What is the role of lymphotoxin released by T cytotoxic cells?

• A. To attract other immune cells
• B. To activate enzymes that destroy DNA
• C. To create channels in cell membranes
• D. To induce apoptosis

Answer: (B)

Lymphotoxin, released by T cytotoxic cells, plays a critical role in the immune response, particularly concerning the destruction of infected or malignant cells. This cytokine is known for its ability to activate specific enzymes that target and degrade DNA within target cells. By damaging the DNA, lymphotoxin effectively disrupts the cellular machinery, leading to cell death.

This function is pivotal in the context of the immune system's ability to eliminate cells that pose a threat to the body, such as those infected with viruses or those that have become cancerous. The targeted action of lymphotoxin highlights the precision of the immune response, as it allows T cytotoxic cells to selectively induce death in cells that exhibit abnormal behavior while sparing surrounding healthy cells.

The other answer options do not accurately capture the primary role of lymphotoxin. For instance, while some immune signaling processes involve attracting other immune cells, lymphotoxin's specific function is more aligned with the direct destruction of cells. Similarly, while inducing apoptosis is a significant outcome of lymphocyte activity, it is more specifically related to the broader role of T cells, whereas lymphotoxin's primary action pertains to the degradation of DNA. The creation of channels in cell membranes relates to the mechanisms used by