Question

Which interleukin inhibits the immune response?
A. IL - 4
B. IL - 13
C. IL - 10
D. IL - 7
Choose the correct answer from the options given below

• A. A only
• B. B only
• C. C only
• D. All A, B, C and D

Hint:

Immunosuppressive Anti-inflammatory Cytokines: IL-10 (CSIF) and TGF-$\beta$. Master pro-inflammatory cytokines = IL-1, TNF-$\alpha$, IL-6, IFN-$\gamma$.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Immunoregulatory and anti-inflammatory cytokine networks: Interleukin-10 (IL-10) functions as a potent master immunosuppressive cytokine secreted by Treg cells.
Key Formula or Approach:
\[ \text{Treg Cells} \xrightarrow{\text{Secrete}} \text{IL-10} + \text{TGF-}\beta \implies \text{Inhibits Th1 Cytokines, Downregulates MHC-II/B7} \implies \text{Suppresses Immunity} \]

Step 2: Detailed Explanation:
In cytokine immunology:
- Interleukin-10 (IL-10 Cytokine Synthesis Inhibitory Factor [CSIF]): The primary anti-inflammatory and immunosuppressive cytokine produced by Regulatory T cells (Tregs), M2 macrophages, and Th2 cells.
- It actively downregulates MHC Class II and co-stimulatory CD80/CD86 expression on antigen-presenting cells (APCs), inhibits macrophage production of pro-inflammatory cytokines (IL-1, IL-6, TNF-$\alpha$, IL-12), and suppresses effector Th1 cell proliferation.
- (IL-4 and IL-13 promote humoral/allergic Th2 responses; IL-7 stimulates lymphocyte development).
Thus, IL-10 (C only) inhibits the immune response.

Step 3: Final Answer:
Therefore, IL-10 (C only) inhibits the immune response, corresponding to option (C).