We would like to thank the entire Lazzaro lab, and especially Susan Rottschaefer, for their help in both reviewing and testing these protocols. This is a product of their cumulative expertise. Work in the Lazzaro lab is supported by grants R01 AI083932 and R01 AI064950 from the US National Institutes of Health.

<ol>
	<li>Lemaitre, B., Hoffmann, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+host+defense+of+Drosophila+melanogaster.">The host defense of Drosophila melanogaster.</a> Annual review of immunology. 25, 697-743 (2007).</li><li>Dionne, M. S., Schneider, 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=Models+of+infectious+diseases+in+the+fruit+fly+Drosophila+melanogaster.">Models of infectious diseases in the fruit fly Drosophila melanogaster.</a> Disease models &amp; mechanisms. 1 (1), 43-9 (2008).</li><li>Rutschmann, S., Jung, A. C., Hetru, C., Reichhart, J. M., Hoffmann, J. A., Ferrandon, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Rel+protein+DIF+mediates+the+antifungal+but+not+the+antibacterial+host+defense+in+Drosophila.">The Rel protein DIF mediates the antifungal but not the antibacterial host defense in Drosophila.</a> Immunity. 12 (5), 569-580 (2000).</li><li>Ayres, J. S., Freitag, N., Schneider, 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=Identification+of+Drosophila+mutants+altering+defense+of+and+endurance+to+Listeria+monocytogenes+infection.">Identification of Drosophila mutants altering defense of and endurance to Listeria monocytogenes infection.</a> Genetics. 178 (3), 1807-1815 (2008).</li><li>Cronin, S. J. F., 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=Genome-wide+RNAi+screen+identifies+genes+involved+in+intestinal+pathogenic+bacterial+infection.">Genome-wide RNAi screen identifies genes involved in intestinal pathogenic bacterial infection.</a> Science. 325 (5938), 340-343 (2009).</li><li>Neyen, C., Bretscher, A. J., Binggeli, O., Lemaitre, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methods+to+study+Drosophila+immunity.">Methods to study Drosophila immunity.</a> Methods. , (2014).</li><li>Dionne, M. S., Pham, L. N., Shirasu-Hiza, M., Schneider, 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=Akt+and+FOXO+dysregulation+contribute+to+infection-induced+wasting+in+Drosophila.">Akt and FOXO dysregulation contribute to infection-induced wasting in Drosophila.</a> Current biology CB. 16 (20), 1977-1985 (2006).</li><li>McKean, K. a., Yourth, C. P., Lazzaro, B. P., Clark, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+evolutionary+costs+of+immunological+maintenance+and+deployment.">The evolutionary costs of immunological maintenance and deployment.</a> BMC evolutionary biology. 8 (1), 76 (2008).</li><li>Kuo, T. -. H., Pike, D. H., Beizaeipour, Z., Williams, 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=Sleep+triggered+by+an+immune+response+in+Drosophila+is+regulated+by+the+circadian+clock+and+requires+the+NFkappaB+Relish.">Sleep triggered by an immune response in Drosophila is regulated by the circadian clock and requires the NFkappaB Relish.</a> BMC neuroscience. 11, 17 (2010).</li><li>Panayidou, S., Ioannidou, E., Apidianakis, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+pathogenic+bacteria,+fungi,+and+viruses+in+Drosophila:+disease+modeling,+lessons,+and+shortcomings.">Human pathogenic bacteria, fungi, and viruses in Drosophila: disease modeling, lessons, and shortcomings.</a> Virulence. 5 (2), 253-269 (2014).</li><li>Keebaugh, E. S., Schlenke, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Insights+from+natural+host&#8211;parasite+interactions:+The+Drosophila+model.">Insights from natural host&#8211;parasite interactions: The Drosophila model.</a> Developmental &amp; Comparative Immunology. 42 (1), 111-123 (2014).</li><li>Howick, V. M., Lazzaro, B. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genotype+and+diet+shape+resistance+and+tolerance+across+distinct+phases+of+bacterial+infection.">Genotype and diet shape resistance and tolerance across distinct phases of bacterial infection.</a> BMC evolutionary biology. 14 (1), 56 (2014).</li><li>Babin, A., Kolly, S., Kawecki, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Virulent+bacterial+infection+improves+aversive+learning+performance+in+Drosophila.">Virulent bacterial infection improves aversive learning performance in Drosophila.</a> Brain, behavior, and immunity. , (2014).</li><li>Chambers, M. C., Song, K. H., Schneider, 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=Listeria+monocytogenes+infection+causes+metabolic+shifts+in+Drosophila+melanogaster.">Listeria monocytogenes infection causes metabolic shifts in Drosophila melanogaster.</a> PLoS ONE. 7 (12), e50679 (2012).</li><li>Fellous, S., Lazzaro, B. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Larval+food+quality+affects+adult+(but+not+larval)+immune+gene+expression+independent+of+effects+on+general+condition.">Larval food quality affects adult (but not larval) immune gene expression independent of effects on general condition.</a> Molecular ecology. 19 (7), 1462-1468 (2010).</li><li>Stone, E. F., Fulton, B. O., Ayres, J. S., Pham, L. N., Ziauddin, J., Shirasu-Hiza, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+circadian+clock+protein+timeless+regulates+phagocytosis+of+bacteria+in+Drosophila.">The circadian clock protein timeless regulates phagocytosis of bacteria in Drosophila.</a> PLoS pathogens. 8 (1), e1002445 (2012).</li><li>Chambers, M. C., Jacobson, E., Khalil, S., Lazzaro, B. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thorax+injury+lowers+resistance+to+infection+in+Drosophila+melanogaster.">Thorax injury lowers resistance to infection in Drosophila melanogaster.</a> Infection and immunity. , (2014).</li><li>Rich, J. T., Neely, J. G., Paniello, R. C., Voelker, C. C. J., Nussenbaum, B., Wang, E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+practical+guide+to+understanding+Kaplan-Meier+curves.">A practical guide to understanding Kaplan-Meier curves.</a> Otolaryngology--head and neck surgery official journal of American Academy of Otolaryngology-Head and Neck Surgery. 143 (3), 331-336 (2010).</li><li>Sokal, R. R., Rohlf, F. J., Freeman, W. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Biometry. , (1995).</li><li>Frydman, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wolbachia+bacterial+infection+in+Drosophila.">Wolbachia bacterial infection in Drosophila.</a> Journal of visualized experiments JoVE. (2), 158 (2007).</li><li>Kuo, T. -. H., Handa, A., Williams, 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=Quantitative+measurement+of+the+immune+response+and+sleep+in+Drosophila.">Quantitative measurement of the immune response and sleep in Drosophila.</a> Journal of visualized experiments JoVE. (70), e4355 (2012).</li><li>Vodovar, N., 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=Drosophila+host+defense+after+oral+infection+by+an+entomopathogenic+Pseudomonas+species.">Drosophila host defense after oral infection by an entomopathogenic Pseudomonas species.</a> Proceedings of the National Academy of Sciences of the United States of America. 102 (32), 11414-11419 (2005).</li><li>Nehme, N. 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=A+model+of+bacterial+intestinal+infections+in+Drosophila+melanogaster.">A model of bacterial intestinal infections in Drosophila melanogaster.</a> PLoS pathogens. 3 (11), e173 (2007).</li><li>Jaenike, J., Polak, M., Fiskin, A., Helou, M., Minhas, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interspecific+transmission+of+endosymbiotic+Spiroplasma+by+mites.">Interspecific transmission of endosymbiotic Spiroplasma by mites.</a> Biology. 3 (1), 23-25 (2007).</li><li>Kanbar, G., Engels, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrastructure+and+bacterial+infection+of+wounds+in+honey+bee+(+Apis+mellifera)+pupae+punctured+by+Varroa+mites.">Ultrastructure and bacterial infection of wounds in honey bee ( Apis mellifera) pupae punctured by Varroa mites.</a> Parasitology research. 90 (5), 349-354 (2003).</li></ol>

