Final answer:
Cytokines have pleiotropic effects on TH1 and TH2 cells, regulating different aspects of the immune response.
Step-by-step explanation:
TH1 cells and TH2 cells are two types of helper T cells that secrete cytokines to regulate the immune response. The pleiotropic effects of cytokines on TH1 cells include stimulating cytotoxic T cells, enhancing their killing of infected cells, promoting differentiation into memory cytotoxic T cells, and stimulating macrophages, neutrophils, and NK cells to become more effective in killing target cells.
On the other hand, cytokines can stimulate TH2 cells to stimulate naive B cells to secrete antibodies. These pleiotropic effects of cytokines help coordinate and enhance different components of the immune response.