Gli autori ringraziano il Dr. Le Trinh e Dr. Tobin per generosamente fornire la α-catenina: linea pesce citrino e Bill Jackman per averci permesso di fare le riprese nel suo laboratorio. Gli autori riconoscono le fonti di finanziamento National Institutes of Health (Grants 5P20RR016463, 8P20GM103423 e R15AI094406) e USDA (Project # ME0-H-1-00517-13). Questo manoscritto è pubblicato come principale dell&#39;agricoltura e delle foreste Esperimento numero di pubblicazione Stazione 3371.

NOTA: Tutti i protocolli di cura zebrafish ed esperimenti sono stati eseguiti in conformità alle linee guida NIH sotto Institutional Animal Care and Use Committee (IACUC) protocollo A2012-11-03. 1. Zebrafish allevamento a 4 giorni dopo la fecondazione <ol><li> Raccogliere AB zebrafish, o qualsiasi altra linee transgeniche, entro il primo 3 ore dopo la fecondazione, come mostrato in un altro video 34. </li><li> Incubare 120 uova in un 15 centimetri piastre Petri contenenti 150 ml di E3 Media (5 NaCl mm 0,17 mM KCl; 0,33 mm CaCl 2; 0,33 mm MgCl 2; 2 HEPES mM; pH 6.8) con il blu di metilene (0,3 mg / ml finale concentrazione) in un incubatore a 33 ° con 12/12 luce / buio fotoperiodo. </li><li> Sostituire la media dopo 6 ore con E3 + PTU (1-fenil-2-tiourea, 10 mg / ml concentrazione finale) e rimuovere le uova morti. </li><li> Incubare per 4 giorni a 33 ° C, lo scambio dei mezzi con fresca E3 + PTU dopo 2 giorni. </li></ol> 2. Inproiezione Micro-ago Preparazione <ol><li> Estrarre borosilicato capillare (OD 1,2 millimetri; ID 0,69 millimetri) in un micro-ago con un estrattore ago con le seguenti impostazioni (550 Calore, 0 Pull, 130 Velocity; 110 Time). NOTA: Le impostazioni variano da filamento a filamento per ottenere micro-aghi di forma simile (vedi Figura 1) e dovrà essere riadattato ogni volta che viene installato un nuovo filamento. </li><li> Riempire un micro-ago con 3 ml di 0,4 micron filtrata salina tampone fosfato (PBS; 137 mM NaCl, 2,7 mM KCl, 10 mM Na 2 HPO 4; 1,8 mm KH 2 PO 4; pH 7.4) con un 20 microlitri microloader pipetta tip. </li><li> Impostare il micro-ago su un supporto micropipetta su un micromanipolatore collegata ad un sistema di iniezione a pressione. Impostare la pressione di iniezione a 30 PSI e la durata dell&#39;impulso a 30 msec. </li><li> Utilizzando una piastra di Petri con acqua distillata, abbassare il micro-ago fino a 1/5 dell&#39;ago è nell&#39;acqua. Agganciare il micro-ago with pinzette sottili appena sotto il livello dell&#39;acqua. Portare il micro-ago fuori dall&#39;acqua e spingere il pedale più volte fino a visualizzare un bolo. </li><li> Misurare il diametro del bolo abbassando il micro-ago su un emocitometro strati con una goccia di tipo A olio per immersione. Regolare la durata dell&#39;impulso per ottenere il volume desiderato (vedi tabella 1). </li><li> Impostare la contropressione per il bolo di rimanere stabile in olio (abbassare la pressione se il bolo aumenta il volume e aumentare la contropressione se il volume di bolo diminuisce). Registrare la durata dell&#39;impulso per ogni micro-ago. </li><li> Rimuovere la PBS dal micro-ago aspirando usando un puntale microloader ed espellere la sinistra-over PBS ponendolo nuovamente l&#39;iniettore e lanciando l&#39;interruttore di impulso continuo. Prenotare ogni micro-ago. </li></ol> 3. Candida Preparazione <ol><li> Streak Candida albicans trasformate con codone ottimizzato dTomato, GFP, BFP, EOS o RemotoRed da uno stock congelati (-80 ° C magazzino in 25% glicerolo) utilizzando un bastoncino di legno su una sterile destrosio lievito peptine (YPD) piastra di agar (10 g estratto / L di lievito, 20 g / L peptone, 20 g / L di destrosio , 20 g / L di agar, autoclave e versò 25 ml in piastre di Petri) e incubare una notte a 30 ° C. </li><li> Scegliere una colonia utilizzando un bastoncino di legno sterile e inoculare 5 ml di liquido YPD (estratto di 10 g / L di lievito, 20 g / L peptone, 20 g / L di destrosio, autoclavato e asetticamente aliquotato in 5 ml di 16 x 150 mm coltura vetro tubi). </li><li> Incubare per una notte a 30 ° C in un tamburo a rulli a 60 rpm. </li><li> Raccogliere 1 ml di C. cultura albicans e il trasferimento in un 1,7 ml provetta da centrifuga sterile. </li><li> Centrifugare a 5.000 g per un paio di secondi. Svuotare il surnatante e aggiungere accuratamente 1 ml di PBS sterile, vortice. Ripetere due volte. </li><li> Contare le colonie usando un emocitometro diluendo 1 ml di brodo 1: 1000 in PBS sterile. </li></ol> 4. Iniettare Zebrafish inla vescica natatoria <ol><li> Riscaldare un piatto di iniezione (2% agarosio) per 30 min in un incubatore a 33 °. </li><li> Al tempo desiderato, rimuovere il 100 dei 150 ml di E3 + PTU dalla piastra Petri 15 centimetri contenente il pesce per iniettare utilizzando una pipetta 25 ml senza aspirare alcun zebrafish. </li><li> Anestetizzare 4 dpf zebrafish aggiungendo 2 ml di un / ml tamponato tricaine metano sulfonato magazzino 4 mg (TR) per i 50 ml supporti rimanenti (concentrazione finale di 200 mg / ml) e attendere 15 min. </li><li> Sotto un microscopio da dissezione, selezionare il pesce con una vescica natatoria gonfiato. Pesce può anche essere proiettato in quel momento per fenotipo omogeneo, come la distribuzione dei neutrofili in mpo: linea GFP utilizzando un epifluorescenza dissezione microscopio. </li><li> Diluire il C. albicans magazzino dalla sua concentrazione iniziale (fase 3.8) a 1,5 x 10 7 unità formanti colonia per ml (ufc / ml) in PBS. </li><li> Trasferire 30 zebrafish sul piatto di iniezione con un tubo di plastica di trasferimentotte e rimuovere il supporto in eccesso. </li><li> Utilizzando uno strumento di pesca-wire (0,012 pollici di diametro filo da pesca super-incollato in un