Questo lavoro è stato sostenuto dal Transregio Sonderforschungsbereich 19 (SFB/TR19, C2) della Deutsche Forschungsgemeinschaft (DFG), il Ministero Federale dell&#39;Economia e della Tecnologia progetto ZIM-KF 2727801MD0 e il Centro di Competenza Innovation - risposte immunitarie umorali in Malattie Cardiovascolari ( ZIK-ESCURSIONE, BMBF FKZ 03Z2CN12) del Ministero federale dell&#39;Istruzione e della Ricerca, in Germania. Corpo e gli esperimenti con gli animali sono stati eseguiti in conformità con le raccomandazioni della Società per Laboratorio Scienze Animali (Gesellschaft für Versuchstierkunde, GV-SOLAS) e la Federazione di Laboratorio europeo di Animal Science Association (FELASA).

1. Isolamento IgG da campioni di pazienti <ol><li> Preparare mini-immunoassorbimento colonne di riempimento 3 ml di anti-IgG sepharose paziente per 2 ml di plasma EDTA in una colonna vuota Econo Pac. IgG isolamento richiede almeno 2 ml di plasma del paziente. </li><li> Collocare un filtro sopra l&#39;anti-IgG Sepharose, tagliare aprire l&#39;estremità inferiore della colonna e premere il filtro per raggiungere una portata di circa 1 goccia / sec. Lasciare la soluzione di conservazione corto di colonna. </li><li> Lavare la colonna con 3 volumi NaCl 0,9% per volume di plasma. </li><li> Pipettare il plasma sulla colonna. Quando il plasma è completamente immerso nel anti-IgG Sepharose, lavare con lo stesso volume 0,9% NaCl. </li><li> Pipetta un volume plasmatico di 0,2 M glicina HCl, pH 2,8 su colonna e lasciare immergere nel Sepharose. Aggiungere un altro volume di glicina HCl sulla colonna. Raccogliere il flusso attraverso un tubo 15 ml e regolare il pH a 7,3 con 0,5 M Tris-HCl, pH 8,0. </li><li> Per rigenerare la colonna, Lavare con 3 volumi di plasma glicina HCl. Dopo un lavaggio finale con 2 volumi 0,9% NaCl, la colonna può essere utilizzato per il campione di plasma successivo. In alternativa, la colonna può essere riempita di soluzione di conservazione e conservata a 4-8 ° C fino a 4 settimane. </li><li> Per uso su cardiomiociti, la frazione IgG collezionati deve essere dializzato contro tampone sperimentale (EB). Per la preparazione della EB, aggiungere 117 mM NaCl, 2,8 mM KCl, 0,6 mM MgCl2, 1,2 mM KH 2 PO 4, 1.2 mM CaCl 2, 10 mM HEPES e 20 mM di glucosio ad 1 L di acqua distillata su un agitatore magnetico e regolare il pH a 7,3. </li><li> Riempire la frazione IgG di un tubo estere di cellulosa membrana di dialisi con un peso molecolare tagliato di 100 kDa. Mettere il tubo in 1 L EB e mescolare lentamente con un agitatore magnetico a 4 ° C. Dopo 8 ore, trasferire il tubo di dialisi in 3 L di EB fresco e dializza per un&#39;altra ora e 20 a 4 ° C. </li><li> Seguendo la dialisi, il calore del campione per 30 min a 57 ° C in un bagno d&#39;acqua a inactivatposta complemento fattori. Determinare la concentrazione totale di IgG e preparare aliquote di 330 mg ogni IgG. Quando si aggiunge il campione di cardiomiociti di misura (fase 4.3), riempire le aliquote di 1 ml con EB. Aliquote non diluiti possono essere conservati a -20 ° C fino ad ulteriore utilizzo. </li></ol> 2. Isolamento di cardiomiociti di ratto <ol><li> Per la preparazione di Ca 2 +-tampone privo di isolamento (IB), aggiungere 110 mM NaCl, 2,6 mM KCl, 1,2 mM MgSO 4, 1,2 mM KH 2 PO 4, 20 mM HEPES e 11 mM di glucosio ad 1 L di acqua distillata con un magnetico agitatore. Portare il pH a 7,4, a temperatura ambiente e filtrare attraverso un filtro 0,2 micron top bottiglia per la sterilizzazione. </li><li> Riempire 80 ml di IB nel serbatoio superiore di un sistema di perfusione Langendorff termostatata. Regolare le impostazioni del termostato per mantenere una temperatura di buffer di 37 ° C e aerare buffer con 95% O 2/5% di CO 2 per 30 min. </li><li> Pesare circa 10.000 - 12.000 U di collagenase tipo II, 175 mg di acidi grassi liberi BSA e si sciolgono in 20 ml contenenti IB 22,5 pl di una mm 100 CaCl2 soluzione madre. Controllare il pH del tampone di isolamento nel serbatoio superiore e regolare se necessario. </li><li> Anestetizzare un ratto Wistar di 175 - 200 g con 375 mg / kg di peso corporeo tiopentale. Aggiungi 2500 UI di eparina alla soluzione tiopentale. Dopo toracotomia, accisa il cuore con cura con un arco aortico intatto e le trasferisce in gelata NaCl 0,9%. Pulire il cuore da sangue e tessuto circostante e trasferimento a fresco 0,9% NaCl. Esporre l&#39;aorta, aprire il riduttore di flusso del sistema Langendorff per ottenere una velocità di gocciolamento di 