Name: conjunctival commensal isolation and identification in mice
Uploaded: 2021-05-01T13:00:00
Description: Watch this Scientific Journal Video about Conjunctival Commensal Isolation and Identification in Mice at JoVE.com

Le financement de P30 DK034854 a soutenu VY, LB et des études dans le Massachusetts Host-Microbiome Center et le financement de NIH / NEI R01 EY022054 a soutenu MG.

Toutes les procédures impliquant des souris suivent les lignes directrices du Comité institutionnel de protection et d’utilisation des animaux. Suivez les directives de sécurité du laboratoire (selon les directives de votre service d’intégrité et de sécurité environnementales en établissement) lorsque vous travaillez avec des micro-organismes et des matières potentiellement contaminées. Utiliser des récipients à déchets et des procédures de décontamination appropriés avant d’éliminer les matières...

<ol>
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J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interactions+between+the+microbiota+and+the+immune+system.">Interactions between the microbiota and the immune system.</a> Science. 336 (6086), 1268-1273 (2010).</li><li>Nagpal, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human-origin+probiotic+cocktail+increases+short+chain+fatty+acid+production+via+modulation+of+mice+and+human+gut+microbiome.">Human-origin probiotic cocktail increases short chain fatty acid production via modulation of mice and human gut microbiome.</a> Scientific Reports. 8 (1), 12649 (2018).</li><li>Graham, J. E., 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=Ocular+pathogen+or+commensal:+a+PCR+based+study+of+surface+bacterial+flora+in+normal+and+dry+eyes.">Ocular pathogen or commensal: a PCR based study of surface bacterial flora in normal and dry eyes.</a> Investigative Ophthalmology and Visual Science. 48 (12), 5616-5623 (2007).</li><li>Wang, C., 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=Sj&#246;gren-Like+Lacrimal+Keratoconjunctivitis+in+Germ-Free+Mice.">Sj&#246;gren-Like Lacrimal Keratoconjunctivitis in Germ-Free Mice.</a> International Journal of Molecular Sciences. 19 (2), 565-584 (2018).</li><li>Ham, B., Hwang, H. B., Jung, S. H., Chang, S., Kang, K. D., Kwon, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distribution+and+diversity+of+ocular+microbial+communities+in+diabetic+patients+compared+with+healthy+subjects.">Distribution and diversity of ocular microbial communities in diabetic patients compared with healthy subjects.</a> Current Eye Research. 43 (3), 314-324 (2018).</li><li>Doan, 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=Paucibacterial+microbiome+and+resident+DNA+virome+of+the+healthy+conjunctiva.">Paucibacterial microbiome and resident DNA virome of the healthy conjunctiva.</a> Investigative Ophthalmology and Visual Science. 57 (13), 5116-5126 (2016).</li><li>Kugadas, A., Gadjeva, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+microbiome+on+ocular+health.">Impact of microbiome on ocular health.</a> Ocular Surface. 14 (3), 342-349 (2016).</li><li>Dong, Q., 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=Diversity+of+bacteria+at+healthy+human+conjunctiva.">Diversity of bacteria at healthy human conjunctiva.</a> Investigative Ophthalmology and Visual Science. 53 (8), 5408-5413 (2011).</li><li>Zegans, M. E., Van Gelder, R. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Considerations+in+understanding+the+ocular+surface+microbiome.">Considerations in understanding the ocular surface microbiome.</a> American Journal of Opthalmology. 158 (3), 420-422 (2014).</li><li>Fleiszig, S. M., Efron, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microbial+flora+in+eyes+of+current+and+former+contact+lens+wearers.">Microbial flora in eyes of current and former contact lens wearers.</a> Journal of Clinical Microbiology. 30 (5), 1156-1161 (1992).</li><li>Lu, X., 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=Neutrophil+L-Plastin+Controls+Ocular+Paucibacteriality+and+Susceptibility+to+Keratitis.">Neutrophil L-Plastin Controls Ocular Paucibacteriality and Susceptibility to Keratitis.</a> Frontiers in Immunology. 11, 547 (2020).</li><li>Johnson, T. R., Case, C. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Laboratory Experiments in Microbiology. , (2010).</li><li>Reiner, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Catalase+Test+Protocol.">Catalase Test Protocol.</a> American Society for Microbiology. , (2010).</li><li>UK SMI. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Standards for Microbiology Investigation. UK SMI. , (2014).</li><li>Sharp, S. E., Searcy, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+mannitol+salt+agar+and+blood+agar+plates+for+identification+and+susceptibility+testing+of+Staphylococcus+aureus+in+specimens+from+cystic+fibrosis+patients.">Comparison of mannitol salt agar and blood agar plates for identification and susceptibility testing of Staphylococcus aureus in specimens from cystic fibrosis patients.</a> Journal of Clinical Microbiology. 44 (12), 4545-4546 (2006).</li><li>Siegman-Igra, Y., Azmon, Y., Schwartz, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Milleri+group+streptococcus--a+stepchild+in+the+viridans+family.">Milleri group streptococcus--a stepchild in the viridans family.</a> European Journal of Clinical Microbiology and Infectious Diseases. 31 (9), 2453-2459 (2012).