capillare borosilicato), fare 3 linee di 10 pesci, tenendo il piatto iniezione verticale e orientare il pesce in verticale. </li><li> Togliere la carta in eccesso. </li><li> Vortice accuratamente il tubo con 1,5 x 10 7 CFU / ml C. albicans. </li><li> Riempire un micro-ago con 3 ml di C. albicans utilizzando una nuova punta microloader pipetta e impostare la durata dell&#39;impulso per l&#39;impostazione appropriata (vedere il punto 2.9). </li><li> Ruotare il piatto iniezione per formare un angolo di 20 ° tra il micro-ago e la testa del pesce, puntando verso la parte posteriore della vescica natatoria (Figura 3A). </li><li> Premere il micro-ago nella vescica natatoria, assicurandosi che il foro dell&#39;ago sia nel lume, e premere il pedale una volta. </li><li> Ripetere l&#39;operazione per ogni pesce e trasferire a un piatto di recupero (25 ml E3 + PTU) inondando il piatto con un E3d svuotamento nel piatto di recupero. </li><li> Trasferire altri 30 pesce al piatto iniezione. </li><li> Ripetere l&#39;iniezione con un nuovo micro-ago riempito con fondo in agitazione C. albicans. </li><li> Fine iniettando controllo PBS, se necessario, usando un piatto diversi di iniezione per evitare la contaminazione e versare in un piatto di recupero separato (passo 4.10). </li></ol> 5. Screening il pesce per desiderata Inoculum <ol><li> Preparare 40 ml di 0,4% bassofondente soluzione di agarosio (LMA) aggiungendo 160 mg di agarosio a basso punto di fusione 40 ml di E3, in ebollizione da microonde fino a completa dissoluzione e raffreddamento a 37 ° C. Aggiungere 400 ml di TR (concentrazione finale di 200 mg / ml), una volta raffreddato. </li><li> Dopo 30 min di recupero, anestetizzare il pesce come descritto (passo 4.3 usando solo 1 ml di TR in 25 mL E3 + PTU, concentrazione finale 200 mg / ml). </li><li> Trasferimento 30 pesci (con il minor numero possibile di mezzi) a 2 ml di LMA in una barca di peso. </li><li> Aspirare singoli pesci con una pipetta di trasferimento e piatto il pesce con 1 goccia di LMA in una piastra di imaging a 96 pozzetti, utilizzando solo i 10 x 6 pozzi centrali. </li><li> Ripetere fino a quando tutti i pesci di schermo vengono caricati alla piastra di imaging. </li><li> Ai media solidificano a temperatura ambiente per 5 min. </li><li> Posizionare il pesce dalla loro parte, facendo in modo che siano a contatto con il fondo di vetro. </li><li> Usando l&#39;obiettivo 20X su un epifluorescenza / microscopio confocale invertita e il filtro appropriato, registrare il numero di C. cellule di lievito albicans in vescica natatoria di ogni pesce. </li><li> Selezionare il pesce con 15-25 cellule di lievito nella vescica natatoria (o inoculo desiderato), eutanasia non selezionata pesce (800 ug / ml di TR in E3) e ritornare pesci selezionato in un piatto profondo Petri con 50 ml di E3 + PTU by aggiungendo 3 gocce di E3 alla piastra di imaging pozzetti selezionati ed aspirando il pesce con una pipetta di plastica trasferimento. </li><li> Incubare a 33 ° C per la durata desiderata. </li></ol> 6. Imaging the Fish post-selezione <ol><li> Al momento desiderato, eliminare 25 dei 50 ml di media E3 + PTU dalla capsula di Petri profondo contenente il pesce di immagine. </li><li> Anestetizzare il pesce come descritto (passo 4.3 usando solo 1 ml di TR in 25 ml E3 + PTU rimanente, la concentrazione finale di 200 mg / ml). </li><li> Piatto il pesce in un piatto di imaging 96-bene e la posizione in modo appropriato (passi 5,3-5,7). </li><li> Immagine di scansione microscopia confocale utilizzando i laser appropriati e filtri di emissione. Prima concentrarsi sul pesce con l&#39;obiettivo 4X in contrasto interferenziale differenziale (DIC) e di acquisire immagini della regione di interesse utilizzando l&#39;obiettivo 20X con i laser confocale in modalità di scansione con 2 velocità msec / pixel e 1024 x 600 pixel aspect ratio. Acquisire Z-stack con 1 micron dimensione del passo, applicando modalità filtro Kalman di 3 fotogrammi. </li><li> Ritorno a un piatto fondo di Petri con 50 ml E3 + PTU o in individuapozzi l (piatto 24 pozzetti cultura, 3 ml E3 + PTU) e incubare a 33 ° C. </li></ol> 7. Dissecting la vescica natatoria <ol><li> Riempire una siringa da 10 ml con grasso alto vuoto. </li><li> Preparare una LMA 2% (passo 5,3 con 160 mg di bassa fusione agarosio in 8 ml di E3). </li><li> Al momento desiderato, anestetizzare il pesce (fase 5.2). </li><li> Trasferire 10 pesci in una provetta 1,7 ml centrifuga con 1 ml di E3 e euthanize aggiungendo 200 ml di 4 mg / ml Tricaine (concentrazione finale 800 mg / ml) al tubo da centrifuga e incubando per 15 minuti a temperatura ambiente. </li><li> Preparare un vetrino di imaging ponendo 4 gocce di grasso per vuoto in un quadrato, distanti 1 cm su un MicroSlide (75 x 25 mm, Figura 2). </li><li> Mettere 2 gocce di 2% LMA nel centro della piazza. </li><li> Posizionare un pesce su un vetrino separato sotto un microscopio da dissezione e verificare che il cuore ha smesso di battere, rimuovere l&#39;acqua in eccesso. </li><li&gt; con una pinzetta belle sezionare il vescica natatoria mantenendo la testa in una posizione fissa con le pinze sinistra e tirando giù l&#39;intestino anteriore con le pinzette destra (Figura 4A). </li><li> Sollevare la vescica natatoria dal condotto pneumatico con le pinzette sinistra, separandolo dal tratto digerente, e posizionarlo al centro della LMA 2% prima che solidifica. </li><li> Inserire una copertura antiscivolo (18 x 18 mm) sulla parte superiore del vetrino imaging e spingerla fino a toccare il grasso per vuoto, nonche la LMA (Figura 2). </li><li> Immagine entro 10 minuti di dissezione, come descritto al punto 6.4. Ripetere il passaggio 7,7-7,11 con gli altri pesci. </li></ol>

