Bu araştırma, Alerji ve Bulaşıcı Hastalıklar, Ulusal Sağlık Enstitüleri Ulusal Enstitüsü İntramural Araştırma Bölümü tarafından desteklenmiştir. Biz bu çalışmalarda kullanılan H57 arasında scFv bize sağlamış Johannes Huppa ve Mark Davis minnettarız. RV bu tekniğin geliştirilmesi sırasında yararlı tartışma Keir Neumann teşekkür etmek istiyorum.

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L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=T+cell+receptor-proximal+signals+are+sustained+in+peripheral+microclusters+and+terminated+in+the+central+supramolecular+activation+cluster.">T cell receptor-proximal signals are sustained in peripheral microclusters and terminated in the central supramolecular activation cluster.</a> Immunity. 25, 117-127 (2006).</li><li>Yokosuka, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Newly+generated+T+cell+receptor+microclusters+initiate+and+sustain+T+cell+activation+by+recruitment+of+Zap70+and+SLP-76.">Newly generated T cell receptor microclusters initiate and sustain T cell activation by recruitment of Zap70 and SLP-76.</a> Nat. Immunol. 6, 1253-1262 (2005).</li><li>Huppa, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TCR-peptide-MHC+interactions+in+situ+show+accelerated+kinetics+and+increased+affinity.">TCR-peptide-MHC interactions in situ show accelerated kinetics and increased affinity.</a> Nature. 463, 963-967 (2010).</li><li>Tolar, P., Pierce, S. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+conformation-induced+oligomerization+model+for+B+cell+receptor+microclustering+and+signaling.">A conformation-induced oligomerization model for B cell receptor microclustering and signaling.</a> Curr. Top. Microbiol. 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C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vav1-mediated+scaffolding+interactions+stabilize+SLP-76+microclusters+and+contribute+to+antigen-dependent+T+cell+responses.">Vav1-mediated scaffolding interactions stabilize SLP-76 microclusters and contribute to antigen-dependent T cell responses.</a> Sci. Signal. 4, ra14-ra14 (2011).</li><li>Purbhoo, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamics+of+subsynaptic+vesicles+and+surface+microclusters+at+the+immunological+synapse.">Dynamics of subsynaptic vesicles and surface microclusters at the immunological synapse.</a> Sci. Signal. 3, ra36-ra36 (2010).</li><li>Lasserre, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ezrin+tunes+T-cell+activation+by+controlling+Dlg1+and+microtubule+positioning+at+the+immunological+synapse.">Ezrin tunes T-cell activation by controlling Dlg1 and microtubule positioning at the immunological synapse.</a> EMBO. J. 29, 2301-2314 (2010).</li><li>Balagopalan, L., Sherman, E., Barr, V. A., Samelson, L. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+techniques+for+assaying+lymphocyte+activation+in+action.">Imaging techniques for assaying lymphocyte activation in action.</a> Nat. Rev. Immunol. 11, 21-33 (2011).</li><li>Axelrod, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chapter+7:+Total+internal+reflection+fluorescence+microscopy.">Chapter 7: Total internal reflection fluorescence microscopy.</a> Methods Cell. Biol. 89, 169-221 (2008).</li><li>Williamson, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pre-existing+clusters+of+the+adaptor+Lat+do+not+participate+in+early+T+cell+signaling+events.">Pre-existing clusters of the adaptor Lat do not participate in early T cell signaling events.</a> Nat. Immunol. 12, 655-662 (2011).</li></ol>

Bu deneylerde kullanılan tüm hayvanların belirli bir patojen içermeyen ortamda muhafaza edildi ve deneyler Sağlık Hayvan Bakım ve Kullanım Kurulu Ulusal Sağlık Enstitüleri tarafından onaylanmıştır.

