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MCMP 422
SPRING 2004
FINAL EXAM A
1. (3 points) Several types of immune cells can directly destroy pathogens either by
engulfing the pathogen (sometimes with the help of other molecules) or by directly
causing the lysis (disruption of the membrane) of virally infected cells. Which of the
following cells can directly destroy pathogens or pathogen infected cells?
a. macrophages and neutrophils
b. TH1 and TH2 T cells
c. natural killer cells (NK)
d. all of the above
e. a and c
2. (3 points) Which of the following are characteristics of INNATE immunity?
a. present BEFORE a pathogen invades the body
b. SPECIFIC for the invading pathogen and no other pathogen
c. imparts LONG TERM immunity through memory cells
d. none of the above
e. b and c
3. (3 points) Starbright is infected with strain A influenza virus on January 1. She
comes down with a case of the flu, but is beginning to recover by January 15. On
February 1, Starbright visits a sick friend and is exposed to both strain A influenza
and Streptococcus pyogenes, the causative agent of strep throat. Starbright, believe it
or not, has never had strep throat. On February 4th, Starbright’s blood is drawn and
examined for antibodies to strain A influenza and antibodies to Streptococcus
pyogenes. Which of the following is/are MOST LIKELY to be found in Starbright’s
blood on February 4th?
a. a low antibody titer (few antibodies) for strain A influenza
b. a high antibody titer for strain A influenza AND a high antibody titer for
Streptococcus pyogenes
c. a high antibody titer for strain A influenza AND a low antibody titer for
Streptococcus pyogenes
d. a low antibody titer for strain A influenza AND a low antibody titer for
Streptococcus pyogenes
e. a low antibody titer for strain A influenza AND a high antibody titer for
Streptococcus pyogenes
4. (3 points) There are several types of recognition molecules in the immune system
that recognize (bind to) “antigens”. Which of the following is TRUE regarding
recognition molecules in the immune system?
a. The B cell antigen receptor (BCR) and the T cell antigen receptor (TCR) both
recognize short peptide sequences (8-10 amino acids or 13 to 25 amino acids)
derived from pathogenic proteins
b. Both the TCR and MHC molecules recognize short peptide sequences (8-10
amino acids or 13 to 25 amino acids) derived from pathogenic proteins
c. The BCR and the TCR both recognize intact protein antigens (i.e., protein
antigens that have NOT been proteolyzed (degraded))
MCMP 422
SPRING 2004
FINAL EXAM A
d. Both the BCR and MHC molecules recognize short peptide sequences (8-10
amino acids or 13 to 25 amino acids) derived from pathogenic proteins
e. The antigen receptors on natural killer cells recognize both intact antigen and
short antigen derived peptide sequences
5. (3 points) The clonal selection theory lies at the heart of the immune response.
Which of the following BEST describes the clonal selection theory?
a. Before puberty millions of lymphocytes are generated each day in the human.
Each INDIVIDUAL lymphocyte expresses thousands of IDENTICAL
receptors for a specific antigenic determinant (epitope). After a pathogen
enters the body, a lymphocyte with receptors that recognize a specific
antigenic determinant within the pathogen is stimulated to divide. This
generates a clone of lymphocytes that recognize a specific epitope within the
pathogen.
b. Before puberty millions of lymphocytes are generated each day in the human.
Each INDIVIDUAL lymphocyte expresses thousands of DIFFERENT receptors
that recognize different antigenic determinants within the pathogen. After a
pathogen enters the body, a lymphocyte that expresses several receptors that
recognize several different epitopes within the pathogen is stimulated to divide.
This generates a clone of lymphocytes that recognize several different epitopes
within the pathogen.
c. Lymphocytes that express receptors for specific antigenic determinants are
generated only AFTER a pathogen enters the body.
d. Lymphocytes do not express receptors that are specific for antigenic determinants
within pathogens.
e. none of the above answers provides a good description of the clonal selection
theory.