None of the authors have competing interests or conflicting interests.

La procedura qui descritta produce infezione qualità rigoroso e alto di Drosophila melanogaster. Gli esempi illustrati concentrati principalmente sulla infezione da Providencia rettgeri ed E. coli, ma il protocollo è altamente adattabile e può essere applicato alle infezioni con diversi batteri su una gamma di condizioni di allevamento host e manutenzione. I dettagli di un approccio sperimentale ottimale dipenderà batterio utilizzato per l&#39;infezione, il genotipo dell&#39;ospite, e le condizioni sperimentali generali. E &#39;fortemente raccomandato di test pilota eventuali nuove condizioni sperimentali prima di avviare i progetti più ambiziosi. Un buon punto di partenza è quello di testare tre dosi di infezione in un range di 100 volte. Altamente patogeni virulenti sono spesso meglio introdotti a dosi infettive molto bassi, dell&#39;ordine di 10 - 100 cellule batteriche per mosca. Gli agenti patogeni più moderati possono essere iniettati in dosi più elevate di circa 1.000 batteri per fly, e non gli agenti patogeni possono essere iniettati in dosi fino a 10.000 batteri per volare. Spesso è istruttivo definire le cinetiche di infezioni nuovi tracciando carico patogeno, la mortalità host e l&#39;attività del sistema immunitario su una serie temporale longitudinale. Poiché la misura del carico patogeno e l&#39;espressione genica ospitante sono prove distruttive, è necessario per infettare le mosche distinti fin dall&#39;inizio dell&#39;esperimento per ogni punto di tempo che deve essere misurato. Al momento di decidere se utilizzare puntura di spillo o iniezione a base microcapillare-, è importante notare che ci sono vantaggi e limitazioni di ogni approccio. Iniezione capillare presenta un volume di liquido nella mosca, che sia modestamente aumenta la pressione turgore e introduce sali o altre molecole che sono sospesi o disciolti nel veicolo. Iniezione capillare richiede anche l&#39;accesso ad un impianto di iniezione o l&#39;acquisto delle attrezzature necessarie. Pinprick Septic non richiede attrezzature speciali e introducesupporti trascurabili nel volo, ed è in genere più efficace per infettare un gran numero di mosche. Tuttavia, le infezioni puntura di spillo non consentono il controllo preciso dosaggio infezione che può essere raggiunto con iniezione capillare. Il presente protocollo focalizzata su un apparato di iniezione che regola meccanicamente volume di iniezione, ma ci sono anche sistemi di iniezione a base di impulsi discreti di aria pressurizzata. 20,21 Questi sono in genere più costosi dei apparecchiatura descritta qui e richiedono la calibrazione dell&#39;impulso aria per ciascun aghi per garantire volumi di iniezione coerenti. Vi è un ampio dibattito, ma pochissimi dati su come le mosche diventano sistemica infettati con i batteri in natura. Alcuni ricercatori ipotizzano che la maggior parte delle infezioni naturali si verificano quando Drosophila ingerire batteri patogeni e batteri sono successivamente in grado di sfuggire l&#39;intestino per stabilire una infezione sistemica. Tuttavia, ci sono molto few batteri noti per essere in grado di attraversare l&#39;intestino di D. melanogaster, e quelli che hanno questa capacità sono altamente letale per le mosche 22,23. Una teoria alternativa è che vola regolarmente subire lesioni cuticolari attraverso fuga dai tentativi di predazione falliti o attacco di acari ectoparassiti. Questa ipotesi è supportata dalla raccolta frequente di selvaggio D. melanogaster recanti macchie melanizzazione che sono indicativi delle ferite guarite (osservazioni non pubblicate). Gli acari sono stati indicati per la trasmissione di infezioni batteriche in Drosophila 24 e le ferite lasciate da acari possono essere secondariamente infettato da batteri nelle api 25. Tuttavia, la frequenza naturale di infezione acari-driven o altrimenti opportunistica di D. melanogaster attraverso violazioni cuticola non è noto. Il protocollo qui descritto consente l&#39;introduzione di batteri direttamente nella emolinfa attraverso l&#39;iniezione quantitativa che bypassa le barriere epiteliali o Immu comportamentalicomunitario. Metodi per alimentare i batteri patogeni a D. melanogaster sono stati descritti in Vodovar et al. 22 e Nehme et al. 23. Molti batteri entomopatogeni rappresentano poco o nessun rischio per la salute umana, consentendo ai ricercatori di lavorare con loro in modo confortevole. Inoltre, molto pochi i batteri hanno la capacità di infettare Drosophila in contatto senza intervento sperimentale, per cui il rischio di diffusione &quot;epidemica&quot; di infezione batterica attraverso un laboratorio di via superfici contaminate o fuggiti mosche è generalmente molto basso. Tuttavia, è opportuno garantire che adeguate misure di contenimento sono in atto per evitare che le mosche infette di fuggire e per riconquistare qualsiasi mosche sfuggito. Il laboratorio deve essere attrezzato ad un livello di sicurezza biologica commisurata a quella dei patogeni in uso, e migliori pratiche standard in microbiologia deve essere impiegato. Il infecti sperimentaleil metodo qui descritto permette di infezioni di Drosophila melanogaster, con qualsiasi dosaggio di qualsiasi batterio arbitrario. Una volta che l&#39;infezione è stata stabilita, è semplice per misurare la cinetica di proliferazione batterica o di liquidazione, per monitorare la mortalità di accoglienza, e di saggiare l&#39;induzione del sistema immunitario dell&#39;ospite. Mosche infetti possono essere facilmente sottoposti ad altri test fenotipici, compresi i test di funzioni fisiologiche che possono modellare o essere modellati dal infezione. Le procedure descritte sono poco costosi, richiedono relativamente poco attrezzature specializzate, e sono facilmente apprese, che li rende suscettibili per l&#39;utilizzo in diversi progetti attraverso una larghezza di laboratori di ricerca e di insegnamento.

