In granuloma formation, the conversion of monocytes to epithelioid histiocytes is primarily driven by which cytokine secreted by activated CD4+ T cells?
- A Interleukin-4 (IL-4)
- B Interferon-gamma (IFN-γ) ✓
- C Tumour necrosis factor-beta (LT-α)
- D Interleukin-17 (IL-17)
Correct answer: B. Interferon-gamma (IFN-γ)
Explanation
IFN-γ secreted by Th1 CD4+ T cells (and NK cells) is the key cytokine that activates macrophages and drives their differentiation into epithelioid histiocytes and giant cells, the cellular core of granulomas. TNF-α provides survival signals for the granuloma. IL-4 drives alternatively-activated (M2) macrophages and tissue repair, not granuloma formation.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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