Development of a Humanized IL33 Mouse

About This Grant

PROJECT SUMMARY: In this R03 application, “Development of a Humanized IL33 Mouse” we plan to engineer and characterize a mouse strain in which the human IL33 gene sequence from ~28 kb (including the 20 kb asthma-associated region) upstream of exon 1 to ~21 kb downstream of exon 8 of human IL33 gene will be cloned into intron 1 of ROSA26 locus in the mouse. This strategy uses a bacterial artificial chromosome (BAC) to insert all of the human regulatory regions which have been associated with allergic disease into the mouse. The targeting strategy uses the PiggyBac technology to deliver a single copy of the transgene into the specific integration site. The strategy includes the upstream regulatory regions because they confer localization of the human IL33 gene expression to the bronchial epithelial cells and the endothelium. That is in contrast to the mouse Il33 gene expression which is located in the lung type 2 alveolar epithelial cell. The mouse will also have lox-p sites introduced into exon 5 which can be used to conditionally delete IL33 expression. Finally, the human IL33 locus will drive an IRES-Citrine reporter that can report on the expression of the human IL33 promoter. This mouse will be crossed to the Il33cherry mouse which is a knock-in/knock-out (mcherry reporter) so that the resulting mouse will only have human IL-33 protein (which is biologically active in mice) from the human IL33 promoter along with a human IL33 Citrine reporter and a mouse Il33 cherry reporter. This mouse will then be compared to wildtype mice in an acute lung allergen challenge model to determine how localization of expression to different lung cell types (bronchial epithelium/endothelium vs type 2 alveolar epithelium) alters the location of lung type 2 infiltrates and the degree of bronchial epithelial remodeling. This proposal will utilize novel spatial transcriptomic technologies to ask important questions about how IL-33 localization alters the architecture of lung type 2 inflammation. This mouse has great potential to advance our understanding of human genetics since the asthma-associated genetic architecture (upstream of the human IL33 gene) will be introduced into the mouse.