Which immunoglobulin class triggers eosinophil activation in parasitic infections?

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Multiple Choice

Which immunoglobulin class triggers eosinophil activation in parasitic infections?

Explanation:
Eosinophils are activated against parasitic invaders mainly through IgE. In a Th2-driven response to helminths, IgE is produced and coats the parasite. Eosinophils have Fc receptors for IgE, so crosslinking of IgE that’s bound to the parasite—or bound to eosinophils themselves—triggers eosinophil degranulation. This releases toxic granule proteins like major basic protein and eosinophil cationic protein, along with reactive oxygen species, which damage the parasite. IL-5 from Th2 cells promotes eosinophil growth and recruitment, strengthening this response. Other antibody classes contribute to different defense mechanisms (opsonization, neutralization, or complement activation) but are not the primary trigger for eosinophil activation in parasitic infections.

Eosinophils are activated against parasitic invaders mainly through IgE. In a Th2-driven response to helminths, IgE is produced and coats the parasite. Eosinophils have Fc receptors for IgE, so crosslinking of IgE that’s bound to the parasite—or bound to eosinophils themselves—triggers eosinophil degranulation. This releases toxic granule proteins like major basic protein and eosinophil cationic protein, along with reactive oxygen species, which damage the parasite. IL-5 from Th2 cells promotes eosinophil growth and recruitment, strengthening this response. Other antibody classes contribute to different defense mechanisms (opsonization, neutralization, or complement activation) but are not the primary trigger for eosinophil activation in parasitic infections.

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