Final answer:
Interferon-γ is secreted by T cells and natural killer cells to enhance the immune response, including activating macrophages and aiding in the maturation of B cells into plasma cells that produce antibodies.
Step-by-step explanation:
Interferon-γ is secreted by T cells and natural killer cells and enhances the immune response, particularly by activating macrophages and helping B cells to multiply and mature into antibody-producing plasma cells. Interferon-γ is a type of cytokine, which are glycoproteins involved in cell signaling, especially in the immune system. When a cell is infected by a virus, it releases interferons to warn and prepare neighboring cells to defend themselves against the viral infection. Interferons help to limit the spread of the infection by stimulating uninfected cells to produce compounds that interfere with viral replication.