</li><li>Mohan, B., Zaman, K., Anand, N., Taneja, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aerococcus+Viridans:+A+Rare+Pathogen+Causing+Urinary+Tract+Infection.">Aerococcus Viridans: A Rare Pathogen Causing Urinary Tract Infection.</a> Journal of Clinical and Diagnostic Research. 11 (1), 1-3 (2017).</li><li>Senneby, E., Nilson, B., Petersson, A. C., Rasmussen, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Matrix-assisted+laser+desorption+ionization-time+of+flight+mass+spectrometry+is+a+sensitive+and+specific+method+for+identification+of+aerococci.">Matrix-assisted laser desorption ionization-time of flight mass spectrometry is a sensitive and specific method for identification of aerococci.</a> Journal of Clinical Microbiology. 51 (4), 1303-1304 (2013).</li><li>Wan, S. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=IL-1R+and+MyD88+contribute+to+the+absence+of+a+bacterial+microbiome+on+the+healthy+murine+cornea.">IL-1R and MyD88 contribute to the absence of a bacterial microbiome on the healthy murine cornea.</a> Frontiers in Microbiology. 9, 1117 (2018).</li><li>Ozkan, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temporal+Stability+and+Composition+of+the+Ocular+Surface+Microbiome.">Temporal Stability and Composition of the Ocular Surface Microbiome.</a> Scientific Reports. 7 (1), 9880 (2017).</li><li>Oliver, J. 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+viable+but+non-culturable+state+in+bacteria.">The viable but non-culturable state in bacteria.</a> Journal of Microbiology. 43 (1), 93-100 (2005).</li><li>Epstein, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+phenomenon+of+microbial+uncultivability.">The phenomenon of microbial uncultivability.</a> Current Opinion in Microbiology. 16 (5), 636-642 (2013).</li><li>Whelan, F. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Culture-enriched+metagenomic+sequencing+enables+in-depth+profiling+of+the+cystic+fibrosis+lung+microbiota.">Culture-enriched metagenomic sequencing enables in-depth profiling of the cystic fibrosis lung microbiota.</a> Nature Microbiology. 5 (2), 379-390 (2020).</li><li>Raymond, 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=Culture-enriched+human+gut+microbiomes+reveal+core+and+accessory+resistance+genes.">Culture-enriched human gut microbiomes reveal core and accessory resistance genes.</a> Microbiome. 7, 56 (2019).</li><li>Peto, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+culture+enrichment+and+sequencing+of+feces+to+enhance+detection+of+antimicrobial+resistance+genes+in+third-generation+cephalosporin+resistant+Enterobacteriaceae.">Selective culture enrichment and sequencing of feces to enhance detection of antimicrobial resistance genes in third-generation cephalosporin resistant Enterobacteriaceae.</a> PLoS One. 14 (11), 0222831 (2019).</li><li>Lauer, B. A., Masters, H. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toxic+effect+of+calcium+alginate+swabs+on+Neisseria+gonorrhoeae.">Toxic effect of calcium alginate swabs on Neisseria gonorrhoeae.</a> Journal of Clinical Microbiology. 26 (1), 54-56 (1988).</li><li>Dubois, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Performances+of+the+Vitek+MS+matrix-assisted+laser+desorption+ionization-time+of+flight+mass+spectrometry+system+for+rapid+identification+of+bacteria+in+routine+clinical+microbiology.">Performances of the Vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry system for rapid identification of bacteria in routine clinical microbiology.</a> Journal of Clinical Microbiology. 50 (8), 2568-2576 (2012).</li><li>Kawakita, 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=double-blind+study+of+the+safety+and+Efficacy+of+1%D-3-Hydroxybutyrate+eye+drops+for+Dry+Eye+Disease.">double-blind study of the safety and Efficacy of 1%D-3-Hydroxybutyrate eye drops for Dry Eye Disease.</a> Scientific Reports. 6, 20855 (2016).</li><li>Lee, H. S., Hattori, T., Stevenson, W., Cahuhan, S. K., Dana, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+of+toll-like+receptor+4+contributes+to+corneal+inflammation+in+experimental+dry+eye+disease.">Expression of toll-like receptor 4 contributes to corneal inflammation in experimental dry eye disease.</a> Investigative Ophthalmology and Visual Science. 53 (9), 5632-5640 (2012).</li><li>Simmons, K. T., Xiao, Y., Pflugfelder, S. C., de Paiva, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inflammatory+response+to+lipopolysaccharide+on+the+ocular+surface+in+a+murine+dry+eye+model.">Inflammatory response to lipopolysaccharide on the ocular surface in a murine dry eye model.</a> Investigative Ophthalmology and Visual Science. 57 (6), 2444-2450 (2016).</li><li>Miller, D., Ioviano, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+microbial+flora+on+the+ocular+surface.">The role of microbial flora on the ocular surface.</a> Current Opinion in Allergy and Immunology. 9 (5), 466-470 (2009).</li><li>Nayyar, A., Gindina, S., Barron, A., Hu, Y., Danias, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Do+epigenetic+changes+caused+by+commensal+microbiota+contribute+to+development+of+ocular+disease?+A+review+of+evidence.">Do epigenetic changes caused by commensal microbiota contribute to development of ocular disease? A review of evidence.</a> Human Genomics. 14 (1), 11 (2020).</li><li>Stevenson, W., 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=Dry+eye+disease:+an+immune-mediated+ocular+surface+disorder.">Dry eye disease: an immune-mediated ocular surface disorder.</a> Archives of Ophthalmology. 130 (1), 90-100 (2012).</li></ol>

