Name: a galleria mellonella oral administration model to study commensal-induced innate immune responses
Uploaded: 2019-03-21T15:00:00
Description: Watch this Scientific Journal Video about A Galleria mellonella Oral Administration Model to Study Commensal-Induced Innate Immune Responses at JoVE.com

This work was funded by the DFG (SPP1656), the DFG research training group 1708, the Bundesministerium f&#252;r Bildung und Forschung (BMBF), and the German Center for Infection Research (DZIF).

1. G. mellonella rearing and preparation of the larvae for the experiments
NOTE: The cycle from egg to last instar larva takes approximately 5-6 weeks.
<ol>
	<li>Transfer the eggs laid by adult moths to 2 L boxes containing wax moth substrate (22% corn grits, 22% wheat meal, 17.5% beeswax, 11% skimmed milk powder, 11% honey, 11% glycerol, 5.5% dried yeast). Perform the whole breeding at 30 &#176;C in the dark.</li>
	<li>Transfer 25 g of substrate containing the larvae into fresh sub...

<ol>
	<li>Nell, S., Suerbaum, S., Josenhans, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+impact+of+the+microbiota+on+the+pathogenesis+of+IBD:+lessons+from+mouse+infection+models.">The impact of the microbiota on the pathogenesis of IBD: lessons from mouse infection models.</a> Nature Reviews Microbiology. 8 (8), 564-577 (2010).</li><li>Muniz, L. R., Knosp, C., Yeretssian, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intestinal+antimicrobial+peptides+during+homeostasis,+infection,+and+disease.">Intestinal antimicrobial peptides during homeostasis, infection, and disease.</a> Frontiers in Immunology. 3, 310 (2012).</li><li>Ivanov, I. I., Honda, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intestinal+commensal+microbes+as+immune+modulators.">Intestinal commensal microbes as immune modulators.</a> Cell Host Microbe. 12 (4), 496-508 (2012).</li><li>Ayres, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inflammasome-microbiota+interplay+in+host+physiologies.">Inflammasome-microbiota interplay in host physiologies.</a> Cell Host Microbe. 14 (5), 491-497 (2013).</li><li>Champion, O. L., Titball, R. W., Bates, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Standardization+of+G.+mellonella+Larvae+to+Provide+Reliable+and+Reproducible+Results+in+the+Study+of+Fungal+Pathogens.">Standardization of G. mellonella Larvae to Provide Reliable and Reproducible Results in the Study of Fungal Pathogens.</a> Journal of Fungi (Basel). 4 (3), (2018).</li><li>Wojda, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunity+of+the+greater+wax+moth+Galleria+mellonella.">Immunity of the greater wax moth Galleria mellonella.</a> Insect Science. , (2016).</li><li>Buchmann, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+of+Innate+Immunity:+Clues+from+Invertebrates+via+Fish+to+Mammals.">Evolution of Innate Immunity: Clues from Invertebrates via Fish to Mammals.</a> Frontiers in Immunology. 5, 459 (2014).</li><li>Lange, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Galleria+mellonella:+A+Novel+Invertebrate+Model+to+Distinguish+Intestinal+Symbionts+From+Pathobionts.">Galleria mellonella: A Novel Invertebrate Model to Distinguish Intestinal Symbionts From Pathobionts.</a> Frontiers in Immunology. 9 (2114), (2018).</li><li>Tsai, C. J., Loh, J. M., Proft, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Galleria+mellonella+infection+models+for+the+study+of+bacterial+diseases+and+for+antimicrobial+drug+testing.">Galleria mellonella infection models for the study of bacterial diseases and for antimicrobial drug testing.</a> Virulence. , 1-16 (2016).</li><li>Bolouri Moghaddam, M. 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=The+potential+of+the+Galleria+mellonella+innate+immune+system+is+maximized+by+the+co-presentation+of+diverse+antimicrobial+peptides.">The potential of the Galleria mellonella innate immune system is maximized by the co-presentation of diverse antimicrobial peptides.</a> Biological Chemistry. 397 (9), 939-945 (2016).