Final answer:
The fas ligand is a transmembrane protein on the surface of killer lymphocytes that activates fas death receptors on the surface of target cells, inducing apoptosis. NK cells and cytotoxic T cells use the fas ligand to eliminate infected or cancerous cells.
Step-by-step explanation:
The fas ligand is a transmembrane protein on the surface of killer lymphocytes that activates fas death receptors on the surface of target cells. When the fas ligand binds to the fas molecule on the target cell, it induces the target cell to undergo apoptosis, resulting in its death. This process plays a crucial role in the immune system's defense against infected or cancerous cells.
For example, natural killer (NK) cells express the fas ligand and can recognize and eliminate target cells by triggering apoptosis. Similarly, cytotoxic T cells can also use the fas ligand to kill infected cells. The fas ligand-fas molecule interaction is a vital mechanism for immune responses and maintaining overall health.