En raison de l’état paucibactérien de la surface oculaire, de nombreux laboratoires ont eu du mal à isoler les commensaux oculaires7,20,ce qui a entraîné un faible nombre d’échantillons avec croissance, une faible abondance et une faible diversité8. Ce procédé améliore significativement les pratiques de culture standard4,21 par l’ajout d’une étape d’enrichissem...

Le but de ce protocole est d’améliorer l’isolement spécifique des microbes aérobies et anaérobies facultatifs viables et rares de la conjonctive oculaire pour caractériser le microbiome oculaire. Des études approfondies ont profilé les communautés muqueuses commensales sur la peau, l’intestin, les voies respiratoires et génitales et montrent que ces communautés influencent le développement du système immunitaire et la réponse1,2,3. Il a été démontré que les communautés commensales oculaires changent au cours de certaines pathologies, telles que la sécheresse oculaire4,le syndrome de Sjögren5 et le diabète6. Pourtant, la capacité de définir une communauté commensale de surface oculaire typique est entravée par leur abondance relativement faible par rapport aux autres sites muqueux6,7,8. Cela suscite une controverse sur l’existence d’un microbiome oculaire résident et, s’il existe, s’il diffère du microbiome cutané et, par conséquent, de son effet local sur le développement et la réponse du système immunitaire inné. Ce protocole peut aider à résoudre cette question.
Généralement, les approches pour définir la niche commensale oculaire sont basées sur des techniques de séquençage et de culture4,7,9. Le séquençage de l’ADNr 16 S et l’analyse BRISK7 montrent une plus grande diversité que les techniques basées sur la culture, mais sont incapables de faire la différence entre les microbes vivants et morts. Étant donné que la surface oculaire est hostile à de nombreux microbes en raison des propriétés antimicrobiennes du film lacryptique4 générant un large éventail de fragments d’ADN, les approches basées sur l’ADN détecteront ces artefacts qui peuvent biaiser les données vers l’identification des bactéries mortes en tant que commensaux résidents plutôt que contaminants. Il en résulte une identification et une caractérisation commensales aberrantes de l’espace oculaire comme étant plus élevées en abondance et en diversité microbles10. Il est donc difficile de définir le microbiome oculaire résident par des méthodes basées sur l’ADN. Considérant que les techniques standard basées sur la culture sont incapables de détecter les commensaux parce que la charge est trop faible11. Notre méthode améliore les pratiques standard en utilisant un écouvillon mince qui peut cibler la conjonctive, évitant ainsi la contamination de la peau voisine, ainsi que le concept selon lequel les organismes viables peuvent être enrichis par une brève culture dans des milieux denses en nutriments dans le but de ressusciter viable mais non cultivable, ainsi que d’enrichir pour les microbes viables rares.
Les résultats, l’abondance relative des commensaux oculaires par écouvillonnage oculaire, caractérisent le microbiome résident de la conjonctive et sont importants à des fins de comparaison. Nos données montrent qu’il y a une différence entre la peau et le microbiote conjonctival, ainsi qu’une plus grande diversité avec l’âge et une différence d’abondance spécifique au sexe. De plus, cette approche a permis de trouver de manière reproductible des différences commensales chez les souris knock-out12. Ce protocole peut être appliqué pour décrire le microbiome oculaire qui peut varier en raison des pratiques de mise en cage, de la géographie ou de l’état pathologique, ainsi que des effets locaux des métabolites et des produits commensaux sur le développement et la réponse du système immunitaire.

<table>
	<tbody>
		<tr>
			<td>0.1 to 10 &#181;l pipet tip</td>
			<td>USA Scientific</td>
			<td>1110-300</td>
			<td>autoclave before use</td>
		</tr>
		<tr>
			<td>0.5 to 10 &#181;l Eppendorf pipet</td>
			<td>Fisher Scientific</td>
			<td>13-690-026</td>
			<td></td>
		</tr>
		<tr>
			<td>1 ml syringe</td>
			<td>Fisher Scientific</td>
			<td>BD309623</td>
			<td>1 syringe for each eye swab group</td>
		</tr>
		<tr>
			<td>1.5 ml Eppendorf tubes</td>
			<td>USA Scientific</td>
			<td>1615-5500</td>
			<td>autoclave before use</td>
		</tr>
		<tr>
			<td>1000 &#181; ml pipet tip</td>
			<td>USA Scientific</td>
			<td>1111-2021</td>
			<td>autoclave before use</td>
		</tr>
		<tr>
			<td>200 to 1000&#181;l Gilson pipetman (P1000)</td>
			<td>Fisher Scientific</td>
			<td>F123602G</td>
			<td></td>
		</tr>
		<tr>
			<td>25 G needle</td>
			<td>Fisher Scientific</td>
			<td>14-826AA</td>
			<td>1 needle per eye swab group</td>
		</tr>
		<tr>
			<td>3 % Hydrogen Peroxide</td>
			<td>Fisher Scientific</td>
			<td>S25359</td>
			<td></td>
		</tr>
		<tr>
			<td>37 &#176; C Incubator</td>
			<td>Lab equipment</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>70 % Isopropanol</td>
			<td>Fisher Scientific</td>
			<td>PX1840-4</td>
			<td></td>
		</tr>
		<tr>
			<td>Ana-Sed Injection (Xylazine 100 mg/ml)</td>
			<td>Santa Cruz Animal Health</td>
			<td>SC-362949Rx</td>
			<td></td>
		</tr>
		<tr>
			<td>BD BBL Gram Stain kit</td>
			<td>Fisher Scientific</td>
			<td>B12539</td>
			<td></td>
		</tr>
		<tr>
			<td>Bunsen Burner</td>
			<td>Lab equipment</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Clean paper towels</td>
			<td>Lab equipment</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cotton Batting/Sterile rolled cotton</td>
			<td>CVS</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Disposable 1 ml Pipets</td>
			<td>Fisher Scientific</td>
			<td>13-711-9AM</td>
			<td>for Gram stain and catalase tests</td>
		</tr>
		<tr>
			<td>E.coli</td>
			<td>ATTC</td>
			<td>ATCC 8739</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass slides</td>
			<td>Fisher Scientific</td>
			<td>12-550-A3</td>
			<td>for Gram stain and catalase tests</td>
		</tr>
		<tr>
			<td>Ketamine (100mg/ml)</td>
			<td>Henry Schein</td>
			<td>9950001</td>
			<td></td>
		</tr>
		<tr>
			<td>Mac Conkey Agar Plates</td>
			<td>Fisher Scientific</td>
			<td>4321270</td>
			<td>store at 4 &#176;C until ready to use</td>
		</tr>
		<tr>
			<td>Mannitol Salt Agar</td>
			<td>Carolina Biological Supply</td>
			<td>784641</td>
			<td>Prepare plates according to mfr&#39;s instructions, store at 4 &#176;C for 1 week</td>
		</tr>
		<tr>
			<td>Mice</td>
			<td>Jackson Labs</td>
			<td>C57/BL6J</td>
			<td></td>
		</tr>
		<tr>
			<td>Petri Dishes</td>
			<td>Fisher Scientific</td>
			<td>08-757-12</td>
			<td>for Mannitol Salt agar plates</td>
		</tr>
		<tr>
			<td>RPI Brain Heart Infusion Media</td>
			<td>Fisher Scientific</td>
			<td>50-488525</td>
			<td>prepare according to directions and autoclave</td>
		</tr>
		<tr>
			<td>SteriFlip (0.22 &#181;m pore size polyester sulfone)</td>
			<td>EMD/Millipore, Fisher Scientifc</td>
			<td>SCGP00525</td>
			<td>to sterilize anesthesia</td>
		</tr>
		<tr>
			<td>Sterile Corning Centrifuge Tube</td>
			<td>Fisher Scientific</td>
			<td>430829</td>
			<td>anesthesia preparation</td>
		</tr>
		<tr>
			<td>Sterile mouse cage</td>
			<td>Lab equipment</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Tooth picks (round bamboo)</td>
			<td>Kitchen Essentials</td>
			<td></td>
			<td>autoclave before use and swab preparation</td>
		</tr>
		<tr>
			<td>Trypticase Soy Agar II with 5% Sheep&#39;s Blood Plates</td>
			<td>Fisher Scientific</td>
			<td>4321261</td>
			<td>store at 4 &#176;C until ready to use</td>
		</tr>
		<tr>
			<td>Vitek target slide</td>
			<td>BioMerieux Inc. Durham,NC</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Vitek-MS</td>
			<td>BioMerieux Inc. Durham,NC</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Vitek-MS CHCA matrix solution</td>
			<td>BioMerieux Inc. Durham, NC</td>
			<td>411071</td>
			<td></td>
		</tr>
		<tr>
			<td>Single use eye drops</td>
			<td>CVS Pharmacy</td>
			<td></td>
			<td>Bausch and Lomb Soothe Lubricant Eye Drops, 28 vials, 0.02 fl oz. each</td>
		</tr>
	</tbody>
</table>