</li><li>Casanova-Torres, A. M., Goodrich-Blair, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immune+Signaling+and+Antimicrobial+Peptide+Expression+in+Lepidoptera.">Immune Signaling and Antimicrobial Peptide Expression in Lepidoptera.</a> Insects. 4 (3), 320-338 (2013).</li><li>Mukherjee, K., 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=Galleria+mellonella+as+a+model+system+for+studying+Listeria+pathogenesis.">Galleria mellonella as a model system for studying Listeria pathogenesis.</a> Applied and Environmental Microbiology. 76 (1), 310-317 (2010).</li><li>Brennan, M., Thomas, D. Y., Whiteway, M., Kavanagh, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Correlation+between+virulence+of+Candida+albicans+mutants+in+mice+and+Galleria+mellonella+larvae.">Correlation between virulence of Candida albicans mutants in mice and Galleria mellonella larvae.</a> FEMS Immunological and Medical Microbiology. 34 (2), 153-157 (2002).</li><li>Miyata, S., Casey, M., Frank, D. W., Ausubel, F. M., Drenkard, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+the+Galleria+mellonella+caterpillar+as+a+model+host+to+study+the+role+of+the+type+III+secretion+system+in+Pseudomonas+aeruginosa+pathogenesis.">Use of the Galleria mellonella caterpillar as a model host to study the role of the type III secretion system in Pseudomonas aeruginosa pathogenesis.</a> Infection and Immunity. 71 (5), 2404-2413 (2003).</li><li>Waidmann, M., 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=Bacteroides+vulgatus+protects+against+Escherichia+coli-induced+colitis+in+gnotobiotic+interleukin-2-deficient+mice.">Bacteroides vulgatus protects against Escherichia coli-induced colitis in gnotobiotic interleukin-2-deficient mice.</a> Gastroenterology. 125 (1), 162-177 (2003).</li><li>Lange, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extensive+Mobilome-Driven+Genome+Diversification+in+Mouse+Gut-Associated+Bacteroides+vulgatus+mpk.">Extensive Mobilome-Driven Genome Diversification in Mouse Gut-Associated Bacteroides vulgatus mpk.</a> Genome Biology and Evolution. 8 (4), 1197-1207 (2016).</li><li>Hermann-Bank, M. L., Skovgaard, K., Stockmarr, A., Larsen, N., Molbak, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Gut+Microbiotassay:+a+high-throughput+qPCR+approach+combinable+with+next+generation+sequencing+to+study+gut+microbial+diversity.">The Gut Microbiotassay: a high-throughput qPCR approach combinable with next generation sequencing to study gut microbial diversity.</a> BMC Genomics. 14, 788 (2013).</li><li>Sato, K., 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=OmpA+variants+affecting+the+adherence+of+ulcerative+colitis-derived+Bacteroides+vulgatus.">OmpA variants affecting the adherence of ulcerative colitis-derived Bacteroides vulgatus.</a> Journal of Medical and Dental Science. 57 (1), 55-64 (2010).</li><li>Freitak, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+maternal+transfer+of+bacteria+can+mediate+trans-generational+immune+priming+in+insects.">The maternal transfer of bacteria can mediate trans-generational immune priming in insects.</a> Virulence. 5 (4), 547-554 (2014).</li><li>Pfaffl, M. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+mathematical+model+for+relative+quantification+in+real-time+RT-PCR.">A new mathematical model for relative quantification in real-time RT-PCR.</a> Nucleic Acids Research. 29 (9), 45 (2001).</li><li>Ramarao, N., Nielsen-Leroux, C., Lereclus, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+insect+Galleria+mellonella+as+a+powerful+infection+model+to+investigate+bacterial+pathogenesis.">The insect Galleria mellonella as a powerful infection model to investigate bacterial pathogenesis.</a> Journal of Visualized Experiments. (70), e4392 (2012).</li><li>Ramarao, N., Nielsen-Leroux, C., Lereclus, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+insect+Galleria+mellonella+as+a+powerful+infection+model+to+investigate+bacterial+pathogenesis.">The insect Galleria mellonella as a powerful infection model to investigate bacterial pathogenesis.</a> Journal of Visualized Experiments. (70), e4392 (2012).</li></ol>

