What is the function of granzymes released by cytotoxic T cells?

What is the function of granzymes released by cytotoxic T cells?

• A. Stimulate antibody production
• B. Induce apoptosis in target cells
• C. Inhibit protein synthesis
• D. Promote phagocytosis

Answer: (B)

Granzymes from cytotoxic T cells trigger programmed cell death (apoptosis) in the target cell. They are delivered into the target through pores formed by perforin, then activate a cascade of proteolytic enzymes (caspases) and mitochondrial pathways that lead to DNA fragmentation and the characteristic features of apoptosis. This selective killing eliminates infected or transformed cells while limiting inflammation from cell lysis. Stimulation of antibody production is a helper T cell/B cell function, not a direct cytotoxic mechanism. Granzymes do not primarily inhibit protein synthesis the way certain bacterial or plant toxins do. They also don’t promote phagocytosis; their role is to kill the target cell so it can be cleared. The best description of their function is inducing apoptosis in the target.

Granzymes from cytotoxic T cells trigger programmed cell death (apoptosis) in the target cell. They are delivered into the target through pores formed by perforin, then activate a cascade of proteolytic enzymes (caspases) and mitochondrial pathways that lead to DNA fragmentation and the characteristic features of apoptosis. This selective killing eliminates infected or transformed cells while limiting inflammation from cell lysis.

Stimulation of antibody production is a helper T cell/B cell function, not a direct cytotoxic mechanism. Granzymes do not primarily inhibit protein synthesis the way certain bacterial or plant toxins do. They also don’t promote phagocytosis; their role is to kill the target cell so it can be cleared. The best description of their function is inducing apoptosis in the target.