Oral immune priming with Bacillus thuringiensis induces a shift in the gene expression of Tribolium castaneum larvae Journal Article

Author(s): Greenwood, Jenny; Milutinović, Barbara; Peuß, Robert; Behrens, Sarah; Essar, Daniela; Rosenstiel, Philip; Schulenburg, Hinrich; Kurtz, Joachim
Article Title: Oral immune priming with Bacillus thuringiensis induces a shift in the gene expression of Tribolium castaneum larvae
Affiliation IST Austria
Abstract: The phenomenon of immune priming, i.e. enhanced protection following a secondary exposure to a pathogen, has now been demonstrated in a wide range of invertebrate species. Despite accumulating phenotypic evidence, knowledge of its mechanistic underpinnings is currently very limited. Here we used the system of the red flour beetle, Tribolium castaneum and the insect pathogen Bacillus thuringiensis (Bt) to further our molecular understanding of the oral immune priming phenomenon. We addressed how ingestion of bacterial cues (derived from spore supernatants) of an orally pathogenic and non-pathogenic Bt strain affects gene expression upon later challenge exposure, using a whole-transcriptome sequencing approach. Results Whereas gene expression of individuals primed with the orally non-pathogenic strain showed minor changes to controls, we found that priming with the pathogenic strain induced regulation of a large set of distinct genes, many of which are known immune candidates. Intriguingly, the immune repertoire activated upon priming and subsequent challenge qualitatively differed from the one mounted upon infection with Bt without previous priming. Moreover, a large subset of priming-specific genes showed an inverse regulation compared to their regulation upon challenge only. Conclusions Our data demonstrate that gene expression upon infection is strongly affected by previous immune priming. We hypothesise that this shift in gene expression indicates activation of a more targeted and efficient response towards a previously encountered pathogen, in anticipation of potential secondary encounter.
Keywords: RNA-sequencing Immune priming Tribolium castaneum Host-parasite interaction Bacillus thuringiensis
Journal Title: BMC Genomics
Volume: 18
Issue 329
ISSN: 1471-2164
Publisher: BioMed Central  
Date Published: 2017-04-26
Copyright Statement: CC BY 4.0
Sponsor: This work was supported by grants BO 2544/7-1, KU 1929/4-2, RO 2994/3-2, SCHU 1415/9-2 within the DFG (German Research Foundation, http://dfg.de/) priority programme 1399 “ Host-parasite coevolution ”
DOI: 10.1186/s12864-017-3705-7
Notes: We thank Hendrik Eggert and Erich Bornberg-Bauer for helpful discussions of the data and Matthew Grigg for help with the illustrations. Furthermore, we thank the iBeetle consortium, in particular Gregor Bucher and the group of Mario Stanke for providing unpublished RNA and EST data. We would further like to thank the three anonymous reviewers for their helpful comments on the manuscript
Open access: yes (OA journal)