Animal models of chronic experimental asthma — strategies for the identification of new therapeutic targets

Over the last decade mouse models of experimental asthma proved to be a valuable tool for the investigation of mechanisms that underlie acute allergic airway inflammation and development of airway hyperresponsiveness, two of the hallmarks of human asthma. Nevertheless, these acute models fail to reflect the aspects of this chronic disease because they do not represent any signs of chronicity and airway remodelling as it is defined by subepithelial fibrosis, goblet cell hyperplasia and airway smooth muscle cell hypertrophy. Recent mouse models were successful in overcoming these limitations by using chronic allergen-challenges. These new models of chronic experimental asthma now proved as a novel tool to examine the complex interaction of infiltrating inflammatory cells and structural cells such as fibroblasts and smooth muscle cells that ultimately leads to airway remodelling and stable airflow limitation. Recent studies clearly demonstrated that T helper 2 (TH2) cells and their typical cytokines play a critical role not only in airway inflammation but also in the development of airway remodelling. Since the transcription factor GATA-3 is essential for TH2 cell development and the production of several TH2 type cytokines this intracellular molecule represents a new promising target for therapeutic intervention in asthma that might even effect airway remodelling.