La mosca della frutta Drosophila melanogaster è uno degli organismi modello premier per lo studio della funzione e l&#39;evoluzione di difesa immunitaria. Drosophila sono poco costosi e facili da dietro, sono altamente suscettibili di manipolazione sperimentale, e sono supportato da una vasta comunità scientifica che si è sviluppato un ampio serie di strumenti di ricerca. Molti aspetti dell&#39;immunità innata sono conservate tra insetti e mammiferi, tra cui trasduzione del segnale mediata da recettori Toll-like e NF-kB fattori di trascrizione della famiglia, di segnalazione JAK / STAT, e le risposte via di JNK. 1,2 La funzione di questi geni e vie can essere interrogato in D. melanogaster con mutazioni o RNAi abbattimenti che le attività di aumentare o diminuire pathway. 3 - 6 Inoltre, Drosophila può essere usato per studiare le conseguenze fisiologiche della infezione e la malattia, anche nel contesto della teoria evoluzionistica storia di vita 7.- 9 Tutti questi studi, tuttavia, dipendono dalla capacità di infettare in modo affidabile le mosche sperimentali in condizioni di trattamento definite. La procedura qui descritta presenta un quadro metodologico per la consegna di infezioni batteriche resistenti e ripetibili di Drosophila melanogaster e successivamente misurare infezione gravità e quantificare la risposta immunitaria. Drosophila può essere naturalmente e sperimentalmente infettato da una grande varietà di parassiti e patogeni, tra cui batteri, funghi, virus, nematodi e vespe parassitoidi. Il protocollo attuale è focalizzata sulla fornitura di un&#39;infezione batterica sistemica. Molti batteri differenti possono essere utilizzati per infettare le mosche, e la scelta dello sperimentatore dovrebbero essere basati sulle precise questioni scientifiche essere chiesto. Ad esempio, isolati clinici umani possono essere impiegati per studiare i meccanismi di virulenza batterica 10, o ecologicamente pertinenti isolati possono essere preferite lad per lo studio evolutivo. 11 Alcuni batteri sono patogeni competenti di D. melanogaster, proliferando su infezioni e che causa la malattia di accoglienza o la morte. Altri batteri sono effettivamente gestiti dal sistema immunitario ospite e cancellati entro pochi giorni. In questa dimostrazione, Providencia rettgeri sarà utilizzato come un agente patogeno proliferativa che può causare la mortalità ospitante e persiste in hosts sopravvissuti. Escherichia coli viene utilizzata come non patogeno che viene eliminato dal sistema immunitario dell&#39;ospite. Infezione sarà stabilito dalla introduzione di batteri direttamente nella cavità del corpo della mosca. Questo approccio bypassa barriere epiteliali e comportamenti protettivi, consentendo indagini di infezione sistemica indipendentemente dal modo naturale della trasmissione. Ci sono due metodi principali per stabilire sperimentalmente infezione sistemica. Nel primo, un nanoinjector e capillare di vetro tirato aghi sono usati per iniettare un numero preciso dibatteri nel volo. Questo metodo ha il vantaggio di consentire una vasta gamma dinamica di dosi infettive e di essere quantitativamente altamente ripetibili. Il secondo approccio è quello di fornire l&#39;infezione con una puntura di spillo settico. Questo approccio ha il vantaggio di essere rapida e non richiede attrezzature speciali. Una volta che le infezioni sono stabiliti, diventa possibile misurare il carico sistemico patogeno, la mortalità host e l&#39;attività inducibile sistema immunitario. Naturalmente, qualsiasi numero di fenotipi supplementari potrebbe concepibilmente essere misurata in infetto D. melanogaster, anche post-infezione fecondità 12, la capacità di apprendimento 13, stato metabolico 14, o per qualsiasi altra caratteristica che si possa immaginare.

