BI432 Immunology
Final Exam
Winter, 1997
1
Name:
1. Match each immunoglobulin isotype in a through d with the description(s) listed below (1-13) that are true
about that isotype. Some of the descriptions may apply to more than one isotype; others may not apply to
any isotype.
a. _____________ IgA
b. _____________IgE
c. __________IgG
d. ___________ IgM.
1. Secreted form is a pentamer of the basic H2L2 unit.
2. binds to Fc receptors on mast cells
3. Multimeric forms have J-chains.
4. Present on the surface of mature, unprimed B cells
5. The most abundant Ig class in serum.
6. Major antibody in secretions such as saliva, tears and colostrum.
7. Present on the surface of immature B cells.
8. The first serum antibody made in a primary immune response.
9. Plays an important role in protecting against pathogens that invade through the gut or respiratory
mucosa.
10. Can participate in ADCC.
2. Indicate whether each of the following statements is true or false. If you think a statement is false. explain
why.
a. Indirect immunofluorescence is a more sensitive technique than direct immunofluorescence.
b. Most antigens induce a polyclonal response.
c. A papain digest of anti-SRBC antibodies can agglutinate sheep red blood cells (SRBC).
d. A pepsin digest of anti-SRBC antibodies can agglutinate sheep red blood cells (SRBC).
e. Indirect immunofluorescence can be performed using a Fab fragment as the initial nonlabeled
antibody.
f. For precipitation to occur, both antigen and antibody must be multivalent.
g. The Ouchterlony technique is a quantitative precipitin technique.
3. For each incomplete statement below (a-d), select the phrase(s) that correctly completes the statement.
More than one choice may be correct.
3a. Recombination of Ig gene segments serves to:
1. promote Ig diversification
4. increase the affinity of Ig for antibody
2. assemble a complete Ig coding sequence
5. all of the above
3. allow changes in coding information during Bcell maturation
3b. Somatic mutation of Ig genes accounts for :
1. allelic exclusion
2. class switching from IgM to IgG
3. affinity maturation
4. all of the above
5. none of the above
3c. The frequency of somatic mutation in Ig genes is greatest during:
1. differentiation of pre-B cells into mature B cells 4. antibody secretion by plasma cells
2. differentiation of pre-T cells into mature T-cells 5. none of the above
3. generation of memory B cells
3d. Kappa and lambda light chain genes
1. are located on the same chromosome
2. associate with only one type of heavy chain
3. can be expressed by the same B cell
4. all of the above
5. none of the above
3e. Generation of combinatorial diversity among Igs involves
1. mRNA splicing
4. one-turn/two-turn joining rule
2. DNA rearrangement
5. switch sites
3. recombination signal sequences
5. Indicate whether each of the properties listed below applies to the T-cell receptor (TCR), B-cell Ig (IG) , or
both (B).
1.
is associated with CD3
5.
is MHC restricted
2.
is monovalent
3.
exists in membrane-bound and
secreted forms
4.
6.
exhibits diversity generated by
imprecise joining of gene segments
7.
contains domains with the Ig fold
exhibits diversity generated by
somatic mutation
6. Indicate whether each of the following statements is true or false. If you think a statement is false, explain
why.
a)
A monoclonal antibody specific for b2 microglobulin can be used to detect both class I MHC and
class II MHC molecules on the surface of cells.
b)
Antigen presenting cells express both class I and class II MHC molecules on their membrane.
7. (10 pts) Cyclosporin A is a powerful immunosuppressive drug that now is given to transplant recipients.
Describe how this drug suppresses the immune response.
Would this drug have to be given continuously or occasionally?
Why?
BI432 Immunology
Final Exam
Winter, 1997
Name:
8. State ONE type of cell that responds to each of the following cytokines and the nature of the response (5 pts)
IL-1
IL-4
IL-2
IL-6
IL-3
9. How do the two subsets of TH cells differ in their roles in the immune system and in the cytokines they
produce? (5 pts)
10. Describe the primary signals required to activate naive B cells. (5pts)
What additional signals, if any, are needed to stimulate proliferation and differentiation of activated B
cells? (5 pts)
11. What is the costimulatory signal in the generation of CTL activity? (4 pts)
What cell membrane molecules are involved in generating this signal? (4 pts)
What is the direct consequence of the costimulatory signal? (4 pts)
How does this consequence impact the generation of CTL activity? (4 pts)
12. HIV, the virus that leads to AIDS, infects and leads to a decrease in the number of CD4+ cells. (15 pts)
3
What effect, if any, would HIV have on the DTH response?
Could this effect be involved in the susceptibility of HIV+ individuals to pathogens that are successfully
dealt
with by HIV- individuals?
If so, how?
13. Would you expect a C1 or a C3 complement deficiency to be more serious clinically? Why? (5 pts)
14. Match each complement component(s) or reaction (a-l) with the appropriate activity or description listed
below (1-12). The numbers may be used once, more than once, or not at all. (15 pts)
a)
C3b
g)
C5b, C6, C7, C8 and C9
b)
C1, C4, C2 and C3
h)
C3
c)
C9
i)
C3a, C5a and C5b67
d)
C3, factor B and factor D
j)
C3a, C4a and C5a
e)
C1q
k)
C4b2a
f)
C4b2a3b
l)
C3b +B
1.
2.
3.
4.
5.
Major amplification step
early components of alternative pathway
components of the membrane- attack complex
mediates opsinization
early components of classical pathway
C3a + C3b
C3bBb + Ba
6. has perforin-like activity
7. binds to Fc region of antibodies
8. chemotatic factors
9. has C3 convertase activity
10. has C5 convertase activity
BI432 Immunology
Final Exam
Winter, 1997
5
Name:
15. What feature(s) of the Sabin polio vaccine cause it to produce an immune response that includes IgA? (5
pts)
16. What is an attenuated organism? What are the advantages and disadvantages of using such an organism as a
vaccine? (15 pts)
17. (10 pts.) What are the two stages in the process of graft rejection?
What occurs in each stage?
18. List the major classes of immunodeficiency diseases, and the name, immune system deficiency and possible
mechanism of production of one example of one of the classes. (10 pts.)