Nous tenons à remercier Alvin et Larry Welch Pang pour leur assistance technique. Ce travail a été financé en partie par le National Institutes of Health (NIH) P50 CA086306 prix, le California Institute for Regenerative Medicine (CIRM) des subventions RC1-00149-1 et RS1-00203-1; prix CIRM Faculté Nouvelle-RN2 00902-1 , le Centre de Caltech-UCLA commun pour la médecine translationnelle, UCLA Center for AIDS Research (CFAR) NIH / NIAID AI028697, l&#39;UCLA AIDS Institute, les outils du CIRM et du Prix de la technologie RT1-01126, et le Programme de recherche multicampus UC et initiatives de la Californie Centre de Découverte médicament antiviral (nombre MRPI-143226).

<ol>
	<li>McCune, J. M., Namikawa, R., Kaneshima, H., Shultz, L. D., Lieberman, M., Weissman, I. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+SCID-hu+mouse:+murine+model+for+the+analysis+of+human+hematolymphoid+differentiation+and+function.">The SCID-hu mouse: murine model for the analysis of human hematolymphoid differentiation and function.</a> Science. 241 (4873), 1632-1639 (1988).</li><li>Bristol, G. C., Gao, L. Y., Zack, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+and+maintenance+of+SCID-hu+mice+for+HIV+research.">Preparation and maintenance of SCID-hu mice for HIV research.</a> Methods. 12 (4), 343-347 (1997).</li><li>Mosier, D. E., Gulizia, R. J., Baird, S. M., Wilson, D. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transfer+of+a+functional+human+immune+system+to+mice+with+severe+combined+immunodeficiency.">Transfer of a functional human immune system to mice with severe combined immunodeficiency.</a> Nature. 335 (6187), 256-259 (1988).</li><li>Melkus, M. W., Estes, J. D., Padgett-Thomas, A., Gatlin, J., Denton, P. W., Othieno, F. A., Wege, A. K., Haase, A. T., Garcia, J. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Humanized+mice+mount+specific+adaptive+and+innate+immune+responses+to+EBV+and+TSST-1.">Humanized mice mount specific adaptive and innate immune responses to EBV and TSST-1.</a> Nat. Med. 12 (11), 1316-1322 (2006).</li><li>Denton, P. W., Estes, J. D., Sun, Z., Othieno, F. A., Wei, B. L., Wege, A. K., Powell, D. A., Payne, D., Haase, A. T., Garcia, J. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antiretroviral+pre-exposure+prophylaxis+prevents+vaginal+transmission+of+HIV-1+in+humanized+BLT+mice.">Antiretroviral pre-exposure prophylaxis prevents vaginal transmission of HIV-1 in humanized BLT mice.</a> PLoS Med. 5 (1), e16 (2008).</li><li>Sun, Z., Denton, P. W., Estes, J. D., Othieno, F. A., Wei, B. L., Wege, A. K., Melkus, M. W., Padgett-Thomas, M. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intrarectal+transmission,+systemic+infection,+and+CD4++T+cell+depletion+in+humanized+mice+infected+with+HIV-1.">Intrarectal transmission, systemic infection, and CD4+ T cell depletion in humanized mice infected with HIV-1.</a> J. Exp. Med. 204 (4), 705-714 (2007).</li><li>Shimizu, S., Hong, P., Arumugam, B., Pokomo, L., Boyer, J., Koizumi, N., Kittipongdaja, P., Chen, A., Bristol, G., Galic, Z., Zack, J. A., Yang, O., Chen, I. S., Lee, B., An, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+highly+efficient+short+hairpin+RNA+potently+down-regulates+CCR5+expression+in+systemic+lymphoid+organs+in+the+hu-BLT+mouse+model.">A highly efficient short hairpin RNA potently down-regulates CCR5 expression in systemic lymphoid organs in the hu-BLT mouse model.</a> Blood. 115 (8), 1534-1544 (2010).</li><li>V, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+HIV+Latency+in+Humanized+BLT+Mice.">Generation of HIV Latency in Humanized BLT Mice.</a> J. Virol. 86 (1), 630-634 (2012).</li><li>Vatakis, D. N., Koya, R. C., Nixon, C. C., Wei, L., Kim, S. G., Avancena, P., Bristol, G., Baltimore, D., Kohn, D. B., Ribas, A., Radu, C. G., Galic, Z., Zack, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antitumor+activity+from+antigen-specific+CD8+T+cells+generated+in+vivo+from+genetically+engineered+human+hematopoietic+stem+cells.">Antitumor activity from antigen-specific CD8 T cells generated in vivo from genetically engineered human hematopoietic stem cells.</a> Proc. Natl. Acad. Sci. U.S.A. 108 (51), 1408-1416 (2011).</li></ol>