conjunctival commensal isolation and identification in mice

La surface oculaire a été une fois considérée privilégiée et abiotique immunisée, mais récemment il s’affiche qu’il y ait une petite, mais persistante présence commensale. L’identification et la surveillance des espèces bactériennes au niveau de la muqueuse oculaire ont été difficiles en raison de leur faible abondance et de la disponibilité limitée de la méthodologie appropriée pour la croissance et l’identification commensales. Il existe deux approches standard : les méthodes de séquençage de l’ADN basées sur la culture ou les méthodes de séquençage de l’ADN. La première méthode est problématique en raison des bactéries récupérables limitées et la seconde approche identifie les bactéries vivantes et mortes conduisant à une représentation aberrante de l’espace oculaire. Nous avons développé une méthode robuste et sensible pour l’isolement bactérien en nous appuyant sur des techniques de culture microbiologique standard. Il s’agit d’une technique basée sur un écouvillon, utilisant un écouvillon mince « en laboratoire » qui cible la conjonctive inférieure, suivi d’une étape d’amplification pour les genres aérobies et anaérobies facultatifs. Ce protocole nous a permis d’isoler et d’identifier des espèces conjonctivales telles que Corynebacterium spp., Coagulase Negative Staphylococcus spp., Streptococcus spp.,etc. L’approche convient pour définir la diversité commensale chez les souris dans différentes conditions de maladie.

Des résultats représentatifs pour une plaque d’écouvillonnage montrant différentes méthodes de placage sont illustrés à la figure 3A montrant des isolats morphologiquement divers de souris C57BL/6. Pour chaque isolat distinct, les colonies ont été comptées dans la bande et l’abondance relative, unités formant colonies (UFC) uniques par écouvillonnage oculaire, a été calculée et tracée à des fins de comparaison. Pour la caractérisation microbiologique, les bactéries ont...

Watch this Scientific Journal Video about Conjunctival Commensal Isolation and Identification in Mice at JoVE.com

Conjunctival Commensal Isolation and Identification in Mice

Présenté ici est un protocole pour l’isolement et l’amplification des bactéries commensales conjonctivales anaérobies aérobies et facultatives de souris utilisant un écouvillon unique d’oeil et une étape basée sur culture d’enrichissement avec l’identification suivante par des méthodes basées microbiologiques et la spectrométrie de masse MALDI-TOF.

Isolement et identification commensaux conjonctivaux chez la souris

The ocular surface was once considered immune privileged and abiotic, but recently it appears that there is a small, but persistent commensal presence. ...

