AAB Medical Technologist (MT) – Generalist Practice Exam

The protein released by natural killer cells that plays a crucial role in lysing pathogenic cells is known as perforin. When natural killer cells identify infected or cancerous cells, they release perforin, which creates pores in the target cell membrane. This pore formation allows granzymes, another type of protein released by the natural killer cells, to enter the target cell and induce apoptosis, or programmed cell death.

Understanding the function of perforin is essential in immunology, as it highlights the mechanisms by which the immune system eliminates threats. Granzymes, while also important, specifically act after perforin has created openings in the infected cell. Interferon and histamine serve different roles in the immune response: interferon is primarily involved in signaling and modulating immune responses, particularly against viral infections, while histamine is involved in allergic responses and the regulation of physiological functions.