2-3/sec e attaccare il cuore alla cannula. </li><li> Perfondere il cuore fino a 3 minuti con una portata di 1 goccia / sec per lavare il sangue rimanente. Inizia a circolare le IB nel sistema Langendorff. Rimuovere 20 ml di tampone dal serbatoio superiore, caricare la soluzione collagenasi e riempire come buffer quanto necessario per raggiungere 80 ml. Far circolare il c<html> ollagenase soluzione per un altro 27 min. Portata deve essere controllata periodicamente e mantenuta a 1 goccia / sec utilizzando il riduttore di flusso. </li><li> Staccare il cuore dalla cannula, pulito da atri e aorta e tagliare in piccoli pezzi. Lasciare che la soluzione di collagenasi di scorrere nel serbatoio inferiore, ridurre il volume ad un massimo di 40 ml e in seguito digerire i ventricoli tritate per 10 - 15 minuti sotto aerazione continua con il 95% O 2/5% di CO 2. Successivamente, filtrare la sospensione cellulare con una garza 200 micron dimensione delle maglie in una provetta da 50 ml. </li><li> Ripristinare il Ca 2 + contenuto delle celle in 3 fasi: centrifugare la sospensione cellulare a 43 xg per 2 minuti a temperatura ambiente e risospendere le cellule in 10 ml contenenti IB 200 mM CaCl 2. Centrifugare nuovamente e risospendere le cellule in 10 ml IB con 500 mM CaCl 2. Dopo una centrifugazione finale risospendere in cardiomiociti EB filtrata sterile (vedi 1.8) ad una densità di 50.000 cellule / ml. </li></ol>e_title &quot;&gt; 3. Fura-2 colorazione dei cardiomiociti <ol><li> Cappotto a 4 coprioggetti ben camerata con 10 laminina pg per bene e attendere che sia completamente asciugato. </li><li> Riempire 1 ml della sospensione cardiomiocita in ogni pozzetto usando una micropipetta con una punta di taglio. Permettere alle cellule di aderire per 1 ora a temperatura ambiente. </li><li> Diluire 10 ml di 1 mg / ml Fura-2 AM soluzione madre in 5 ml di EB. Conservare la soluzione di colorazione al buio. </li><li> Togliere celle buffer e distaccato dal coprioggetto e pipettare 0,5 ml di soluzione colorante in ogni pozzetto. Incubare le cellule per 10 minuti sotto agitazione moderata. Successivamente, togliere la soluzione colorante, lavare le cellule una volta con 1 ml di EB e riempire EB 0,5 ml in tutti i pozzetti. Evitare la luce diretta durante il processo di colorazione e tenere sempre le cellule colorate al buio. </li></ol> 4. Registrazione di accorciamento cellulare e Ca 2 + transitori <ol><li> Posizionare il coprioggetto a camera su un m inversa fluorescenzaicroscope collegato ad un calcio miociti e sistema di registrazione contrattilità. Posizionare un elettrodo di misura con un afflusso ed efflusso del tubo nel primo pozzetto. Cardiomiociti Superfuse con 1 ml / min EB e iniziare la stimolazione elettrica (20 V, 1 Hz, durata di 5 msec). Permettere alle cellule di adattarsi alla stimolazione per circa 2 min. </li><li> Scegli una cardiomiociti intatto a forma di asta con striatura chiara e costante contrazione. Posizionare la cella al centro del campo visivo e aprire il canale. Orientare la cella orizzontalmente all&#39;interno dell&#39;area video ruotando l&#39;adattatore inquadratura cella e spostando la fase microscopio. </li><li> Regolare il bordo rilevare elementi di controllo della zona video (Figura 2), aprire il canale fluorescente e registrare 10-15 contrazioni per ottenere la riduzione iniziale delle cellule e Ca 2 + transitori. </li><li> Chiudere il canale di luce del microscopio per evitare sbiancamento della macchia fluorescenza. Accendere il flusso attraverso da EB al campionebypass con una valvola a 3 vie e cardiomiociti superfuse con 1 ml di IgG paziente. Fermare la pompa poco prima che l&#39;aria raggiunga il bene. </li><li> Aprire il canale di luce e registrarne un altro 10-15 contrazioni per ottenere la risposta acuta cella. Mettere in pausa la registrazione e chiudere il canale di nuovo luce. Ripetere la registrazione dopo 2 e 5 min. </li><li> Estrarre l&#39;elettrodo di pozzo. Pulire accuratamente le provette con EB e continuare con il pozzo successivo del coprioggetti incamerata. </li><li> Analizzare l&#39;accorciamento cella e Ca 2 + temporaneo con il software IonWizard utilizzando il &quot;Edge-Length/Length&quot; e la finestra &quot;fura 2-numerico sottratto / Ratio&quot;, rispettivamente. Calcolare la variazione percentuale dal accorciamento cellula iniziale e Ca 2 + transitoria dell&#39;altezza del picco cui la linea di base (bl% picco h) per l&#39;acuta, il 2 min e la risposta di 5 min. </li></ol>

