Antigen‐specific recognition

Question 1

1. A hapten is best defined as being:

A An epitope

B A paratope

C A small chemical grouping that reacts with preformed antibodies

D A carrier

E An immunogen

Answer 1

C A small chemical grouping that reacts with preformed antibodies

Question 2

2. A discontinuous antigen epitope is:

A Presented by MHC molecules

B Usually concave

C Representative of only a minority of B-cell epitopes

D Produced by a continuous linear peptide sequence

E Produced by amino acid residues on non-adjacent polypeptide sequences

Answer 2

E Produced by amino acid residues on non-adjacent polypeptide sequences

Question 3

3. Binding of antigen to antibody:

A Is usually unaffected by molecular rigidity

B Is unaffected by the presence or absence of water molecules

C Involves covalent bonding

D Is optimized by spatial complementarity

E Is usually unaffected by pH

Answer 3

D Is optimized by spatial complementarity

Question 4

4. The intermolecular forces that contribute to the interaction between antibody and antigen:

A Are all electrostatic

B Are all van der Waals

C Are all hydrophobic

D Are all hydrogen bonds

E Rely on a combination of the above

Answer 4

E Rely on a combination of the above

Question 5

5. Which of the following statements is NOT TRUE of affinity?

A A measure of the strength of the binding of antigen to antibody

B The equilibrium constant of the Ag/Ab complex

C Avidity

D Related to the free energy change of the Ag/Ab interaction

E Related to specificity

Answer 5

C Avidity

Question 6

6. What is the structure recognized by the αβ T-cell receptor on the cell surface of an antigen-presenting cell?

A Native protein antigen plus major histocompatibility complex (MHC) molecule

B Processed (peptide) antigen plus MHC

C Processed peptide antigen

D Native antigen

E MHC alone

Answer 6

B Processed (peptide) antigen plus MHC

Question 7

7. The processing of cytosolic protein involves:

A Transport into late endosomes

B Proteasome-mediated cleavage

C Displacement of invariant chain

D Displacement of β2-microglobulin

E Binding to the MHC class II groove

Answer 7

B Proteasome-mediated cleavage

Question 8

8. Which of the following statements does NOT apply to the immunoproteasome?

A It is generated in response to IFNγ stimulation

B It contains the β-1i subunit

C It contains the β-5i subunit

D Very few of the peptides generated are 8–10 residues in length

E It contains a 19s regulator

Answer 8

D Very few of the peptides generated are 8–10 residues in length

Question 9

9. Antigen processing for presentation by MHC class II molecules involves:

A DM

B ERp57

C TAP1 and TAP2

D Calnexin

E Proteasomal-mediated cleavage

Answer 9

A DM

Question 10

10. The processed peptide binding to the MHC class I groove:

A Is usually more than 11 amino acids long

B Hangs over the ends of the groove

C Usually binds to the groove through two anchor residues

D Is mainly recognized by the CDR2 of the T-cell receptor chains

E Is mostly derived from exogenous protein taken in by endocytosis

Answer 10

C Usually binds to the groove through two anchor residues

Question 11

11. TCR recognition of peptide-MHC class II depends on:

A Covalent binding

B Very high affinity interactions

C CDR-mediated binding

D A minimum of two peptides occupying the binding groove of each MHC molecule

E The presence of β2 microglobulin

Answer 11

C CDR-mediated binding

Question 12

12. Cross-presentation of exogenous antigen to αβ T-cells does NOT require the involvement of:

A Peptide-MHC recognition by the T-cell receptor

B Antigen-processing

C MHC class I

D MHC class II

E An antigen-presenting cell

Answer 12

D MHC class II

Question 13

13. An example of a “non-classical” MHC molecule is:

A H-2A

B HLA-C

C H-2L

D H-2E

E H-2M

Answer 13

E H-2M

Question 14

14. Which of the following statements is TRUE of CD1?

A CD1 is encoded in the MHC region

B CD1 structurally is most similar to MHC class II molecules

C CD1 can present antigens to γδ, but not αβ T-cells

D CD1 can present lipid antigens

E CD1 is encoded by a single gene

Answer 14

D CD1 can present lipid antigens

Question 15

15. Which of the following statements is TRUE of iNKT cells?

A iNKT cells bear diverse TCRα chains

B iNKT cells have a limited TCRβ chain repertoire

C iNKT cells comprise 2–3% of T-cells in the mouse liver

D Following stimulation, iNKT cells secrete IFNγ but not IL-4

E iNKT cells are restricted by classical MHC molecules

Answer 15

B iNKT cells have a limited TCRβ chain repertoire

Question 16

16. Which of the following statements is TRUE of superantigens?

A Superantigens do not cause pathology

B Superantigens are not mitogenic for T-cells

C Superantigens bind to MHC class III

D Superantigens bind to all members of a given V β TCR family

E Superantigens have to be processed before recognition by the T-cell

Answer 16

D Superantigens bind to all members of a given V β TCR family

Question 17

17. αβ T-cells recognizing MHC plus processed peptide can:

A Themselves produce antibody to directly eliminate extracellular organisms

B Release histamine

C Develop into γδ T-cells

D Directly kill viruses

E Recognize an intracellular infection

Answer 17

E Recognize an intracellular infection

Question 18

18. Which of the following statements is TRUE about an epitope?

A An epitope is the area on an antigen that contacts antibody

B An epitope is the area on an antibody that contacts antigen

C An epitope requires both antigen-binding arms of the antibody molecule for its recognition

D An epitope is usually composed of a linear sequence of amino acids

E An epitope is usually associated with a concave region of the antigen

Answer 18

A An epitope is the area on an antigen that contacts antibody

Question 19

19. The single best unique description of the interaction of the αβ T-cell receptor with peptide-MHC is that it:

A Involves non-covalent forces

B Results in T-cell activation

C Requires the peptide to be presented by MHC class I

D Involves CDR (complementarity-determining region) binding to both peptide and MHC

E Is of relatively low affinity compared with antibody binding to native antigen

Answer 19

D Involves CDR (complementarity-determining region) binding to both peptide and MHC

Question 20

20. What is the single best definition of the most common form of antigen recognized by the T-cell receptor (TCR)?

A Native protein

B Cleaved

C A short peptide

D Linear

E Accessible

Answer 20

C A short peptide