito vectors. These methods are detailed and simplified here for the lethal and non-lethal strains of P. berghei and P. yoelii but can also be applied with some adjustments to P. chabaudi and P. vinckei rodent malaria species.

Due to the striking similarities of the life cycle and biology of rodent malaria parasites to human malaria parasites, rodent malaria models have become indispensable for malaria research. Herein, we standardized some of the most important techniques used in the phenotypic analysis of wild-type and transgenic rodent malaria species.

Analyse phénotypique des stades du sang asexué et sexuel du parasite du paludisme des rongeurs et des stades des moustiques

Recent advances in genetics and systems biology technologies have promoted our understanding of the biology of malaria parasites on the molecular level. ...