Question

Which of the following interleukin is secreted by T helper 2 cells?

• A. IL 11
• B. IL 7
• C. IL 1
• D. IL 13

Hint:

Th2 cytokines include IL-4, IL-5, IL-6, IL-10 and IL-13.

Answer 1

The Correct Option is D

Step 1: Recall the Th subsets. CD4+ helper T cells differentiate mainly into Th1 and Th2 subsets, each with a characteristic cytokine profile.

Step 2: Th2 cytokines. T helper 2 (Th2) cells secrete IL-4, IL-5, IL-6, IL-10 and IL-13. These drive B cell antibody responses (especially IgE), eosinophil activity and allergic or anti-parasitic immunity. Among the given options, IL-13 is the Th2 cytokine, so option d is correct.

Step 3: Contrast with Th1. Th1 cells secrete IL-2 and interferon-gamma, which activate macrophages and support cell-mediated immunity. IL-13 is not part of the Th1 set.

Step 4: Why the others are wrong. IL-1 is produced mainly by macrophages and is a pro-inflammatory cytokine, IL-7 is largely from stromal and bone marrow cells supporting lymphocyte development, and IL-11 is a stromal-cell cytokine involved in thrombopoiesis. None of these are Th2 products, leaving IL-13 as the answer.