AUTHOR=Lange Anna , Schäfer Andrea , Bender Annika , Steimle Alexander , Beier Sina , Parusel Raphael , Frick Julia-Stefanie 

TITLE=Galleria mellonella: A Novel Invertebrate Model to Distinguish Intestinal Symbionts From Pathobionts

JOURNAL=Frontiers in Immunology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2018.02114

DOI=10.3389/fimmu.2018.02114

ISSN=1664-3224

ABSTRACT=<p>Insects and mammals share evolutionary conserved innate immune responses to maintain intestinal homeostasis. We investigated whether the larvae of the greater wax moth <italic>Galleria mellonella</italic> may be used as an experimental organism to distinguish between symbiotic <italic>Bacteroides vulgatus</italic> and pathobiotic <italic>Escherichia coli</italic>, which are mammalian intestinal commensals. Oral application of the symbiont or pathobiont to <italic>G. mellonella</italic> resulted in clearly distinguishable innate immune responses that could be verified by analyzing similar innate immune components in mice <italic>in vivo</italic> and <italic>in vitro</italic>. The differential innate immune responses were initiated by the recognition of bacterial components <italic>via</italic> pattern recognition receptors. The pathobiont detection resulted in increased expression of reactive oxygen and nitrogen species related genes as well as antimicrobial peptide gene expression. In contrast, the treatment/application with symbiotic bacteria led to weakened immune responses in both mammalian and insect models. As symbionts and pathobionts play a crucial role in development of inflammatory bowel diseases, we hence suggest <italic>G. mellonella</italic> as a future replacement organism in inflammatory bowel disease research.</p>