<ol>
	<li>Roger, V. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heart+disease+and+stroke+statistics--2011+update:+a+report+from+the+American+Heart+Association.">Heart disease and stroke statistics--2011 update: a report from the American Heart Association.</a> Circulation. 123 (4), e18 (2011).</li><li>Caforio, A. L., Vinci, A., Iliceto, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anti-heart+autoantibodies+in+familial+dilated+cardiomyopathy.">Anti-heart autoantibodies in familial dilated cardiomyopathy.</a> Autoimmunity. 41 (6), 462 (2008).</li><li>Yoshikawa, T., Baba, A., Nagatomo, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autoimmune+mechanisms+underlying+dilated+cardiomyopathy.">Autoimmune mechanisms underlying dilated cardiomyopathy.</a> Circ. J. 73 (4), 602 (2009).</li><li>Felix, S. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hemodynamic+effects+of+immunoadsorption+and+subsequent+immunoglobulin+substitution+in+dilated+cardiomyopathy:+Three-month+results+from+a+randomized+study.">Hemodynamic effects of immunoadsorption and subsequent immunoglobulin substitution in dilated cardiomyopathy: Three-month results from a randomized study.</a> Journal of the American College of Cardiology. 35 (6), 1590 (2000).</li><li>Staudt, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+immunoglobulin+G3+subclass+in+dilated+cardiomyopathy:+results+from+protein+A+immunoadsorption.">Role of immunoglobulin G3 subclass in dilated cardiomyopathy: results from protein A immunoadsorption.</a> Am. Heart J. 150 (4), 729 (2005).</li><li>Nikolaev, V. O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+fluorescence+method+for+the+rapid+detection+of+functional+beta1-adrenergic+receptor+autoantibodies+in+heart+failure.">A novel fluorescence method for the rapid detection of functional beta1-adrenergic receptor autoantibodies in heart failure.</a> J. Am. Coll. Cardiol. 50 (5), 423 (2007).</li><li>Jahns, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autoantibodies+activating+human+beta1-adrenergic+receptors+are+associated+with+reduced+cardiac+function+in+chronic+heart+failure.">Autoantibodies activating human beta1-adrenergic receptors are associated with reduced cardiac function in chronic heart failure.</a> Circulation. 99 (5), 649 (1999).</li><li>Gocayne, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Primary+structure+of+rat+cardiac+beta-adrenergic+and+muscarinic+cholinergic+receptors+obtained+by+automated+DNA+sequence+analysis:+further+evidence+for+a+multigene+family.">Primary structure of rat cardiac beta-adrenergic and muscarinic cholinergic receptors obtained by automated DNA sequence analysis: further evidence for a multigene family.</a> Proceedings of the National Academy of Sciences. 84 (23), 8296 (1987).</li><li>Jaenicke, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+complete+sequence+of+the+human+beta-myosin+heavy+chain+gene+and+a+comparative+analysis+of+its+product.">The complete sequence of the human beta-myosin heavy chain gene and a comparative analysis of its product.</a> Genomics. 8 (2), 194 (1990).</li><li>Piper, H. M., Volz, A., Schwartz, P., Piper, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Cell Culture Techniques in Heart and Vessel Research. , (1990).</li><li>Kubin, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microvascular+endothelial+cells+remodel+cultured+adult+cardiomyocytes+and+increase+their+survival.">Microvascular endothelial cells remodel cultured adult cardiomyocytes and increase their survival.</a> Am. J. Physiol. 276 (6 Pt. 2), H2179 (1999).</li><li>Grynkiewicz, G., Poenie, M., Tsien, R. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+generation+of+Ca2++indicators+with+greatly+improved+fluorescence+properties.">A new generation of Ca2+ indicators with greatly improved fluorescence properties.</a> J. Biol. Chem. 260 (6), 3440 (1985).</li><li>Magnusson, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autoimmunity+in+idiopathic+dilated+cardiomyopathy.+Characterization+of+antibodies+against+the+beta+1-adrenoceptor+with+positive+chronotropic+effect.">Autoimmunity in idiopathic dilated cardiomyopathy. Characterization of antibodies against the beta 1-adrenoceptor with positive chronotropic effect.</a> Circulation. 89 (6), 2760 (1994).</li><li>Wakefield, I. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+application+of+in+vitro+methods+to+safety+pharmacology.">The application of in vitro methods to safety pharmacology.</a> Fundam. Clin. Pharmacol. 16 (3), 209 (2002).</li><li>Kajzar, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toward+physiological+conditions+for+cell+analyses:+forces+of+heart+muscle+cells+suspended+between+elastic+micropillars.">Toward physiological conditions for cell analyses: forces of heart muscle cells suspended between elastic micropillars.</a> Biophys. J. 94 (5), 1854 (2008).</li></ol>

Nessun conflitto di interessi dichiarati.

Il metodo proposto offre un modo adatto a rilevare autoanticorpi funzionalmente efficaci cardiaci in pazienti con DCM di origine poco chiara. In confronto ad altri metodi, ad esempio il rilevamento di anticorpi funzionali attivi contro l&#39;β1-adrenocettori da loro impatto sui livelli di cAMP 6, il nostro metodo è indipendente da uno specifico epitopo. Naturalmente ci sono altri saggi indipendenti epitopi descritti nella letteratura, cioè contando il tasso battendo cardiomiociti neonatal...

