Which immune mechanism is characterized by the direct destruction of infected cells?

Cell-mediated immunity is primarily characterized by the direct destruction of infected cells. This mechanism involves T lymphocytes, particularly cytotoxic T cells, which can recognize and bind to infected cells displaying foreign antigens on their surface. Once bound, cytotoxic T cells release perforins and granzymes that induce apoptosis, or programmed cell death, in the infected cells. This targeted approach allows for the elimination of cells harboring pathogens, such as viruses, without causing widespread damage to neighboring healthy cells.

In contrast to cell-mediated immunity, phagocytosis is the process by which macrophages and other phagocytes engulf and digest pathogens, but it does not involve direct cell-to-cell killing. Antibody-mediated immunity, also known as humoral immunity, relies on the production of antibodies by B cells that neutralize pathogens rather than directly destroying infected cells. Infection control is a broader term that encompasses various strategies to prevent the spread of infection, but it is not specific to the mechanism of cell destruction. Therefore, cell-mediated immunity is the mechanism that directly targets and eliminates infected cells.