The G. mellonella model is a frequently used model to assess bacterial virulence factors in a systemic infection approach21. Since many pathogens and bacteria enter the host via the oral colonization or infection route, new insights need to be found to evaluate G. mellonella as a model for oral colonization and infection.
The possibility to rear G. mellonella between 15-37 &#176;C is a great advantage since most mammalian models maintain body ...

The intestinal microbiome is an essential component for maintenance of homeostasis, and involves both innate and adaptive immune responses1,2. The commensal microbiota community is characterized by different main commensal constituents: symbionts that confer beneficial effects by important immunomodulatory functions, and pathobionts that can have detrimental effects in genetically predisposed hosts and promote and trigger intestinal inflammation3,4. Many studies on symbionts and pathobionts and their influence on the host immune system have been published mainly studying adaptive immune responses.
Since these studies involve many animals for the investigations and the protection and replacement of animals used for experimentation is of increasing public interest, we seek to find a replacement model to allow for a screening of different bacterial immunogenic properties. Insects, especially Galleria mellonella, are a widely used replacement model in infection research. G. mellonella combines different advantages such as low costs and high throughput; it allows oral administration of bacteria, which is the natural exposure route, and it allows for systemic infection5,6. G. mellonella further enables incubation at 37 &#176;C, which is the physiological body temperature of mammals and the optimum for bacterial virulence factor expression5. The main advantage of G. mellonella is the conserved innate immune system that enables the discrimination of self from non-self and encodes a variety of pattern recognition receptors like apolipophorin or the opsonin hemolin6,7. Upon microbe recognition, G. mellonella can trigger different downstream humoral immune responses. It can induce oxidative stress responses and secrete reactive oxygen species (ROS) which involves the activity of NOS (nitric oxidase synthase) and NOX (NADPH oxidase)6,8. In addition, G. mellonella activates a potent antimicrobial peptide (AMP) response, which results in the secretion of a mixture of different AMPs such as gloverin, moricin, cecropin or the defensin-like gallerimycin6,8,9,10. Generally, AMPs have quite broad host specificity against Gram-positive and Gram-negative bacteria and fungi and have to provide an potent response since insects are lacking any adaptive response10. Gloverin is an AMP active against bacteria and fungi and inhibits outer membrane formation6,11. Moricins exhibit their antimicrobial function against Gram-positive and Gram-negative bacteria by penetrating the membrane and forming a pore9,11. Cecropins provide activity against bacteria and fungi and permeabilize the membrane similarly like moricins9,10. Gallerimycin is a defensin-like peptide with anti-fungal properties9. Interestingly, it was found that the combination of cecropin and gallerimycin had a synergistic activity against E. coli10.
Due to their easy-to-use character G. mellonella larvae are an often used infection model to assess bacterial pathogenicity. In particular, studies in which data obtained from G. mellonella correlate with data obtained from mice support the strength of this alternative host model. It was found that the most pathogenic serotypes of Listeria monocytogenes in a mouse infection model lead also to higher mortality rates in G. mellonella after systemic infection. Further, less virulent serotypes turned out to be also less virulent in the G. mellonella model12. Similar observations have been made with the human pathogenic fungi Candida albicans. Virulence of different C. albicans strains has been assessed by systemic infection and subsequent monitoring of larval survival. Mouse avirulent strains were also avirulent or exhibited reduced virulence in G. mellonella, whereas the mouse virulent strains lead also to high larval mortality13. The G. mellonella model could further be used to identify type 3 secretion system pathogenicity factors of Pseudomonas aeruginosa14.
Since most investigations involving G. mellonella were focused on virulence factors using the systemic infection approach we were especially interested in providing a method suitable for the analysis of intestinal commensals in an oral force-feeding model in which we can apply a distinct dosage of bacteria per larvae and not only observe the larval mortality rate but analyze different hallmarks of innate immune responses to maintain intestinal homeostasis.
Our method helps to increase the use of G. mellonella as a replacement model since we combine the application of bacteria and the analysis of RNA expression. It is not only useful to strengthen the meaning of bacterial pathogenesis studies when including the analysis of immune responses after oral administration and not only the observation of mortality rates after systemic infection. Our methods allows for the analysis of immunogenic properties of bacterial non-pathogenic commensals since it is provides more complex conditions than cell culture by offering an intestinal barrier in a living organism.