<table border="0" cellpadding="0" cellspacing="0" width="815">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Reagent</td>
			<td style="width:239px;">Company&#160;</td>
			<td style="width:177px;">Part Number</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Incubator</td>
			<td style="width:239px;">Powers Scientific, Inc</td>
			<td style="width:177px;">DROS52SD</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Paintbrush</td>
			<td style="width:239px;"></td>
			<td style="width:177px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">CO2 Flypads</td>
			<td style="width:239px;">FlyStuff</td>
			<td style="width:177px;">59-114</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">CO2</td>
			<td style="width:239px;">Airgas</td>
			<td>CD FG50</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Drosophila rearing mix&#160;</td>
			<td style="width:239px;"></td>
			<td style="width:177px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">6 oz Square Bottom Bottles, polypropylene</td>
			<td style="width:239px;">Genesee Scientific</td>
			<td style="width:177px;">32-130</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Nosterile Extra Large Cotton Balls</td>
			<td style="width:239px;">Fisher brand</td>
			<td style="width:177px;">22-456-882</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Microscope</td>
			<td style="width:239px;">Olympus Corporation</td>
			<td style="width:177px;">SZ51</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Drosophila Vials polystyrene</td>
			<td style="width:239px;">VWR international</td>
			<td style="width:177px;">89092-720</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Nosterile Large Cotton Balls</td>
			<td style="width:239px;">Fisher brand</td>
			<td style="width:177px;">22-456-883</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">2L flask</td>
			<td style="width:239px;">VWR international</td>
			<td>89000-370</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Petri Dishes with Clear Lids, Raised Ridge; 100 . x 15 mm;</td>
			<td style="width:239px;">VWR international</td>
			<td style="width:177px;">25384-302</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">LB Agar, Miller</td>
			<td style="width:239px;">Difco</td>
			<td style="width:177px;">244520</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Innoculing Loop</td>
			<td style="width:239px;">VWR international</td>
			<td>80094-488</td>
		</tr>
		<tr height="105">
			<td height="105" style="height:105px;width:399px;">Rainin Clasic Pipettes in various sizes 
			0.1 &#181;l to 2 &#181;l, 
			2 &#181;l to 20 &#181;l, 
			20 &#181;l to 200 &#181;l, 
			100 &#181;l to 1000</td>
			<td style="width:239px;">Rainin</td>
			<td style="width:177px;">PR-2 
			PR-20 
			PR-200 
			PR-1000</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:399px;">Micropipette tips (assorted sizes)</td>
			<td style="width:239px;">VWR international</td>
			<td style="width:177px;">30128-376 
			53503-810 
			16466-008</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Luria Broth Base, Miller</td>
			<td style="width:239px;">Difco</td>
			<td>241420</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Disposable Culture Tubes Borosilicate Glass</td>
			<td style="width:239px;">VWR international</td>
			<td style="width:177px;">47729-576</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">S-500 Orbital Shaker</td>
			<td style="width:239px;">VWR international</td>
			<td style="width:177px;">14005-830</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">centrifuge</td>
			<td style="width:239px;">VWR international</td>
			<td style="width:177px;">37001-300</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">PBS pH 7.4 10x</td>
			<td style="width:239px;">Invitrogen</td>
			<td style="width:177px;">70011044</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">SmartSpec 3000 Spectrophotometer</td>
			<td style="width:239px;">Bio-Rad</td>
			<td style="width:177px;">170-2501</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Semimicrovolume Cuvettes</td>
			<td style="width:239px;">Bio-Rad</td>
			<td style="width:177px;">223-9955</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Vertical Capillary Puller</td>
			<td style="width:239px;">Kopf Needle Pipette Puller</td>
			<td style="width:177px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">3.5&#39;&#39; Replacement glass Capillaries for Nanojet II</td>
			<td style="width:239px;">Drummond Sientific Company</td>
			<td style="width:177px;">3-000-203-G/X</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Nanoject II</td>
			<td style="width:239px;">Drummond Sientific Company</td>
			<td style="width:177px;">3-000-204</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Forceps</td>
			<td style="width:239px;">Fine Science Tools</td>
			<td style="width:177px;">11255-20</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">10mL Syringe</td>
			<td style="width:239px;">BD</td>
			<td style="width:177px;">309604</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Mineral Oil, White, light</td>
			<td>Macron Fine Chemicals</td>
			<td>6358-10</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">minutein pins</td>
			<td style="width:239px;">Fine Science Tools</td>
			<td style="width:177px;">26002-10</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">1.5mL&#160; Microcentrifuge tubes; Seal Rite</td>
			<td style="width:239px;">USA Scientific Inc.</td>
			<td style="width:177px;">1615-5500</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Motorized Pestle; Talboys Laboratory Stirrer</td>
			<td style="width:239px;">Troemner</td>
			<td style="width:177px;">103</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Talboys High Throughput Homogenizer</td>
			<td style="width:239px;">OPS Diagnostics</td>
			<td style="width:177px;">930145</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">5/32&#39;&#39; Grinding Balls</td>
			<td>OPS Diagnostics</td>
			<td style="width:177px;">GBSS 156-5000-01</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Vortex Genie</td>
			<td style="width:239px;">Scientific indurstries inc.</td>
			<td style="width:177px;">G560</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Multichannel Pipettor (10uL-300uL)</td>
			<td style="width:239px;">Sartorius</td>
			<td>730360</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;"></td>
			<td style="width:239px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">WASP2 Whitley Automated Spiral Plater</td>
			<td style="width:239px;">Microbiology International</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:399px;">ProtoCOL automated colony counter / plate counter/ plate reader&#160;</td>
			<td style="width:239px;">Microbiology International</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">TRIzol</td>
			<td style="width:239px;">Life Technologies</td>
			<td style="width:177px;">15596-026</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">qPCR tubes; Low-Profile 0.2 ml 8-Tube Strips</td>
			<td style="width:239px;">Bio-Rad</td>
			<td style="width:177px;">TLS0801</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">qPCR caps; Optical Flat 8-Cap Strips</td>
			<td style="width:239px;">Bio-Rad</td>
			<td style="width:177px;">TCS0803</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">RQ1 RNase-Free DNase</td>
			<td style="width:239px;">Promega</td>
			<td style="width:177px;">m610a</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">M-MLV Reverse Transcriptase</td>
			<td style="width:239px;">Promega</td>
			<td style="width:177px;">m170b</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">dNTPs</td>
			<td style="width:239px;">Promega</td>
			<td style="width:177px;">U1240</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">Oligo-dT</td>
			<td style="width:239px;">IDT</td>
			<td style="width:177px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:399px;">&#160;SsoAdvanced SYBR Green Supermix</td>
			<td style="width:239px;">Bio-Rad</td>
			<td style="width:177px;">172-5260</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">CFX Connect Real-Time PCR Detection System</td>
			<td style="width:239px;">Bio-Rad</td>
			<td style="width:177px;">185-5200</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">RNasin Ribonuclease Inhibitor</td>
			<td>Promega</td>
			<td>N2115</td>
		</tr>
	</tbody>
</table>

systemic bacterial infection and immune defense phenotypes in drosophila melanogaster

La mosca della frutta Drosophila melanogaster è uno degli organismi modello premier per lo studio della funzione e l&#39;evoluzione di difesa immunitaria. Molti aspetti dell&#39;immunità innata sono conservate tra insetti e mammiferi, e dato che Drosophila può essere facilmente manipolato geneticamente e sperimentalmente, sono potenti per studiare la funzione del sistema immunitario e le conseguenze fisiologiche della malattia. La procedura permette dimostrato qui infezione di mosche dall&#39;introduzione di batteri direttamente nella cavità del corpo, bypassando barriere epiteliali e forme più passivi di difesa e consentendo attenzione alla infezione sistemica. Il procedimento comprende i protocolli per i tassi di mortalità misurazione ospitante, carico patogeno sistemica, e il grado di induzione del sistema immunitario dell&#39;ospite. Questa procedura infezione è poco costoso, robusto e quantitativamente ripetibile, e può essere usato in studi di genetica funzionale, storia di vita evolutiva e fisiologia.