Cette méthode identifie les micro-organismes conjonctivaux oculaires viables, ce qui est difficile en raison de l’environnement hostile des yeux. Il peut aider à déterminer s’il existe un microbiome oculaire et comment la présence bactérienne change dans les maladies oculaires. Contrairement au séquençage de l’ADN, qui identifie à la fois les micro-organismes viables et non viables, cette méthode n’identifie que les micro-organismes viables, ce qui permet de mieux comprendre la communauté commensale oculaire.Les études suggèrent que les maladies oculaires difficiles à diagnostiquer telles que l’œil sec non autoimmun et autoimmun aient une présence bactérienne oculaire unique. Cette méthode pourrait être utilisée pour diagnostiquer les maladies oculaires avec des signatures microbiennes distinctives. Commencez par autoclaver la quantité appropriée de battages de coton et de cure-dents pour le nombre de souris à écouvillons, puis pincez 1/2 un centimètre de long morceau de pâte de coton et taquinez-le en tirant sur les bords pour former une couche poreuse unique plate s’arrêtant juste avant que la batte ne s’effondre.Faites pivoter la batte autour de l’une des extrémités pointues du cure-dent en tenant légèrement la pièce étirée sur la pointe du cure-dent car elle est tordue. L’écouvillon fini aura une très fine couche de coton tendue sur la pointe s’étendant sur environ 1/2 à un centimètre de la pointe. Insérez les écouvillons dans un petit bécher, écouvillonnez le côté vers le bas, puis couvrez-les et autoclavez-les.Nettoyez l’aire de travail avec un désinfectant pour minimiser la contamination et aliquotez 0,5 millilitres d’infusion stérile de cœur cérébral, ou des milieux BHI dans des micro-tubes à centrifuger stériles étiquetés de 1,5 millilitre. Coiffez les tubes dans un rack et réglez le rack sur la glace. Configurez le flux de travail de gauche à droite en commençant par la station d’anesthésie de la souris, qui contient la cage avec les souris expérimentales, la cage stérile vide, l’anesthésie à température ambiante, l’aiguille de calibre 25 et une seringue d’un millilitre.Ensuite, préparez une station d’écouvillonnage qui contient le BHI aliquoted sur la glace, des écouvillons stérilisés, des gouttes oculaires lubrifiantes, un récipient à biorisque, des serviettes en papier propre et un spray à 70% d’isopropanol. Enfin, configurez la station de placage avec des plaques de gélose au sang à température ambiante, une pipette de 10 microlitres, 10 embouts jetables stériles microlitres et un conteneur de déchets à biorisque. Assurez-vous que la souris est correctement anesthésiée en serrant un coussinet arrière.Ne continuez que s’il n’y a pas de mouvement. Assignez une main pour manipuler les souris anesthésiées et les autres mains pour manipuler l’écouvillon oculaire et la culture. Retirez la souris de la cage et placez-la sur la surface de travail positionnée sur le côté avec l’œil gauche exposé.Vaporisez l’isopropanol aux mains gantées et séchez-les avec une serviette en papier. Décapez le tube micro-centrifugeuse BHI étiqueté avec la main de manipulation du support dédiée et replacez les deux dans le rack. Trempez la pointe enduite de coton de l’écouvillon dans le BHI, puis retirez l’écouvillon du tube tout en faisant tourbillonner la pointe deux fois contre la chambre à air pour éliminer l’excès de liquide et l’enlever.Avec la main de manipulation de la souris, tenez doucement la souris par la peau du cou. D’autre part, placez le bout de l’écouvillon de l’œil contre la région conjonctivale médiale de l’œil gauche. Relâchez légèrement le globe oculaire et déplacez l’écouvillon dans un mouvement de lavage de fenêtre entre la paupière inférieure et l’œil 10 fois, en maintenant une pression constante.Sans toucher la fourrure, retirez doucement la pointe de l’écouvillon perpendiculairement à l’endroit où il a été inséré. Placez le côté coton-tige vers le bas, directement dans un tube micro-centrifugeur étiqueté avec un support BHI. Appliquez un goutte oculaire sur l’œil écorché.Si vous le souhaitez, acquérir des écouvillons de peau ou de fourrure pour les échantillons témoins, en stérilisant les gants de manière appropriée entre chaque écouvillon. Lorsque vous avez terminé, retournez la souris dans la cage. Laissez l’écouvillon reposer pendant 10 à 15 minutes sur de la glace, puis stérilisez les mains gantées et retirez l’écouvillon tout en mélangeant la pointe dans le support pendant 10 rotations.Retirez l’écouvillon en faisant tourbillonner la pointe contre la paroi interne du tube pendant cinq rotations et jetez-le dans un récipient à biorisque. Répétez le processus pour chaque souris. Enrichir l’échantillon en incubant le tube statiquement pendant une heure à 37 degrés Celsius.Pendant l’incubation, étiquetez une plaque de TSA à température ambiante par écouvillon de souris ou écouvillon de contrôle et divisez-la en deux. Retirez les échantillons enrichis de l’incubateur et placez-les sur de la glace. Vortex brièvement les échantillons à mélanger, puis aliquote 10 microlitres de l’échantillon sur la plaque TSA et incliner la plaque pour former une bande.Répétez cette opération deux fois. De l’autre côté de la ligne de séparation des plaques, créez 10 points avec 10 microlitres d’échantillon chacun. Incuber les plaques à 37 degrés Celsius pendant 18 heures, deux jours et quatre jours dans une chambre propre qui empêche les plaques de gélose de sécher.Comptez les colonies dans les bandes. Notez la morphologie et calculez les unités formant colonies par écouvillon pour les isolats morphologiquement similaires. Regardez les points où des organismes uniques ne sont pas capturés dans les bandes.Pour faciliter la visualisation, nous avons plaqué les bactéries densément dans les plaques du milieu et de droite. Typiquement, nous avons observé beaucoup moins de bactéries dans les plaques d’écouvillonnage oculaire. Notez qu’à l’occasion, les écouvillons oculaires peuvent ne pas produire de bactéries récupérables.Une plaque représentative d’écouvillonnage d’oeil avec les isolats morphologiquement divers d’une souris noire de six C57 est montrée ici. Pour chaque isolat distinct, les colonies ont été comptées dans la bande et l’abondance relative a été calculée et tracée. Pour la caractérisation microbiologique, les bactéries ont été prélevées à partir de plaques d’écouvillonnage individuelles pour les yeux de souris afin de produire une plaque TSA maîtresse.Lorsque la croissance est apparue, des tests supplémentaires ont été effectués pour caractériser ou identifier les microbes. La plaque maîtresse a été utilisée pour fournir suffisamment d’inoculum pour élargir les isolats respectifs. Pour identifier des isolats, un plat de TSA a été strié et incubé pendant la nuit, et la milliseconde de MALDI-TOF a été exécutée.Des exemples d’isolats présentés ici ont été identifiés comme streptocoques acidominimus et Aerococcus viridans. Des niveaux significativement différents d’organizations commensales ont été récupérés de six souris noires C57 mâles et femelles. Streptococcus acidominimus, Aerococcus viridans coagule les staphylocoques négatifs et E.coli ont été isolés chez les souris noires C57 six N.Lorsque vous essayez ce protocole, gardez à l’esprit que le meilleur résultat sera obtenu en recouvrant l’écouvillon finement et en prenant le temps pendant le pas de l’écouvillonnage oculaire. Si l’accès à la SP MALDI-TOF est limité, les isolats peuvent être identifiés par des tests microbiologiques et biochimiques.

conjunctival-commensal-isolation-and-identification-in-mice

Research

JoVE Journal

Immunology and Infection

Isolation and Analysis of Brain-sequestered Leukocytes from Plasmodium berghei ANKA-infected Mice