<table border="0" cellpadding="0" cellspacing="0" style="width:701px;" width="702">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">1.5 mL tubes</td>
			<td style="width:200px;">Eppendorf</td>
			<td style="width:119px;">0030120086</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">100 bp DNA ladder&#160;</td>
			<td style="width:200px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">15628019</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1-Bromo-3-Chloropropane (BCP)</td>
			<td>Sigma-Aldrich</td>
			<td style="width:119px;">B9673</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">2 mL tubes</td>
			<td style="width:200px;">Eppendorf</td>
			<td style="width:119px;">0030120094</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">2x Mangomix</td>
			<td style="width:200px;">Bioline</td>
			<td style="width:119px;">BIO-25033</td>
			<td>Colony PCR</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">50 mL tubes</td>
			<td style="width:200px;">Greiner Bio-One</td>
			<td style="width:119px;">210 261</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Agarose</td>
			<td style="width:200px;">Biozym</td>
			<td style="width:119px;">840004</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Beeswax</td>
			<td style="width:200px;">Mixed-Store.de</td>
			<td style="width:119px;">&#160;-</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Brain heart infusion broth</td>
			<td>Thermo Fisher Scientific</td>
			<td style="width:119px;">CM1135</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">CloneJET PCR Cloning Kit</td>
			<td style="width:200px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">K1232</td>
			<td>Cloning vector for 16S fragments</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Corn grits</td>
			<td style="width:200px;">Osterm&#252;hle Naturkost GmbH</td>
			<td style="width:119px;">306</td>
			<td>Organic cultivation</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Difco LB Agar, Miller (Luria-Bertani)</td>
			<td>Becton Dickinson</td>
			<td style="width:119px;">BD</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Difoco LB Broth, Miller (Luria-Bertani)</td>
			<td>Becton Dickinson</td>
			<td style="width:119px;">244610</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">DNA-free DNA Removal Kit&#160;</td>
			<td style="width:200px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">244510</td>
			<td>&#160;Dnase digestion</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dried yeast</td>
			<td style="width:200px;">Rapunzel</td>
			<td style="width:119px;">&#160;-</td>
			<td>Organic cultivation</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dulbecco&#39;s Phosphate-Buffered Saline (DPBS)</td>
			<td>Thermo Fisher Scientific</td>
			<td style="width:119px;">14040</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Ethanol</td>
			<td style="width:200px;">VWR</td>
			<td style="width:119px;">20821.330</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Glycerol</td>
			<td>Sigma-Aldrich</td>
			<td style="width:119px;">W252506</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Honey</td>
			<td style="width:200px;">Osterm&#252;hle Naturkost GmbH</td>
			<td style="width:119px;">487</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Isopropanol&#160;</td>
			<td style="width:200px;">VWR</td>
			<td style="width:119px;">20842.330</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Lightcycler 480 Instrument II</td>
			<td style="width:200px;">Roche Molecular Systems</td>
			<td style="width:119px;">5015278001</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">LightCycler 480 Multiwell Plate 96, white</td>
			<td style="width:200px;">Roche Molecular Systems</td>
			<td style="width:119px;">4729692001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Manual Microsyringe Pump with Digital Display</td>
			<td>World Precision Instruments</td>
			<td style="width:119px;">DMP</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Micro-Fine+ U-100 insulin syringe 0.3 x 8 mm</td>
			<td>Becton Dickinson</td>
			<td style="width:119px;">324826</td>
			<td>Oral administration</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Mortar, unglazed</td>
			<td style="width:200px;">VWR</td>
			<td>410-9327&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Nanodrop</td>
			<td>Thermo Fisher Scientific</td>
			<td style="width:119px;">13-400-518</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Nuclease-free water&#160;</td>
			<td style="width:200px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">10977035</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Oxoid AnaeroGen sachets&#160;</td>
			<td>Thermo Fisher Scientific</td>
			<td style="width:119px;">AN0025A</td>
			<td>Quality and quantity of RNA</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">PCR stripes</td>
			<td style="width:200px;">Biozym</td>
			<td style="width:119px;">710970</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Pestle, unglazed grinding surface</td>
			<td style="width:200px;">VWR</td>
			<td>410-9324&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Phusion proof-reading enzyme&#160;</td>
			<td style="width:200px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">F553S</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Primers</td>
			<td style="width:200px;">Biomers</td>
			<td style="width:119px;">&#160;-</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">PureYield Plasmid Miniprep System</td>
			<td style="width:200px;">Promega</td>
			<td style="width:119px;">A1222</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">QuantiFast SYBR Green PCR kit&#160;</td>
			<td style="width:200px;">Qiagen</td>
			<td style="width:119px;">204056</td>
			<td>qPCR for bacterial copy number measurment</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">QuantiFast SYBR Green RT-PCR Kit&#160;</td>
			<td style="width:200px;">Qiagen</td>
			<td>204156</td>
			<td>qRT-PCR for gene expression measurements</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">QuantiTect Reverse Transcription Kit&#160;</td>
			<td style="width:200px;">Qiagen</td>
			<td style="width:119px;">205311</td>
			<td>cDNA synthesis</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Qubit Assay Tubes</td>
			<td style="width:200px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">Q32856</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Qubit dsHS DNA kit&#160;</td>
			<td style="width:200px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">Q32851</td>
			<td>Quantification of plasmid and cDNA samples</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Qubit fluorometer</td>
			<td style="width:200px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">Q33226</td>
			<td>Quantification of plasmid and cDNA samples</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">RNase-ExitusPlus</td>
			<td style="width:200px;">AppliChem</td>
			<td style="width:119px;">A7153</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Rnasin Ribonuclease Inhibitor</td>
			<td style="width:200px;">Promega</td>
			<td style="width:119px;">N2511</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Skimmed milk powder</td>
			<td>Sucofin</td>
			<td style="width:119px;">&#160;-</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">SYBR safe DNA Gel Stain</td>
			<td style="width:200px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">S33102</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">TRI reagent&#160;</td>
			<td>Sigma-Aldrich</td>
			<td style="width:119px;">T9424</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Weighing boat</td>
			<td>VWR</td>
			<td style="width:119px;">10803-148</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Wheat meal</td>
			<td style="width:200px;">Osterm&#252;hle Naturkost GmbH</td>
			<td style="width:119px;">6462</td>
			<td>Organic cultivation</td>
		</tr>
	</tbody>
</table>

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.

The G. mellonella hemolymph infection model in widely used to analyze the virulence factors of a huge variety of pathogens. Most measurements include the analysis of larvae mortality, which is a quite easy method. Nevertheless, this method does not allow conclusions about immune responses in general and link the results of G. mellonella immune responses with vertebrate immune mechanisms. The G. mellonella oral administration model on the other hand is only rarel...

Watch this Scientific Journal Video about A Galleria mellonella Oral Administration Model to Study Commensal-Induced Innate Immune Responses at JoVE.com

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.

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 ...

