title: Specific immune priming in the invasive ctenophore Mnemiopsis leidyi.
abstract: Specific immune priming enables an induced immune response upon repeated pathogen encounter. As a functional analogue to vertebrate immune memory, such adaptive plasticity has been described, for instance, in insects and crustaceans. However, towards the base of the metazoan tree our knowledge about the existence of specific immune priming becomes scattered. Here, we exposed the invasive ctenophore Mnemiopsis leidyi repeatedly to two different bacterial epitopes (Gram-positive or -negative) and measured gene expression. Ctenophores experienced either the same bacterial epitope twice (homologous treatments) or different bacterial epitopes (heterologous treatments). Our results demonstrate that immune gene expression depends on earlier bacterial exposure. We detected significantly different expression upon heterologous compared with homologous bacterial treatment at three immune activator and effector genes. This is the first experimental evidence for specific immune priming in Ctenophora and generally in non-bilaterian animals, hereby adding to our growing notion of plasticity in innate immune systems across all animal phyla.
authors.affiliation: GEOMAR Helmholtz Centre for Ocean Research Kiel, Evolutionary Ecology of Marine Fishes, , Düsternbrooker Weg 20, Kiel 24105, Germany.
authors.forename: Sören
authors.initials: S
authors.lastname: Bolte
authors.forename: Olivia
authors.initials: O
authors.lastname: Roth
authors.forename: Eva E R
authors.initials: EE
authors.lastname: Philipp
authors.forename: Julia
authors.initials: J
authors.lastname: Saphörster
authors.forename: Philip
authors.initials: P
authors.lastname: Rosenstiel
authors.forename: Thorsten B H
authors.initials: TB
authors.lastname: Reusch
mesh_terms: D000818:Animals; D001424:Bacterial Infections / Q000276:immunology; D037302:Ctenophora / Q000235:genetics* / Q000276:immunology* / Q000382:microbiology*; D017931:DNA Primers / Q000235:genetics; D000939:Epitopes / Q000737:chemistry; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D007107:Immune System; D053526:Listonella; D058642:Planococcus Bacteria; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D000939:Epitopes
keywords: adaptive plasticity; bacteria; basal metazoan; ctenophore; immune priming; invertebrate