Which cytokine, produced by Th2 cells, provides the signal that drives class switch recombination of B cells toward IgE production during helminthic infection?
- A IFN-gamma
- B IL-12
- C IL-4 ✓
- D TGF-beta
Correct answer: C. IL-4
Explanation
IL-4 from Th2 cells signals through the IL-4 receptor and STAT6 pathway to induce germline epsilon transcripts and AID expression, directing switch recombination to the IgE heavy chain constant region. IFN-gamma from Th1 cells instead promotes switching to IgG subclasses such as IgG1 in humans, while TGF-beta promotes IgA class switching in mucosal tissues.
Reference: Basic Immunology, Abbas, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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