The type of adaptive immunity that destroys intracellular pathogens via lymphoid cells is called _____ immunity.

• A. Humoral
• B. Innate Immunity
• C. Cellular
• D. Adaptive Immunity

Answer: (C)

Cell-mediated immunity uses T lymphocytes to eliminate cells that are infected with intracellular pathogens, which is essential because antibodies can’t reach pathogens hiding inside host cells. Cytotoxic T cells (CD8+) recognize viral or other intracellular antigens presented on MHC class I on infected cells and kill those cells by releasing perforin and granzymes. Helper T cells (CD4+ Th1) support and activate macrophages to destroy intracellular microbes as well. Since antibodies circulate in body fluids and primarily target extracellular threats, they’re not effective against intracellular pathogens, making cellular immunity the appropriate pathway. The question describes this T cell–driven, intracellular-targeting response, so cellular immunity is the correct label.