title: Establishment of ex vivo systems to identify compounds acting on innate immune responses and to determine their target molecules using transgenic Drosophila.
abstract: Innate immunity is an evolutionarily conserved self-defense mechanism against microbial infections. In Drosophila, induction of antimicrobial peptides is a major immune response that is regulated by two distinct signaling pathways called the IMD pathway and the Toll pathway, similar to the tumor necrosis factor-alpha signaling and Toll-like receptor/interleukin-1 signaling pathways, respectively, in mammals. In mammals, innate immunity interacts with adaptive immunity and has a key role in the regulated immune response. Therefore, innate immunity is a pharmaceutical target for the development of immune regulators. Previously, based on the striking conservation between the mechanisms that regulate Drosophila immunity and human innate immunity, we established an ex vivo culture in which compounds acting on innate immunity can be evaluated using a reporter gene that reflects activation of the IMD pathway [Yajima et al. [Yajima, M., Takada, M., Takahashi, N., Kikuchi, H., Natori, S., Oshima, Y., Kurata, S., 2003. A newly established in vitro culture using transgenic Drosophila reveals functional coupling between the phospholipase A2-generated fatty acid cascade and lipopolysaccharide-dependent activation of the immune deficiency (imd) pathway in insect immunity. The Biochemical Journal 371(Pt 1), 205-210] Biochem J 371, 205-210]. Here, we combined the ex vivo culture with a reporter gene that reflects the heat shock response and demonstrated that the resulting systems are useful for screening compounds that act specifically on innate immunity, including mammalian innate immune responses. Identification of target molecules is essential for the development of more potent medicines with fewer side effects. In this study, we also established ex vivo systems capable of identifying target molecules of the identified compounds using targeted activation of the IMD pathway.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan.
authors.forename: Mizuki
authors.initials: M
authors.lastname: Sekiya
authors.forename: Kazunori
authors.initials: K
authors.lastname: Ueda
authors.forename: Tomomitsu
authors.initials: T
authors.lastname: Fujita
authors.forename: Minoru
authors.initials: M
authors.lastname: Kitayama
authors.forename: Haruhisa
authors.initials: H
authors.lastname: Kikuchi
authors.forename: Yoshiteru
authors.initials: Y
authors.lastname: Oshima
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Kurata
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified / Q000276:immunology*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D018925:Chemokines / Q000276:immunology; D004330:Drosophila / Q000235:genetics / Q000276:immunology*; D029721:Drosophila Proteins / Q000096:biosynthesis* / Q000235:genetics; D042783:Endothelial Cells; D005227:Fatty Acids / Q000378:metabolism; D017930:Genes, Reporter; D006358:Hot Temperature; D006801:Humans; D007113:Immunity, Innate / Q000187:drug effects*; D007155:Immunologic Factors / Q000494:pharmacology; D007814:Larva; D008070:Lipopolysaccharides / Q000494:pharmacology; D010741:Phospholipases A / Q000378:metabolism; D054467:Phospholipases A2; D011401:Promoter Regions, Genetic; D051193:Toll-Like Receptors / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D018925:Chemokines; C054756:DptA protein, Drosophila; D029721:Drosophila Proteins; D005227:Fatty Acids; D007155:Immunologic Factors; D008070:Lipopolysaccharides; C068721:Tl protein, Drosophila; D051193:Toll-Like Receptors; C439909:imd protein, Drosophila; C482199:lipopolysaccharide, E coli O55-B5; D010741:Phospholipases A; D054467:Phospholipases A2