<table border="1"><tbody><tr><td> Nome del reagente / attrezzature </td><td> Azienda </td><td> Numero di catalogo </td><td> Commenti </td></tr><tr><td> Immunosorba conservazione soluzione </td><td> Fresenius Medical Care </td><td> 903609211 </td><td></td></tr><tr><td> Collagenasi di tipo 2 </td><td> Cella di sistema </td><td> LS004176 </td><td></td></tr><tr><td> BSA, acidi grassi liberi </td><td> Sigma-Aldrich </td><td> A6003 </td><td></td></tr><tr><td> Laminina </td><td> Sigma-Aldrich </td><td> L2020 </td><td></td></tr><tr><td> Fura-2 AM </td><td> Sigma-Aldrich </td><td> F0888 </td><td> 1 mg / ml in DMSO </td></tr><tr><td> Econo Pac Cromatografia Colonne </td><td> BioRad </td><td> 732-1010 </td><td></td></tr><tr><td> Spectra / Por Biotech Cellulosa Ester dialisi Membrane </td><td> Spectrumlabs </td><td> 131417 </td><td></td></tr><tr><td> 4 ben Chambered vetrino </td><td> Nunc </td><td> 155383 </td><td></td></tr><tr><td> Calcio miociti e Sistema di registrazione contrattilità </td><td> IonOptix </td><td></td><td></td></tr><tr><td> IonWizard 6,0 ​​software di analisi </td><td> IonOptix </td><td></td><td></td></tr></tbody></table>

measurement of antibody effects on cellular function of isolated cardiomyocytes

Cardiomiopatia dilatativa (DCM) è una delle principali cause di insufficienza cardiaca nei giovani adulti 1. Sebbene predisposizione genetica ed esposizione a sostanze tossiche sono note cause per questa malattia in circa un terzo dei pazienti, l&#39;origine di DCM rimane poco chiara. In un numero considerevole di questi pazienti, gli anticorpi contro epitopi cardiaci sono stati individuati e sono sospettati di svolgere un ruolo centrale nella insorgenza e la progressione della malattia 2,3. L&#39;importanza di autoanticorpi cardiache è sottolineata da un miglioramento emodinamico osservato nei pazienti DCM dopo l&#39;eliminazione di autoanticorpi da immunoassorbimento 3-5. Una varietà di antigeni specifici sono già stati individuati 2,3 e anticorpi contro tali obiettivi possono essere rilevati da immunosaggi. Tuttavia, questi test non può discriminare tra stimolante (e quindi funzionalmente efficaci) e bloccando autoanticorpi. Vi è una crescente evidence che questa distinzione è cruciale 6,7. Si può anche ritenere che gli obiettivi di un certo numero di anticorpi cardiotropic sono ancora da identificare e pertanto non può essere rilevato dal test immunologici. Pertanto, abbiamo stabilito un metodo per la rilevazione di anticorpi funzionalmente attivi cardiotropic, indipendentemente dal loro rispettivo antigene. Lo sfondo per il metodo è l&#39;alta omologia di solito osservata per le regioni funzionali di proteine ​​cardiache nei mammiferi tra 8,9. Questo suggerisce che gli anticorpi diretti contro antigeni cardiaci umani reazione crociata con non umani cellule bersaglio, che permette prove di IgG da pazienti DCM su cardiomiociti di ratto adulto. Il nostro metodo si compone di 3 fasi: la prima, IgG è isolato dal plasma del paziente con sefarosio accoppiati anti-IgG anticorpi ottenuti da colonne immunoassorbimento (PlasmaSelect, Teterow, Germania). Secondo, cardiomiociti adulti sono isolati mediante perfusione con collagenasi in un apparato perfusione Langendorff utilizzando apROTOCOLLO modificato da lavori precedenti 10,11. I cardiomiociti ottenuti sono allegati alla laminina rivestite chambered vetrini colorati con Fura-2, un inibitore selettivo colorante fluorescente che può essere facilmente portato nella cella di osservare intracellulare di calcio (Ca 2 +) contenuti 12. Nell&#39;ultimo passaggio, l&#39;effetto del paziente IgG sulla riduzione delle cellule e Ca 2 + transitori di cardiomiociti campo stimolate è monitorato on-line utilizzando un calcio commerciale miociti e sistema di monitoraggio contrattilità (IonOptix, Milton, MA, USA) collegato ad una fluorescente standard di inversa microscopio.

Due esempi per la misurazione di inotropismo cellulare nel campo stimolato cardiomiociti adulti (figura 2) utilizzando una miociti Ca 2 + e registrazione contrattilità sono riportati di seguito. Figura 3 dà l&#39;impressione di una misura di controllo, mentre in figura 4 l&#39;effetto di anticorpi cardiodepressive di un paziente con DCM è mostrato. In entrambi gli esempi, accorciamento cellula iniziale e Ca 2 + trans...

Watch this Scientific Journal Video about Measurement of Antibody Effects on Cellular Function of Isolated Cardiomyocytes at JoVE.com

Measurement of Antibody Effects on Cellular Function of Isolated Cardiomyocytes

Il metodo proposto offre un modo per rilevare funzionali autoanticorpi cardiotropic efficaci nel plasma di pazienti con cardiomiopatia dilatativa, indipendentemente l&#39;antigene specifico, analizzando l&#39;impatto di immunoglobulina paziente isolato su accorciamento cellulare e transienti di calcio intracellulare in cardiomiociti isolati di ratto.

