IL-1β is Crucial for Induction of Coronary Artery Inflammation in a Mouse Model of Kawasaki Disease
Background—Kawasaki disease (KD) is the most common cause of acute vasculitis and acquired cardiac disease in US children. Untreated, children may develop coronary artery aneurysms, myocardial infarction and sudden death as a result of the illness. Up to a third of KD patients fail to respond to intravenous gammaglobulin (IVIG), the standard therapy, and alternative treatments are being investigated. Genetic studies have indicated a possible role for IL-1β in KD. We therefore explored the role of IL-1β in a murine model of KD.
Methods and Results—Using an established mouse model of KD that involves injection of Lactobacillus casei cell wall extract (LCWE), we investigated the role of IL-1β and caspase-1 (activated by the inflammasome and required for IL-1β maturation) in coronary arteritis, and evaluated the efficacy of IL-1 receptor antagonist (IL-1Ra) as a potential treatment. LCWE-induced IL-1β maturation and secretion was dependent on the NLRP3 inflammasome in macrophages. Both caspase1-deficient and IL-1R-deficient mice were protected from LCWE-induced coronary lesions. Injection of recombinant IL-1β to caspase-1-deficient mice restored the ability of LCWE to cause coronary lesions in response to LCWE. Furthermore, daily injections of the IL-1Ra prevented LCWE-mediated coronary lesions, up to three days after LCWE injection.
Conclusions—Our results strongly suggest that caspase-1 and IL-1β play critical roles in the development of coronary lesions in this KD mouse model, blocked by IL-1Ra. Therefore, anti-IL-1β treatment strategies may constitute an effective, more targeted treatment of KD to prevent coronary lesions.
- Received October 7, 2011.
- Accepted January 18, 2012.
- Copyright © 2012, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited