Eosinophils accumulate in tissues in parasitic infestations and allergic reactions. Which cytokine is the principal driver of eosinophil growth, activation, and recruitment from bone marrow?
- A IFN-gamma
- B IL-13
- C IL-5 ✓
- D GM-CSF
Correct answer: C. IL-5
Explanation
IL-5, secreted by Th2 cells and innate lymphoid cells, is the signature eosinophilopoietic cytokine driving maturation, marrow release, and activation of eosinophils. Their granule contents include major basic protein, which is toxic to helminths. IFN-gamma marks Th1 immunity and suppresses Th2 responses, GM-CSF acts broadly on granulocyte and monocyte lineages rather than selectively, and IL-13 promotes IgE class switching and mucus production, not eosinophil recruitment itself.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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