Final answer:
Interferon-gamma is primarily produced by activated T cells and natural killer (NK) cells. It has multiple functions in the immune system, including enhancing the activation and functioning of immune cells, promoting B cell production and maturation, and increasing the cytotoxic T cells' ability to kill infected cells.
Step-by-step explanation:
Interferon-gamma (IFN-y) is primarily produced by activated T cells and natural killer (NK) cells. IFN-y has multiple functions in the immune system. It enhances the activation and functioning of other immune cells, such as macrophages and dendritic cells. IFN-y also promotes the production and maturation of B cells and enhances the ability of cytotoxic T cells to kill infected cells.