1. What event initiates an adaptive immune response?
A. The interaction of a B cell with a TH cell
B. The expression of cytokines CD4 or CD8
C. The
... [Show More] production of MHC class I or II molecules
D. The interaction of a naïve T cell with an antigen-presenting cell
E. The phagocytosis of a pathogen by a macrophage answer- D
3. CD4+ T cells recognize:
A. CD8+ markers.
B. IgM.
C. MHC class I peptides.
D. MHC class II peptides.
E. both MHC class I and class II peptides. answer- D
5. CD4+ T cells become helper T cells in response to:
A. exposure to antigen.
B. exposure to MHC class II peptide.
C. exposure to any MHC peptide.
D. exposure to MZ B cells.
E. exposure to TNF-a. answer- B
8. Bonds formed between the T cell and a dendritic cell are relatively weak. Which of the following help to strengthen this association so that a T cell can see which antigen is being presented by a dendritic cell?
A. CD28/LFA-5
B. CD 28
C. ICAM-1/LFA-1
D. IL-2R
E. Pattern-recognition molecules answer- C
9. Which of the following is required for T-cell activation?
A. Antigen-specific TCR binding to MHC peptide
B. Expression of CD4+ or CD8+
C. Interaction with CD80, CD86, or ICOS-L
D. Both A and B
E. Both A and C answer- E
10. Co-receptor molecules are required by TC and TH cells so that the TCR can stably bind to the MHC peptide presenting the antigen. Which co-receptor molecules are common to both TC and TH cells and their respective antigen presenting cells?
A. CD2/LFA-3
B. CD28/B7
C. CD45R/CD22
D. LFA-1/ICAM-1
E. All but B answer- E
11. CTLA-4 is a co-stimulatory receptor on T cells that belongs to the same family as the CD28 co-stimulatory receptor. However, CTLA-4 is antagonistic to CD28. Which of the following could be a functional advantage of CTLA-4 expression within the immune response?
A. CTLA-4 competes with CD28 for ligand binding so that, if CD28 binds to its ligand, the response will be magnified.
B. CTLA-4 is often given to immunosuppressed individuals to trigger an immune response.
C. CTLA-4 limits the immune response of TC and TH cells after an infection has been cleared.
D. CTLA-4 limits TC activity in healthy individuals during a viral infection.
E. CTLA-4 reduces the lag time between antigen presentation to a TH cell and B cell activation. answer- C
12. PD-1 is a negative co-stimulatory signal expressed by tumor cells. What advantage would the expression of PD-1 have in a tumor cell avoiding the immune response?
A. None. Tumor cells are recognized as self and therefore do not pose a health threat.
B. Tumor cells can avoid being killed by activated TC cells.
C. Tumor cells can avoid apoptosis triggered by TH cells.
D. Tumor cells avoid phagocytosis by den [Show Less]