E. coli Nissle 1917 is a safe mucosal delivery vector for a birch-grass pollen chimera to prevent allergic poly-sensitization.

Allergic poly-sensitization affects a large number of allergic patients and poses a great challenge for their treatment. In this study we evaluated the effects of the probiotic Escherichia coli Nissle 1917 (EcN) expressing a birch and grass pollen allergen chimera 'Bet v 1, Phl p 1 and Phl p 5' (EcN-Chim) on allergy prevention after oral or intranasal application in poly-sensitized mice. In contrast to oral application, intranasal pretreatment with EcN-Chim prior to poly-sensitization led to a significant reduction of lung inflammation (eosinophils, IL-5, and IL-13 in bronchoalveolar lavage) along with suppressed levels of allergen-specific serum IgE. The suppression was associated with increased levels of allergen-specific IgA in lungs and serum IgG2a along with increased Foxp3, TGF-ß, and IL-10 mRNA in bronchial lymph nodes. In vitro EcN induced high levels of IL-10 and IL-6 in both lung and intestinal epithelial cells. Importantly, using in vivo imaging techniques we demonstrated that intranasally applied EcN do not permanently colonize nose, lung, and gut and this strain might therefore be a safe delivery vector against allergy in humans. In conclusion, our data show that intranasal application of recombinant EcN expressing a multiallergen chimera presents a novel and promising treatment strategy for prevention of allergic poly-sensitization.

Correction: E. coli Nissle 1917 is a safe mucosal delivery vector for a birch-grass pollen chimera to prevent allergic poly-sensitization.

Following the publication of this article, the authors have requested that the Acknowledgements section be amended to include the financing source of the study. The correct Acknowledgments should be as follows: We gratefully acknowledge funding from the Austrian Science Fund SFB F46 and DK MCCA W1248-B30, OeAD-GmbH grants (FR13/2016) and from the Amadeus partnership Hubert Curein French and Austrian program. We thank the BioImaging Center of Lille (Frank Lafont) for the use of the IVIS Lumina XR. We gratefully thank Katharina Ambroz, Elke Korb, Karin Baier, Erika Garner-Spitzer, Joshua Tobias, Gwenaëlle Verbrugghe, and Jéremy Desramaut for their technical assistance and helpful discussions.

Developmental and digestive flexibilities in the midgut of a polyphagous pest, the cotton bollworm, Helicoverpa armigera.

Developmental patterns and survival of the cotton bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), a polyphagous insect pest, have been studied with reference to the effect of diet on major gut digestive enzymes (amylases, proteases, and lipases). Significant correlations between nutritional quality of the diet and larval and pupal mass were observed when H. armigera larvae were fed on various host plants viz. legumes (chickpea and pigeonpea), vegetables (tomato and okra), flowers (rose and marigold), and cereals (sorghum and maize). Larvae fed on diets rich in proteins and/or carbohydrates (pigeonpea, chickpea, maize, and sorghum) showed higher larval mass and developed more rapidly than larvae fed on diets with low protein and carbohydrate content (rose, marigold, okra, and tomato). Low calorific value diets like rose and marigold resulted in higher mortality (25-35%) of H. armigera. Even with highly varying development efficiency and larval/pupal survival rates, H. armigera populations feeding on different diets completed their life cycles. Digestive enzymes of H. armigera displayed variable expression levels and were found to be regulated on the basis of macromolecular composition of the diet. Post-ingestive adaptations operating at the gut level, in the form of controlled release of digestive enzymes, might be a key factor contributing to the physiological plasticity in H. armigera.