Daclizumab acts through –
**Core Concept**
Daclizumab is a humanized monoclonal antibody that targets the interleukin-2 receptor alpha (IL-2Rα) subunit on the surface of T cells. This receptor plays a crucial role in the activation and proliferation of T cells, which are central to the immune response.
**Why the Correct Answer is Right**
Daclizumab binds to the IL-2Rα subunit, preventing the interaction between IL-2 and its receptor. This blockade inhibits the activation and proliferation of T cells, thereby reducing the immune response. By targeting the IL-2Rα subunit, daclizumab exerts its immunosuppressive effects.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because daclizumab does not act through the calcineurin pathway, which is a different mechanism of action for immunosuppressive agents like cyclosporine.
**Option B:** This option is incorrect because daclizumab does not act through the inhibition of adenosine triphosphate (ATP) production, which is a mechanism of action for some immunosuppressive agents.
**Option C:** This option is incorrect because daclizumab does not act through the inhibition of the complement system, which is a different mechanism of action for some immunosuppressive agents.
**Clinical Pearl / High-Yield Fact**
Daclizumab is used in the treatment of multiple sclerosis and in organ transplantation to prevent rejection. Its ability to target the IL-2Rα subunit makes it a valuable immunosuppressive agent in these contexts.
**Correct Answer:**
.