The authors have nothing to disclose.

Anticipi e limitazioni della microiniezione modello di malattia vescica natatoria Il modello qui presentato è un&#39;estensione del modello di immersione mucosa candidosi descritto in Gratacap et al (2013).; aggiunge i vantaggi di un tempo un&#39;infezione controllata, una dose un&#39;infezione altamente riproducibile, e quindi una maggiore efficienza. Dimostriamo qui nuovi metodi che permettono non invasivo documentazione temporale delle dinamiche di infezione in modo molto dettaglia...

Mucosal infections can lead to life threatening bloodstream infections due to the damage of the epithelial barrier, which allows pathogens access to the systemic environment1,2. In addition, mucosal infections can also cause significant immunopathology even when contained externally3-5. The commensal unicellular fungus Candida albicans is present in the majority of the population in the oral cavity and other mucosal sites6-9. Although normally contained by innate and adaptive immune responses, innate immune defects and medical interventions can lead to severe mucosal candidiasis. The assault on the epithelial barrier results in an increased risk of life threatening disseminated disease as well as immunopathology, as in the case of vulvo-vaginal candidiasis, additionally C. albicans colonization has been linked with lung immune homeostasis10,11. Disseminated candidiasis is now the fourth most common bloodstream infection in intensive care units12 and mortality as high as 40% makes it a major concern. Due to the increase in immunomodulatory treatments for patients with autoimmune diseases, cancer or organ transplants, it is imperative to understand the interaction between this pathogen and the mucosal immune compartment.
The majority of cell biological advances regarding C. albicans-cell interactions at the mucosal level come from in vitro13-15 and murine models16-18. Both these approaches have distinct advantages, but the ability to image live cells at high resolution in an intact host has limited the temporal and spatial characterization of the infection. For these studies, there is the need for an in vivo model where the interaction of pathogen, innate immune and epithelial cells can be visualized in an intact vertebrate host.
The zebrafish has emerged as an invaluable tool for the understanding of human disease, mainly due to its transparency and amenability to genetic manipulation. Cell and organ development have been imaged in exquisite detail, which has led to the description of novel immune cell behaviors, such as T cell behavior in the developing thymus19 or the battle between intracellular mycobacteria and phagocytes20-22. Recent work has described intestinal microbe-host interactions in zebrafish and shown that microbial colonization of the intestinal tract affects host intestinal physiology and resistance to other infections23,24. Furthermore, infection through the gut epithelium has been described for several pathogens.
In contrast to the intestinal tract, the swimbladder represents a more isolated and complementary mucosal model. This organ is an extension of the developing gut tube and forms anteriorly to the liver and pancreas25,26. It produces surfactant, mucus and antimicrobial peptides27,28 and anatomically, as well as ontogenetically, this organ is considered a homologue of the mammalian lung29,30. Since the pneumatic duct remains connected to the gut in the zebrafish, this allows for immersion infection to occur naturally. Remarkably, the only known naturally occurring infections of fish with Candida species are C. albicans infections in the swimbladder31. We recently described an experimental immersion infection model where C. albicans infects the swimbladder, and found that this infection recapitulates some of the hallmarks of C. albicans-epithelial interaction in vitro32,33. 
In the method presented here, the original immersion infection model is improved by directly injecting C. albicans into the swimbladder of 4 days post fertilization (dpf) zebrafish. This allows for precise temporal control of infection as well as a highly reproducible inoculum. It permits detailed intravital imaging, coupled with the versatility of the zebrafish model. As an example of what can be done with this method, we present the spatio-temporal dynamics of C. albicans growth along with neutrophil recruitment to the site of infection. Because zebrafish swimbladder tissue is challenging to image intravitally, we also present a rapid swimbladder dissection technique that improves fluorescence signal and microscopic resolution. These methods expand the toolbox for fungal, immunological, and aquaculture research as well as describing a novel infection route that may be translated to model other fungal, bacterial or viral infections of mucosal surfaces.