Our protocol expands the use of G.mellonella from a systemic infection model to a model that allows bacterial administration via the natural oral route. G.mellonella is a suitable replacement model for rodents in analyzing different hallmarks of innate micro-post interactions as the larvae can be used for human pathogenic bacteria. Begin by transferring the eggs laid by adult moths to two liter boxes containing wax moth substrate, at 30 degrees Celsius, in the dark.After one to two weeks, transfer 25 grams of larva containing substrate into fresh substrate, when small and tiny larva become visible. Synchronize the larvae after two weeks according to their size, into groups of 30 to 40 larvae in new two liter containers on wax moth substrate. After two weeks, select larvae for the experiment by weight.Using only pale, fast moving larvae with a mass of 180 to 200 milligrams. To force feed the larvae, load an insulin syringe with a blunt-ended needle for oral application, with one times 10 to the seventh bacteria per 10 microliters of DPBS per larva. Load the syringe into a microsyringe pump.Wait for a larva to open its mouth parts before inserting the syringe carefully between the mandibles and delivering the bacteria. When all of the larva have been fed, incubate the animals in the dark at 37 degrees Celsius, between one to 24 hours. For larva processing, clean a safety hood with ethanol and spray reagent for preventing RNase contamination.Snap freeze the living larva in liquid nitrogen. Homogenize each individual frozen larva using a mortar and pestle and a small volume of liquid nitrogen. When a powdered homogenate has been produced, transfer the homogenate to a disposable wait boat and wait for the liquid nitrogen to evaporate.When all of the larva have been homogenized, mix the powdered homogenates with one milliliter of TRIzol in a two milliliter tube. Incubate the mixture at room temperature for one hour. At the end of the incubation, pellet the homogenate by centrifugation.Transfer the supernatant into a new tube. Mix the supernatant with 200 microliters of 1-Bromo-3-chloropropane, or BCP. Vortex and incubate for five minutes at room temperature, followed by a 10 minute incubation on ice.At the end of the second incubation, centrifuge the BCP added reaction and transfer the upper transparent layer into a new, two milliliter tube. Precipitate the RNA of the transferred upper layer with 500 microliters of isopropanol by mixing and inverting the tube for five minutes. Then collect the precipitate RNA by centrifugation.Wash the precipitated RNA pellet with 500 microliters of 75%ethanol and dry the RNA for five to 10 minutes at room temperature. When the ethanol has evaporated, add 100 microliters of ribonuclease inhibitor in nuclease-free water to the dried RNA pellet, and carefully vortex the tube until the pellet is completely dissolved. Measure the RNA quality and quantity by standard protocols, ensuring that the 260 to 280 ratio is approximately two, and the 260 to 230 ratio is in the range of two to 2.2.Then use five micrograms of the isolated RNA for DNase digestion and gene expression analysis, according to standard protocols. G.mellonella is able to clear the initial force fed bacterial load until no bacteria are detectable. With the 16s gene copy numbers of both B.vulgatus and E.coli substantially decreased within 24 hours.Commensal administered a G.mellonella larvae induce RNA gene expression of various innate immunity marker genes. For example, the LPS recognition molecules, apolipophorin and hemolin are generally expressed more highly in the E.coli administered larvae compared to B.vulgatus administered larvae. Further, the production of reactive oxygen and nitrogen species are strongly upregulated upon E.coli force feeding compared to B.vulgatus, as well as antioxidative GST gene expression.In addition, differential microbial peptide expression is induced more strongly after E.coli administration than in response to B.vulgatus force feeding. Remember to use only healthy, white, quickly moving larvae, to use patience during force feeding to avoid stressing the larvae and to include all of the necessary controls. The activation of G.mellonella immune markers can be determined directly by RUS or GST activity assays and the abundance of ANPs can be determined by bacterial growth inhibition assays.This technique can be used as a screening tool for commensal and pathogenic bacteria and for exploring intestinal symbiomes and pathobiomes without sacrifice of many vertebrates. Always use the appropriate personal protective equipment when working with liquid nitrogen, BCP, or TRIzol substances.

a-galleria-mellonella-oral-administration-model-to-study-commensal

Research

JoVE Journal

Immunology and Infection

The Insect Galleria mellonella as a Powerful Infection Model to Investigate Bacterial Pathogenesis