Misurazione degli effetti degli anticorpi sulla funzione cellulare di cardiomiociti isolati

Dilated cardiomyopathy  (DCM) is one of the main causes for heart failure in younger adults1.  Although genetic disposition and exposition to toxic ...

measurement-antibody-effects-on-cellular-function-isolated

Research

JoVE Journal

Immunology and Infection

11.8K Views.  University Medicine Greifswald. Il metodo proposto offre un modo per rilevare funzionali autoanticorpi cardiotropic efficaci nel plasma di pazienti con cardiomiopatia dilatativa, indipendentemente l'antigene specifico, analizzando l'impatto di immunoglobulina paziente isolato su accorciamento cellulare e transienti di calcio intracellulare in cardiomiociti isolati di ratto.

Video: Measurement of Antibody Effects on Cellular Function of Isolated Cardiomyocytes

Measurement of Cytosolic Ca2+ in Isolated Contractile Lymphatics

Lymphatic vessels comprise a multifunctional transport system that maintains fluid homeostasis, delivers lipids to the central circulation, and acts as a surveillance system for potentially harmful antigens, optimizing mucosal immunity and adaptive immune responses1. Lymph is formed from interstitial fluid that enters blind-ended initial lymphatics, and then is transported against a pressure gradient in larger collecting lymphatics. Each collecting lymphatic is made up of a series of segments called lymphangions, separated by bicuspid valves that prevent backflow. Each lymphangion possesses a contractile cycle that propels lymph against a pressure gradient toward the central circulation2. This phasic contractile pattern is analogous to the cardiac cycle, with systolic and diastolic phases, and with a lower contraction frequency4. In addition, lymphatic smooth muscle generates tone and displays myogenic constriction and dilation in response to increases and decreases in luminal pressure, respectively5. A hybrid of molecular mechanisms that support both the phasic and tonic contractility of lymphatics are thus proposed.
Contraction of smooth muscle is generally regulated by the cytosolic Ca2+ concentration ([Ca2+]i) plus sensitivity to Ca2+, of the contractile elements in response to changes in the environment surrounding the cell6. [Ca2+]i is determined by the combination of the movement of Ca2+ through plasma membrane ligand or voltage gated Ca2+ channels and the release and uptake of Ca2+ from internal stores. Cytosolic Ca2+ binds to calmodulin and activates enzymes such as myosin light chain (MLC) kinase (MLCK), which in turn phosphorylates MLC leading to actin-myosin-mediated contraction8. However, the sensitivity of this pathway to Ca2+ can be regulated by the MLC phosphatase (MLCP)9. MLCP activity is regulated by Rho kinase (ROCK) and the myosin phosphatase inhibitor protein CPI-17.
Here, we present a method to evaluate changes in [Ca2+]i over time in isolated, perfused lymphatics in order to study Ca2+-dependent and Ca2+-sensitizing mechanisms of lymphatic smooth muscle contraction. Using isolated rat mesenteric collecting lymphatics we studied stretch-induced changes in [Ca2+]i and contractile activity. The isolated lymphatic model offers the advantage that pressure, flow, and the chemical composition of the bath solution can be tightly controlled. [Ca2+]i was determined by loading lymphatics with the ratiometric, Ca2+-binding dye Fura-2. These studies will provide a new approach to the broader problem of studying the different molecular mechanisms that regulate phasic contractions versus tonic constriction in lymphatic smooth muscle.

Measurement of Cytosolic Ca2+ in Isolated Contractile Lymphatics

We introduce an approach to evaluate the cytosolic Ca2+ concentration in isolated lymphatics to study Ca2+-dependent and Ca2+-sensitizing mechanisms of lymphatic smooth muscle contraction.

Misura della Ca citosolico 2 + In isolati Linfatici contrattile

Lymphatic vessels comprise a multifunctional transport system that maintains fluid homeostasis, delivers lipids to the central circulation, and acts as a ...

Ricerca

Immunologia e infezioni

A Microplate Assay to Assess Chemical Effects on RBL-2H3 Mast Cell Degranulation: Effects of Triclosan without Use of an Organic Solvent

Mast cells play important roles in allergic disease and immune defense against parasites. Once activated (e.g. by an allergen), they degranulate, a process that results in the exocytosis of allergic mediators. Modulation of mast cell degranulation by drugs and toxicants may have positive or adverse effects on human health. Mast cell function has been dissected in detail with the use of rat basophilic leukemia mast cells (RBL-2H3), a widely accepted model of human mucosal mast cells3-5. Mast cell granule component and the allergic mediator &#946;-hexosaminidase, which is released linearly in tandem with histamine from mast cells6, can easily and reliably be measured through reaction with a fluorogenic substrate, yielding measurable fluorescence intensity in a microplate assay that is amenable to high-throughput studies1. Originally published by Naal et al.1, we have adapted this degranulation assay for the screening of drugs and toxicants and demonstrate its use here.
Triclosan is a broad-spectrum antibacterial agent that is present in many consumer products and has been found to be a therapeutic aid in human allergic skin disease7-11, although the mechanism for this effect is unknown. Here we demonstrate an assay for the effect of triclosan on mast cell degranulation. We recently showed that triclosan strongly affects mast cell function2. In an effort to avoid use of an organic solvent, triclosan is dissolved directly into aqueous buffer with heat and stirring, and resultant concentration is confirmed using UV-Vis spectrophotometry (using &#949;280 = 4,200 L/M/cm)12. This protocol has the potential to be used with a variety of chemicals to determine their effects on mast cell degranulation, and more broadly, their allergic potential.