Aucun conflit d&#39;intérêt déclaré.

Le modèle modifié BLT souris humanisée associée à l&#39;imagerie TEP in vivo sont des outils puissants pour étudier les maladies chroniques de l&#39;homme. Ce système prend le modèle de souris BLT et elle avance au-delà de la portée limitée de recherche sur le VIH. En outre, il est un grand système dans lequel nous pouvons examiner les divers protocoles de thérapie génique ainsi que des techniques de diagnostic avant qu&#39;ils ne puissent atteindre le milieu clinique. Celui-ci couplée avec le fa...

<table border="1"><tbody><tr><td> Nom du réactif </td><td> Entreprise </td><td> Numéro de catalogue </td><td> Commentaires (optionnel) </td></tr><tr><td> PBS </td><td> Invitrogen </td><td> 10010049 </td><td></td></tr><tr><td> RPMI 1640 </td><td></td><td> A1049101 </td><td></td></tr><tr><td> Iscove </td><td></td><td> 12440061 </td><td></td></tr><tr><td> Sérum de veau foetal </td><td></td><td> 16000085 </td><td></td></tr><tr><td> Collagénase de type IV </td><td> Sigma Aldrich </td><td> C5138 </td><td></td></tr><tr><td> Hyaluronidase </td><td></td><td> H3506 </td><td></td></tr><tr><td> DNAse I </td><td> Roche Diagnostics </td><td> 10104159001 &lt;/ Td&gt; <td></td></tr><tr><td> Piptazo (Zosyn) </td><td> Pfizer </td><td></td><td> <a href="http://labeling.pfizer.com/showlabeling.aspx?id=416" target="_blank">Pipéracilline / tazobactam combinaison</a> </td></tr><tr><td> Ficoll (Ficoll-Paque Plus) </td><td> GE Healthcare Life Sciences </td><td> 17-1440-02 </td><td></td></tr><tr><td> MACS tampon </td><td> Miltenyi Biotech </td><td> Voir les commentaires </td><td> MACS mémoire tampon: PBS supplémenté avec 0,5% de sérum de veau foetal et 2 mM de citrate dextrose formule-A </td></tr><tr><td> CD34 à micro-Kit </td><td></td><td> 130-046-702 </td><td></td></tr><tr><td> Colonnes LS </td><td></td><td> 130-042-401 </td><td></td></tr><tr><td> Rétronectine </td><td> Takara </td><td> T100A </td><td></td></tr><tr><td&gt; Matrigel </td><td> BD Biosciences </td><td> 354263 </td><td></td></tr><tr><td> Isofluorane </td><td> Baxter </td><td></td><td> <a href="http://www.baxter.com/healthcare_professionals/products/forane.html" target="_blank">http://www.baxter.com/healthcare_professionals/products/forane.html</a> </td></tr><tr><td> Carprofène (Rimadyl) </td><td> Pfizer Animal Health </td><td></td><td> <a href="https://www.rimadyl.com/default.aspx" target="_blank">https://www.rimadyl.com/default.aspx</a> </td></tr></tbody></table>

