Final answer:
In THA, macrophages and TH1 helper T lymphocytes mediate the immune response by stimulating each other to effectively target and destroy intracellular pathogens, with macrophages acting on the frontline.
Step-by-step explanation:
The cells involved in mediating responses to metal ions in THA are primarily macrophages and helper T lymphocytes (specifically TH1 cells). Macrophages, as part of the innate immune system, play a frontline defense role and can stimulate naive T cells to differentiate into TH1 cells. These TH1 cells, in turn, secrete cytokines that enhance the macrophages' ability to ingest and destroy intracellular pathogens like Mycobacterium tuberculosis.
B Lymphocytes also play a role when stimulated by TH2 pathway, where they differentiate into plasma cells capable of secreting antibodies. In TH1-mediated immune responses, macrophages activated by TH1 cells can efficiently target and destroy both intracellular bacteria and tumor cells.