Mast cell degranulation, the release of allergic mediators, is important in allergy, asthma, and parasite defense. Here we demonstrate techniques1 for assessing effects of drugs and toxicants on degranulation, methodology recently utilized to exhibit the powerful inhibitory effect of antibacterial agent triclosan2.

Un saggio di micropiastre per valutare gli effetti chimici su RBL-2H3 Mast cellule Degranulazione: Effetti del Triclosan senza l&#39;uso di un solvente organico

Mast cells play important roles in allergic disease and immune defense against parasites. Once activated (e.g. by an allergen), they degranulate, a ...

Methods for Quantitative Detection of Antibody-induced Complement Activation on Red Blood Cells

Antibodies against red blood cells (RBCs) can lead to complement activation resulting in an accelerated clearance via complement receptors in the liver (extravascular hemolysis) or leading to intravascular lysis of RBCs. Alloantibodies (e.g. ABO) or autoantibodies to RBC antigens (as seen in autoimmune hemolytic anemia, AIHA) leading to complement activation are potentially harmful and can be - especially when leading to intravascular lysis - fatal1. Currently, complement activation due to (auto)-antibodies on RBCs is assessed in vitro by using the Coombs test reflecting complement deposition on RBC or by a nonquantitative hemolytic assay reflecting RBC lysis1-4. However, to assess the efficacy of complement inhibitors, it is mandatory to have quantitative techniques. Here we describe two such techniques. First, an assay to detect C3 and C4 deposition on red blood cells that is induced by antibodies in patient serum is presented. For this, FACS analysis is used with fluorescently labeled anti-C3 or anti-C4 antibodies. Next, a quantitative hemolytic assay is described. In this assay, complement-mediated hemolysis induced by patient serum is measured making use of spectrophotometric&#160;detection of the released hemoglobin. Both of these assays are very reproducible and quantitative, facilitating studies of antibody-induced complement activation.

Here we describe two assays for measuring complement activation induced by antibodies against red blood cells. The major advantage over the current assays is their quantitative and easy-to-interpret nature.

Metodi per quantitativa individuazione di anticorpi indotta da attivazione del complemento sui globuli rossi

Antibodies against red blood cells (RBCs) can lead to complement activation resulting in an accelerated clearance via complement receptors in the liver ...

Analyzing the Effects of Stromal Cells on the Recruitment of Leukocytes from Flow

Stromal cells regulate the recruitment of circulating leukocytes during inflammation through cross-talk with neighboring endothelial cells. Here we describe two in vitro &#8220;vascular&#8221; models for studying the recruitment of circulating neutrophils from flow by inflamed endothelial cells. A major advantage of these models is the ability to analyze each step in the leukocyte adhesion cascade in order, as would occur in vivo. We also describe how both models can be adapted to study the role of stromal cells, in this case mesenchymal stem cells (MSC), in regulating leukocyte recruitment.
Primary endothelial cells were cultured alone or together with human MSC in direct contact on Ibidi microslides or on opposite sides of a Transwell filter for 24 hr. Cultures were stimulated with tumor necrosis factor alpha (TNF&#945;) for 4 hr and incorporated into a flow-based adhesion assay. A bolus of neutrophils was perfused over the endothelium for 4 min. The capture of flowing neutrophils and their interactions with the endothelium was visualized by phase-contrast microscopy.
In both models, cytokine-stimulation increased endothelial recruitment of flowing neutrophils in a dose-dependent manner. Analysis of the behavior of recruited neutrophils showed a dose-dependent decrease in rolling and a dose-dependent increase in transmigration through the endothelium. In co-culture, MSC suppressed neutrophil adhesion to TNF&#945;-stimulated endothelium.
Our flow based-adhesion models mimic the initial phases of leukocyte recruitment from the circulation. In addition to leukocytes, they can be used to examine the recruitment of other cell types, such as therapeutically administered MSC or circulating tumor cells. Our multi-layered co-culture models have shown that MSC communicate with endothelium to modify their response to pro-inflammatory cytokines, altering the recruitment of neutrophils. Further research using such models is required to fully understand how stromal cells from different tissues and conditions (inflammatory disorders or cancer) influence the recruitment of leukocytes during inflammation.

The ability of inflamed endothelium to recruit leukocytes from flow is regulated by mesenchymal stromal cells. We describe two in vitro models incorporating primary human cells that can be used to assess neutrophil recruitment from flow and examine the role that mesenchymal stromal cells play in regulating this process.

Analizzando gli effetti delle cellule stromali per il reclutamento dei leucociti da portata

Stromal cells regulate the recruitment of circulating leukocytes during inflammation through cross-talk with neighboring endothelial cells. Here we ...