Biz burada TIRFM ve yapay ZPT gibi cam desteklenen lipid bilayers kullanarak antijen spesifik primer fare T hücrelerinde sinyal okumak için bir sistem açıklar. Tekniği başarıyla bu hücrelerde GFP tagged proteinleri dayanır. T hücrelerine transferiyle her zaman zor bir iştir. Tipik olarak, retrovirüslerin ya Lentivirüs kullanılarak elektroporasyon ya da gen aktarımının kullanılır. Bir teknik diğerinden üstün değildir, her ikisi kendi sınırlamaları ve avantajları var. 1) Bu retrovirüslerin ancak Lentivirüs için gerekli olduğu hücrelerinin aktif bölünmesi edilmesi gerekmemektedir, ve 2) ifade seviyesini hücreleri görüntüleme önce inkübe edilir zamanda değişen kontrol edilebilir: bu elektroporasyon aşağıdaki avantajlara sahiptir bulmak. Büyük dezavantajı biz çok zor primer hücrelerde boyutu büyük olan proteinlerin ifade bulmak olmasıdır. Biz elektroporasyon sonra bize çok iyi bir hücre canlılığı veren bir yöntem sundu. Sonuç olarak, bu applicab olduğusiRNA aracılı gen susturulması elde etmek için bunu kullanmaya le. Biz de burada chromatically düzeltilir ve farklı dalga boylarında için ayrı hizalama gerektirmez özelleştirilmiş bir iki kanal aynı anda satın TIRF mikroskop açıklar. Bu yetenekleri, ancak, ticari olarak temin edilebilir. Sistemimiz TIRF mikroskopi alanında uzmanlar tarafından yayınlanan ve ticari alternatiflerine göre çok daha ucuzdur ilkelerine dayanmaktadır. Bizim tasarım Olası eleştirilerden biri, biz farklı uyarma dalga boyları için geliş aynı açı ile olmasıdır. Bu farklı uyarma dalga boyları için farklı bir TIRF penetrasyon derinliği neden olacaktır. Biz fani bir dalga katlanarak çürüyen alan ve TIRF alan derinliğini dalga doğrusal bir fonksiyonu olduğu için bu etkiler küçük olduğunu düşünüyorum. Cam yüzeye yakın florofor iki dalga boyları arasında laser yoğunluklarındaki fark yaşayacaksınız. Pe yakın florofor içinyonunun derinliği, yoğunluğu farkı iki dalga boyu 488 ve 561 nm için iki dalga boyu 488 ve 640 nm ve 1.15 kat için 1,3 misli olacaktır. Aynı sistemi TIRF aydınlatma kullanan süper çözünürlük teknikleri ile bağlantılı olarak da kullanılabilir. Ayrıca özel dahili bir iki kamera sistemi tarif var. TIRF sistemi gibi benzer aparatları, aynı zamanda, ticari olarak mevcuttur. Sistemimiz dalga boylarında farklı kombinasyonları ile kullanımına izin veren, filtre ve dichroics değiştirmek için esneklik sunar. Bizim sistemin dezavantajı iki görüntü uyum için yapılması gereken dönme bir derecesidir. Bu sorun piezo tahrik ve uyum dönme dereceleri sunarlar kamera standlar ile çözülebilir. Biz de başarıyla kameralar farklı olduğunu ve değişik piksel boyutlarında sahip olduğu, bu mikroskop iki kamera sistemi hayata geçirdik. Tek tek kanalda duyarlılık ve büyük bir dy gerekirse, bu tür bir sistem yararlı olacaktırBaşka bir aralık içinde pi ile, her ikisi de aynı kamera nadiren mevcuttur. Biz bize 16 mikron piksel boyutu vardır fotometri Quant-EM kamera ile 12.9 mikron bir etkin piksel boyutu veren 2x2 binning de fotometri HQ-2 kamera kullanıldı. A 180 mm odak uzunluğu tüp lens Quant-EM için kullanılan ve 145 mm odak uzaklığı tüp lens HQ-2 kamera kullanıldı. HQ-2 Metamorph yazılım ve Quant-EM dış tetik modu ayrı bir bilgisayarda mikro yöneticisi yazılımı ile kontrol edildi kullanılarak kontrol edildi. Dış tetik Metamorph ve configure aydınlatma ayarlarında ek bir deklanşör olarak uygulanmıştır ölçüm hesaplama DAC kurulu, bir dijital çıkış kullanarak Quant-EM kamera sağlanmıştır. Tüp mercek uzunluklan oranı etkili bir piksel boyutu oranı ile eşleşir. Bir temsili hizalama Şekil 5 de gösterilmiştir.

