Biol. 456/556, Immunology
Tuesday, March 6, 2018
EXAM AA
Second Exam, Spring Semester 2018
Multiple Choice Questions. Please pick the BEST answer from the list of potential answers and use the
Scantron to record your choice. MAKE SURE you have filled in YOUR NetID, BANNER ID
NUMBER, AND EXAM VERSION on the scantron.
1. Which of the following is the best definition of Major Histocompatibility Complex (MHC)
restriction as it was originally described? (The Zinkernagal and Doherty experiments)
A. Transplanted tissue or organs are only rejected if the donor and recipient match at the MHC.
B. Cytotoxic T cells can only kill virus-infected cells if they are both from a different MHC
type.
C. Cytotoxic T cells can only kill virus-infected cells if they are both from the same MHC type.
D. The number of MHC alleles you have restricts the diversity of peptides you can present.
2. If an antigen such as Hepatitis B were introduced into the thymus of a human fetus, which stage of T
cell development would you expect to be most affected?
A. Positive selection of αβ T cells.
B. Negative selection of αβ T cells.
C. Both positive and negative selection of αβ T cells.
D. Junctional diversity of the TCR α chain.
3. An MHC class I molecule was found to bind the following peptides:
Tyr-Gly-Pro-Cys-Ala-Ser-Ile-Gly-Lys-Leu
Tyr-Cys-Gly-Gln-Trp-Met-Ile-Ala-Lys-Pro
Tyr-Ala-Trp-Ser-Asp-Arg-Val-Met-Lys-Leu
Tyr-Gly-Gly-Ser-Asp-Ala-Leu-Pro-Lys-Met
(All peptides sequences in the same orientation: amino terminal end to carboxy terminal end.)
Based on the above observations, which of the following peptides would you also expect it to bind
the same MHC class I molecule equally well?
A. Met-Tyr-Ser-Asp-Arg-Lys-Asn-Gln-Pro-Leu
B. Arg-Tyr-Gly-Ser-Trp-Met-Val-Gln-Lys-Leu
C. Tyr-Asp-Met-Asp-Trp-Met-Asp-Gln-Lys-Gly
D. Tyr-Gly-Ala-Cys-Val-Glu-Val-Tyr-Ile-Leu
4. Someone deficient in MHC class I expression in the thymus for hereditary reasons would also be
expected to be deficient in which of the following?
A. CD4+ T cell development.
B. CD8+ T cell development.
C. B cell responses.
D. γδ T cell development.
1
Biol. 456/556, Immunology
Tuesday, March 6, 2018
EXAM AA
Second Exam, Spring Semester 2018
5. A new species of mammal (Roberto milleri) is discovered in the Amazon basin. A clever
immunologist determines that there are eight different combinations of MHC class II molecules found
on the surface of this species' macrophages. Based on this information what is the minimum number
of MHC class II genes, alpha and beta combined, needed to encode all these molecules? Assume a
heterozygous state.
A. Four.
B. Six.
C. Eight.
D. Twelve.
6. Which of the following is an outcome of positive selection during T cell development in the
thymus?
A. Selection for developing T cells with T cell receptors that cannot bind self-peptides.
B. Selection for developing T cells with T cell receptors that can bind MHC molecules.
C. Elimination of developing T cells that have failed to rearrange their b chain genes properly.
D. Elimination of developing T cells that have failed to express VpreB and λ5 properly.
7. If you treated a cell with a drug that blocks the function of the TAP molecule, which of the
following pathways of antigen presentation would likely still function normally?
A. Endogenous or cytosolic.
B. Exogenous or endosomic.
C. Both.
D. Neither
8. Which of the following best defines the function of the Autoimmune Regulator (AIRE) protein?
A. A transcription factor that controls expression of housekeeping genes in the thymus.
B. A protein used to generate peptides for negative selection in the thymus medulla.
C. A protein degraded by proteasomes to generate peptides for positive selection in the thymus
cortex.