The study of bacterial virulence often requires a suitable animal model. Mammalian models of infection are costly and may raise ethical issues. The use of insects as infection models provides a valuable alternative. Compared to other non-vertebrate model hosts such as nematodes, insects have a relatively advanced system of antimicrobial defenses and are thus more likely to produce information relevant to the mammalian infection process. Like mammals, insects possess a complex innate immune system1. Cells in the hemolymph are capable of phagocytosing or encapsulating microbial invaders, and humoral responses include the inducible production of lysozyme and small antibacterial peptides2,3. In addition, analogies are found between the epithelial cells of insect larval midguts and intestinal cells of mammalian digestive systems. Finally, several basic components essential for the bacterial infection process such as cell adhesion, resistance to antimicrobial peptides, tissue degradation and adaptation to oxidative stress are likely to be important in both insects and mammals1. Thus, insects are polyvalent tools for the identification and characterization of microbial virulence factors involved in mammalian infections.
Larvae of the greater wax moth Galleria mellonella have been shown to provide a useful insight into the pathogenesis of a wide range of microbial infections including mammalian fungal (Fusarium oxysporum, Aspergillus fumigatus, Candida albicans) and bacterial pathogens, such as Staphylococcus aureus, Proteus vulgaris, Serratia marcescens Pseudomonas aeruginosa, Listeria monocytogenes or Enterococcus faecalis4-7. Regardless of the bacterial species, results obtained with Galleria larvae infected by direct injection through the cuticle consistently correlate with those of similar mammalian studies: bacterial strains that are attenuated in mammalian models demonstrate lower virulence in Galleria, and strains causing severe human infections are also highly virulent in the Galleria model8-11. Oral infection of Galleria is much less used and additional compounds, like specific toxins, are needed to reach mortality.
G. mellonella larvae present several technical advantages: they are relatively large (last instar larvae before pupation are about 2 cm long and weight 250 mg), thus enabling the injection of defined doses of bacteria; they can be reared at various temperatures (20 &deg;C to 30 &deg;C) and infection studies can be conducted between 15 &deg;C to above 37 &deg;C12,13, allowing experiments that mimic a mammalian environment. In addition, insect rearing is easy and relatively cheap. Infection of the larvae allows monitoring bacterial virulence by several means, including calculation of LD5014, measurement of bacterial survival15,16 and examination of the infection process17. Here, we describe the rearing of the insects, covering all life stages of G. mellonella. We provide a detailed protocol of infection by two routes of inoculation: oral and intra haemocoelic. The bacterial model used in this protocol is Bacillus cereus, a Gram positive pathogen implicated in gastrointestinal as well as in other severe local or systemic opportunistic infections18,19.

The Insect Galleria mellonella as a Powerful Infection Model to Investigate Bacterial Pathogenesis

Oral and intra haemocolic infection of larvae of the greater wax moth Galleria mellonella is described. This insect can be used to study virulence factors of entomopathogenic as well as mammalian opportunistic bacteria. Rearing of the insects, methods of infection and examples of in vivo analysis are described.

The study of bacterial virulence often requires a suitable animal model. Mammalian models of infection are costly and may raise ethical issues. The use of ...

An In vitro Model to Study Immune Responses of Human Peripheral Blood Mononuclear Cells to Human Respiratory Syncytial Virus Infection

Human respiratory syncytial virus (HRSV) infections present a broad spectrum of disease severity, ranging from mild infections to life-threatening bronchiolitis. An important part of the pathogenesis of severe disease is an enhanced immune response leading to immunopathology.	Here, we describe a protocol used to investigate the immune response of human immune cells to an HRSV infection. First, we describe methods used for culturing, purification and quantification of HRSV. Subsequently, we describe a human in vitro model in which peripheral blood mononuclear cells (PBMCs) are stimulated with live HRSV. This model system can be used to study multiple parameters that may contribute to disease severity, including the innate and adaptive immune response. These responses can be measured at the transcriptional and translational level. Moreover, viral infection of cells can easily be measured using flow cytometry. Taken together, stimulation of PBMC with live HRSV provides a fast and reproducible model system to examine mechanisms involved in HRSV-induced disease.

An In vitro Model to Study Immune Responses of Human Peripheral Blood Mononuclear Cells to Human Respiratory Syncytial Virus Infection

Human respiratory syncytial virus (HRSV) can cause severe bronchiolitis in young infants. Part of the pathogenesis of severe HRSV disease is caused by the host immune response. Stimulation of primary human immune cells with HRSV provides a fast and reproducible model system to study activation of inflammatory pathways and infection.

Human respiratory syncytial  virus (HRSV) infections present a broad spectrum of disease severity, ranging  from mild infections to life-threatening ...

Use of Galleria mellonella as a Model Organism to Study Legionella pneumophila Infection

Legionella pneumophila, the causative agent of a severe pneumonia named Legionnaires&#39; disease, is an important human pathogen that infects and replicates within alveolar macrophages. Its virulence depends on the Dot/Icm type IV secretion system (T4SS), which is essential to establish a replication permissive vacuole known as the Legionella containing vacuole (LCV). L. pneumophila infection can be modeled in mice however most mouse strains are not permissive, leading to the search for novel infection models. We have recently shown that the larvae of the wax moth Galleria mellonella are suitable for investigation of L. pneumophila infection. G. mellonella is increasingly used as an infection model for human pathogens and a good correlation exists between virulence of several bacterial species in the insect and in mammalian models. A key component of the larvae&#39;s immune defenses are hemocytes, professional phagocytes, which take up and destroy invaders. L. pneumophila is able to infect, form a LCV and replicate within these cells. Here we demonstrate protocols for analyzing L. pneumophila virulence in the G. mellonella model, including how to grow infectious L. pneumophila, pretreat the larvae with inhibitors, infect the larvae and how to extract infected cells for quantification and immunofluorescence microscopy. We also describe how to quantify bacterial replication and fitness in competition assays. These approaches allow for the rapid screening of mutants to determine factors important in L. pneumophila virulence, describing a new tool to aid our understanding of this complex pathogen.

