What type of cells are activated by interferons during a viral infection?

Interferons are a group of signaling proteins that play a crucial role in the immune response, particularly during viral infections. When a cell becomes infected by a virus, it releases interferons as a way to alert neighboring cells about the viral threat.

Natural killer (NK) cells are a type of lymphocyte that are specifically activated by interferons. They have the ability to recognize and destroy virus-infected cells, thereby limiting the spread of the virus. Interferons enhance the activity of NK cells, promoting their ability to recognize and eliminate infected cells.

Macrophages are another critical component of the immune response, and they are also influenced by interferons. Interferons can enhance the phagocytic activity of macrophages and increase their ability to present antigens, which helps in orchestrating a more effective immune response.

Since both natural killer cells and macrophages are activated and have their functions enhanced by interferons during a viral infection, the correct choice encompasses both cell types. Therefore, the combination of the activation of both macrophages and natural killer cells through the action of interferons justifies why that answer is appropriate.