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How does IgE help mast cells respond to parasites and worms?
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immune system
Stimulation of immune response by activated helper T cells. Activated by complex interaction with molecules on the surface of a macrophage or some other antigen-presenting cell, a helper T cell proliferates into two general subtypes, TH1 and TH2. These in turn stimulate the complex pathways of the cell-mediated immune response and the humoral immune response, respectively.
IgE antibodies play a critical role in defending the body against large multicellular parasites, such as hookworms, by binding to specific receptors on the surface of mast cells.12
When parasitic antigens bind to these IgE molecules, the mast cells are triggered to release pharmacologically active chemicals from their granules. This process initiates several physiological responses designed to dislodge the invaders:12
- Vascular changes: A sudden increase in the permeability of local blood vessels occurs.1
- Platelet activation: Platelets are activated and adhere to the site, releasing their own active agents.1
- Muscle contraction: Smooth muscle in the gut or respiratory tubes contracts.1
- Fluid secretion: The body increases the secretion of fluids to help flush out the parasites.1
Additionally, IgE works alongside eosinophil granulocytes to destroy parasites like the flatworms responsible for schistosomiasis. In this mechanism, eosinophils attach to the IgE-bound worms and release granular chemicals that degrade the parasite's protective outer skin.1