Final answer:
Cell-mediated immunity is responsible for contact sensitivity, the elimination of tumor cells, and the rejection of foreign tissue grafts. This involves T lymphocytes, particularly cytotoxic T cells, that identify and destroy non-self cells. The correct option is D. All of the above.
Step-by-step explanation:
Cell-mediated immunity is responsible for a variety of actions within the immune system, specifically:
- Contact sensitivity
- Elimination of tumor cells being neoantigens
- Rejection of foreign tissue grafts
These actions are crucial in defending the body against pathogens, cancer cells, and recognizing foreign tissue. T lymphocytes, including cytotoxic T cells, play a central role in recognizing and reacting to non-self cells, whether those cells come from incompatible transplanted tissue, are altered by viruses or other pathogens or are cancer cells presenting abnormal antigens. As such, cell-mediated immunity is a fundamental aspect of the adaptive immune response.