The cytokine interleukin-33 mediates anaphylactic shock

Area of Science:

• Immunology
• Allergy Research
• Cytokine Signaling

Background:

• Anaphylactic shock involves elevated immunoglobulin-E (IgE) antibodies and Fc epsilon Receptor I (Fc epsilonRI) signaling.
• Interleukin-33 (IL-33) is a newly identified cytokine and a ligand for the orphan receptor ST2.
• Elevated IL-33 levels are observed in atopic patients during anaphylactic shock and in atopic dermatitis.

Purpose of the Study:

• To investigate the role of the novel cytokine IL-33 in inducing anaphylactic shock.
• To explore the molecular mechanisms by which IL-33 mediates anaphylaxis.
• To assess IL-33 as a potential therapeutic target for anaphylaxis.

Main Methods:

• Induction of anaphylactic shock in murine models using IL-33.
• In vitro studies on IgE-sensitized mast cells stimulated with IL-33.
• Analysis of molecular pathways including calcium mobilization, NF-kappaB activation, and mediator release.

Main Results:

• IL-33 potently induced antigen-independent anaphylaxis in mice.
• IL-33 directly stimulated mast cell degranulation, eicosanoid, and cytokine production.
• Molecular mechanisms involved phospholipase D1 and sphingosine kinase 1 activation, leading to calcium mobilization and mediator secretion.

Conclusions:

• IL-33 plays a significant pathophysiological role in anaphylaxis.
• IL-33 acts in a T cell-independent, mast cell-dependent manner.
• IL-33 represents a promising therapeutic target for treating anaphylaxis.