We describe a method for isolation and characterization of adherent inflammatory cells from brain blood vessels of P. berghei ANKA-infected mice. Infection of susceptible mouse-strains with this parasite strain results in the induction of experimental cerebral malaria, a neurologic syndrome that recapitulates certain important aspects of Plasmodium falciparum-mediated severe malaria in humans 1,2 . Mature forms of blood-stage malaria express parasitic proteins on the surface of the infected erythrocyte, which allows them to bind to vascular endothelial cells. This process induces obstructions in blood flow, resulting in hypoxia and haemorrhages 3 and also stimulates the recruitment of inflammatory leukocytes to the site of parasite sequestration.
Unlike other infections, i.e neutrotopic viruses4-6, both malaria-parasitized red blood cells (pRBC) as well as associated inflammatory leukocytes remain sequestered within blood vessels rather than infiltrating the brain parenchyma. Thus to avoid contamination of sequestered leukocytes with non-inflammatory circulating cells, extensive intracardial perfusion of infected-mice prior to organ extraction and tissue processing is required in this procedure to remove the blood compartment. After perfusion, brains are harvested and dissected in small pieces. The tissue structure is further disrupted by enzymatic treatment with Collagenase D and DNAse I. The resulting brain homogenate is then centrifuged on a Percoll gradient that allows separation of brain-sequestered leukocytes (BSL) from myelin and other tissue debris. Isolated cells are then washed, counted using a hemocytometer and stained with fluorescent antibodies for subsequent analysis by flow cytometry.
This procedure allows comprehensive phenotypic characterization of inflammatory leukocytes migrating to the brain in response to various stimuli, including stroke as well as viral or parasitic infections. The method also provides a useful tool for assessment of novel anti-inflammatory treatments in pre-clinical animal models.

Isolation and Analysis of Brain-sequestered Leukocytes from Plasmodium berghei ANKA-infected Mice

A method for isolation of adherent inflammatory leukocytes from brain blood vessels of Plasmodium berghei ANKA-infected mice is described. The method allows quantification as well as phenotypic characterization of isolated leukocytes after staining with fluorescent antibodies and subsequent analysis by flow cytometry.

Isolement et analyse de Brain-séquestrés de leucocytes<em&gt; Plasmodium berghei</em&gt; ANKA-souris infectées

We describe a method for isolation and  characterization of adherent inflammatory cells from brain blood vessels of P. berghei ANKA-infected mice. ...

Recherche

Immunologie et infection

Rapid Identification of Gram Negative Bacteria from Blood Culture Broth Using MALDI-TOF Mass Spectrometry

An important role of the clinical microbiology laboratory is to provide rapid identification of bacteria causing bloodstream infection. Traditional identification requires the sub-culture of signaled blood culture broth with identification available only after colonies on solid agar have matured. MALDI-TOF MS is a reliable, rapid method for identification of the majority of clinically relevant bacteria when applied to colonies on solid media. The application of MALDI-TOF MS directly to blood culture broth is an attractive approach as it has potential to accelerate species identification of bacteria and improve clinical management. However, an important problem to overcome is the pre-analysis removal of interfering resins, proteins and hemoglobin&#160;contained in blood culture specimens which, if not removed, interfere with the MS spectra and can result in insufficient or low discrimination identification scores. In addition it is necessary to concentrate bacteria to develop spectra of sufficient quality. The presented method describes the concentration, purification, and extraction of Gram negative bacteria allowing for the early identification of bacteria from a signaled blood culture broth.

The application of matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (MS) directly to blood culture broth expedites the identification of bacteria. The presented method is a rapid and reliable method for identification of Gram negative bacteria directly from blood culture broth.

Identification rapide des bactéries à Gram négatif de sang Bouillon de culture à l&#39;aide MALDI-TOF spectrométrie de masse

An important role of the clinical microbiology laboratory is to provide rapid identification of bacteria causing bloodstream infection. Traditional ...

Isolation, Identification, and Purification of Murine Thymic Epithelial Cells

The thymus is a vital organ for T lymphocyte development. Of thymic stromal cells, thymic epithelial cells (TECs) are particularly crucial at multiple stages of T cell development: T cell commitment, positive selection and negative selection. However, the function of TECs in the thymus remains incompletely understood. In the article, we provide a method to isolate TEC subsets from fresh mouse thymus using a combination of mechanical disruption and enzymatic digestion. The method allows thymic stromal cells and thymocytes to be efficiently released from cell-cell and cell-extracellular matrix connections and to form a single-cell suspension. Using the isolated cells, multiparameter flow cytometry can be applied to identification and characterization of TECs and dendritic cells. Because TECs are a rare cell population in the thymus, we also describe an effective way to enrich and purify TECs by depleting thymocytes, the most abundant cell type in the thymus. Following the enrichment, cell sorting time can be decreased so that loss of cell viability can be minimized during purification of TECs. Purified cells are suitable for various downstream analyses like Real Time-PCR, Western blot and gene expression profiling. The protocol will promote research of TEC function and as well as the development of in vitro T cell reconstitution.

Here we describe an efficient method for isolation, identification, and purification of mouse thymic epithelial cells (TECs). The protocol can be utilized for studies of thymus function for normal T cell development, thymus dysfunction, and T cell reconstitution.

Isolement, identification et la purification de cellules murines thymique épithéliales

The thymus is a vital organ for T lymphocyte development. Of thymic stromal cells, thymic epithelial cells (TECs) are particularly crucial at multiple ...