<table border="0" cellpadding="0" cellspacing="0" width="784">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:261px;">Name</td>
			<td style="width:259px;">Company</td>
			<td style="width:176px;">Catalog Number</td>
			<td style="width:88px;">Comments</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1.7 mL tubes</td>
			<td>Axygen</td>
			<td>MCT-175-C</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Deep Petri dishes</td>
			<td>Fisher Scientific</td>
			<td>89107-632</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Transfer pipettes</td>
			<td>Fisher Scientific</td>
			<td>13-711-7M</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Yeast Extract</td>
			<td>VWR Scientific</td>
			<td>90000-726</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Peptone</td>
			<td>VWR Scientific</td>
			<td>90000-264</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dextrose</td>
			<td>Fisher Scientific</td>
			<td>D16-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Agar</td>
			<td>VWR Scientific</td>
			<td>90000-760</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fine tweezers (Dumont Dumoxel #5)</td>
			<td>Fine Science Tools</td>
			<td>11251-30</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Wooden Dowels</td>
			<td>VWR Scientific</td>
			<td>10805-018</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Low Melt Agarose</td>
			<td>VWR Scientific</td>
			<td>12001-722</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Flaming Brown Micropipette Puller</td>
			<td>Sutter Instruments</td>
			<td>P-97</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Borosilicate capillary</td>
			<td>Sutter Instruments</td>
			<td>BF120-69-10</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MPPI-3 Injection system</td>
			<td>Applied Scientific Instrumentation</td>
			<td>MPPI-3</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Back Pressure Unit</td>
			<td>Applied Scientific Instrumentation</td>
			<td>BPU</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Micropipette Holder kit</td>
			<td>Applied Scientific Instrumentation</td>
			<td>MPIP</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Foot Switch</td>
			<td>Applied Scientific Instrumentation</td>
			<td>FSW</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Micromanipulator</td>
			<td>Applied Scientific Instrumentation</td>
			<td>MM33</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Magnetic Base</td>
			<td>Applied Scientific Instrumentation</td>
			<td>Magnetic Base</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tricaine methane sulfonate</td>
			<td>Western Chemical Inc.</td>
			<td>MS-222</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dissecting Scope</td>
			<td>Olympus</td>
			<td colspan="2">SZ61 top SZX-ILLB2-100 base</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Confocal Microscope</td>
			<td>Olympus</td>
			<td colspan="2">IX-81 with FV-1000 laser scanning confocal system</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">20x microscope objective</td>
			<td>Olympus</td>
			<td>UPlanSApo 20x/0.75</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Roller drum</td>
			<td>New Brunswick Scientific</td>
			<td>TC-7</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Microloader pipette tips</td>
			<td>Eppendorf</td>
			<td>930001007</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Glass culture tubes (16 x 150 mm)</td>
			<td>VWR Scientific</td>
			<td>60825-435</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">NaCl</td>
			<td>VWR Scientific</td>
			<td>BDH4534-500GP</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">KCl</td>
			<td>VWR Scientific</td>
			<td>BDH4532-500GP</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MgSO4</td>
			<td>VWR Scientific</td>
			<td>BDH0246-500GP</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">HEPES (Corning)</td>
			<td>VWR Scientific</td>
			<td>BDH4520-500GP</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Children clay (Play-Doh)</td>
			<td>Hasbro</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">CaCl2</td>
			<td>Fisher Scientific</td>
			<td>C69-500</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Methylene Blue</td>
			<td>VWR Scientific</td>
			<td>VW6276-0</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">PTU</td>
			<td>Sigma</td>
			<td>P7629-10G</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Petri dishes</td>
			<td>Fisher Scientific</td>
			<td>FB0875712</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hemocytometer (Hausser scientific)</td>
			<td>VWR Scientific</td>
			<td>15170-172</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Type A immersion oil</td>
			<td>Blue Marble Products</td>
			<td>51935</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Centrifuge</td>
			<td>Eppendorf</td>
			<td>5424</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Vortex Genie</td>
			<td>VWR Scientific</td>
			<td>14216-184</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Agarose (Lonza)</td>
			<td>VWR Scientific</td>
			<td>12001-870</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Na2HPO4</td>
			<td>Fisher Scientific</td>
			<td>S374-500</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">KH2PO4</td>
			<td>Fisher Scientific</td>
			<td>P285-500</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fishing wire</td>
			<td>Stren</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">96 well imaging plate (Sensoplate)</td>
			<td>Greiner Bio-One</td>
			<td>655892</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">High vacuum grease (Dow Corning)</td>
			<td>VWR Scientific</td>
			<td>59344-055</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Microslide (25 x 75 mm)</td>
			<td>VWR Scientific</td>
			<td>48300-025</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cover slips (18 x 18 mm), No 1.5</td>
			<td>VWR Scientific</td>
			<td>48366-045</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">15 cm Petri dish (Olympus plastics)</td>
			<td>Genesee Scientific</td>
			<td>32-106</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Glycerol (EMD chemicals)</td>
			<td>VWR Scientific</td>
			<td>EMGX0185-5</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">24-well culture dish (Olympus plastics)</td>
			<td>Genesee Scientific</td>
			<td>25-107</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Weight boats (8.9 cm)</td>
			<td>VWR Scientific</td>
			<td>89106-766</td>
			<td></td>
		</tr>
	</tbody>
</table>

modeling mucosal candidiasis in larval zebrafish by swimbladder injection

Difesa precoce contro i patogeni delle mucose consiste sia una barriera epiteliale e cellule immunitarie innate. La immunocompetency di entrambi, e la loro intercomunicazione, sono di primaria importanza per la protezione contro le infezioni. Le interazioni di cellule immunitarie innate epiteliali e con un agente patogeno è meglio studiati in vivo, in cui il comportamento complesso si sviluppa nel tempo e nello spazio. Tuttavia, i modelli esistenti non consentono un facile spazio-temporale delle immagini della battaglia con i patogeni a livello della mucosa. Il modello sviluppato qui crea un&#39;infezione della mucosa con iniezione diretta del patogeno fungino, Candida albicans, nella vescica natatoria di zebrafish giovanile. L&#39;infezione risultante permette imaging ad alta risoluzione di comportamenti epiteliale e innata cellule immunitarie durante lo sviluppo della malattia della mucosa. La versatilità di questo metodo permette di interrogatorio di accoglienza per sondare la sequenza riportata di eventi immunitari che portano a phreclutamento agocyte e di esaminare il ruolo di particolari tipi di cellule e percorsi molecolari nella protezione. Inoltre, il comportamento del patogeno come funzione di attacco immunitario può essere ripreso simultaneamente utilizzando proteine ​​esprimono fluorescente C. albicans. Risoluzione spaziale Aumento della interazione ospite-patogeno è possibile anche utilizzando la tecnica rapida vescica natatoria dissezione descritta. Il modello di infezione della mucosa descritto qui è semplice e altamente riproducibile, che lo rende uno strumento prezioso per lo studio della mucosa candidosi. Questo sistema può anche essere sostanzialmente traducibile ad altri patogeni mucosali come microbi micobatteri, batteriche o virali che normalmente infettano attraverso superfici epiteliali.