Flow Cytometric Analysis of Particle-bound Bet v 1 Allergen in PM10

Flow cytometry is a method widely used to quantify suspended solids such as cells or bacteria in a size range from 0.5 to several tens of micrometers in diameter. In addition to a characterization of forward and sideward scatter properties, it enables the use of fluorescent labeled markers like antibodies to detect respective structures. Using indirect antibody staining, flow cytometry is employed here to quantify birch pollen allergen (precisely Bet v 1)-loaded particles of 0.5 to 10 &#181;m in diameter in inhalable particulate matter (PM10, particle size &#8804;10 &#181;m in diameter). PM10 particles may act as carriers of adsorbed allergens possibly transporting them to the lower respiratory tract, where they could trigger allergic reactions.
So far the allergen content of PM10 has been studied by means of enzyme linked immunosorbent assays (ELISAs) and scanning electron microscopy. ELISA measures the dissolved and not the particle-bound allergen. Compared to scanning electron microscopy, which can visualize allergen-loaded particles, flow cytometry may additionally quantify them. As allergen content of ambient air can deviate from birch pollen count, allergic symptoms might perhaps correlate better with allergen exposure than with pollen count. In conjunction with clinical data, the presented method offers the opportunity to test in future experiments whether allergic reactions to birch pollen antigens are associated with the Bet v 1 allergen content of PM10 particles &#62;0.5 &#181;m.

Here, we present a protocol to quantify allergen-loaded particles by flow cytometry. Ambient particulate matter particles may act as carriers of adsorbed allergens. We show here that flow cytometry, a method widely used to characterize suspended solids &#62;0.5 &#181;m in diameter, can be used to measure these allergen-loaded particles.

Flusso analisi di citometria di Particle-bound Bet v 1 allergene in PM10

Flow cytometry is a method widely used to quantify suspended solids such as cells or bacteria in a size range from 0.5 to several tens of micrometers in ...

Peptide Scanning-assisted Identification of a Monoclonal Antibody-recognized Linear B-cell Epitope

The identification of an antigenic epitope by the immune system allows for the understanding of the protective mechanism of neutralizing antibodies that may facilitate the development of vaccines and peptide drugs. Peptide scanning is a simple and efficient method that straightforwardly maps the linear epitope recognized by a monoclonal antibody (mAb). Here, the authors present an epitope determination methodology involving serially truncated recombinant proteins, synthetic peptide design, and dot-blot hybridization for the antigenic recognition of nervous necrosis virus coat protein using a neutralizing mAb. This technique relies on the dot-blot hybridization of synthetic peptides and mAbs on a polyvinylidene fluoride (PVDF) membrane. The minimum antigenic region of a viral coat protein recognized by the RG-M56 mAb can be narrowed down by step-by-step trimmed peptide mapping onto a 6-mer peptide epitope. In addition, alanine scanning mutagenesis and residue substitution can be performed to characterize the binding significance of each amino acid residue making up the epitope. The residues flanking the epitope site were found to play critical roles in peptide conformation regulation. The identified epitope peptide may be used to form crystals of epitope peptide-antibody complexes for an x-ray diffraction study and functional competition, or for therapeutics.

Here, the authors present a simple and efficient protocol to define a linear antigenic epitope using a purified monoclonal antibody and peptide scanning through dot-blot hybridization. The identified epitope can then be used in therapeutic and diagnostic applications.

Identificazione di un Epitopo Lineare B-cell monoclonale riconosciuto Peptide scansione-assistito

The identification of an antigenic epitope by the immune system allows for the understanding of the protective mechanism of neutralizing antibodies that ...

Intraperitoneal Glucose Tolerance Test, Measurement of Lung Function, and Fixation of the Lung to Study the Impact of Obesity and Impaired Metabolism on Pulmonary Outcomes

Obesity and respiratory disorders are major health problems. Obesity is becoming an emerging epidemic with an expected number of over 1 billion obese individuals worldwide by 2030, thus representing a growing socioeconomic burden. Simultaneously, obesity-related comorbidities, including diabetes as well as heart and chronic lung diseases, are continuously on the rise. Although obesity has been associated with increased risk for asthma exacerbations, worsening of respiratory symptoms, and poor control, the functional role of obesity and perturbed metabolism in the pathogenesis of chronic lung disease is often underestimated, and underlying molecular mechanisms remain elusive. This article aims to present methods to assess the effect of obesity on metabolism, as well as lung structure and function. Here, we describe three techniques for mice studies: (1) assessment of intraperitoneal glucose tolerance (ipGTT) to analyze the effect of obesity on glucose metabolism; (2) measurement of airway resistance (Res) and respiratory system compliance (Cdyn) to analyze the effect of obesity on lung function; and (3) preparation and fixation of the lung for subsequent quantitative histological assessment. Obesity-related lung diseases are probably multifactorial, stemming from systemic inflammatory and metabolic dysregulation that potentially adversely influence lung function and the response to therapy. Therefore, a standardized methodology to study molecular mechanisms and the effect of novel treatments is essential.

The incidence of obesity is rising and increases the risk of chronic lung diseases. To establish the underlying mechanisms and preventive strategies, well-defined animal models are needed. Here, we provide three methods (glucose-tolerance-test, body plethysmography, and lung fixation) to study the effect of obesity on pulmonary outcomes in mice.

Prova di tolleranza di glucosio intraperitoneale, misura della funzione polmonare e la fissazione del polmone per studiare l'impatto dell'obesità e metabolismo alterato sugli esiti polmonare

Obesity and respiratory disorders are major health problems. Obesity is becoming an emerging epidemic with an expected number of over 1 billion obese ...

