Lymphocyte activation Flashcards
1. What is CD8 a marker of?
A B-cells
B Helper T-cells
C Cytotoxic T-cells
D An activated macrophage
E A neutrophil precursor
C Cytotoxic T-cells
2. Which of the following statements is TRUE of CD4?
A CD4 is essentially an intracellular glycoprotein
B CD4 is heterodimeric
C CD4 binds processed peptide in its outer groove
D CD4 binds to MHC class II on antigen-presenting cells
E CD4 is highly polymorphic
D CD4 binds to MHC class II on antigen-presenting cells
3. Which of the following is characteristic of B- but not T-cells?
A Class I MHC
B CD3
C Measles virus receptor
D Polyclonal activation by concanavalin A (ConA)
E Transmembrane surface immunoglobulin
E Transmembrane surface immunoglobulin
4. When a resting naive T-cell engages its specific MHC–peptide complex displayed on the surface of a fibroblast, it:
A Undergoes blast cell formation
B Produces IL-2
C Moves from G0 to G1 of the cell cycle
D Becomes anergic
E Secretes IL-1
D Becomes anergic
5. What is the T-cell ligand binding B7 on a professional antigen-presenting cell?
A CD28
B CD2
C LFA-1
D ICAM-1
E VCAM-1
A CD28
6. Which of the following statements is TRUE of Sos (Son of sevenless)?
A Sos itself directly activates Raf
B Sos is recruited to non-phosphorylated LAT
C Sos is a guanine nucleotide exchange factor
D Sos is a GTPase-activating protein
E Sos is phosphorylated by Mek
C Sos is a guanine nucleotide exchange factor
7. Protein tyrosine kinase activity following T-cell stimulation:
A Phosphorylates and thereby activates phospholipase Cγ1
B Is an inherent property of the T-cell receptor α and β chains
C Is an inherent property of CD3
D Is decreased
E Is unrelated to phosphorylation of the CD3-associated ζ chains
A Phosphorylates and thereby activates phospholipase Cγ1
8. The early increase in phospholipase Cγ1 activity following T-cell stimulation:
A Represents a sensitive regulatory negative feedback control mechanism
B Dephosphorylates protein tyrosine kinase inhibitors
C Accelerates hydrolysis of diacylglycerol
D Accelerates hydrolysis of phosphatidylinositol diphosphate
E Accelerates hydrolysis of inositol triphosphate
D Accelerates hydrolysis of phosphatidylinositol diphosphate
9. The nuclear AP-1 site responsible for 90% of IL-2 enhancer activity binds:
A The Oct-1 transcriptional factor
B The Fos/Jun transcription factors
C The nuclear factor of activated T-cells (NFAT)
D The NFκB transcriptional factor
E Polyclonal mitogenic agents such as ConA
B The Fos/Jun transcription factors
10. In the immunological synapse:
A The acetylcholine receptor in expressed on the T-cell
B Production of substance P by the antigen-presenting cell is a key event
C The initial interaction between TCR and MHC is unstable
D Adhesion molecule pairs eventually move to the center of the synapse
E The B7–CD28 interaction is redundant
C The initial interaction between TCR and MHC is unstable
11. Lipopolysaccharide (LPS) from Gram-negative bacteria is:
A A thymus-dependent antigen
B A type 2 thymus-independent antigen
C A polyclonal activator of murine B-cells
D Cross-links Ig receptors on B-cells
E Produces high affinity IgG memory responses
C A polyclonal activator of murine B-cells
12. The carrier T-cell epitope on a thymus-dependent antigen:
A Behaves like a hapten
B Needs to be polymeric
C Need not be physically connected to the B-cell epitope
D Is a carbohydrate
E Stimulates help for the B-cell response
E Stimulates help for the B-cell response
13. T-cell help for antibody production:
A Depends on T-cell recognition of native antigen bound to B-cell surface Ig
B Depends on T-cell recognition of antigen processed by the B-cell
C Involves class I MHC on the B-cell
D Can occur in X-irradiated mice
E Is a feature of the antibody response to pneumococcal polysaccharide SIII
B Depends on T-cell recognition of antigen processed by the B-cell
14. Cross-linking of B-cell surface receptors:
A Is a characteristic feature of thymus-dependent antigens
B Lowers the intracellular Ca2+ concentration
C Rapidly phosphorylates the Ig-α and Ig-β chains of the surface Ig receptor
D Requires contiguity of two B-cell epitopes of different specificity on the same antigen molecule
E Cannot be achieved by anti-idiotypic antibodies
C Rapidly phosphorylates the Ig-α and Ig-β chains of the surface Ig receptor
15. Activation of resting B-cells by T-helper cells depends directly upon costimulatory interaction between:
A CD40 and CD40L
B B7 and CD28
C B7 and CTLA-4
D CD4 and MHC class II
E ICAM-1 and LFA-1
A CD40 and CD40L