Microiniezione nella vescica natatoria posteriori Il metodo sperimentale qui presentato descrive l&#39;iniezione di una dose costante di C. cellule di lievito albicans nella vescica natatoria di 4 dpf zebrafish. Lavoro precedente con il modello di immersione suggerisce che la risposta immunitaria vescica natatoria a C. albicans è simile a mammiferi mucosa candidosi 32. Qui mostriamo un metodo di infezione modificato che è più semplice, riproducibile e ra...

Watch this Scientific Journal Video about Modeling Mucosal Candidiasis in Larval Zebrafish by Swimbladder Injection at JoVE.com

Modeling Mucosal Candidiasis in Larval Zebrafish by Swimbladder Injection

In vivo spatio-temporal interactions of pathogen and immune defenses at the mucosal level are not easily imaged in existing vertebrate hosts. The method presented here describes a versatile platform to study mucosal candidiasis in live vertebrates using the swimbladder of the juvenile zebrafish as an infection site.

Modellazione mucosa Candidosi in Zebrafish larvale da vescica natatoria Injection

Early defense against mucosal pathogens consists of both an epithelial barrier and innate immune cells. The immunocompetency of both, and their ...

modeling-mucosal-candidiasis-larval-zebrafish-swimbladder

Universidad de Cartagena UDEC

Research

JoVE Journal

Immunology and Infection

10.1K Views.  University of Maine. In vivo spatio-temporal interactions of pathogen and immune defenses at the mucosal level are not easily imaged in existing vertebrate hosts. The method presented here describes a versatile platform to study mucosal candidiasis in live vertebrates using the swimbladder of the juvenile zebrafish as an infection site.

Video: Modeling Mucosal Candidiasis in Larval Zebrafish by Swimbladder Injection

Non-invasive Imaging of Disseminated Candidiasis in Zebrafish Larvae

Disseminated candidiasis caused by the pathogen Candida albicans is a clinically important problem in hospitalized individuals and is associated with a 30 to 40% attributable mortality6. Systemic candidiasis is normally controlled by innate immunity, and individuals with genetic defects in innate immune cell components such as phagocyte NADPH oxidase are more susceptible to candidemia7-9. Very little is known about the dynamics of C. albicans interaction with innate immune cells in vivo. Extensive in vitro studies have established that outside of the host C. albicans germinates inside of macrophages, and is quickly destroyed by neutrophils10-14. In vitro studies, though useful, cannot recapitulate the complex in vivo environment, which includes time-dependent dynamics of cytokine levels, extracellular matrix attachments, and intercellular contacts10, 15-18. To probe the contribution of these factors in host-pathogen interaction, it is critical to find a model organism to visualize these aspects of infection non-invasively in a live intact host. 
The zebrafish larva offers a unique and versatile vertebrate host for the study of infection. For the first 30 days of development zebrafish larvae have only innate immune defenses2, 19-21, simplifying the study of diseases such as disseminated candidiasis that are highly dependent on innate immunity. The small size and transparency of zebrafish larvae enable imaging of infection dynamics at the cellular level for both host and pathogen. Transgenic larvae with fluorescing innate immune cells can be used to identify specific cells types involved in infection22-24. Modified anti-sense oligonucleotides (Morpholinos) can be used to knock down various immune components such as phagocyte NADPH oxidase and study the changes in response to fungal infection5. In addition to the ethical and practical advantages of using a small lower vertebrate, the zebrafish larvae offers the unique possibility to image the pitched battle between pathogen and host both intravitally and in color. 
The zebrafish has been used to model infection for a number of human pathogenic bacteria, and has been instrumental in major advances in our understanding of mycobacterial infection3, 25. However, only recently have much larger pathogens such as fungi been used to infect larva5, 23, 26, and to date there has not been a detailed visual description of the infection methodology. Here we present our techniques for hindbrain ventricle microinjection of prim25 zebrafish, including our modifications to previous protocols. Our findings using the larval zebrafish model for fungal infection diverge from in vitro studies and reinforce the need to examine the host-pathogen interaction in the complex environment of the host rather than the simplified system of the Petri dish5.

The rapid development, small size and transparency of zebrafish are tremendous advantages for the study of innate immune control of infection1-4. Here we demonstrate techniques for infecting zebrafish larvae using the fungal pathogen Candida albicans by microinjection, methodology recently used to implicate phagocyte NADPH oxidase activity in control of fungal dimorphism5.

Non invasiva Imaging di candidosi disseminata nelle larve Zebrafish

Disseminated candidiasis caused by the pathogen Candida albicans is a clinically important problem in hospitalized individuals and is associated with a 30 ...