using the blt humanized mouse as a stem cell based gene therapy tumor model

De petits modèles animaux tels que des souris ont été largement utilisées pour étudier les maladies humaines et à développer de nouvelles interventions thérapeutiques. Malgré la richesse des informations obtenues à partir de ces études, les caractéristiques uniques de l&#39;immunité de la souris ainsi que la spécificité d&#39;espèce des maladies virales comme le virus de l&#39;immunodéficience humaine (VIH) a conduit au développement de modèles murins humanisés. Les modèles précédents impliquaient l&#39;utilisation de C. B 17 scid / scid souris et la transplantation de l&#39;homme thymus foetal et le foie du fœtus appelés ton / liv (SCID-hu) 1, 2 ou le transfert adoptif de l&#39;homme leucocytes du sang périphérique (SCID-huPBL ) 3. Les deux modèles ont été principalement utilisés pour l&#39;étude de l&#39;infection par le VIH. L&#39;une des principales limites de ces deux modèles est le manque de reconstitution stable de cellules immunitaires humaines dans la périphérie pour en faire un modèle plus physiologiquement pertinente pour étudier la maladie du VIH. À cette fin, le bourdonnement BLTmodèle de souris anized a été développé. BLT est synonyme de moelle osseuse / foie / thymus. Dans ce modèle, de 6 à 8 semaine vieux NOD.Cg-Prkdcscid Il2rgtm1Wjl / SZJ (NSG) des souris immunodéprimées recevoir l&#39;implant ton / liv comme dans le modèle de souris SCID-hu ne doit être suivie d&#39;une deuxième transplantation de cellules souches hématopoïétiques humaines 4. L&#39;avantage de ce système est la reconstitution complète du système immunitaire humain dans la périphérie. Ce modèle a été utilisé pour étudier l&#39;infection à VIH et la latence 5-8. Nous avons généré une version modifiée de ce modèle dans lequel nous utilisons génétiquement modifiés cellules souches hématopoïétiques humaines (HHSC) pour construire l&#39;implant ton / liv suivie d&#39;une injection autologue de transduction HHSC 7, 9. Cette approche se traduit par la génération de lignées génétiquement modifiées. Plus important encore, nous avons adapté ce système pour étudier le potentiel de générer des cellules fonctionnelles T cytotoxiques (CTL) exprimant un mélanome récepteur des cellules T spécifiques. En utilisant ce modèle, nous avons pu évaluer la fonctionnalité de notre CTL transgénique en utilisant en direct par émission de positrons (TEP) pour déterminer la régression tumorale (9). L&#39;objectif de ce protocole est de décrire le processus de génération de ces souris transgéniques et d&#39;évaluer l&#39;efficacité in vivo utilisant l&#39;imagerie TEP en direct. Comme une note, car nous utilisons des tissus humains et les vecteurs lentiviraux, nos installations sont conformes aux directives du NIH pour la CDC de biosécurité de niveau 2 (BSL2) avec des précautions particulières (BSL2 +). En outre, les souris NSG sont gravement immunodéprimés par conséquent, leur logement et de maintenance doivent être conformes aux normes les plus élevées de santé ( <a href="http://jaxmice.jax.org/research/immunology/005557-housing.html" target="_blank">http://jaxmice.jax.org/research/immunology/005557-housing.html</a> ).

Un diagramme du processus de transplantation est illustré à la figure 1A. Une image de l&#39;implant ton / liv est montré dans la figure 1B. Le tissu thymique se développe normalement et a une distribution physiologique des humains CD4 et CD8 des lymphocytes T. Après reconstitution, les animaux sont porteurs d&#39;un système immunitaire humain avec une distribution normale des CD4, CD8 des lymphocytes T et d&#39;autres lignées de cellules immunitaires. <p class="jove_content"...

Watch this Scientific Journal Video about Using the BLT Humanized Mouse as a Stem Cell based Gene Therapy Tumor Model at JoVE.com

Using the BLT Humanized Mouse as a Stem Cell based Gene Therapy Tumor Model

La génération et la caractérisation des tumeurs des cellules T spécifiques en utilisant des souris humanisés est décrit ici. Human tissu thymique et génétiquement modifiés cellules souches hématopoïétiques humaines sont transplantées dans des souris immunodéprimées. Cela se traduit par la reconstitution d&#39;un système immunitaire humain ingénierie permettant l&#39;examen in vivo des réponses anti-tumorales immunitaires.

Utilisation de la souris BLT humanisé comme une tumeur de cellules souches Gene Therapy modèle basé sur

Small animal models such as mice have been extensively used to study human  disease and to develop new therapeutic interventions. Despite the wealth of  ...

