Final answer:
The main function of Th1 T helper cells is to activate cell-mediated immune responses by secreting cytokines that stimulate other immune cells like macrophages, cytotoxic T cells, and NK cells.
Step-by-step explanation:
Th1 T helper cells, a critical component of the immune system, have the main function of activating cell-mediated immune responses.
They execute this role by secreting cytokines that enhance the capabilities of various immune cells such as macrophages, cytotoxic T cells (Tc), and natural killer (NK) cells.
In particular, Th1 cells stimulate Tc cells to more effectively destroy infected cells and assist NK cells in eliminating early cancers.
This influential interaction between Th1 cells and other immune cells is fundamental to counteracting intracellular pathogens and neoplastic cells, ensuring the body's defenses remain robust against these threats.