Ricerca

Immunologia e infezioni

In vitro Coculture Assay to Assess Pathogen Induced Neutrophil Trans-epithelial Migration

Mucosal surfaces serve as protective barriers against pathogenic organisms.&#160;Innate immune responses are activated upon sensing pathogen leading to the infiltration of tissues with migrating inflammatory cells, primarily neutrophils.&#160;This process has the potential to be destructive to tissues if excessive or held in an unresolved state.&#160; Cocultured in vitro models can be utilized to study the unique molecular mechanisms involved in pathogen induced neutrophil trans-epithelial migration.&#160;This type of model provides versatility in experimental design with opportunity for controlled manipulation of the pathogen, epithelial barrier, or neutrophil.&#160;Pathogenic infection of the apical surface of polarized epithelial monolayers grown on permeable transwell filters instigates physiologically relevant basolateral to apical trans-epithelial migration of neutrophils applied to the basolateral surface.&#160;The in vitro model described herein demonstrates the multiple steps necessary for demonstrating neutrophil migration across a polarized lung epithelial monolayer that has been infected with pathogenic P. aeruginosa (PAO1).&#160;Seeding and culturing of permeable transwells with human derived lung epithelial cells is described, along with isolation of neutrophils from whole human blood and culturing of PAO1 and nonpathogenic K12 E. coli (MC1000).&#160; The emigrational process and quantitative analysis of successfully migrated neutrophils that have been mobilized in response to pathogenic infection is shown with representative data, including positive and negative controls.&#160;This in vitro model system can be manipulated and applied to other mucosal surfaces.&#160;Inflammatory responses that involve excessive neutrophil infiltration can be destructive to host tissues and can occur in the absence of pathogenic infections.&#160;A better understanding of the molecular mechanisms that promote neutrophil trans-epithelial migration through experimental manipulation of the in vitro coculture assay system described herein has significant potential to identify novel therapeutic targets for a range of mucosal infectious as well as inflammatory diseases.

In vitro Coculture Assay to Assess Pathogen Induced Neutrophil Trans-epithelial Migration

Neutrophil trans-epithelial migration in response to mucosal bacterial infection contributes to epithelial injury and clinical disease.&#160;An in vitro model has been developed that combines pathogen, human neutrophils, and polarized human epithelial cell layers grown on transwell filters to facilitate investigations towards unraveling the molecular mechanisms orchestrating this phenomenon.

In vitro Test di cocultura per valutare la migrazione transeteliale neutrofila indotta da agenti patogeni

Mucosal surfaces serve as protective barriers against pathogenic organisms.&#160;Innate immune responses are activated upon sensing pathogen leading to ...

Non-invasive Imaging of the Innate Immune Response in a Zebrafish Larval Model of Streptococcus iniae Infection

The aquatic pathogen, Streptococcus iniae, is responsible for over 100 million dollars in annual losses for the aquaculture industry and is capable of causing systemic disease in both fish and humans. A better understanding of S. iniae disease pathogenesis requires an appropriate model system. The genetic tractability and the optical transparency of the early developmental stages of zebrafish allow for the generation and non-invasive imaging of transgenic lines with fluorescently tagged immune cells. The adaptive immune system is not fully functional until several weeks post fertilization, but zebrafish larvae have a conserved vertebrate innate immune system with both neutrophils and macrophages. Thus, the generation of a larval infection model allows the study of the specific contribution of innate immunity in controlling S. iniae infection.
The site of microinjection will determine whether an infection is systemic or initially localized. Here, we present our protocols for otic vesicle injection of zebrafish aged 2-3 days post fertilization as well as our techniques for fluorescent confocal imaging of infection. A localized infection site allows observation of initial microbe invasion, recruitment of host cells and dissemination of infection. Our findings using the zebrafish larval model of S. iniae infection indicate that zebrafish can be used to examine the differing contributions of host neutrophils and macrophages in localized bacterial infections. In addition, we describe how photolabeling of immune cells can be used to track individual host cell fate during the course of infection.

Non-invasive Imaging of the Innate Immune Response in a Zebrafish Larval Model of Streptococcus iniae Infection

Here, we present a protocol for the generation and imaging of a localized bacterial infection in the zebrafish otic vesicle.

Imaging non invasiva della risposta immunitaria innata in un modello di Zebrafish larvale<em&gt; Streptococcus iniae</em&gt; Infezione

The aquatic pathogen, Streptococcus iniae, is responsible for over 100 million dollars in annual losses for the aquaculture industry and is capable of ...

Intranasal Administration of Recombinant Influenza Vaccines in Chimeric Mouse Models to Study Mucosal Immunity

Vaccines are one of the greatest achievements of mankind, and have saved millions of lives over the last century. Paradoxically, little is known about the physiological mechanisms that mediate immune responses to vaccines perhaps due to the overall success of vaccination, which has reduced interest into the molecular and physiological mechanisms of vaccine immunity. However, several important human pathogens including influenza virus still pose a challenge for vaccination, and may benefit from immune-based strategies. 
Although influenza reverse genetics has been successfully applied to the generation of live-attenuated influenza vaccines (LAIVs), the addition of molecular tools in vaccine preparations such as tracer components to follow up the kinetics of vaccination in vivo, has not been addressed. In addition, the recent generation of mouse models that allow specific depletion of leukocytes during kinetic studies has opened a window of opportunity to understand the basic immune mechanisms underlying vaccine-elicited protection. Here, we describe how the combination of reverse genetics and chimeric mouse models may help to provide new insights into how vaccines work at physiological and molecular levels, using as example a recombinant, cold-adapted, live-attenuated influenza vaccine (LAIV). We utilized laboratory-generated LAIVs harboring cell tracers as well as competitive bone marrow chimeras (BMCs) to determine the early kinetics of vaccine immunity and the main physiological mechanisms responsible for the initiation of vaccine-specific adaptive immunity. In addition, we show how this technique may facilitate gene function studies in single animals during immune responses to vaccines. We propose that this technique can be applied to improve current prophylactic strategies against pathogens for which urgent medical countermeasures are needed, for example influenza, HIV, Plasmodium, and hemorrhagic fever viruses such as Ebola virus.

There is an overall lack of knowledge about how vaccines work. Here we propose the combined use of reverse genetics and bone marrow chimeric mice to gain insight into the early host immune responses to vaccines with a special focus on dendritic cells and T cell immunity.