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Research

JoVE Journal

Immunology and Infection

18.6K vues.  David Geffen School of Medicine at UCLA. La génération et la caractérisation des tumeurs des cellules T spécifiques en utilisant des souris humanisés est décrit ici. Human tissu thymique et génétiquement modifiés cellules souches hématopoïétiques humaines sont transplantées dans des souris immunodéprimées. Cela se traduit par la reconstitution d'un système immunitaire humain ingénierie permettant l'examen in vivo des réponses anti-tumorales immunitaires.

Vidéo: Using the BLT Humanized Mouse as a Stem Cell based Gene Therapy Tumor Model

Generation of Multivirus-specific T Cells to Prevent/treat Viral Infections after Allogeneic Hematopoietic Stem Cell Transplant

Viral infections cause morbidity and mortality in allogeneic hematopoietic stem cell transplant (HSCT) recipients. We and others have successfully generated and infused T-cells specific for Epstein Barr virus (EBV), cytomegalovirus (CMV) and Adenovirus (Adv) using monocytes and EBV-transformed lymphoblastoid cell (EBV-LCL) gene-modified with an adenovirus vector as antigen presenting cells (APCs). As few as 2x105/kg trivirus-specific cytotoxic T lymphocytes (CTL) proliferated by several logs after infusion and appeared to prevent and treat even severe viral disease resistant to other available therapies. The broader implementation of this encouraging approach is limited by high production costs, complexity of manufacture and the prolonged time (4-6 weeks for EBV-LCL generation, and 4-8 weeks for CTL manufacture &#x2013; total 10-14 weeks) for preparation. To overcome these limitations we have developed a new, GMP-compliant CTL production protocol. First, in place of adenovectors to stimulate T-cells we use dendritic cells (DCs) nucleofected with DNA plasmids encoding LMP2, EBNA1 and BZLF1 (EBV), Hexon and Penton (Adv), and pp65 and IE1 (CMV) as antigen-presenting cells. These APCs reactivate T cells specific for all the stimulating antigens. Second, culture of activated T-cells in the presence of IL-4 (1,000U/ml) and IL-7 (10ng/ml) increases and sustains the repertoire and frequency of specific T cells in our lines. Third, we have used a new, gas permeable culture device (G-Rex) that promotes the expansion and survival of large cell numbers after a single stimulation, thus removing the requirement for EBV-LCLs and reducing technician intervention. By implementing these changes we can now produce multispecific CTL targeting EBV, CMV, and Adv at a cost per 106 cells that is reduced by &gt;90%, and in just 10 days rather than 10 weeks using an approach that may be extended to additional protective viral antigens. Our FDA-approved approach should be of value for prophylactic and treatment applications for high risk allogeneic HSCT recipients.

A rapid, simple and cost-effective protocol for the generation of donor-derived multivirus-specific CTLs (rCTL) for infusion to allogeneic hematopoietic stem cell transplant (HSCT) recipients at risk of developing CMV, Adv or EBV infections. This manufacturing process is GMP-compliant and should ensure the broader implementation of T-cell immunotherapy beyond specialized centers.

Génération de cellules T spécifiques Multivirus pour prévenir / traiter les infections virales, après allogreffe de cellules souches hématopoïétiques

Viral infections cause morbidity and mortality in allogeneic hematopoietic stem cell transplant (HSCT) recipients. We and others have successfully ...

