Methods to Investigate the Roles for β-Arrestin-2 in Allergic Inflammatory Airway Disease

Spatial and temporal control of gene expression using cre/loxP technology is a major methodological advance for biomedical research. The ability to alter gene expression after an in vivo disease model has been established and allows researchers the opportunity to examine the impact of that gene on the perpetuation of a disease, a mechanistic insight that is arguably more therapeutically relevant than developmental mechanisms.We used the cre/LoxP technology in mice to show that β-arrestin-2, a gene previously shown to be required for the development of the asthma phenotype, is also required for the perpetuation of, at least, the airway hyperresponsiveness characteristic of that phenotype. Here we describe stepwise methods for the activation of the cre-loxP technology and induction of murine allergic inflammatory airway disease. We comment on the unanticipated problems encountered, which we speculate were a result of interactions between the allergen and β-arrestin-2 gene (Arrb2) regulation and the effect of tamoxifen on the asthma phenotype. The issues encountered here may be generally applicable to cre/loxP utilization in inflammatory disease models, especially if the gene of interest is associated with the inflammatory cascade.