Answer
Natural Killer (NK) cells are the type of lymphocyte involved in nonspecific defense. NK cells are part of the innate immune system and play a crucial role in detecting and eliminating virus-infected cells and cancer cells without the need for prior exposure to specific antigens.
NK cells are particularly effective at identifying and destroying abnormal cells because they recognize changes in the surface proteins of these cells. When an NK cell encounters a target cell that displays abnormal or reduced levels of major histocompatibility complex (MHC) class I molecules, which are usually present on the surface of healthy cells, the NK cell becomes activated. Activated NK cells release cytotoxic granules containing perforin and granzymes. Perforin forms pores in the target cell's membrane, allowing granzymes to enter and induce apoptosis (programmed cell death).
This ability to recognize and eliminate a wide range of abnormal cells without prior sensitization makes NK cells an important component of the body's nonspecific defense against infections and cancer.
Work Step by Step
Natural Killer (NK) cells are the type of lymphocyte involved in nonspecific defense. NK cells are part of the innate immune system and play a crucial role in detecting and eliminating virus-infected cells and cancer cells without the need for prior exposure to specific antigens.
NK cells are particularly effective at identifying and destroying abnormal cells because they recognize changes in the surface proteins of these cells. When an NK cell encounters a target cell that displays abnormal or reduced levels of major histocompatibility complex (MHC) class I molecules, which are usually present on the surface of healthy cells, the NK cell becomes activated. Activated NK cells release cytotoxic granules containing perforin and granzymes. Perforin forms pores in the target cell's membrane, allowing granzymes to enter and induce apoptosis (programmed cell death).
This ability to recognize and eliminate a wide range of abnormal cells without prior sensitization makes NK cells an important component of the body's nonspecific defense against infections and cancer.