Intranasale somministrazione di ricombinante Influenza vaccini nei modelli chimerico topo per studiare immunità delle mucose

Vaccines are one of the greatest achievements of mankind, and have saved millions of lives over the last century. Paradoxically, little is known about the ...

Noninvasive Sampling of Mucosal Lining Fluid for the Quantification of In Vivo Upper Airway Immune-mediator Levels

This protocol describes noninvasive sampling of undisturbed upper airway mucosal lining fluid. It also details the extraction procedure used prior to the analysis of immune mediators in fluid eluates for the study of the airway topical immune signature, without the need for stimulation procedures (often used by other techniques). The mucosal lining fluid is sampled on a strip of filter paper placed at the anterior part of the inferior turbinate and left for 2 min of absorption. Analytes are eluted from the filter papers, and the extracted protein-based eluates are analyzed by an electrochemiluminescence-based immunoassay, allowing for the high-sensitivity quantification of low- and high-level analytes in the same sample. We measured the in vivo levels of 20 preselected immune mediators related to specific immune signaling pathways in the upper airway mucosa, but the technique is not limited to that specific panel or sampling site. The technique was first implemented in 7-year-old children from the Copenhagen Prospective Studies on Asthma in Childhood2000 (COPSAC2000) cohort with allergic rhinitis. It was thereafter used in the longitudinal COPSAC2010 birth cohort, sampled at 1 month, 2 years, and 6 years of age and at instances of acute respiratory symptoms. We successfully obtained and analyzed samples from 620 (89%) of 700 1-month-old children; a few samples were below the assay detection limit (reported as the median (Inter-Quartile Range (IQR)). The number of samples below the detection limit (i.e.&#160;from 0 to the set point for the lower limit of detection) for each mediator was 29 (7.25 - 119.5). This technique enables the quantification of the in vivo airway mucosal immune profile from birth, can be applied longitudinally, and can be applied to studies on the effect of genetics and early-life environmental exposures, pathophysiology, endotyping, and monitoring of respiratory diseases, and development and evaluation of novel therapeutics.

Noninvasive Sampling of Mucosal Lining Fluid for the Quantification of In Vivo Upper Airway Immune-mediator Levels

This protocol describes a noninvasive technique for the sampling of undisturbed mucosal lining fluid from the upper airways. It can be used to perform the quantification of in vivo levels of protein mediators, such as cytokines and chemokines, in subjects of all ages.

Campionamento non invasivo del rivestimento mucoso fluido per la quantificazione dei livelli di Immune-mediatore In Vivo delle vie respiratorie superiore

This protocol describes noninvasive sampling of undisturbed upper airway mucosal lining fluid. It also details the extraction procedure used prior to the ...

Bile Salt-induced Biofilm Formation in Enteric Pathogens: Techniques for Identification and Quantification

Biofilm formation is a dynamic, multistage process that occurs in bacteria under harsh environmental conditions or times of stress. For enteric pathogens, a significant stress response is induced during gastrointestinal transit and upon bile exposure, a normal component of human digestion. To overcome the bactericidal effects of bile, many enteric pathogens form a biofilm hypothesized to permit survival when transiting through the small intestine. Here we present methodologies to define biofilm formation through solid-phase adherence assays as well as extracellular polymeric substance (EPS) matrix detection and visualization. Furthermore, biofilm dispersion assessment is presented to mimic the analysis of events triggering release of bacteria during the infection process. Crystal violet staining is used to detect adherent bacteria in a high-throughput 96-well plate adherence assay. EPS production assessment is determined by two assays, namely microscopy staining of the EPS matrix and semi-quantitative analysis with a fluorescently-conjugated polysaccharide binding lectin. Finally, biofilm dispersion is measured through colony counts and plating. Positive data from multiple assays support the characterization of biofilms and can be utilized to identify bile salt-induced biofilm formation in other bacterial strains.

This protocol enables the reader to analyze bile salt-induced biofilm formation in enteric pathogens using a multifaceted approach to capture the dynamic nature of bacterial biofilms by assessing adherence, extracellular polymeric substance matrix formation, and dispersion.

Formazione di Biofilm indotta da sali biliari in patogeni enterici: tecniche di identificazione e quantificazione

Biofilm formation is a dynamic, multistage process that occurs in bacteria under harsh environmental conditions or times of stress. For enteric pathogens, ...

Modeling Tuberculosis in Mycobacterium marinum Infected Adult Zebrafish

Mycobacterium tuberculosis is currently the deadliest human pathogen causing 1.7 million deaths and 10.4 million infections every year. Exposure to this bacterium causes a wide disease spectrum in humans ranging from a sterilized infection to an actively progressing deadly disease. The most common form is the latent tuberculosis, which is asymptomatic, but has the potential to reactivate into a fulminant disease. Adult zebrafish and its natural pathogen Mycobacterium marinum have recently proven to be an applicable model to study the wide disease spectrum of tuberculosis. Importantly, spontaneous latency and reactivation as well as adaptive immune responses in the context of mycobacterial infection can be studied in this model. In this article, we describe methods for the experimental infection of adult zebrafish, the collection of internal organs for the extraction of nucleic acids for the measurement of mycobacterial loads and host immune responses by quantitative PCR. The in-house-developed, M. marinum-specific qPCR assay is more sensitive than the traditional plating methods as it also detects DNA from non-dividing, dormant or recently dead mycobacteria. As both DNA and RNA are extracted from the same individual, it is possible to study the relationships between the diseased state, and the host and pathogen gene-expression. The adult zebrafish model for tuberculosis thus presents itself as a highly applicable, non-mammalian in vivo system to study host-pathogen interactions.

Modeling Tuberculosis in Mycobacterium marinum Infected Adult Zebrafish

Here, we present a protocol to model human tuberculosis in an adult zebrafish using its natural pathogen Mycobacterium marinum. Extracted DNA and RNA from the internal organs of infected zebrafish can be used to reveal the total mycobacterial loads in the fish and the host&#39;s immune responses with qPCR.

