Project A1 will assess the role of pulmonary and intestinal microbiome composition in C3a-dependent regulation of allergic asthma. Project A2 will focus on the interplay between cDC and ILC in the context of microbiome dysregulation. Project A3 will delineate the mechanisms underlying Treg and B cell-mediated suppression of food allergy in order to develop novel preventive measures. Project A5 will define the role of epithelial trans- and paracellular migration of neutrophils for asthma development. Project A6 will dissect the multiple roles of gliadin in food allergy development and dysbiosis. Project A7 will define the role of the C5a/C5aR1 axis in transcriptional Th2 programming of cDCs in allergic asthma. The MD/PhD project will focus on the protective role of obesity in allergic asthma.