REVIEW QUESTIONS FOR CELL MEDIATED IMMUNITY
1. What are the components of the TCR complex? Which of these components are
responsible for antigen recognition and which for signal transduction?
2. What are some of the molecules in addition to the TCR that T cells use to initiate
their responses to antigens, and what are the functions of these molecules?
3. What is costimulation? What is the physiologic significance of costimulation? What
are some of the ligand-receptor pairs involved in costimulation?
4. Summarize the links among antigen recognition, the major biochemical signaling
pathways in T cells, and the production of transcription factors.
5. What is the principal growth factor for T cells? Why do antigen-specific T cells
expand more than other (bystander) T cells on exposure to an antigen?
6. What are the mechanisms by which CD4+ effector T cells activate other
leukocytes?
7. What are the major properties of memory T lymphocytes?
8. Why do naive T cells migrate preferentially to lymphoid organs and differentiated
effector T cells (which have been activated by antigen) migrate preferentially to
tissues that are sites of infection?
9. What are the types of T lymphocyte–mediated immune reactions that eliminate
microbes that are sequestered in the vesicles of phagocytes and microbes that live
in the cytoplasm of infected host cells?
10. What are the major subsets of CD4+ effector T cells, how do they differ, and what
are their roles in defense against different types of infectious pathogens?
11. What are the mechanisms by which T cells activate macrophages, and what are the
responses of macrophages that result in the killing of ingested microbes?
12. How do CD8+ CTLs kill cells infected with viruses?
13. What are some of the mechanisms by which intracellular microbes resist the
effector mechanisms of cell-mediated immunity?