Questa sezione illustra i risultati ottenibili dopo l&#39;infezione batterica di Drosophila melanogaster. La Figura 1 mostra quella dose infezione varia con la densità ottica della sospensione batterica utilizzato per l&#39;iniezione, e che la dose erogata può essere attendibilmente stimato omogeneizzazione e placcatura vola immediatamente dopo l&#39;iniezione . Come illustrato in figura 2, diversi agenti patogeni possono causare diversi livelli di mortalità host (figura 2A) e mortalità ospitante può essere dose-dipendente (Figura 2B). È importante sottolineare che questo protocollo consente diversi tipi di infezioni da raggiungere: Providencia rettgeri può causare un&#39;infezione cronica, subletale che persiste per 20 giorni o più (Figura 3A). Tuttavia, altri batteri come Escerichia coli saranno per lo più cancellati dalla mosca ospitante entro sei ore dopo l&#39;infezione (Figura 3B). Induzione di sys immunitarioTEM può essere stimata attraverso l&#39;isolamento di RNA e la successiva qRT-PCR dei trascritti peptidi antibatterici (Figura 4A e B). Analogamente ma meno quantitativamente, mosche esprimendo GFP sotto il controllo del peptide antimicrobico promotori genici può essere utilizzato per visualizzare l&#39;induzione del sistema immunitario (Figura 4C). <img alt="Figura 1" src="/files/ftp_upload/52613/52613fig1.jpg" /> . Figura 1: Determinazione Infectious Dose mosche sono stati iniettati con 50 nl di sospensioni batteriche che coprono una gamma di densità ottiche (,0001-,05). Le mosche erano immediatamente omogeneizzati e piastrate per determinare il numero di batteri introdotto dalla iniezione. Carica batterica iniziale è strettamente correlato con OD iniziale iniettato (r 2 = 0,96) <img alt="Figura 2" src="/files/ftp_upload/52613/52613fig2.jpg" /> <strong&gt; Figura 2:. La sopravvivenza dopo iniezione con batteri patogeni cinque a sette maschi vecchi giorni sono stati iniettati con 50 nl di una sospensione di batteri o supporti sterili e monitorato per la sopravvivenza. (A) mosche wild type sono stati iniettati con circa 5.000 batteri di una delle tre specie diverse. Il tasso di mortalità di accoglienza dipende in larga misura dalla specie batterica usati per l&#39;infezione. (B) mosche wild type sono stati iniettati con tre diverse dosi di Enterococcous faecalis - 50, 500 e 5.000 batteri per volare. Le mosche muoiono più rapidamente quando infettati con dosi superiori infettive (C) Un mutante del sistema immunitario e la sua wild-type linea di controllo isogenico sono stati iniettati con circa 500 Burkholderia cepacia. Un confronto Log-Rank coppie dimostra che la wild-type fly sopravvive l&#39;infezione significativamente migliore rispetto al mutante (χ 2 = 59,02, df = 1, p &lt;0,0001). Figura 3:. Carica batterica dopo iniezione mosche sono state iniettate con circa il (A) 5000 P. rettgeri (B) 3.400 E. coli. Carica batterica è stata determinata immediatamente dopo l&#39;iniezione e in vari punti temporali successivi. Ciascun punto di dati rappresenta la carica batterica di una mosca. E. coli è rapidamente eliminato da host sfidato mentre P. rettgeri persiste per il resto della vita dell&#39;ospite ,. <img alt="Figura 4" src="/files/ftp_upload/52613/52613fig4.jpg" /> Figura 4: Induzione immunitario genica dopo l&#39;iniezione. (A) Le mosche sono stati iniettati con 50 nl di P. rettgeri o PBS sterile sia nel torace, o sono stati lasciati non manipolata a parte CO <sub&gt; 2 anestesia. Sei ore dopo l&#39;infezione, le mosche sono stati raccolti per l&#39;isolamento di RNA e espressione del Diptericin Un gene è stato determinato utilizzando qRT-PCR. (A) I livelli di espressione sono rappresentati graficamente come rapporto tra Diptericin Una trascrizione di rp49 trascrizione e scalato in modo tale che il controllo CO 2 è definito come aventi un livello di espressione di 1. Le barre rappresentano la media e l&#39;errore standard di rapporti da ciascuna condizione (n = 4). Livelli (B) di espressione vengono rappresentati graficamente come ΔΔCT 2 con il valore medio C T da CO 2 aesthesia linea di controllo utilizzati come condizione uninduced standard. Le barre rappresentano l&#39;errore medio e standard ΔΔC T da ciascuna condizione (n = 4). Mentre non vi è alcuna differenza di induzione trascrizione causa al sito di iniezione, il confronto di pannelli A e B mostra come il metodo ΔΔC T può potenzialmente sovrastimare i livelli di induzione. (C) Vola esprimono GFP sotto il controllo del Diptericin Un promotore sono stati iniettati con 50 nl di P. rettgeri (OD = 0,1) e poi ripreso sette giorni più tardi. Il pannello GFP mostra l&#39;espressione di GFP nel corpo grasso addominale di mosche infette, indicando l&#39;attivazione della Diptericin Un promotore in linea con infezione da batteri, ma non controlli multimediali a iniezione. <table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td> Gene </td><td> Avanti </td><td> Reverse </td></tr><tr><td> rp49 (chiamato anche rpL32) </td><td> 5 &#39;AGGCCCAAGATCGTGAAGAA 3&#39; </td><td> 5 &#39;GACGCACTCTGTTGTCGATACC 3&#39; </td></tr><tr><td> Diptericin A </td><td> 5 &#39;GCGGCGATGGTTTTGG 3&#39; </td><td> 5 &#39;CGCTGGTCCACACCTTCTG 3&#39; </td></tr><tr><td> Drosomycin </td><td> 5 &#39;CTGCCTGTCCGGAAGATACAA 3 &#39; </td><td> 5 &#39;TCCCTCCTCCTTGCACACA 3&#39; </td></tr><tr><td> Defensin </td><td> 5 &#39;GAGGATCATGTCCTGGTGCAT 3&#39; </td><td> 5 &#39;TCGCTTCTGGCGGCTATG 3&#39; </td></tr><tr><td> Attacin A </td><td> 5 &#39;CGTTTGGATCTGACCAAGG 3&#39; </td><td> 5 &#39;AAAGTTCCGCCAGGTGTGAC 3&#39; </td></tr><tr><td> Metchnikowan </td><td> 5 &#39;AACTTAATCTTGGAGCGATTTTTCTG 3&#39; </td><td> 5 &#39;ACGGCCTCGTATCGAAAATG 3&#39; </td></tr></tbody></table> Tabella 1: Primer per qRT-PCR.

Watch this Scientific Journal Video about Systemic Bacterial Infection and Immune Defense Phenotypes in Drosophila Melanogaster at JoVE.com

Systemic Bacterial Infection and Immune Defense Phenotypes in Drosophila Melanogaster

Drosophila melanogaster is an outstanding model organism for studying innate immune systems and the physiological consequences of infection and disease. This protocol describes how to deliver robust and quantitatively repeatable bacterial infections to D. melanogaster, and how to subsequently measure infection severity and quantify the host immune response.