Neutrophil Isolation and Analysis to Determine their Role in Lymphoma Cell Sensitivity to Therapeutic Agents

Neutrophils are the most abundant (40% to 75%) type of white blood cells and among the first inflammatory cells to migrate towards the site of inflammation. They are key players in the innate immune system and play major roles in cancer biology. Neutrophils have been proposed as key mediators of malignant transformation, tumor progression, angiogenesis and in the modulation of the antitumor immunity; through their release of soluble factors or their interaction with tumor cells. To characterize the specific functions of neutrophils, a fast and reliable method is coveted for in vitro isolation of neutrophils from human blood. Here, a density gradient separation method is demonstrated to isolate neutrophils as well as mononuclear cells from the blood. The procedure consists of layering the density gradient solution such as Ficoll carefully above the diluted blood obtained from patients diagnosed with chronic lymphocytic leukemia (CLL), followed by centrifugation, isolation of mononuclear layer, separation of neutrophils from RBCsby dextran then lysis of residual erythrocytes. This method has been shown to isolate neutrophils &#8805; 90 % pure. To mimic the tumor microenvironment, 3-dimensional (3D) experiments were performed using basement membrane matrix such as Matrigel. Given the short half-life of neutrophils in vitro, 3D experiments with fresh human neutrophils cannot be performed. For this reason promyelocytic HL60 cells are differentiated along the granulocytic pathway using the differentiation inducers dimethyl sulfoxide (DMSO) and retinoic acid (RA). The aim of our experiments is to study the role of neutrophils on the sensitivity of lymphoma cells to anti-lymphoma agents. However these methods can be generalized to study the interactions of neutrophils or neutrophil-like cells with a large range of cell types in different situations.

Neutrophils are the most abundant type of white blood cells. The isolation of neutrophils from human blood by density gradient separation method and the differentiation of human promyelocytic (HL60) cells along the granulocytic pathway are described here; to test their role on sensitivity of lymphoma cells to anti-lymphoma agents.

Neutrophiles Isolement et analyse pour déterminer leur rôle dans le lymphome cellulaire Sensibilité aux agents thérapeutiques

Neutrophils are the most abundant (40% to 75%) type of white blood cells and among the first inflammatory cells to migrate towards the site of ...

Identification of Plasmodesmal Localization Sequences in Proteins In Planta

Plasmodesmata (Pd) are cell-to-cell connections that function as gateways through which small and large molecules are transported between plant cells. Whereas Pd transport of small molecules, such as ions and water, is presumed to occur passively, cell-to-cell transport of biological macromolecules, such proteins, most likely occurs via an active mechanism that involves specific targeting signals on the transported molecule. The scarcity of identified plasmodesmata (Pd) localization signals (PLSs) has severely restricted the understanding of protein-sorting pathways involved in plant cell-to-cell macromolecular transport and communication. From a wealth of plant endogenous and viral proteins known to traffic through Pd, only three PLSs have been reported to date, all of them from endogenous plant proteins. Thus, it is important to develop a reliable and systematic experimental strategy to identify a functional PLS sequence, that is both necessary and sufficient for Pd targeting, directly in the living plant cells. Here, we describe one such strategy using as a paradigm the cell-to-cell movement protein (MP) of the Tobacco mosaic virus (TMV). These experiments, that identified and characterized the first plant viral PLS, can be adapted for discovery of PLS sequences in most Pd-targeted proteins.

Identification of Plasmodesmal Localization Sequences in Proteins In Planta

Plant intercellular connections, the plasmodesmata (Pd), play central roles in plant physiology and plant-virus interactions. Critical to Pd transport are sorting signals that direct proteins to Pd. However, our knowledge about these sequences is still in its infancy. We describe a strategy to identify Pd localization signals in Pd-targeted proteins.

Identification de séquences de localisation Plasmodesmal en protéines In Planta

Plasmodesmata (Pd) are cell-to-cell connections that function as gateways through which small and large molecules are transported between plant cells. ...

Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages

Salmonella typhimurium is a facultative intracellular bacterium that causes gastroenteritis in humans. After invasion of the lamina propria, S. typhimurium bacteria are quickly detected and phagocytized by macrophages, and contained in vesicles known as phagosomes in order to be degraded. Isolation of S. typhimurium-containing phagosomes have been widely used to study how S. typhimurium infection alters the process of phagosome maturation to prevent bacterial degradation. Classically, the isolation of bacteria-containing phagosomes has been performed by sucrose gradient centrifugation. However, this process is time-consuming, and requires specialized equipment and a certain degree of dexterity. Described here is a simple and quick method for the isolation of S. typhimurium-containing phagosomes from macrophages by coating the bacteria with biotin-streptavidin-conjugated magnetic beads. Phagosomes obtained by this method can be suspended in any buffer of choice, allowing the utilization of isolated phagosomes for a broad range of assays, such as protein, metabolite, and lipid analysis. In summary, this method for the isolation of S. typhimurium-containing phagosomes is specific, efficient, rapid, requires minimum equipment, and is more versatile than the classical method of isolation by sucrose gradient-ultracentrifugation.

Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages

We describe here a simple and quick method for the isolation of Salmonella typhimurium-containing phagosomes from macrophages by coating the bacteria with biotin and streptavidin.

Isolement de Salmonella typhimurium-contenant des Phagosomes des Macrophages

Salmonella typhimurium is a facultative intracellular bacterium that causes gastroenteritis in humans. After invasion of the lamina propria, S. ...

Identification and Isolation of Oligopotent and Lineage-committed Myeloid Progenitors from Mouse Bone Marrow

Myeloid progenitors that yield neutrophils, monocytes and dendritic cells (DCs) can be identified in and isolated from the bone marrow of mice for hematological and immunological analyses. For example, studies of the cellular and molecular properties of myeloid progenitor populations can reveal mechanisms underlying leukemic transformation, or demonstrate how the immune system responds to pathogen exposure. Previously described flow cytometry strategies for myeloid progenitor identification have enabled significant advances in many fields, but the fractions they identify are very heterogeneous. The most commonly used gating strategies define bone marrow fractions that are enriched for the desired populations, but also contain large numbers of &#34;contaminating&#34; progenitors. Our recent studies have resolved much of this heterogeneity, and the protocol we present here permits the isolation of 6 subpopulations of oligopotent and lineage-committed myeloid progenitors from 2 previously described bone marrow fractions. The protocol describes 3 stages: 1) isolation of bone marrow cells, 2) enrichment for hematopoietic progenitors by magnetic-activated cell sorting (lineage depletion by MACS), and 3) identification of myeloid progenitor subsets by flow cytometry (including fluorescence-activated cell sorting, FACS, if desired). This approach permits progenitor quantification and isolation for a variety of in vitro and in vivo applications, and has already yielded novel insight into pathways and mechanisms of neutrophil, monocyte, and DC differentiation.

