The development and treatment of asthma remains a subject of considerable interest in the medical community. Previous studies implicate an important role of cytokines in the pathology of asthma. In this current study, we examined whether redox-active protein thioredoxin 1 (TRXI) could prevent airway remodeling in an ovalbumin (OVA)-driven mouse chronic antigen exposure asthma model. Balb/c mice were sensitized and then challenged nine times with OVA (days 19-45). In this protocol, airway remodeling was established by day 34. Administration of recombinant human TRXI during antigen challenge (days 18-32) significantly inhibited airway remodeling, eosinophilic pulmonary inflammation, airway hyperresponsiveness and resulted in decreased lung expression of eotaxin, macrophage inflammatory protein-la and IL-13. Airway remodeling and eosinophilic pulmonary inflammation was also prevented in chronic OVA-exposed Balb/c human TRXI transgenic mice. Importantly, TRX1-administration, after the establishment of airway remodeling (days 35-45), resulted in improved airway pathology. Our results suggest TRXI prevents the development of airway remodeling, and also improves established airway remodeling by inhibiting production of chemokines and Th2 cytokines in the lungs. (C) 2007 Elsevier Inc. All rights reserved.