Recherche

Immunologie et infection

Introducing Shear Stress in the Study of Bacterial Adhesion

During bacterial infections a sequence of interactions occur between the pathogen and its host. Bacterial adhesion to the host cell surface is often the initial and determining step of the pathogenesis. Although experimentally adhesion is mostly studied in static conditions adhesion actually takes place in the presence of flowing liquid. First encounters between bacteria and their host often occur at the mucosal level, mouth, lung, gut, eye, etc. where mucus flows along the surface of epithelial cells. Later in infection, pathogens occasionally access the blood circulation causing life-threatening illnesses such as septicemia, sepsis and meningitis. A defining feature of these infections is the ability of these pathogens to interact with endothelial cells in presence of circulating blood. The presence of flowing liquid, mucus or blood for instance, determines adhesion because it generates a mechanical force on the pathogen. To characterize the effect of flowing liquid one usually refers to the notion of shear stress, which is the tangential force exerted per unit area by a fluid moving near a stationary wall, expressed in dynes/cm2. Intensities of shear stress vary widely according to the different vessels type, size, organ, location etc. (0-100 dynes/cm2). Circulation in capillaries can reach very low shear stress values and even temporarily stop during periods ranging between a few seconds to several minutes 1. On the other end of the spectrum shear stress in arterioles can reach 100 dynes/cm2 2. The impact of shear stress on different biological processes has been clearly demonstrated as for instance during the interaction of leukocytes with the endothelium 3. To take into account this mechanical parameter in the process of bacterial adhesion we took advantage of an experimental procedure based on the use of a disposable flow chamber 4. Host cells are grown in the flow chamber and fluorescent bacteria are introduced in the flow controlled by a syringe pump. We initially focused our investigations on the bacterial pathogen Neisseria meningitidis, a Gram-negative bacterium responsible for septicemia and meningitis. The procedure described here allowed us to study the impact of shear stress on the ability of the bacteria to: adhere to cells 1, to proliferate on the cell surface 5and to detach to colonize new sites 6 (Figure 1). Complementary technical information can be found in reference 7. Shear stress values presented here were chosen based on our previous experience1 and to represent values found in the literature. The protocol should be applicable to a wide range of pathogens with specific adjustments depending on the objectives of the study.

During the infection process, a key step is the adhesion of pathogens with host cells. In most instances this adhesion step occurs in the presence of mechanical stress generated by flowing liquid. We describe a technique that introduces shear stress as an important parameter in the study of bacterial adhesion.

Présentation de contrainte de cisaillement dans l&#39;étude de l&#39;adhésion bactérienne

During bacterial infections a sequence of interactions occur between the pathogen and its host. Bacterial adhesion to the host cell surface is often the ...

Expanding Cytotoxic T Lymphocytes from Umbilical Cord Blood that Target Cytomegalovirus, Epstein-Barr Virus, and Adenovirus

Virus infections after stem cell transplantation are among the most common causes of death, especially after cord blood (CB) transplantation (CBT) where the CB does not contain appreciable numbers of virus-experienced T cells which can protect the recipient from infection.1-4 We and others have shown that virus-specific CTL generated from seropositive donors and infused to the recipient are safe and protective.5-8 However, until recently, virus-specific T cells could not be generated from cord blood, likely due to the absence of virus-specific memory T cells. 
In an effort to better mimic the in vivo priming conditions of na&iuml;ve T cells, we established a method that used CB-derived dendritic cells (DC) transduced with an adenoviral vector (Ad5f35pp65) containing the immunodominant CMV antigen pp65, hence driving T cell specificity towards CMV and adenovirus.9 At initiation, we use these matured DCs as well as CB-derived T cells in the presence of the cytokines IL-7, IL-12, and IL-15.10 At the second stimulation we used EBV-transformed B cells, or EBV-LCL, which express both latent and lytic EBV antigens. Ad5f35pp65-transduced EBV-LCL are used to stimulate the T cells in the presence of IL-15 at the second stimulation. Subsequent stimulations use Ad5f35pp65-transduced EBV-LCL and IL-2. 
From 50x106 CB mononuclear cells we are able to generate upwards of 150 x 106 virus-specific T cells that lyse antigen-pulsed targets and release cytokines in response to antigenic stimulation.11 These cells were manufactured in a GMP-compliant manner using only the 20% fraction of a fractionated cord blood unit and have been translated for clinical use.

Here we describe the first good manufacturing practice (GMP)-compliant method of producing virus-specific cytotoxic T lymphocytes (CTL) from umbilical cord blood, a source of predominantly na&#238;ve T cells.

L&#39;expansion des lymphocytes T cytotoxiques à partir de sang de cordon ombilical qui cytomégalovirus cible, le virus Epstein-Barr Virus et Adénovirus

Virus infections after stem cell transplantation are among the most common causes of death, especially after cord blood (CB) transplantation (CBT) where ...