Use of Galleria mellonella as a Model Organism to Study Legionella pneumophila Infection

The larva of the wax moth Galleria mellonella was recently established as an in vivo model to study Legionella pneumophila infection. Here, we demonstrate fundamental techniques to characterize the pathogenesis of Legionella in the larvae, including inoculation, measurement of bacterial virulence and replication as well as extraction and analysis of infected hemocytes.

Legionella pneumophila, the causative agent of a severe pneumonia named Legionnaires&#39; disease, is an important human pathogen that infects and ...

Using RNA-interference to Investigate the Innate Immune Response in Mouse Macrophages

Macrophages are key phagocytic innate immune cells. When macrophages encounter a pathogen, they produce antimicrobial proteins and compounds to kill the pathogen, produce various cytokines and chemokines to recruit and stimulate other immune cells, and present antigens to stimulate the adaptive immune response. Thus, being able to efficiently manipulate macrophages with techniques such as RNA-interference (RNAi) is critical to our ability to investigate this important innate immune cell. However, macrophages can be technically challenging to transfect and can exhibit inefficient RNAi-induced gene knockdown. In this protocol, we describe methods to efficiently transfect two mouse macrophage cell lines (RAW264.7 and J774A.1) with siRNA using the Amaxa Nucleofector 96-well Shuttle System and describe procedures to maximize the effect of siRNA on gene knockdown. Moreover, the described methods are adapted to work in 96-well format, allowing for medium and high-throughput studies. To demonstrate the utility of this approach, we describe experiments that utilize RNAi to inhibit genes that regulate lipopolysaccharide (LPS)-induced cytokine production.

In this protocol, we describe methods to efficiently transfect murine macrophage cell lines with siRNAs using the Amaxa Nucleofector 96-well Shuttle System, stimulate the macrophages with lipopolysaccharide, and monitor the effects on inflammatory cytokine production.

Macrophages are key phagocytic innate immune cells.  When macrophages encounter a pathogen, they produce antimicrobial proteins and compounds to kill the ...

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.

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

Increased Recovery Time and Decreased LPS Administration to Study the Vagus Nerve Stimulation Mechanisms in Limited Inflammatory Responses

Inflammation is a local response to infection and tissue damage mediated by activated macrophages, monocytes, and other immune cells that release cytokines and other mediators of inflammation. For a long time, humoral and cellular mechanisms have been studied for their role in regulating the immune response, but recent advances in the field of immunology and neuroscience have also unraveled specific neural mechanisms with interesting therapeutic potential. The so-called cholinergic anti-inflammatory pathway (CAP) has been described to control innate immune responses and inflammation in a very potent manner. In the early 2000s, Tracey and collaborators developed a technique that stimulates the vagus nerve and mimics the effect of the pathway. The methodology is based on the electrical stimulation of the vagus nerve at low voltage and frequency, in order to avoid any side effects of overstimulation, such as deregulation of heart rate variability. Electrical devices for stimulation are now available, making it easy to set up the methodology in the laboratory. The goal of this research was to investigate the potential involvement of prostaglandins in the CAP. Unfortunately, based on earlier attempts, we failed to use the original protocol, as the induced inflammatory response either was too high or was not suitable for enzymatic metabolism properties. The different settings of the original surgery protocol remained mostly unchanged, but the conditions regarding inflammatory induction and the time point before sacrifice were improved to fit our purposes (i.e., to investigate the involvement of the CAP in more limited inflammatory responses). 
The modified version of the original protocol, presented here, includes a longer time range between vagus nerve stimulation and analysis, which is associated with a lower induction of inflammatory responses. Additionally, while decreasing the level of lipopolysaccharides (LPS) to inject, we also came across new observations regarding mechanistic properties in the spleen.

Vagus nerve stimulation has proven to have a strong efficacy for decreasing peripheral inflammation. Here, we present a modified vagus nerve stimulation protocol that allows for further examinations of the cholinergic anti-inflammatory mechanisms in limited inflammatory responses.

Inflammation is a local response to infection and tissue damage mediated by activated macrophages, monocytes, and other immune cells that release ...

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.

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

A Mouse Model to Assess Innate Immune Response to Staphylococcus aureus Infection

Staphylococcus aureus (S. aureus)&#160;infections, including methicillin resistant stains, are an enormous burden on the healthcare system. With incidence rates of S. aureus infection climbing annually, there is a demand for additional research in its&#160;pathogenicity. Animal models of infectious disease advance our understanding of the host-pathogen response and lead to the development of effective therapeutics. Neutrophils play a primary role in the innate immune response that controls S. aureus infections by forming an abscess to wall off the infection and facilitate bacterial clearance; the number of neutrophils that infiltrate an S. aureus skin infection often correlates with disease outcome. LysM-EGFP mice, which possess the enhanced green fluorescent protein (EGFP) inserted in the Lysozyme M (LysM) promoter region (expressed primarily by neutrophils), when used in conjunction with in vivo whole animal fluorescence imaging (FLI) provide&#160;a means of quantifying neutrophil emigration noninvasively and longitudinally into wounded skin. When combined with a bioluminescent S. aureus strain and sequential in vivo whole animal bioluminescent imaging (BLI), it is possible to longitudinally monitor both the neutrophil recruitment dynamics and in vivo bacterial burden at the site of infection in anesthetized mice from onset of infection to resolution or death. Mice are more resistant to a number of virulence factors produced by S. aureus that facilitate effective colonization and infection in humans. Immunodeficient mice provide a more sensitive animal model to examine persistent S. aureus infections and the ability of therapeutics to boost innate immune responses. Herein, we characterize responses in LysM-EGFP mice that have been bred to MyD88-deficient mice (LysM-EGFP&#215;MyD88-/- mice) along with wild-type LysM-EGFP mice to investigate S. aureus skin wound infection. Multispectral simultaneous detection enabled study of neutrophil recruitment dynamics by using in vivo FLI, bacterial burden by using in vivo BLI, and wound healing longitudinally and noninvasively over time.