<table border="1"><tbody><tr><td> Reaktif Adı </td><td> Şirket </td><td> Katalog numarası </td><td> Yorumlar </td></tr><tr><td> Fare T hücreleri için Amaxa Nucleofector Kit </td><td> Lonza A.Ş. </td><td> VPA-1006 </td><td></td></tr><tr><td> PureLink HiPure Plazmid Midiprep Kiti </td><td> Yaşam Teknolojileri </td><td> K2100-05 </td><td> Endotoksin serbest DNA preparatlarıyla için </td></tr><tr><td> Amaxa Nucleofector Aygıt </td><td> Lonza A.Ş. </td><td> AAD-1001 </td><td></td></tr><tr><td> Rekombinant Mürin IL-2 </td><td> Peprotech A.Ş. </td><td> 212-12 </td><td></td></tr><tr><td> Fluoresbrite Multifluorescent Mikroküreler 0.20μm </td><td> Polysciences, Inc </td><td> 24050-5 </td><td></td></tr><tr><td> Lab-Tek II 8-iyi odacıklı coverglass </td><td> Thermo Scientific, Nunc </td><td> 155409 </td><td></td></tr></tbody></table>

a tirf microscopy technique for real-time, simultaneous imaging of the tcr and its associated signaling proteins

Bu ana doku uyumu kompleksine (pMHC) antijen sunan hücreler (APC) yüzeyinde ifade edilen proteinleri ile bağlı antijenik peptit parçaları tarafından angaje olduğunda sinyalleşme T hücre reseptör (TCR) ile başlatılır. TCR kompleksi ligand bağlama TCRαβ heterodimer oluşur ilişkilendiren CD3 dimerler (εδ ve heterodimerler εγ ve ζζ homodimer) 1 ile kovalent olmayan. Reseptörünün angajman üzerine, CD3 ζ zincirleri LCK, Src kinaz ailesi tarafından fosforile edilir. Bu daha sonra lck tarafından fosforile ve aktive edilir Syk aile kinaz, Zap70, istihdamına yol açar. Bundan sonra, Zap70 farklı sinyal molekülleri 2 büyük bir sayı içeren proksimal sinyalleşme kompleksinin oluşumunu başlatan, bağdaştırıcı proteinler LAT ve SLP76 fosforile. Kalsiyum ve Ras-bağımlı tra bu kompleks sonunda sonuçların oluşumuoyma yazıyı faktörü aktivasyonu ve T hücre farklılaşması 2 yol gen ifadesi programları karmaşık bir dizi sonuçta başlatılması. TCR sinyalleri (ve farklılaşma oluşan durum) antijen potens ve çapraz co-stimulatory/co-inhibitory ile kemokin ve 3-4 sitokin reseptörleri gibi diğer birçok faktör tarafından modüle edilir. Çeşitli stimülasyon koşullar altında proksimal sinyalizasyon kompleksinin zamansal ve mekansal organizasyon incelenmesi, bu nedenle, TCR sinyal yolu gibi diğer sinyal yolları tarafından düzenlenmesi anlamanın anahtarıdır. T hücrelerinde plazma membranında TCR tarafından başlatılan sinyalizasyon incelemek için bir çok faydalı modelin sistemi olarak daha önce anlatılan cam 5-6 destekli lipid bilayers vardır. Onlar yapay APC&#39;ler olarak T hücreleri-hizmet için antijenik pMHC kompleksleri, yapışma, ve eş-uyarıcı moleküller sunmak için kullanılabilir. Görüntüleme yöntemi ile T hücreleri ile etkileşentoplam iç yansıma florasan mikroskobu (TIRFM) kullanılarak çift katlı lipid, biz 7-8 cam ve hücre yüzeyi arasındaki boşluğun içinde 100 nm için uyarma kısıtlayabilirsiniz. Bu bize resim öncelikle sinyal olaylar plazma membranı meydana gelen sağlar. Biz görüntüleme TCR kompleks proteinler sinyal alımı ilgilenen, biz iki kamera TIRF görüntüleme sistemi tanımlamak neyin H57 antikor floresan Fab etiketlenmiş TCR, (fragman antijen bağlama) parçaları (hibridoma H57-597 arınmış , ATCC, ATCC No: GFP ile etiketlenmiş TCRβ için spesifik olan HB-218), ve sinyal proteinleri, aynı anda ve gerçek zamanlı olarak görüntülenmiştir edilebilir. Bu strateji, T hücrelerinin hem de ve TCR gerçekleştiğini sinyalizasyon olaylar son derece dinamik doğası nedeniyle gereklidir. Bu görüntüleme yöntemi görüntü tek ligandlar 9-11 yanı sıra aktif reseptörlerine sinyal moleküllerinin alımı ve araştırmacılar izin verdi12-16 in-situ biyokimya eğitim için mükemmel bir sistemdir.

