Which cytokine is primarily associated with the activation of cytotoxic T cells?

• A. Interleukin 1
• B. Interleukin 2
• C. Granulysin
• D. Alpha interferons

Answer: (B)

The activation of cytotoxic T cells is primarily associated with Interleukin 2. This cytokine, produced mainly by helper T cells, plays a crucial role in promoting the proliferation and differentiation of cytotoxic T cells. When a naive cytotoxic T cell encounters its specific antigen presented on MHC class I molecules, the presence of Interleukin 2 enhances its ability to multiply and become an effective effector cell capable of targeting and killing infected or malignant cells.

In the immune response, Interleukin 2 acts as a growth factor for T cells, driving their activation and expansion. This is critical for establishing a robust adaptive immune response, ensuring that the body can effectively eliminate infected cells and tumor cells.

Other cytokines listed play different roles in the immune response; for instance, Interleukin 1 is involved in inflammation and activating immune responses, granulysin is a protein released by cytotoxic cells that aids in cellular lysis, and alpha interferons primarily have antiviral effects by inhibiting viral replication in host cells.