Sistemica infezione batterica e immunitario Difesa fenotipi in<em&gt; Drosophila melanogaster</em

The fruit fly Drosophila melanogaster is one of the premier model organisms for studying the function and evolution of immune defense. Many aspects of ...

systemic-bacterial-infection-immune-defense-phenotypes-drosophila

Nanyang Technological University

Research

JoVE Journal

Immunology and Infection

Systemic Bacterial Infection and Immune Defense Phenotypes in Drosophila Melanogaster

24.5K Views.  Cornell University. Drosophila melanogaster is an outstanding model organism for studying innate immune systems and the physiological consequences of infection and disease. This protocol describes how to deliver robust and quantitatively repeatable bacterial infections to D. melanogaster, and how to subsequently measure infection severity and quantify the host immune response.

Video: Systemic Bacterial Infection and Immune Defense Phenotypes in Drosophila Melanogaster

Seven Steps to Stellate Cells

Hepatic stellate cells are liver-resident cells of star-like morphology and are located in the space of Disse between liver sinusoidal endothelial cells and hepatocytes1,2. Stellate cells are derived from bone marrow precursors and store up to 80% of the total body vitamin A1, 2. Upon activation, stellate cells differentiate into myofibroblasts to produce extracellular matrix, thus contributing to liver fibrosis3. Based on their ability to contract, myofibroblastic stellate cells can regulate the vascular tone associated with portal hypertension4. Recently, we demonstrated that hepatic stellate cells are potent antigen presenting cells and can activate NKT cells as well as conventional T lymphocytes5. 

 Here we present a method for the efficient preparation of hepatic stellate cells from mouse liver. Due to their perisinusoidal localization, the isolation of hepatic stellate cells is a multi-step process. In order to render stellate cells accessible to isolation from the space of Disse, mouse livers are perfused in situ with the digestive enzymes Pronase E and Collagenase P. Following perfusion, the liver tissue is subjected to additional enzymatic treatment with Pronase E and Collagenase P in vitro. Subsequently, the method takes advantage of the massive amount of vitamin A-storing lipid droplets in hepatic stellate cells. This feature allows the separation of stellate cells from other hepatic cell types by centrifugation on an 8% Nycodenz gradient. The protocol described here yields a highly pure and homogenous population of stellate cells. Purity of preparations can be assessed by staining for the marker molecule glial fibrillary acidic protein (GFAP), prior to analysis by fluorescence microscopy or flow cytometry. Further, light microscopy reveals the unique appearance of star-shaped hepatic stellate cells that harbor high amounts of lipid droplets. 


 Taken together, we present a detailed protocol for the efficient isolation of hepatic stellate cells, including representative images of their morphological appearance and GFAP expression that help to define the stellate cell entity.

Here we describe a method for the isolation of hepatic stellate cells from mouse liver. For stellate cell purification, mouse livers are digested in situ and in vitro by pronase-collagenase treatment prior to density gradient centrifugation. This technique yields highly pure hepatic stellate cells.

Sette passi per Stellate Cellule

Hepatic stellate cells are liver-resident  cells of star-like morphology and are located in the space of Disse between  liver sinusoidal endothelial cells ...

Ricerca

Immunologia e infezioni

Measuring Bacterial Load and Immune Responses in Mice Infected with Listeria monocytogenes

Listeria monocytogenes (Listeria) is a Gram-positive facultative intracellular pathogen1. Mouse studies typically employ intravenous injection of Listeria, which results in systemic infection2. After injection, Listeria quickly disseminates to the spleen and liver due to uptake by CD8&alpha;+ dendritic cells and Kupffer cells3,4. Once phagocytosed, various bacterial proteins enable Listeria to escape the phagosome, survive within the cytosol, and infect neighboring cells5. During the first three days of infection, different innate immune cells (e.g. monocytes, neutrophils, NK cells, dendritic cells) mediate bactericidal mechanisms that minimize Listeria proliferation. CD8+ T cells are subsequently recruited and responsible for the eventual clearance of Listeria from the host, typically within 10 days of infection6.
Successful clearance of Listeria from infected mice depends on the appropriate onset of host immune responses6	. There is a broad range of sensitivities amongst inbred mouse strains7,8. Generally, mice with increased susceptibility to Listeria infection are less able to control bacterial proliferation, demonstrating increased bacterial load and/or delayed clearance compared to resistant mice. Genetic studies, including linkage analyses and knockout mouse strains, have identified various genes for which sequence variation affects host responses to Listeria infection6,8-14. Determination and comparison of infection kinetics between different mouse strains is therefore an important method for identifying host genetic factors that contribute to immune responses against Listeria. Comparison of host responses to different Listeria strains is also an effective way to identify bacterial virulence factors that may serve as potential targets for antibiotic therapy or vaccine design.
We describe here a straightforward method for measuring bacterial load (colony forming units [CFU] per tissue) and preparing single-cell suspensions of the liver and spleen for FACS analysis of immune responses in Listeria-infected mice. This method is particularly useful for initial characterization of Listeria infection in novel mouse strains, as well as comparison of immune responses between different mouse strains infected with Listeria. We use the Listeria monocytogenes EGD strain15 that, when cultured on blood agar, exhibits a characteristic halo zone around each colony due to &beta;-hemolysis1 (Figure 1). Bacterial load and immune responses can be determined at any time-point after infection by culturing tissue homogenate on blood agar plates and preparing tissue cell suspensions for FACS analysis using the protocols described below. We would note that individuals who are immunocompromised or pregnant should not handle Listeria, and the relevant institutional biosafety committee and animal facility management should be consulted before work commences.

Measuring Bacterial Load and Immune Responses in Mice Infected with Listeria monocytogenes

Listeria monocytogenes is a model organism for studying immune responses and genetic susceptibility to intracellular bacteria in mice. This method enables one to measure bacterial load and generate single-cell suspensions of the liver and spleen from mice for FACS analysis to determine changes in immune cells due to Listeria infection.

Misurazione della carica batterica e Risposte immunitarie in topi infettati con Listeria monocytogenes</em

Listeria monocytogenes (Listeria) is a Gram-positive facultative intracellular pathogen1. Mouse studies typically employ intravenous injection of ...

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.