D. A transcription factor that controls ectopic expression of tissue specific genes in the thymus.
9. Which of the following could contribute to differences in the population of mature T cells found in
unrelated individuals?
A. Differences in combinations of V, D, and J segments of their T cell receptors.
B. Differences created by positive selection on the MHC molecules expressed in the thymus.
C. Differences created by negative selection on self-peptides presented in the thymus.
D. All of the above.
10. True or False? MHC molecules bind peptides derived from both self and foreign antigens.
A. True.
B. False.
2
Biol. 456/556, Immunology
Tuesday, March 6, 2018
EXAM AA
Second Exam, Spring Semester 2018
11. Affinity maturation of an antibody response involves which of the following molecular events?
A. Recognition of recombination signal sequences by the RAG recombinase.
B. Deamination of cytosines by activation induced deaminase (AID).
C. Hyper-mutation of the framework regions.
D. Switching from making lambda light chains to kappa light chains.
12. Which of the following are common to both B cells and T cells?
A. Using the recombination activating genes.
B. Converting cell surface antigen receptor to secreted antibody by alternative RNA splicing.
C. Binding of unprocessed antigen.
D. All of the above.
13. Mice homozygous for a mutation in the Fas gene are unable to produce the Fas protein. Which of
the following characteristics would you expect to find in these mice?
A. A deficiency pre-Tα.
B. Inability to undergo V-D-J recombination in developing T cells.
C. Failure to express pre-Tα in developing T cells.
D. None of the above.
14. T cells dying by the process of apoptosis demonstrate which of the following characteristics?
A. Degradation of their chromatin.
B. Failure to express MHC class I molecules.
C. Failure to express MHC class II molecules.
D. Release of chromium.
15. Which of the following could contribute to differences in the population of T cells found in
identical (monozygotic) twins?
A. Differences in the self-peptides presented in the thymus.
B. Differences due to expression of different MHC alleles in the thymus.
C. Differences in combinations of V, D, and J segments of their T cell receptors.
D. All of the above.
16. What is the function of the pre-Tα protein in developing thymocytes?
A. To provide peptides for positive selection.
B. To substitute for the antibody light chains prior to their gene rearrangement.
C. To substitute for the T cell receptor β chain prior to its gene rearrangement.
D. To substitute for the T cell receptor α chain prior to its gene rearrangement.
17. Which of the following is the best definition of monoclonal antibodies?
A. Antibodies purified from the serum of an immune mouse.
B. Antibodies specific for epitopes on the surface of human T cells.
C. Antibodies of a single specificity produced by a hybridoma.
D. Antibodies that are a hybrid between human and mouse.
3
Biol. 456/556, Immunology
Tuesday, March 6, 2018
EXAM AA
Second Exam, Spring Semester 2018
18. Some viruses have evolved to have proteins that are resistant to ubiquitination. What advantage
does this have for the virus?
A. It helps prevent detection of their peptides presented on MHC class II molecules.
B. It helps prevent detection of their peptides presented on MHC class I molecules.
C. It allows the virus to have proteins that look more like host cell proteins.
D. It limits protein synthesis using viral genes.
19. Which of the following components of the antigen presentation machinery serve in the exogenous
or endosomic pathway?
A. Low Mobility Protein (LMP)
B. Transporter of Antigenic Peptides (TAP)
C. Invariant Chain.
D. α subunits of the proteasome.
20. Mature T cells capable of helping B cells generate antibody responses express which of the
following on their surface?
A. CD3 and CD8.
B. CD3 alone.
C. CD4 and CD8.
D.CD3 and CD4.
21. Variation in which antigenic peptides an MHC class I molecule can bind is determined by
polymorphism in what part of the MHC molecule?