Assessment of Antibody-based Drugs Effects on Murine Bone Marrow and Peritoneal Macrophage Activation

Macrophages are phagocytic innate immune cells, which initiate immune responses to pathogens and contribute to healing and tissue restitution. Macrophages are equally important in turning off inflammatory responses. We have shown that macrophages stimulated with intravenous immunoglobulin (IVIg) can produce high amounts of the anti-inflammatory cytokine, interleukin 10 (IL-10), and low levels of pro-inflammatory cytokines in response to bacterial lipopolysaccharides (LPS). IVIg is a polyvalent antibody, primarily immunoglobulin Gs (IgGs), pooled from the plasma of more than 1,000 blood donors. It is used to supplement antibodies in patients with immune deficiencies or to suppress immune responses in patients with autoimmune or inflammatory conditions. Infliximab, a therapeutic anti-tumor necrosis factor alpha (TNF&#945;) antibody, has also been shown to activate macrophages to produce IL-10 in response to inflammatory stimuli. IVIg and other antibody-based biologics can be tested to determine their effects on macrophage activation. This paper describes methods for derivation, stimulation, and assessment of murine bone marrow macrophages activated by antibodies in vitro and murine peritoneal macrophages activated with antibodies in vivo. Finally, we demonstrate the use of western blotting to determine the contribution of specific cell signaling pathways to anti-inflammatory macrophage activity. These protocols can be used with genetically modified mice, to determine the effect of a specific protein(s) on anti-inflammatory macrophage activation. These techniques can also be used to assess whether specific biologics may act by changing macrophages to an IL-10-producing anti-inflammatory activation state that reduces inflammatory responses in vivo. This can provide information on the role of macrophage activation in the efficacy of biologics during disease models in mice, and provide insight into a potential new mechanism of action in people. Conversely, this may caution against the use of specific antibody-based biologics to treat infectious disease, particularly if macrophages play an important role in host defense against that infection.

Antibody-based drugs have revolutionized treatment for inflammatory diseases. In addition to having direct effects on specific targets, antibodies can activate macrophages to become anti-inflammatory. This protocol describes how anti-inflammatory macrophage activation can be assessed in vitro, using mouse bone marrow macrophages, and in vivo, using peritoneal macrophages.

Valutazione degli effetti di farmaci a base di anticorpi sul midollo osseo murino e l'attivazione dei macrofagi peritoneali

Macrophages are phagocytic innate immune cells, which initiate immune responses to pathogens and contribute to healing and tissue restitution. Macrophages ...

A Method for the Measurement of Salivary Gland Function in Mice

Patients with Sj&#246;gren&#39;s syndrome, an autoimmune disease affecting the exocrine glands, develop salivary gland inflammation and have reduced saliva production. Similarly, saliva production is severely compromised in patients receiving radiation treatment for head and neck cancers. Rodent models, developed to mimic these clinical conditions, facilitate an understanding of the disease pathogenesis and allow for the development of new therapeutic strategies. Therefore, the ability to accurately, reproducibly, and repeatedly measure salivary gland function in animal models is critical. Building on procedures previously described in the literature, a method was developed that meets these criteria and was used to evaluate salivary gland function in mice. An additional advantage of this new method is that it is easily mastered, and has little inter-operator variation. Salivary gland function is evaluated as the amount (weight or volume) or rate (mL/min) of saliva produced in response to pilocarpine stimulation. The collected saliva is a good source for the analyses of protein content, immunoglobulin concentrations, and other biomolecules.

Salivary gland hypofunction is a frequent consequence of autoimmune disease and radiation therapy. Reproducible evaluation of salivary gland function in mouse models of these diseases is a technical challenge. Here, a simple method for accurate and reproducible measurement of saliva production in mice is described.

Un metodo per la misurazione della funzione della ghiandola salivaria in topi

Patients with Sj&#246;gren&#39;s syndrome, an autoimmune disease affecting the exocrine glands, develop salivary gland inflammation and have reduced ...

Construction of Synthetic Phage Displayed Fab Library with Tailored Diversity

Demand for monoclonal antibodies (mAbs) in basic research and medicine is increasing yearly. Hybridoma technology has been the dominant method for mAb development since its first report in 1975. As an alternative technology, phage display methods for mAb development are increasingly attractive since Humira, the first phage-derived antibody and one of the best-selling mAbs, was approved for clinical treatment of rheumatoid arthritis in 2002. As a non-animal based mAb development technology, phage display bypasses antigen immunogenicity, humanization, and animal maintenance that are required from traditional hybridoma technology based antibody development. In this protocol, we describe a method for construction of synthetic phage-displayed Fab libraries with diversities of 109-1010 obtainable with a single electroporation. This protocol consists of: 1) high-efficiency electro-competent cell preparation; 2) extraction of uracil-containing single-stranded DNA (dU-ssDNA); 3) Kunkel&#39;s method based oligonucleotide-directed mutagenesis; 4) electroporation and calculation of library size; 5) protein A/L-based enzyme-linked immunosorbent assay (ELISA) for folding and functional diversity evaluation; and 6) DNA sequence analysis of diversity.

This protocol describes a detailed procedure for the construction of a phage-displayed synthetic antibody library with tailored diversity. Synthetic antibodies have broad applications from basic research to disease diagnostics and therapeutics.

Costruzione del fago sintetico visualizzato favolosa biblioteca con diversità su misura

Demand for monoclonal antibodies (mAbs) in basic research and medicine is increasing yearly. Hybridoma technology has been the dominant method for mAb ...