Modellazione di tubercolosi in Zebrafish adulto infettato di Mycobacterium marinum

Mycobacterium tuberculosis is currently the deadliest human pathogen causing 1.7 million deaths and 10.4 million infections every year. Exposure to this ...

The Galleria mellonella Waxworm Infection Model for Disseminated Candidiasis

Candida species are common fungal commensals of humans colonizing the skin, mucosal surfaces, and gastrointestinal tract. Under certain conditions, Candida can overgrow their natural niches resulting in debilitating mucosal infections as well as life-threatening systemic infections, which are a major focus of investigation due to their associated high mortality rates. Animal models of disseminated infection exist for studying disease progression and dissecting the characteristics of Candida pathogenicity. Of these, the Galleria mellonella waxworm infection model provides a cost-effective experimental tool for high-throughput investigations of systemic virulence. Many other bacterial and eukaryotic infectious agents have been effectively studied in G. mellonella to understand pathogenicity, making it a widely accepted model system. Yet, variation in the method used to infect G. mellonella can alter phenotypic outcomes and complicate interpretation of the results. Here, we outline the benefits and drawbacks of the waxworm model to study systemic Candida pathogenesis and detail an approach to improve reproducibility. Our results highlight the range of mortality kinetics in G. mellonella and describe the variables which can modulate these kinetics. Ultimately, this method stands as an ethical, rapid, and cost-effective approach to study virulence in a model of disseminated candidiasis.

The Galleria mellonella Waxworm Infection Model for Disseminated Candidiasis

Galleria mellonella serves as an invertebrate model for disseminated candidiasis. Here, we detail the infection protocol and provide supporting data for the model&#39;s effectiveness.

Il modello di infezione del Waxworm di Galleria mellonella per candidosi disseminata

Candida species are common fungal commensals of humans colonizing the skin, mucosal surfaces, and gastrointestinal tract. Under certain conditions, ...

Induction of Mouse Lung Injury by Endotracheal Injection of Bleomycin

Pulmonary fibrosis is a hallmark of several human lung diseases with a different etiology. Since current therapies are rather limited, mouse models continue to be an essential tool for developing new antifibrotic strategies. Here we provide an effective method to investigate in vivo antifibrotic activity of human mesenchymal stromal cells obtained from whole umbilical cord (hUC-MSC) in attenuating bleomycin-induced lung injury. C57BL/6 mice receive a single endotracheal injection of bleomycin (1.5 U/kg body weight) followed by a double infusion of hUC-MSC (2.5 x 105) into the tail vein, 24 h and 7 days after the bleomycin administration. Upon sacrifice at days 8, 14, or 21, inflammatory and fibrotic changes, collagen content, and hUC-MSC presence in explanted lung tissue are analyzed. The injection of bleomycin into the mouse&#160;trachea allows the direct targeting of the lungs, leading to extensive pulmonary inflammation and fibrosis. The systemic administration of a double dose of hUC-MSC results in the early blunting of the bleomycin-induced lung injury. Intravenously infused hUC-MSC are transiently engrafted into the mouse lungs, where they exert their anti-inflammatory and antifibrotic activity. In conclusion, this protocol has been successfully applied for the preclinical testing of hUC-MSC in an experimental mouse model of human pulmonary fibrosis. However, this technique can be easily extended both to study the effect of different endotracheally administered substances on the pathophysiology of the lungs and to validate new anti-inflammatory and antifibrotic systemic therapies.

Here we present an effective method to investigate the antifibrotic activity of intravenously infused human mesenchymal stromal cells obtained from the whole umbilical cord following the induction of lung injury by an endotracheal injection of bleomycin in C57BL/6 mice. This protocol can be easily extended to the preclinical testing of other therapeutics.

Induzione di lesioni polmonari del topo da Iniezione endotracheale di Bleomycin

Pulmonary fibrosis is a hallmark of several human lung diseases with a different etiology. Since current therapies are rather limited, mouse models ...

Targeting Drugs to Larval Zebrafish Macrophages by Injecting Drug-Loaded Liposomes

Zebrafish (Danio rerio) larvae have developed into a popular model to investigate host-pathogen interactions and the contribution of innate immune cells to inflammatory disease due to their functionally conserved innate immune system. They are also widely used to examine how innate immune cells help guide developmental processes. By taking advantage of the optical transparency and genetic tractability of larval zebrafish, these studies often focus on live imaging approaches to functionally characterize fluorescently marked macrophages and neutrophils within intact animals. Due to their diverse functional heterogeneity and ever-expanding roles in disease pathogenesis, macrophages have received significant attention. In addition to genetic manipulations, chemical interventions are now routinely used to manipulate and examine macrophage behavior in larval zebrafish. Delivery of these drugs is typically limited to passive targeting of free drug through direct immersion or microinjection. These approaches rely on the assumption that any changes to macrophage behavior are the result of a direct effect of the drug on the macrophages themselves, and not a downstream consequence of a direct effect on another cell type. Here, we present our protocols for targeting drugs specifically to larval zebrafish macrophages by microinjecting drug-loaded fluorescent liposomes. We reveal that poloxamer 188-modified drug-loaded blue fluorescent liposomes are readily taken up by macrophages, and not by neutrophils. We also provide evidence that drugs delivered in this way can impact macrophage activity in a manner consistent with the mechanism of action of the drug. This technique will be of value to researchers wanting to ensure targeting of drugs to macrophages and when drugs are too toxic to be delivered by traditional methods like immersion.

Here, we describe the synthesis of drug-loaded liposomes and their microinjection into larval zebrafish for the purpose of targeting drug delivery to macrophage-lineage cells.

Mirare i farmaci ai macrofagi di pesce zebra larvale iniettando liposomi caricati con droga

Zebrafish (Danio rerio) larvae have developed into a popular model to investigate host-pathogen interactions and the contribution of innate immune cells ...