A. The α1 and α2 domains.
B. The α2 and α3 domains.
C. The α1 and b1 domains.
D. The bβ2-microglobulin domain.
22. True or False? γδ T cells are derived from B cells whereas αβ T cells are derived from thymocytes.
A. True.
B. False.
23. Which of the following are characteristic of the CD8 molecule?
A. A receptor for MHC class II molecules.
B. A receptor found on all mature T cells.
C. A receptor for MHC class I molecules.
D. All of the above.
24. Which of the following contributes to whether or not a developing T cell becomes an αβ or γδ T
cell?
A. Alternative mRNA splicing.
B. Which MHC class I or II molecules the T cell receptor is restricted by.
C. Whether or not the T cell develops in the cortex or medulla of the thymus.
D. Which T cell receptor genes undergo V(D)J recombination.
4
Biol. 456/556, Immunology
Tuesday, March 6, 2018
EXAM AA
Second Exam, Spring Semester 2018
25. What is the benefit of keeping the LMP, TAP and MHC class Iα chain genes closely linked in the
MHC region?
A. None, it is an accident of evolution.
B. This allows the genes to co-evolve common preferences for peptides generated for
presentation.
C. This prevents the genes from being lost from the genome.
D. This prevents viruses from co-opting the genes for their own use.
26. Which of the following best explain the ubiquitous expression of MHC class I molecules in your
body?
A. All cell types need to be able to present antigens to B cells.
B. All cell types have to be able to present antigens to CD4+ T cells.
C. All cell types have the potential to become cancer cells or be virally infected.
D. Ubiquitin is found in all cell types.
27. Which of the following is (are) needed as part of the MHC class I molecule for it to be successfully
expressed on the cell surface?
A. A peptide that can bind to the peptide-binding groove of the alpha chain.
B. β 2-microglobulin.
C. The class Iα chain.
D. All of the above.
28. More than a century ago, Almroth Wright demonstrated that the presence of immune serum
enhanced phagocytosis and called it oposonization. Based on what we now know which of the
following molecules help explain the oposonization phenomenon?
A. Toll like receptors.
B. Fc receptors.
C. β2-microglobulin.
D. The high affinity IL-2 receptor.
29. Which of the following contributes the most to whether a T cell will be CD4+ or CD8+?
A. Whether its T cell receptor binds MHC class I or class II molecules preferentially.
B. Whether it survives positive selection or not.
C. What antigenic peptide it is specific for.
D. Whether it binds self-peptides or not.
30. Isotype switching and affinity maturation both involve which molecular event (s)?
A. Deamination of cytidines by activation-induced cytidine deaminase (AID).
B. Hypermutation of the complementarity determining regions.
C. Alternative mRNA splicing.
D. All of the above
31. True or False? Class I genes of the Major Histocompatibility Complex (MHC) are limited in their
expression by allelic exclusion.
A. True.
B. False.
5
Biol. 456/556, Immunology
Tuesday, March 6, 2018
EXAM AA
Second Exam, Spring Semester 2018
32. The Loch Ness Monster has 4 different types of MHC class II, A, B, C and D, and is heterozygous
at all loci. How many different MHC class II molecules could be found on Nessie’s macrophages?
A. 4.
B. 12.
C. 16.
D. Not enough information.
33. Someone deficient in MHC class II expression in the thymus for hereditary reasons would also be
expected to be deficient in which of the following?
A. CD4+ T cell development.
B. CD8+ T cell development.
C. B cell responses.
D. γδ T cell development.
34. IgM and IgD can be co-expressed on the B cell surface because of which of the following genetic
mechanisms?
A. Using both maternal and paternal alleles of the Ig heavy chain locus.
B. Alternative RNA splicing.
C. DNA deletion of the genomic region between the IgM and IgD constant domain exons.
D. Synthesizing IgD heavy chain instead of IgG.
35. A virus that can only infect lung epithelial cells, enters a host and some of the viral particles are
phagocytosed by macrophages. Peptides derived from this virus are presented on the macrophage cell
surface. These peptides are likely presented on which type of molecule?
