IL-33 is a new member of the IL-1 cytokine family that promotes Th2 inflammation.
Video: Interleukin-1 binding to its receptor on a cell surface, created from structural data.
Endobronchial biopsies were obtained from adults with mild, moderate, and severe asthma, and from control subjects.
Higher levels of IL-33 transcripts were detected in biopsies from asthmatic compared with control subjects, and especially in subjects with severe asthma.
Airway smooth muscle cells (ASMC) are a source of the IL-33 cytokine and show IL-33 expression at both protein and mRNA levels.
TNF-alpha up-regulates IL-33 in a dose-dependent manner. Dexamethasone fails to abolish TNF-alpha-induced IL-33 up-regulation. IFN-gamma also increases IL-33.
IL-33 appears to be a novel inflammatory marker of severe and refractory asthma.
Severe asthma - differential diagnosis and management (click to enlarge the image).
Increased expression of IL-33 in severe asthma: evidence of expression by airway smooth muscle cells. Préfontaine D, Lajoie-Kadoch S, Foley S, Audusseau S, Olivenstein R, Halayko AJ, Lemière C, Martin JG, Hamid Q. J Immunol. 2009 Oct 15;183(8):5094-103.
Interleukin 33 (IL-33)