Final answer:
T cells, specifically helper T cells, interact with other cells by secreting cytokines to enhance immune responses, while cytotoxic T cells kill infected cells and regulatory T cells suppress inappropriate immune reactions.
Step-by-step explanation:
T cells function by interacting with other cells and inducing them to change. A primary type of T cells are helper T cells (Th), which bear the CD4 molecule and secrete cytokines to enhance immune responses.
Helper T cells can further differentiate into various subtypes, including T¹₁, TH2, TH17, or memory T cells, based on the cytokines they are exposed to and their functions in stimulating adaptive and innate immune defenses.
Another type, cytotoxic T cells (Tc), directly kills infected cells following engagement with APC signals. Lastly, regulatory T cells play a role in suppressing inappropriate immune reactions to harmless or “self” antigens, maintaining immune system balance.