Final answer:
Helper T cells are a type of T lymphocyte that play a crucial role in the immune response. TH1 cells are stimulated by interleukin-12 (IL-12) and secrete interferon-γ (IFN-γ) to enhance cell-mediated responses. They promote the activities of macrophages, cytotoxic T cells, and natural killer (NK) cells.
Step-by-step explanation:
Helper T cells are a type of T lymphocyte that play a crucial role in the immune response. There are three major subpopulations of helper T cells: TH1, TH2, and TH17. TH1 cells are stimulated by interleukin-12 (IL-12) and secrete interferon-γ (IFN-γ) in response. They generally promote cell-mediated responses, enhancing the activities of macrophages, cytotoxic T cells, and natural killer (NK) cells. Helper T cells are a type of T lymphocyte that play a crucial role in the immune response.