A. MHC Class I
B. MHC Class II
C. Either MHC Class I or II
D. Neither MHC Class I nor II
36. A B cell with IgD on its surface is likely to be which of the following?
A. A primary B cell not yet exposed to antigen.
B. An immature B cell that has not yet switched to IgM.
C. A memory B cell.
D. A γδT cell.
37. Do memory B cells that have an increased binding affinity for antigen due to mutations require
more or less antigen to be activated?
A. More.
B. Less.
38. Which of the following do secreted (soluble) IgM and IgA have in common?
A. They both use only Ig kappa as their light chain. Whereas IgG and IgE use lambda.
B. They are both made in abundance upon first exposure to antigen.
C. They both opsonize antigen.
D. They exist in a polymeric form.
6
Biol. 456/556, Immunology
Tuesday, March 6, 2018
EXAM AA
Second Exam, Spring Semester 2018
39. Which of the following are common to both T and B cells?
A. Recombinatorial diversity contributes to overall clonal diversity.
B. Combinatorial diversity contributes to overall clonal diversity.
C. Junctional diversity contributes to overall clonal diversity.
D. All of the above.
40. Which of the following are common to both T and B cells??
A. Affinity maturation in the memory pool.
B. Clonally antigen specific
C..Isotype switching.
D. Restricted to antigens presented on MHC.
41. Which of the following classes of MHC molecules would you expect to find on a macrophage, a
professional antigen presenting cell?
A. Class I.
B. Class II.
C. Both Class I and Class II.
D. Neither Class I nor Class II.
42. Variation in which antigenic peptides an MHC class II molecule can bind is determined by
polymorphism in what part of the MHC molecule?
A. The α1 and α 2 domains.
B. The α 2 and α 3 domains.
C. The α 1 and β1 domains.
D. The β2-microglobulin domain.
43. Failure of a developing T cell to successfully rearrange a T cell receptor α chain would likely result
in which of the following?
A. Death by apoptosis.
B. Becoming a CD8+ T cell rather than a CD4+ T cell.
C. Being restricted only to Class I MHC but not Class II.
D. An auto-reactive, anti-self T cell.
44. True or False? αβ T cells are restricted to binding MHC Class I molecules; γδ T cells are restricted
to binding Class II molecules.
A. True.
B. False.
45. Where in the thymus would you most likely find single positive T cells?
A. Cortical region.
B. Medullary region.
C. Germinal center.
D. Hassall's corpuscle.
7
Biol. 456/556, Immunology
Tuesday, March 6, 2018
EXAM AA
Second Exam, Spring Semester 2018
46. How does a B cell know it just encountered the antigen it is specific for?
A. The antigen triggers the B cell to rearrange its light chain genes.
B. Macrophages present the B cell with the antigen on MHC Class III.
C. Soluble Ig presents the antigen to the B cell via an Fc receptor.
D. The antigen cross-links multiple Ig on the B cell surface.
47. Which of the following is an outcome of negative selection during T cell development in the
thymus?
A. Selection for developing T cells with T cell receptors that can bind MHC molecules.
B. Selection for developing T cells with T cell receptors that do not bind self-peptides.
C. Elimination of developing T cells that have failed to rearrange their a chain genes properly.
D. Elimination of developing T cells that have failed to express VpreB and l5 properly.
48. Thymus involution refers to which of the following events?
A. The thymus is slowly replaced by fat tissue as the animal ages.
B. The thymus stops making γδ T cells and starts making αβ T cells.
C. The thymus stops making CD4+ T cells and starts making CD8+ T cells.
D. The thymus appearance around the 10th week of gestation in the human embryo.
49. The substrate for the caspase activatable DNase (CAD) is?
A. RNA.
B. DNA.
C. Caspases.
D. Fas ligand.
50. Which of the following may contribute to whether a particular Ig isotype will bind to a particular
Fc receptor?
A. The isotype of the antibody.
B. The pH in the environment where the binding is occurring.
C. The binding affinity of the Fc receptor.
D. All of the above.
8