L&#39;introduzione di shear stress nello studio di adesione batterica

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

Flow Cytometric Isolation of Primary Murine Type II Alveolar Epithelial Cells for Functional and Molecular Studies

Throughout the last years, the contribution of alveolar type II epithelial cells (AECII) to various aspects of immune regulation in the lung has been increasingly recognized. AECII have been shown to participate in cytokine production in inflamed airways and to even act as antigen-presenting cells in both infection and T-cell mediated autoimmunity 1-8. Therefore, they are especially interesting also in clinical contexts such as airway hyper-reactivity to foreign and self-antigens as well as infections that directly or indirectly target AECII. However, our understanding of the detailed immunologic functions served by alveolar type II epithelial cells in the healthy lung as well as in inflammation remains fragmentary. Many studies regarding AECII function are performed using mouse or human alveolar epithelial cell lines 9-12. Working with cell lines certainly offers a range of benefits, such as the availability of large numbers of cells for extensive analyses. However, we believe the use of primary murine AECII allows a better understanding of the role of this cell type in complex processes like infection or autoimmune inflammation. Primary murine AECII can be isolated directly from animals suffering from such respiratory conditions, meaning they have been subject to all additional extrinsic factors playing a role in the analyzed setting. As an example, viable AECII can be isolated from mice intranasally infected with influenza A virus, which primarily targets these cells for replication 13. Importantly, through ex vivo infection of AECII isolated from healthy mice, studies of the cellular responses mounted upon infection can be further extended.
Our protocol for the isolation of primary murine AECII is based on enzymatic digestion of the mouse lung followed by labeling of the resulting cell suspension with antibodies specific for CD11c, CD11b, F4/80, CD19, CD45 and CD16/CD32. Granular AECII are then identified as the unlabeled and sideward scatter high (SSChigh) cell population and are separated by fluorescence activated cell sorting 3.
In comparison to alternative methods of isolating primary epithelial cells from mouse lungs, our protocol for flow cytometric isolation of AECII by negative selection yields untouched, highly viable and pure AECII in relatively short time. Additionally, and in contrast to conventional methods of isolation by panning and depletion of lymphocytes via binding of antibody-coupled magnetic beads 14, 15, flow cytometric cell-sorting allows discrimination by means of cell size and granularity. Given that instrumentation for flow cytometric cell sorting is available, the described procedure can be applied at relatively low costs. Next to standard antibodies and enzymes for lung disintegration, no additional reagents such as magnetic beads are required. The isolated cells are suitable for a wide range of functional and molecular studies, which include in vitro culture and T-cell stimulation assays as well as transcriptome, proteome or secretome analyses 3, 4.

We describe the rapid isolation of primary murine type II alveolar epithelial cells (AECII) by flow cytometric negative selection. These AECII show high viability and purity and are suitable for a wide range of functional and molecular studies regarding their role in respiratory conditions such as autoimmune or infectious diseases.

Flusso Isolamento citometrica di primari murini di tipo II cellule alveolari epiteliali per gli studi funzionali e molecolari

Throughout  the last years, the contribution of alveolar type II epithelial cells (AECII)  to various aspects of immune regulation in the lung has been ...

Quantitative Measurement of the Immune Response and Sleep in Drosophila

A complex interaction between the immune response and host behavior has been described in a wide range of species. Excess sleep, in particular, is known to occur as a response to infection in mammals 1 and has also recently been described in Drosophila melanogaster2. It is generally accepted that sleep is beneficial to the host during an infection and that it is important for the maintenance of a robust immune system3,4. However, experimental evidence that supports this hypothesis is limited4, and the function of excess sleep during an immune response remains unclear. We have used a multidisciplinary approach to address this complex problem, and have conducted studies in the simple genetic model system, the fruitfly Drosophila melanogaster. We use a standard assay for measuring locomotor behavior and sleep in flies, and demonstrate how this assay is used to measure behavior in flies infected with a pathogenic strain of bacteria. This assay is also useful for monitoring the duration of survival in individual flies during an infection. Additional measures of immune function include the ability of flies to clear an infection and the activation of NF&kappa;B, a key transcription factor that is central to the innate immune response in Drosophila. Both survival outcome and bacterial clearance during infection together are indicators of resistance and tolerance to infection. Resistance refers to the ability of flies to clear an infection, while tolerance is defined as the ability of the host to limit damage from an infection and thereby survive despite high levels of pathogen within the system5. Real-time monitoring of NF&kappa;B activity during infection provides insight into a molecular mechanism of survival during infection. The use of Drosophila in these straightforward assays facilitates the genetic and molecular analyses of sleep and the immune response and how these two complex systems are reciprocally influenced.

Quantitative Measurement of the Immune Response and Sleep in Drosophila

To understand a link between the immune response and behavior, we describe a method to measure locomotor behavior in Drosophila during bacterial infection as well as the ability of flies to mount an immune response by monitoring survival, bacterial load, and real-time activity of a key regulator of innate immunity, NF&kappa;B.

Misurazione quantitativa della risposta immunitaria e nel sonno<em&gt; Drosophila</em

A complex interaction between the immune response and  host behavior has been described in a wide range of species. Excess sleep, in  particular, is known ...

Bacterial Leaf Infiltration Assay for Fine Characterization of Plant Defense Responses using the Arabidopsis thaliana-Pseudomonas syringae Pathosystem

In the absence of specialized mobile immune cells, plants utilize their localized programmed cell death and Systemic Acquired Resistance to defend themselves against pathogen attack. The contribution of a specific Arabidopsis gene to the overall plant immune response can be specifically and quantitatively assessed by assaying the pathogen growth within the infected tissue. For over three decades, the hemibiotrophic bacterium Pseudomonas syringae pv. maculicola ES4326 (Psm ES4326) has been widely applied as the model pathogen to investigate the molecular mechanisms underlying the Arabidopsis immune response. To deliver pathogens into the leaf tissue, multiple inoculation methods have been established, e.g., syringe infiltration, dip inoculation, spray, vacuum infiltration, and flood inoculation. The following protocol describes an optimized syringe infiltration method to deliver virulent Psm ES4326 into leaves of adult soil-grown Arabidopsis plants and accurately screen for enhanced disease susceptibility (EDS) towards this pathogen. In addition, this protocol can be supplemented with multiple pre-treatments to further dissect specific immune defects within different layers of plant defense, including Salicylic Acid (SA)-Triggered Immunity (STI) and MAMP-Triggered Immunity (MTI).

Bacterial Leaf Infiltration Assay for Fine Characterization of Plant Defense Responses using the Arabidopsis thaliana-Pseudomonas syringae Pathosystem

Quantification of pathogen growth is a powerful tool to characterize various Arabidopsis thaliana (hereafter: Arabidopsis) immune responses. The method described here presents an optimized syringe infiltration assay to quantify the Pseudomonas syringae pv. maculicola ES4326 growth in adult Arabidopsis leaves.