PRP as a New Approach to Prevent Infection: Preparation and In vitro Antimicrobial Properties of PRP

Implant-associated infection is becoming more and more challenging to the healthcare industry worldwide due to increasing antibiotic resistance, transmission of antibiotic resistant bacteria between animals and humans, and the high cost of treating infections.
In this study, we disclose a new strategy that may be effective in preventing implant-associated infection based on the potential antimicrobial properties of platelet-rich plasma (PRP). Due to its well-studied properties for promoting healing, PRP (a biological product) has been increasingly used for clinical applications including orthopaedic surgeries, periodontal and oral surgeries, maxillofacial surgeries, plastic surgeries, sports medicine, etc.
PRP could be an advanced alternative to conventional antibiotic treatments in preventing implant-associated infections. The use of PRP may be advantageous compared to conventional antibiotic treatments since PRP is less likely to induce antibiotic resistance and PRP's antimicrobial and healing-promoting properties may have a synergistic effect on infection prevention. It is well known that pathogens and human cells are racing for implant surfaces, and PRP's properties of promoting healing could improve human cell attachment thereby reducing the odds for infection. In addition, PRP is inherently biocompatible, and safe and free from the risk of transmissible diseases.
For our study, we have selected several clinical bacterial strains that are commonly found in orthopaedic infections and examined whether PRP has in vitro antimicrobial properties against these bacteria. We have prepared PRP using a twice centrifugation approach which allows the same platelet concentration to be obtained for all samples. We have achieved consistent antimicrobial findings and found that PRP has strong in vitro antimicrobial properties against bacteria like methicillin-sensitive and methicillin-resistant Staphylococcus aureus, Group A Streptococcus, and Neisseria gonorrhoeae. Therefore, the use of PRP may have the potential to prevent infection and to reduce the need for costly post-operative treatment of implant-associated infections.

PRP as a New Approach to Prevent Infection: Preparation and In vitro Antimicrobial Properties of PRP

Implant-associated infection is a significant clinical complication. This study describes an approach using platelet-rich plasma (PRP) to prevent implant-associated infections, presents the protocol for preparing PRP with constant platelet concentration, and reports the newly identified antimicrobial properties of PRP and related protocols for examining such antimicrobial properties in vitro.

PRP comme une nouvelle approche pour prévenir l&#39;infection: Préparation et<em&gt; In vitro</em&gt; Propriétés antimicrobiennes de PRP

Implant-associated infection is becoming more and more challenging to the healthcare industry worldwide due to increasing antibiotic resistance, ...

Cell-based Flow Cytometry Assay to Measure Cytotoxic Activity

Cytolytic activity of CD8+ T cells is rarely evaluated. We describe here a new cell-based assay to measure the capacity of antigen-specific CD8+ T cells to kill CD4+ T cells loaded with their cognate peptide. Target CD4+ T cells are divided into two populations, labeled with two different concentrations of CFSE. One population is pulsed with the peptide of interest (CFSE-low) while the other remains un-pulsed (CFSE-high). Pulsed and un-pulsed CD4+ T cells are mixed at an equal ratio and incubated with an increasing number of purified CD8+ T cells. The specific killing of autologous target CD4+ T cells is analyzed by flow cytometry after coculture with CD8+ T cells containing the antigen-specific effector CD8+ T cells detected by peptide/MHCI tetramer staining. The specific lysis of target CD4+ T cells measured at different effector versus target ratios, allows for the calculation of lytic units, LU30/106 cells. This simple and straightforward assay allows for the accurate measurement of the intrinsic capacity of CD8+ T cells to kill target CD4+ T cells.

This protocol describes a sensitive, cell-based cytotoxicity assay. By enumerating the decrease in frequency of live target CD4+ T cells in the presence of an increasing number of effector CD8+ T cells, this assay allows for the direct assessment of cytolytic activity of antigen-specific CD8+ T cells.

Cytolytic activity of CD8+ T cells is rarely evaluated. We describe here a new cell-based assay to measure the capacity of antigen-specific CD8+ T cells ...