Watch this Scientific Journal Video about A TIRF Microscopy Technique for Real-time, Simultaneous Imaging of the TCR and its Associated Signaling Proteins at JoVE.com

A TIRF Microscopy Technique for Real-time, Simultaneous Imaging of the TCR and its Associated Signaling Proteins

Dolayısıyla, bu işe dahil olan proteinlerin mekansal ve zamansal davranışlarını incelemek için önemli sinyal anlamak için; plazma zarının içinde ya da hücre içi konumlara ya proteinlerin kompartımanlara büyük ölçüde sinyal sonuçlarını etkileyebilecek bir düzenleyici mekanizmadır. Burada T hücrelerinde sinyal iletimi çalışmak üzere bir TIRF mikroskopi tabanlı sistemi tanımlamak, ama genel olarak uygulanabilir.

Gerçek zamanlı, TCR Eşzamanlı Görüntüleme ve İlişkili Sinyal Proteinler için TIRF Mikroskopi Tekniği

Signaling is initiated through the T Cell Receptor (TCR) when it is engaged by antigenic peptide fragments bound by Major Histocompatibility Complex ...

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Research

JoVE Journal

Immunology and Infection

23.7K Görüntüleme.  National Institute of Allergy and Infectious Diseases, National Institutes of Health. Dolayısıyla, bu işe dahil olan proteinlerin mekansal ve zamansal davranışlarını incelemek için önemli sinyal anlamak için; plazma zarının içinde ya da hücre içi konumlara ya proteinlerin kompartımanlara büyük ölçüde sinyal sonuçlarını etkileyebilecek bir düzenleyici mekanizmadır. Burada T hücrelerinde sinyal iletimi çalışmak üzere bir TIRF mikroskopi tabanlı sistemi tanımlamak, ama genel olarak uygulanabilir.

Video: A TIRF Microscopy Technique for Real-time, Simultaneous Imaging of the TCR and its Associated Signaling Proteins

Real-time Imaging of Leukotriene B4 Mediated Cell Migration and BLT1 Interactions with &beta;-arrestin

G-protein coupled receptors (GPCRs) belong to the seven transmembrane protein family and mediate the transduction of extracellular signals to intracellular responses. GPCRs control diverse biological functions such as chemotaxis, intracellular calcium release, gene regulation in a ligand dependent manner via heterotrimeric G-proteins1-2. Ligand binding induces a series of conformational changes leading to activation of heterotrimeric G-proteins that modulate levels of second messengers such as cyclic adenosine monophosphate (cAMP), inositol triphosphate (IP3) and diacyl glycerol (DG). Concomitant with activation of the receptor ligand binding also initiates a series of events to attenuate the receptor signaling via desensitization, sequestration and/or internalization. The desensitization process of GPCRs occurs via receptor phosphorylation by G-protein receptor kinases (GRKs) and subsequent binding of &beta;-arrestins3. &beta;-arrestins are cytosolic proteins and translocate to membrane upon GPCR activation, binding to phosphorylated receptors (most cases) there by facilitating receptor internalization 4-6.
Leukotriene B4 (LTB4) is a pro-inflammatory lipid molecule derived from arachidonic acid pathway and mediates its actions via GPCRs, LTB4 receptor 1 (BLT1; a high affinity receptor) and LTB4 receptor 2 (BLT2; a low affinity receptor)7-9. The LTB4-BLT1 pathway has been shown to be critical in several inflammatory diseases including, asthma, arthritis and atherosclerosis10-17. The current paper describes the methodologies developed to monitor LTB4-induced leukocyte migration and the interactions of BLT1 with &beta;-arrestin and , receptor translocation in live cells using microscopy imaging techniques18-19.
Bone marrow derived dendritic cells from C57BL/6 mice were isolated and cultured as previously described 20-21. These cells were tested in live cell imaging methods to demonstrate LTB4 induced cell migration. The human BLT1 was tagged with red fluorescent protein (BLT1-RFP) at C-terminus and &beta;-arrestin1 tagged with green fluorescent protein (&beta;-arr-GFP) and transfected the both plasmids into Rat Basophilic Leukomia (RBL-2H3) cell lines18-19. The kinetics of interaction between these proteins and localization were monitored using live cell video microscopy. The methodologies in the current paper describe the use of microscopic techniques to investigate the functional responses of G-protein coupled receptors in live cells. The current paper also describes the use of Metamorph software to quantify the fluorescence intensities to determine the kinetics of receptor and cytosolic protein interactions.