Batterica Leaf Infiltrazione Assay per Fine Caratterizzazione di risposte di difesa delle piante che utilizzano il<em&gt; Arabidopsis thaliana-Pseudomonas syringae</em&gt; Patosistema

In the absence of specialized mobile immune cells, plants utilize their localized programmed cell death and Systemic Acquired Resistance to defend ...

Extraction of Hemocytes from Drosophila melanogaster Larvae for Microbial Infection and Analysis

During the pathogenic infection of Drosophila melanogaster, hemocytes play an important role in the immune response throughout the infection. Thus, the goal of this protocol is to develop a method to visualize the pathogen invasion in a specific immune compartment of flies, namely hemocytes. Using the method presented here, up to 3 &#215; 106 live hemocytes can be obtained from 200 Drosophila 3rd instar larvae in 30 min for ex vivo infection. Alternatively, hemocytes can be infected in vivo through injection of 3rd instar larvae followed by hemocyte extraction up to 24 h post-infection. These infected primary cells were fixed, stained, and imaged using confocal microscopy. Then, 3D representations were generated from the images to definitively show pathogen invasion. Additionally, high-quality RNA for qRT-PCR can be obtained for the detection of pathogen mRNA following infection, and sufficient protein can be extracted from these cells for Western blot analysis. Taken together, we present a method for definite reconciliation of pathogen invasion and confirmation of infection using bacterial and viral pathogen types and an efficient method for hemocyte extraction to obtain enough live hemocytes from Drosophila larvae for ex vivo and in vivo infection experiments.

Extraction of Hemocytes from Drosophila melanogaster Larvae for Microbial Infection and Analysis

This method demonstrates how to visualize pathogen invasion into insect cells with three-dimensional (3D) models. Hemocytes from Drosophila larvae were infected with viral or bacterial pathogens, either ex vivo or in vivo. Infected hemocytes were then fixed and stained for imaging with a confocal microscope and subsequent 3D cellular reconstruction.

Estrazione di emociti da larve di Drosophila melanogaster per infezione microbica e l'analisi

During the pathogenic infection of Drosophila melanogaster, hemocytes play an important role in the immune response throughout the infection. Thus, the ...

Establishment of Viral Infection and Analysis of Host-Virus Interaction in Drosophila Melanogaster

Virus spreading is a major cause of epidemic diseases. Thus, understanding the interaction between the virus and the host is very important to extend our knowledge of prevention and treatment of viral infection. The fruit fly Drosophila melanogaster has proven to be one of the most efficient and productive model organisms to screen for antiviral factors and investigate virus-host interaction, due to powerful genetic tools and highly conserved innate immune signaling pathways. The procedure described here demonstrates a nano-injection method to establish viral infection and induce systemic antiviral responses in adult flies. The precise control of the viral injection dose in this method enables high experimental reproducibility. Protocols described in this study include the preparation of flies and the virus, the injection method, survival rate analysis, the virus load measurement, and an antiviral pathway assessment. The influence effects of viral infection by the flies' background were mentioned here. This infection method is easy to perform and quantitatively repeatable; it can be applied to screen for host/viral factors involved in virus-host interaction and to dissect the crosstalk between innate immune signaling and other biological pathways in response to viral infection.

Establishment of Viral Infection and Analysis of Host-Virus Interaction in Drosophila Melanogaster

This protocol describes how to establish viral infection in vivo in Drosophila melanogaster using the nano-injection method and basic techniques to analyze virus-host interaction.

Istituzione dell'infezione virale e analisi dell'interazione ospite-Virus in Drosophila Melanogaster

Virus spreading is a major cause of epidemic diseases. Thus, understanding the interaction between the virus and the host is very important to extend our ...

Toxicity Study of Zinc Oxide Nanoparticles in Cell Culture and in Drosophila melanogaster

Zinc oxide nanoparticles (ZnO NPs) have a wide range of applications, but the number of reports on ZnO NP-associated toxicity has grown rapidly in recent years. However, studies that elucidate the underlying mechanisms for ZnO NP-induced toxicity are scanty. We determined the toxicity profiles of ZnO NPs using both in vitro and in vivo experimental models. A significant decrease in cell viability was observed in ZnO NP-exposed MRC5 lung fibroblasts, showing that ZnO NPs exert cytotoxic effects. Similarly, interestingly, gut exposed to ZnO NPs exhibited a dramatic increase in reactive oxygen species levels (ROS) in the fruit fly Drosophila. More in-depth studies are required to establish a risk assessment for the increased usage of ZnO NPs by consumers.

Toxicity Study of Zinc Oxide Nanoparticles in Cell Culture and in Drosophila melanogaster

We describe a detailed protocol for evaluating the toxicological profiles of zinc oxide nanoparticles (ZnO NPs) in particular, the type of cell death in human MRC5 lung fibroblasts and ROS formation in the fruit fly Drosophila.

Studio di tossicità delle nanoparticelle di ossido di zinco nella coltura cellulare e nella drosophila melanogaster

Zinc oxide nanoparticles (ZnO NPs) have a wide range of applications, but the number of reports on ZnO NP-associated toxicity has grown rapidly in recent ...

Assessing the Cellular Immune Response of the Fruit Fly, Drosophila melanogaster, Using an In Vivo Phagocytosis Assay

In all animals, innate immunity provides an immediate and robust defense against a broad spectrum of pathogens. Humoral and cellular immune responses are the main branches of innate immunity, and many of the factors regulating these responses are evolutionarily conserved between invertebrates and mammals. Phagocytosis, the central component of cellular innate immunity, is carried out by specialized blood cells of the immune system. The fruit fly, Drosophila melanogaster, has emerged as a powerful genetic model to investigate the molecular mechanisms and physiological impacts of phagocytosis in whole animals. Here we demonstrate an injection-based in vivo phagocytosis assay to quantify the particle uptake and destruction by Drosophila blood cells, hemocytes. The procedure allows researchers to precisely control the particle concentration and dose, making it possible to obtain highly reproducible results in a short amount of time. The experiment is quantitative, easy to perform, and can be applied to screen for host factors that influence pathogen recognition, uptake, and clearance.

Assessing the Cellular Immune Response of the Fruit Fly, Drosophila melanogaster, Using an In Vivo Phagocytosis Assay

This protocol describes an in vivo phagocytosis assay in adult Drosophila melanogaster to quantify phagocyte recognition and clearance of microbial infections.

Valutare la risposta immunitaria cellulare del moscerino della frutta, Drosophila melanogaster, utilizzando un test di fagocitosi In Vivo

In all animals, innate immunity provides an immediate and robust defense against a broad spectrum of pathogens. Humoral and cellular immune responses are ...