We demonstrate how to identify and isolate 6 subsets of myeloid progenitors from murine bone marrow using a combination of magnetic and fluorescence sorting (MACS and FACS). This protocol can be used for in vitro culture assays (methylcellulose or liquid cultures), in vivo adoptive transfer experiments, and RNA/protein analyses.

Identification et isolement des Oligopotent et des progéniteurs myéloïdes Lineage-commis de moelle osseuse de souris

Myeloid progenitors that yield neutrophils, monocytes and dendritic cells (DCs) can be identified in and isolated from the bone marrow of mice for ...

Isolation and Identification of Extravascular Immune Cells of the Heart

The immune system is an essential component of a healthy heart. The myocardium is home to a rich population of different immune cell subsets with functional compartmentalization both during steady state and during different forms of inflammation. Until recently, the study of immune cells in the heart required the use of microscopy or poorly developed digestion protocols, which provided enough sensitivity during severe inflammation but were unable to confidently identify small &#8212; but key &#8212; populations of cells during steady state. Here, we discuss a simple method combining enzymatic (collagenase, hyaluronidase and DNAse) and mechanical digestion of murine hearts preceded by intravascular administration of fluorescently-labelled antibodies to differentiate small but unavoidable intravascular cell contaminants. This method generates a suspension of isolated viable cells that can be analyzed by flow cytometry for identification, phenotyping and quantification, or further purified with fluorescence-activated cell sorting or magnetic bead separation for transcriptional analysis or in vitro studies. We include an example of a step-by-step flow cytometric analysis to differentiate the key macrophage and dendritic cell populations of the heart. For a medium sized experiment (10 hearts) the completion of the procedure requires 2&#8211;3 h.

This protocol presents a simple and efficient method to isolate, identify and quantify immune cells residing in the myocardium of mice during steady state or inflammation. The protocol combines enzymatic and mechanical digestion for the generation of a single cell suspension that can be further analyzed by flow cytometry.

Isolement et Identification des cellules immunitaires extravasculaires du coeur

The immune system is an essential component of a healthy heart. The myocardium is home to a rich population of different immune cell subsets with ...

A Galleria mellonella Oral Administration Model to Study Commensal-Induced Innate Immune Responses

The investigation of the immunogenic potential of commensal bacteria on the host immune system is one essential component when studying intestinal host-microbe interactions. It is well established that different commensals exhibit a different potential to stimulate the host intestinal immune system. Such investigations involve vertebrate animals, especially rodents. Since increasing ethical concerns are linked with experiments involving vertebrates, there is a high demand for invertebrate replacements models. 
Here, we provide a Galleria mellonella oral administration model using commensal non-pathogenic bacteria and the possible assessment of the immunogenic potential of commensals on the G. mellonella immune system. We demonstrate that G. mellonella is a useful alternative invertebrate replacement model that allows the analysis of commensals with different immunogenic potential such as Bacteroides vulgatus and Escherichia coli. Interestingly, the bacteria exhibited no killing effect on the larvae, which is similar to mammals. The immune responses of G. mellonella were comparable with vertebrate innate immune responses and involve recognition of the bacteria and production of antimicrobial molecules. We propose that G. mellonella was able to restore previous microbiota balance, which is well known from healthy mammalian individuals. Although providing comparable innate immune responses in both G. mellonella and vertebrates, G. mellonella does not harbor an adaptive immune system. Since the investigated components of the innate immune system are evolutionary conserved, the model allows a prescreening and first analysis of bacterial immunogenic properties.

A Galleria mellonella Oral Administration Model to Study Commensal-Induced Innate Immune Responses

Here, we provide a detailed protocol for an oral administration model using Galleria mellonella larvae and how to characterize induced innate immune responses. Using this protocol, researchers without practical experience will be able to use the G. mellonella force-feeding method.

Un modèle d’Administration orale à des réponses immunitaires innées Study Commensal-Induced Galleria mellonella

The investigation of the immunogenic potential of commensal bacteria on the host immune system is one essential component when studying intestinal ...

Quantifying Human Norovirus Virus-like Particles Binding to Commensal Bacteria Using Flow Cytometry

Commensal bacteria are well established to impact infection of eukaryotic viruses. Direct binding between the pathogen and the host microbiome is responsible for altering infection for many of these viruses. Thus, characterizing the nature of virus-bacteria binding is a foundational step needed for elucidating the mechanism(s) by which bacteria alter viral infection. For human norovirus, commensal bacteria enhance B cell infection. The virus directly binds to these bacteria, indicating that this direct interaction is involved in the mechanism of infection enhancement. A variety of techniques can be used to quantify interactions between bacteria and viruses including scintillation counting of radiolabeled viruses and polymerase chain reaction (PCR). Both methods require the use of live virus, which may need to be generated in the laboratory. Currently, none of the established in vitro culture systems available for human norovirus are robust enough to allow for generation of highly concentrated viral stocks. In lieu of live virus, virus-like particles (VLPs) have been used to characterize the interactions between norovirus and bacteria. Herein a flow cytometry method is described with uses virus specific antibodies to quantify VLP binding to gram-negative and gram-positive bacteria. Inclusion of both bacteria only and isotype controls allowed for optimization of the assay to reduce background antibody binding and accurate quantification of VLP attachment to the bacteria tested. High VLP:bacterium ratios result in VLPs binding to large percentages of the bacterial population. However, when VLP quantities are decreased, the percent of bacteria bound also decreases. Ultimately, this method can be employed in future experiments elucidating the specific conditions and structural components that regulate norovirus:bacterial interactions.

The goal of this protocol is to quantify binding of the eukaryotic pathogen human norovirus to bacteria. After performing an initial virus-bacterium attachment assay, flow cytometry is used to detect virally-bound bacteria within the population.