Real-time Imaging of Leukotriene B4 Mediated Cell Migration and BLT1 Interactions with &amp;#946;-arrestin

This paper describes the methodology to determine the chemotactic response of leukocytes to specific ligands and identify interactions between the cell surface receptors and cytosolic proteins using live cell imaging techniques.

Lökotrien B Gerçek zamanlı görüntüleme 4 Hücre aracılığı ile Göç ve β-arrestin BLT1 Etkileşimleri

G-protein coupled receptors (GPCRs) belong to the seven transmembrane protein family and mediate the transduction of extracellular signals to ...

İmmünoloji ve Enfeksiyon

Real-time Live Imaging of T-cell Signaling Complex Formation

Protection against infectious diseases is mediated by the immune system 1,2. T lymphocytes are the master coordinators of the immune system, regulating the activation and responses of multiple immune cells 3,4. T-cell activation is dependent on the recognition of specific antigens displayed by antigen presenting cells (APCs). The T-cell antigen receptor (TCR) is specific to each T-cell clone and determines antigen specificity 5. The binding of the TCR to the antigen induces the phosphorylation of components of the TCR complex. In order to promote T-cell activation, this signal must be transduced from the membrane to the cytoplasm and the nucleus, initiating various crucial responses such as recruitment of signaling proteins to the TCR;APC site (the immune synapse), their molecular activation, cytoskeletal rearrangement, elevation of intracellular calcium concentration, and changes in gene expression 6,7. The correct initiation and termination of activating signals is crucial for appropriate T-cell responses. The activity of signaling proteins is dependent on the formation and termination of protein-protein interactions, post translational modifications such as protein phosphorylation, formation of protein complexes, protein ubiquitylation and the recruitment of proteins to various cellular sites 8. Understanding the inner workings of the T-cell activation process is crucial for both immunological research and clinical applications.
Various assays have been developed in order to investigate protein-protein interactions; however, biochemical assays, such as the widely used co-immunoprecipitation method, do not allow protein location to be discerned, thus precluding the observation of valuable insights into the dynamics of cellular mechanisms. Additionally, these bulk assays usually combine proteins from many different cells that might be at different stages of the investigated cellular process. This can have a detrimental effect on temporal resolution. The use of real-time imaging of live cells allows both the spatial tracking of proteins and the ability to temporally distinguish between signaling events, thus shedding light on the dynamics of the process 9,10. We present a method of real-time imaging of signaling-complex formation during T-cell activation. Primary T-cells or T-cell lines, such as Jurkat, are transfected with plasmids encoding for proteins of interest fused to monomeric fluorescent proteins, preventing non-physiological oligomerization 11. Live T cells are dropped over a coverslip pre-coated with T-cell activating antibody 8,9, which binds to the CD3/TCR complex, inducing T-cell activation while overcoming the need for specific activating antigens. Activated cells are constantly imaged with the use of confocal microscopy. Imaging data are analyzed to yield quantitative results, such as the colocalization coefficient of the signaling proteins.

We describe a live-cell imaging method that provides insight into protein dynamics during the T-cell activation process. We demonstrate the combined usage of the T-cell spreading assay, confocal microscopy and imaging analysis to yield quantitative results to follow signaling complex formation throughout T-cell activation.

T hücre gerçek zamanlı Canlı Görüntüleme Kompleks Oluşum Sinyal

Protection against infectious diseases is mediated by the immune system 1,2. T lymphocytes are the master coordinators of the immune system, regulating ...

Real-time Imaging of Endothelial Cell-cell Junctions During Neutrophil Transmigration Under Physiological Flow

During inflammation, leukocytes leave the circulation and cross the endothelium to fight invading pathogens in underlying tissues. This process is known as leukocyte transendothelial migration. Two routes for leukocytes to cross the endothelial monolayer have been described: the paracellular route, i.e., through the cell-cell junctions and the transcellular route, i.e., through the endothelial cell body. However, it has been technically difficult to discriminate between the para- and transcellular route. We developed a simple in vitro assay to study the distribution of endogenous VE-cadherin and PECAM-1 during neutrophil transendothelial migration under physiological flow conditions. Prior to neutrophil perfusion, endothelial cells were briefly treated with fluorescently-labeled antibodies against VE-cadherin and PECAM-1. These antibodies did not interfere with the function of both proteins, as was determined by electrical cell-substrate impedance sensing and FRAP measurements. Using this assay, we were able to follow the distribution of endogenous VE-cadherin and PECAM-1 during transendothelial migration under flow conditions and discriminate between the para- and transcellular migration routes of the leukocytes across the endothelium.