Humanized Mouse Model to Study Bacterial Infections Targeting the Microvasculature

Neisseria meningitidis causes a severe, frequently fatal sepsis when it enters the human blood stream. Infection leads to extensive damage of the blood vessels resulting in vascular leak, the development of purpuric rashes and eventual tissue necrosis. Studying the pathogenesis of this infection was previously limited by the human specificity of the bacteria, which makes in vivo models difficult. In this protocol, we describe a humanized model for this infection in which human skin, containing dermal microvessels, is grafted onto immunocompromised mice. These vessels anastomose with the mouse circulation while maintaining their human characteristics. Once introduced into this model, N. meningitidis adhere exclusively to the human vessels, resulting in extensive vascular damage, inflammation and in some cases the development of purpuric rash. This protocol describes the grafting, infection and evaluation steps of this model in the context of N. meningitidis infection. The technique may be applied to numerous human specific pathogens that infect the blood stream.

Neisseria meningitidis is a human specific pathogen that infects blood vessels. In this protocol human microvessels are introduced into a mouse by grafting human skin onto immunocompromised mice. Bacteria adhere extensively to the human vessels, leading to vascular damage and development of the purpuric rash typically observed in human cases.

Souris humanisée modèle pour étudier les infections bactériennes Cibler la microvascularisation

Neisseria meningitidis causes a severe, frequently fatal sepsis when it enters the human blood stream. Infection leads to extensive damage of the blood ...

Automated Cell Enrichment of Cytomegalovirus-specific T cells for Clinical Applications using the Cytokine-capture System

The adoptive transfer of pathogen-specific T cells can be used to prevent and treat opportunistic infections such as cytomegalovirus (CMV) infection occurring after allogeneic hematopoietic stem-cell transplantation. Viral-specific T cells from allogeneic donors, including third party donors, can be propagated ex vivo in compliance with current good manufacturing practice (cGMP), employing repeated rounds of antigen-driven stimulation to selectively propagate desired T cells. The identification and isolation of antigen-specific T cells can also be undertaken based upon the cytokine capture system of T cells that have been activated to secrete gamma-interferon (IFN-&#947;). However, widespread human application of the cytokine capture system (CCS) to help restore immunity has been limited as the production process is time-consuming and requires a skilled operator. The development of a second-generation cell enrichment device such as CliniMACS Prodigy now enables investigators to generate viral-specific T cells using an automated, less labor-intensive system. This device separates magnetically labeled cells from unlabeled cells using magnetic activated cell sorting technology to generate clinical-grade products, is engineered as a closed system and can be accessed and operated on the benchtop. We demonstrate the operation of this new automated cell enrichment device to manufacture CMV pp65-specific T cells obtained from a steady-state apheresis product obtained from a CMV seropositive donor. These isolated T cells can then be directly infused into a patient under institutional and federal regulatory supervision. All the bio-processing steps including removal of red blood cells, stimulation of T cells, separation of antigen-specific T cells, purification, and washing are fully automated. Devices such as this raise the possibility that T cells for human application can be manufactured outside of dedicated good manufacturing practice (GMP) facilities and instead be produced in blood banking facilities where staff can supervise automated protocols to produce multiple products.

The goal of this protocol is to manufacture pathogen-specific clinical-grade T cells using a bench-top, automated, second generation cell enrichment device that incorporates a closed cytokine capture system and does not require dedicated staff or use of a GMP facility. The cytomegalovirus pp65-specific-T cells generated can be directly administered to patients.

Cellules T d&#39;enrichissement de cellules automatisé de cytomégalovirus spécifique pour des applications cliniques utilisant le système de capture de cytokine

The adoptive transfer of pathogen-specific T cells can be used to prevent and treat opportunistic infections such as cytomegalovirus (CMV) infection ...

Organoids as Model for Infectious Diseases: Culture of Human and Murine Stomach Organoids and Microinjection of Helicobacter Pylori

Recently infection biologists have employed stem cell derived cultures to answer the need for new and better models to study host-pathogen interactions. Three cellular sources have been used: Embryonic stem cells (ESC), induced pluripotent stem cells (iPSC) or adult stem cells. Here, culture of mouse and human gastric organoids derived from adult stem cells is described and used for infection with the gastric pathogen Helicobacter pylori. Human gastric glands are isolated from resection material, seeded in a basement matrix and embedded in medium containing growth factors epidermal growth factor (EGF), R-spondin, Noggin, Wnt, fibroblast growth factor (FGF) 10, gastrin and transforming growth factor (TGF) beta inhibitor. In these conditions, gastric glands grow into 3-dimensional organoids containing 4 lineages of the stomach. The organoids expand indefinitely and can be frozen and thawed similarly as cell lines. For infection studies, bacteria are microinjected into the lumen of the organoids. Infected organoids are processed for imaging. The described methods can be adapted to other organoids and infections with other bacteria, viruses or parasites. This allows the study of infection-induced changes in primary cells.