A Mouse Model to Assess Innate Immune Response to Staphylococcus aureus Infection

An approach is described for real-time detection of the innate immune response to cutaneous wounding and Staphylococcus aureus infection of mice. By comparing LysM-EGFP mice (which possess fluorescent neutrophils) with a LysM-EGFP crossbred immunodeficient mouse strain, we advance our understanding of infection and the development of approaches to combat infection.

Staphylococcus aureus (S. aureus)&#160;infections, including methicillin resistant stains, are an enormous burden on the healthcare system. With incidence ...

Use of the Invertebrate Galleria mellonella as an Infection Model to Study the Mycobacterium tuberculosis Complex

Tuberculosis is the leading global cause of infectious disease mortality and roughly a quarter of the world&#8217;s population is believed to be infected with Mycobacterium tuberculosis. Despite decades of research, many of the mechanisms behind the success of M. tuberculosis as a pathogenic organism remain to be investigated, and the development of safer, more effective antimycobacterial drugs are urgently needed to tackle the rise and spread of drug resistant tuberculosis. However, the progression of tuberculosis research is bottlenecked by traditional mammalian infection models that are expensive, time consuming, and ethically challenging. Previously we established the larvae of the insect Galleria mellonella (greater wax moth) as a novel, reproducible, low cost, high-throughput and ethically acceptable infection model for members of the M. tuberculosis complex. Here we describe the maintenance, preparation, and infection of G. mellonella with bioluminescent Mycobacterium bovis BCG lux. Using this infection model, mycobacterial dose dependent virulence can be observed, and a rapid readout of in vivo mycobacterial burden using bioluminescence measurements is easily achievable and reproducible. Although limitations exist, such as the lack of a fully annotated genome for transcriptomic analysis, ontological analysis against genetically similar insects can be carried out. As a low cost, rapid, and ethically acceptable model for tuberculosis, G. mellonella can be used as a pre-screen to determine drug efficacy and toxicity, and to determine comparative mycobacterial virulence prior to the use of conventional mammalian models. The use of the G. mellonella-mycobacteria model will lead to a reduction in the substantial number of animals currently used in tuberculosis research.

Use of the Invertebrate Galleria mellonella as an Infection Model to Study the Mycobacterium tuberculosis Complex

Galleria mellonella was recently established as a reproducible, cheap, and ethically acceptable infection model for the Mycobacterium tuberculosis complex. Here we describe and demonstrate the steps taken to establish successful infection of G. mellonella with bioluminescent Mycobacterium bovis BCG lux.

Tuberculosis is the leading global cause of infectious disease mortality and roughly a quarter of the world&#8217;s population is believed to be infected ...

Isolation of Tonsillar Mononuclear Cells to Study Ex Vivo Innate Immune Responses in a Human Mucosal Lymphoid Tissue

Studying isolated cells from mucosa-associated lymphoid tissues (MALT) allows understanding of immune cells response in pathologies involving mucosal immunity, because they can model host-pathogen interactions in the tissue. While isolated cells derived from tissues were the first cell culture model, their use has been neglected because tissue can be hard to obtain. In the present protocol, we explain how to easily process and culture tonsillar mononuclear cells (TMCs) from healthy human tonsils to study innate immune responses upon activation, mimicking viral infection in mucosal tissues. Isolation of TMCs from the tonsils is quick, because the tonsils barely have any epithelium and yield up to billions of all major immune cell types. This method allows detection of cytokine production using several techniques, including immunoassays, qPCR, microscopy, flow cytometry, etc., similar to the use of peripheral mononuclear cells (PBMCs) from blood. Furthermore, TMCs show a higher sensitivity to drug testing than PBMCs, which needs to be considered for future toxicity assays. Thus, ex vivo TMCs cultures are an easy and accessible mucosal model.

In the present protocol, we explain how to easily process and culture tonsillar mononuclear cells from healthy humans undergoing partial surgical tonsillectomy to study innate immune responses upon activation, mimicking viral infection in mucosal tissues.

Studying isolated cells from mucosa-associated lymphoid tissues (MALT) allows understanding of immune cells response in pathologies involving mucosal ...