Leukocytes cross the endothelial monolayer using the paracellular or the transcellular route. We developed a simple assay to follow the distribution of endogenous junctional VE-cadherin and PECAM-1 during leukocyte transendothelial migration under physiological flow to discriminate between the two transmigration routes.

Nötrofil Hicret altında Fizyolojik Akış sırasında endotel hücre-hücre Eklemlerinin Gerçek zamanlı Görüntüleme

During inflammation, leukocytes leave the circulation and cross the endothelium to fight invading pathogens in underlying tissues. This process is known ...

Real-time Imaging of Myeloid Cells Dynamics in ApcMin/+ Intestinal Tumors by Spinning Disk Confocal Microscopy

Myeloid cells are the most abundant immune cells within tumors and have been shown to promote tumor progression. Modern intravital imaging techniques enable the observation of live cellular behavior inside the organ but can be challenging in some types of cancer due to organ and tumor accessibility such as intestine. Direct observation of intestinal tumors has not been previously reported. A surgical procedure described here allows direct observation of myeloid cell dynamics within the intestinal tumors in live mice by using transgenic fluorescent reporter mice and injectable tracers or antibodies. For this purpose, a four-color, multi-region, micro-lensed spinning disk confocal microscope that allows long-term continuous imaging with rapid image acquisition has been used. ApcMin/+ mice that develop multiple adenomas in the small intestine are crossed with c-fms-EGFP mice to visualize myeloid cells and with ACTB-ECFP mice to visualize intestinal epithelial cells of the crypts. Procedures for labeling different tumor components, such as blood vessels and neutrophils, and the procedure for positioning the tumor for imaging through the serosal surface are also described. Time-lapse movies compiled from several hours of imaging allow the analysis of myeloid cell behavior in situ in the intestinal microenvironment.

Real-time Imaging of Myeloid Cells Dynamics in ApcMin/+ Intestinal Tumors by Spinning Disk Confocal Microscopy

By using transgenic reporter mice and injectable fluorescent labels, long-term intravital spinning disk confocal microscopy enables direct visualization of myeloid cell behavior into intestinal adenoma in the ApcMin/+ colorectal cancer model.

Miyeloid hücrelerin Dynamics Gerçek zamanlı Görüntüleme<em&gt; Süm<sup&gt; Min / +</sup</em&gt; Bağırsak Tümörleri Disk Eşodaklı Mikroskopi Spinning tarafından

Myeloid cells are the most abundant immune cells within tumors and have been shown to promote tumor progression. Modern intravital imaging techniques ...

Simultaneous Quantification of T-Cell Receptor Excision Circles (TRECs) and K-Deleting Recombination Excision Circles (KRECs) by Real-time PCR

T-cell receptor excision circles (TRECs) and K-deleting recombination excision circles (KRECs) are circularized DNA elements formed during recombination process that creates T- and B-cell receptors. Because TRECs and KRECs are unable to replicate, they are diluted after each cell division, and therefore persist in the cell. Their quantity in peripheral blood can be considered as an estimation of thymic and bone marrow output. By combining well established and commonly used TREC assay with a modified version of KREC assay, we have developed a duplex quantitative real-time PCR that allows quantification of both newly-produced T and B lymphocytes in a single assay. The number of TRECs and KRECs are obtained using a standard curve prepared by serially diluting TREC and KREC signal joints cloned in a bacterial plasmid, together with a fragment of T-cell receptor alpha constant gene that serves as reference gene. Results are reported as number of TRECs and KRECs/106 cells or per ml of blood. The quantification of these DNA fragments have been proven useful for monitoring immune reconstitution following bone marrow transplantation in both children and adults, for improved characterization of immune deficiencies, or for better understanding of certain immunomodulating drug activity.