Stem cell derived cultures harbor tremendous potential to model infectious diseases. Here, the culture of mouse and human gastric organoids derived from adult stem cells is described. The organoids are microinjected with the gastric pathogen Helicobacter pylori.

Organoïdes de modèle pour les maladies infectieuses: la culture des droits humains et murins organoïdes d&#39;estomac et microinjection de Helicobacter pylori

Recently infection biologists have employed stem cell derived cultures to answer the need for new and better models to study host-pathogen interactions. ...

Flow Cytometry-based Assay for the Monitoring of NK Cell Functions

Natural killer (NK) cells are an important part of the human tumor immune surveillance system. NK cells are able to distinguish between healthy and virus-infected or malignantly transformed cells due to a set of germline encoded inhibitory and activating receptors. Upon virus or tumor cell recognition a variety of different NK cell functions are initiated including cytotoxicity against the target cell as well as cytokine and chemokine production leading to the activation of other immune cells. It has been demonstrated that accurate NK cell functions are crucial for the treatment outcome of different virus infections and malignant diseases. Here a simple and reliable method is described to analyze different NK cell functions using a flow cytometry-based assay. NK cell functions can be evaluated not only for the whole NK cell population, but also for different NK cell subsets. This technique enables scientists to easily study NK cell functions in healthy donors or patients in order to reveal their impact on different malignancies and to further discover new therapeutic strategies.

A simple and reliable method is described here to analyze a set of NK cell functions such as degranulation, cytokine and chemokine production within different NK cell subsets.

Cytométrie de flux à base de test pour la surveillance des cellules NK Fonctions

Natural killer (NK) cells are an important part of the human tumor immune surveillance system. NK cells are able to distinguish between healthy and ...

A CFSE-based Assay to Study the Migration of Murine Skin Dendritic Cells into Draining Lymph Nodes During Infection with Mycobacterium bovis Bacille Calmette-Gu&#233;rin

Dendritic cells (DCs) are important for initiating immune responses, in part through their ability to acquire and shuttle antigen to the draining lymph node (DLN). The mobilization of DCs to the DLN is complex and remains to be fully elucidated during infection. Herein described is the use of an innovative, simple assay that relies on the fluorochrome 5- and 6-carboxyfluorescein diacetate succinimidyl ester (CFSE) to track the migration of DCs during footpad infection with Mycobacterium bovis Bacille Calmette-Gu&#233;rin (BCG) in C57BL/6 mice. This assay enables the characterization of skin DC sub-populations that actively relocate to the draining, popliteal LN in response to BCG. This protocol originates from a BCG model where migratory skin DCs were identified by flow cytometry. The assay is amiable to the study and identification of DCs or other cells that home to the popliteal LN after inoculation of microbes, their metabolites or other inflammatory stimuli in the footpad, and consequently to study factors that regulate the migration of these cells.

A CFSE-based Assay to Study the Migration of Murine Skin Dendritic Cells into Draining Lymph Nodes During Infection with &lt;em&gt;Mycobacterium bovis&lt;/em&gt; Bacille Calmette-Gu&amp;#233;rin

An assay in mice to track cell migration from skin to draining lymph node is described which enables the characterization of skin Dendritic cells mobilized to the lymph node after footpad infection with Bacille Calmette-Gu&#233;rin.

Un test basé CFSE pour étudier la migration de la peau murine cellules dendritiques dans les ganglions lymphatiques de drainage lors de l&#39;infection avec<em&gt; Mycobacterium bovis</em&gt; Bacille Calmette-Guérin

Dendritic cells (DCs) are important for initiating immune responses, in part through their ability to acquire and shuttle antigen to the draining lymph ...