Exam Review

6. An antigen that causes allergies
8. Receptors on the surface of NK cells which detect infected cells.
9. The process during which a cell commits suicide.
10. Not viewing self as an attacker
11. B or T cell
12. A peptide which includes a special initiator amino acid that is characteristic of proteins made by bacteria.
15. White blood cells
16. Liquid that leaks out of blood vessels into tissues.
18. Increase in number
21. Target of an antibody or a T cell.
23. To decorate with fragments of complement proteins or with antibodies.
24. Protein used for communication between leukocytes.
25. Second line of defense
26. Third level of defense
27. Battle cytokine, mainly secreted by Th1 helper T cells and NK cells.

1. Physical manifestations caused by the immune system's battle against invaders.
2. The CD4 and CD8 molecules on T cells
3. White blood cells that are the precursors of macrophages or dendritic cells.
4. Receptors on the surface of NK cells which detect the expression of class 1 MHC molecules and inhibit killing.
5. Hormone-like messenger molecules that cells use to communicate.
7. Travels from the tissues to the secondary lymph organs to activate naive T cells.
13. Proteins encoded by the major histocompatibility complex.
14. Type 1 interferons. Warning cytokines secreted by virus-infected cells.
17. presenting cells Cells that can present antigen efficiently to T cells via MHC molecules
19. Cells such as macrophages and neutrophils that engulf invaders.
20. The antigen which a B or T cell's receptors recognize and bind to.
22. A disease causing agent.