Simultaneous Quantification of T-Cell Receptor Excision Circles TRECs and K-Deleting Recombination Excision Circles KRECs by Real-time PCR

Here, we describe a method for simultaneous quantification of T-cell receptor excision circles (TRECs) and K-deleting recombination excision circles (KRECs). The TREC/KREC assay can be used as marker of thymic and bone marrow output.

T-hücre reseptörleri Eksizyon Circles Eşzamanlı Niceleme (TREC) ve K-silme Rekombinasyon Eksizyon Circles (KRECs) Gerçek zamanlı PCR ile

T-cell receptor excision circles (TRECs) and K-deleting recombination excision circles (KRECs) are circularized DNA elements formed during recombination ...

Analysis of Yersinia enterocolitica Effector Translocation into Host Cells Using Beta-lactamase Effector Fusions

Many gram-negative bacteria including pathogenic Yersinia spp. employ type III secretion systems to translocate effector proteins into eukaryotic target cells. Inside the host cell the effector proteins manipulate cellular functions to the benefit of the bacteria. To better understand the control of type III secretion during host cell interaction, sensitive and accurate assays to measure translocation are required. We here describe the application of an assay based on the fusion of a Yersinia enterocolitica effector protein fragment (Yersinia outer protein; YopE) with TEM-1 beta-lactamase for quantitative analysis of translocation. The assay relies on cleavage of a cell permeant FRET dye (CCF4/AM) by translocated beta-lactamase fusion. After cleavage of the cephalosporin core of CCF4 by the beta-lactamase, FRET from coumarin to fluorescein is disrupted and excitation of the coumarin moiety leads to blue fluorescence emission. Different applications of this method have been described in the literature highlighting its versatility. The method allows for analysis of translocation in vitro and also in in vivo, e.g., in a mouse model. Detection of the fluorescence signals can be performed using plate readers, FACS analysis or fluorescence microscopy. In the setup described here, in vitro translocation of effector fusions into HeLa cells by different Yersinia mutants is monitored by laser scanning microscopy. Recording intracellular conversion of the FRET reporter by the beta-lactamase effector fusion in real-time provides robust quantitative results. We here show exemplary data, demonstrating increased translocation by a Y. enterocolitica YopE mutant compared to the wild type strain.

Analysis of Yersinia enterocolitica Effector Translocation into Host Cells Using Beta-lactamase Effector Fusions

Effector translocation into host cells via a type III secretion system is a common virulence strategy among gram-negative bacteria. A beta-lactamase effector fusion based assay for quantitative analysis of translocation was applied. In Yersinia infected cells, conversion of a FRET reporter by the beta-lactamase is monitored using laser scanning microscopy.

Analizi<em&gt; Yersinia enterocolitica</emAna Hücreleri içine&gt; Efektör Translokasyon Beta-laktamaz Effector Fusions kullanma

Many gram-negative bacteria including pathogenic Yersinia spp. employ type III secretion systems to translocate effector proteins into eukaryotic target ...

Imaging Neutrophils and Monocytes in Mesenteric Veins by Intravital Microscopy on Anaesthetized Mice in Real Time

Efficient immune response is dependent on rapid mobilization of blood leukocytes to the site of infection or injury. Investigating leukocyte migration in vivo is crucial for understanding the molecular basis of leukocyte transendothelial migration and interaction with vascular endothelium. One powerful approach involves intravital microscopy on transgenic mice expressing fluorescent proteins in cells of interest.
Here we present a protocol for imaging monocytes and neutrophils in the CX3CR1gfp/wt mouse i.v. injected with orange dye-labeled neutrophils with an inverted confocal microscope. Time-lapse movies gathered from 30 min&#160;to several hours of imaging allow the analysis of leukocyte behavior in mesenteric veins under both steady state and inflammatory conditions. We also describe the steps to locally induce blood vessel inflammation with TLR2/TLR1 agonist Pam3SK4 and monitor the subsequent recruitment of neutrophils and monocytes.
The presented technique can also be used to monitor other populations of leukocytes and investigate molecules implicated in leukocyte recruitment or trafficking using other stimuli or transgenic mice.

We detail a protocol to monitor the behavior of neutrophils and monocytes in mesenteric veins under steady state and inflammatory conditions using intravital confocal microscopy on anaesthetized mice.

Real Time Anestetize Farelerde Intravital Mikroskopi Mezenterik Damarlardaki nötrofiller ve monositler Görüntüleme

Efficient immune response is dependent on rapid mobilization of blood leukocytes to the site of infection or injury. Investigating leukocyte migration in ...

Purification of Viral DNA for the Identification of Associated Viral and Cellular Proteins

The goal of this protocol is to isolate herpes simplex virus type 1 (HSV-1) DNA from infected cells for the identification of associated viral and cellular proteins by mass spectrometry. Although proteins that interact with viral genomes play major roles in determining the outcome of infection, a comprehensive analysis of viral genome associated proteins was not previously feasible. Here we demonstrate a method that enables the direct purification of HSV-1 genomes from infected cells. Replicating viral DNA is selectively labeled with modified nucleotides that contain an alkyne functional group. Labeled DNA is then specifically and irreversibly tagged via the covalent attachment of biotin azide via a copper(I)-catalyzed azide-alkyne cycloaddition or click reaction. Biotin-tagged DNA is purified on streptavidin-coated beads and associated proteins are eluted and identified by mass spectrometry. This method enables the selective targeting and isolation of HSV-1 replication forks or whole genomes from complex biological environments. Furthermore, adaptation of this approach will allow for the investigation of various aspects of herpesviral infection, as well as the examination of the genomes of other DNA viruses.

The goal of this protocol is to specifically tag and selectively isolate viral DNA from infected cells for the characterization of viral genome associated proteins.

Teşhis edilmesi için kullanılan ilişkili Viral ve hücresel proteinler Viral DNA'ın arıtma

The goal of this protocol is to isolate herpes simplex virus type 1 (HSV-1) DNA from infected cells for the identification of associated viral and ...

Real-time Imaging and Quantification of Fungal Biofilm Development Using a Two-Phase Recirculating Flow System

In oropharyngeal candidiasis, members of the genus Candida must adhere to and grow on the oral mucosal surface while under the effects of salivary flow. While models for the growth under flow have been developed, many of these systems are expensive, or do not allow imaging while the cells are under flow. We have developed a novel apparatus that allows us to image the growth and development of Candida albicans cells under flow and in real-time. Here, we detail the protocol for the assembly and use of this flow apparatus, as well as the quantification of data that are generated. We are able to quantify the rates that the cells attach to and detach from the slide, as well as to determine a measure of the biomass on the slide over time. This system is both economical and versatile, working with many types of light microscopes, including inexpensive benchtop microscopes, and is capable of extended imaging times compared to other flow systems. Overall, this is a low-throughput system that can provide highly detailed real-time information on the biofilm growth of fungal species under flow.

We describe the assembly, operation, and cleaning of a flow apparatus designed to image fungal biofilm formation in real time while under flow. We also provide and discuss quantitative algorithms to be used on the acquired images.

Gerçek zamanlı görüntüleme ve miktar iki aşamalı dolaşım akış sistemi kullanarak mantar biyofilm gelişimi

In oropharyngeal candidiasis, members of the genus Candida must adhere to and grow on the oral mucosal surface while under the effects of salivary flow. ...

Image Processing Protocol for the Analysis of the Diffusion and Cluster Size of Membrane Receptors by Fluorescence Microscopy

Particle tracking on a video sequence and the posterior analysis of their trajectories is nowadays a common operation in many biological studies. Using the analysis of cell membrane receptor clusters as a model, we present a detailed protocol for this image analysis task using Fiji (ImageJ) and Matlab routines to: 1) define regions of interest and design masks adapted to these regions; 2) track the particles in fluorescence microscopy videos; 3) analyze the diffusion and intensity characteristics of selected tracks. The quantitative analysis of the diffusion coefficients, types of motion, and cluster size obtained by fluorescence microscopy and image processing provides a valuable tool to objectively determine particle dynamics and the consequences of modifying environmental conditions. In this article we present detailed protocols for the analysis of these features. The method described here not only allows single-molecule tracking detection, but also automates the estimation of lateral diffusion parameters at the cell membrane, classifies the type of trajectory and allows complete analysis thus overcoming the difficulties in quantifying spot size over its entire trajectory at the cell membrane.

Here, we present a protocol for single particle tracking image analysis that allows quantitative evaluation of diffusion coefficients, types of motion and cluster sizes of single particles detected by fluorescence microscopy.

Görüntü membran reseptörleri Floresans mikroskobu tarafından küme boyutunu ve Difüzyon analizi için protokol işleme

Particle tracking on a video sequence and the posterior analysis of their trajectories is nowadays a common operation in many biological studies. Using ...