6. (3 points) Which of the following is/are NOT a function of the Fc regions of
immunoglobulin (antibody) molecules?
a. opsonization of bacteria
b. neutralizing toxins
c. serving as the BCR on B cells and in this capacity binding intact pathogens
d. all of the above are NOT functions of the Fc regions of immunoglobulins
e. b and c
7. (3 points) Which of the following cells can function at the site of an infection
WITHOUT having to be first activated at a distal (far away) site?
a. CD8+ T cells
b. TH2 T cells
c. macrophages and neutrophils
d. B cells
e. a and b
8. (3 points) Immunoglobulins (antibodies (Abs)) specifically bind to antigenic
determinants on the surface of pathogens. Which of the following is/are TRUE
MCMP 422
SPRING 2004
FINAL EXAM A
regarding the physical interaction between an immunoglobulin molecule and an
antigenic determinant?
a. The interaction involves the antigenic determinant and a region of the Ab that
contains roughly the first 100 amino acids of the light and heavy chains.
b. All the amino acid residues in the light chain of the Ab molecule that physically
contact the antigenic determinant are found next to each other in the LINEAR
sequence of the light chain.
c. All the amino acid residues in the heavy chain of the Ab molecule that physically
contact the antigenic determinant are found next to each other in the LINEAR
sequence of the heavy chain.
d. all of the above
e. a and b
9. (3 points) When the sequence of the DNA encoding the BCRs and TCRs is
determined in a hematopoietic stem cell, the DNA encoding the variable regions and
the constant regions of the receptors are located far apart on the chromosome. When
the same sequence is determined in a mature lymphocyte, the DNA encoding the
variable region and the constant region of the expressed antigen receptor are adjacent
(next to each other) on the chromosome. Which of the following statements is/are
TRUE regarding this observation?
a. This rearrangement of DNA evolved as a mechanism to generate diversity in the
immune system
b. This rearrangement of DNA occurs AFTER a pathogen enters the body and is
directed by the specific antigenic determinants on the pathogen
c. This rearrangement of DNA is not directed by a pathogen, but occurs randomly, in
the absence of a pathogen
d. This rearrangement of DNA occurs in the secondary lymphoid tissues
e. a and c
10. (3 points) Although the regions of antigen receptors on the protein level are generally
referred to as variable (V) and constant (C), on the DNA level they actually include
other regions. Regarding these other regions, which of the following statements is/are
TRUE regarding this observation?
a. Both the DNA encoding the constant regions of the BCR light chains and the
constant regions of the TCR alpha () chains contain J segments
b. Both the DNA encoding the constant regions of the BCR heavy chains and the
constant regions of the TCR beta () chains contain J segments and D segments
c. The J segments of the antigen receptor DNA are located between the first and
second domain of the constant region in both the BCR and the TCR
d. a and b
e. none of the above
11. (3 points) Unlike TCRs, BCRs continue to evolve during an immune response.
Which of the following is/are TRUE regarding the evolution of BCRs?
MCMP 422
SPRING 2004
FINAL EXAM A
a. B cells expressing BCRs of higher affinity for a particular pathogen are selected for
survival in the germinal centers of lymph nodes BEFORE the pathogen enters the
body
b. B cells expressing BCRs of higher affinity for a particular pathogen are selected for
survival in the germinal centers of lymph nodes AFTER the pathogen enters the
body
c. BCRs of higher affinity for a pathogen are generated by random point (single
amino acid) mutations in the variable regions of both the light and heavy chains
d. none of the above
e. b and c
12 (3 points) Antigen presentation by MHC molecules is critical to an effective immune
response. Which of the following is/are TRUE regarding the presentation of antigen
by MHC molecules?
a. MHC I molecules present “antigen” to cytotoxic (killer) T cells
b. MHC class II molecules present “antigen” to TH1 and TH2 cells T cells
c. MHC I molecules are mainly responsible for presenting viral “ antigens” to the
appropriate lymphocytes
d. all of the above
e. a and b
13 (3 points) Where a pathogen replicates in the body dictates how it will be “seen” by
the immune system. Which of the following is/are TRUE regarding how the immune
system reacts to pathogens?
a. Peptides from bacteria replicating outside of cells are presented to T cells by
MCH class II molecules
b. Peptides from viruses are presented to T cells by MHC class I molecules
c. Peptides from viruses are degraded in the cytosol by proteasomes and transported
into the endoplasmic reticulum, while peptides from extracellular bacteria are
degraded in the phagolysosome
d. all of the above
e. none of the above
14. (3 points) Which of the following is/are TRUE regarding MHC molecules and the
DNA that encodes them?
a. The MHC locus (DNA that encodes MHC molecules) is said to be the most
polymorphic locus in the human genome. This means that the DNA at this locus
undergoes frequent recombination to generate several different versions of both
MHC I and MHC II molecules
b. A single cell can express both MHC I and MHC II molecules, but on that single
cell all the MHC I molecules will be identical and all the MHC II molecules will
be identical
c. In the absence of foreign antigens MHC I and MHC II molecules are synthesized,
but remain in the cell and are not transported to the cell surface
d. none of the above
e. a and b
MCMP 422
SPRING 2004
FINAL EXAM A
15. (3 points) The following is found on a hospital chart for patient X: HLA-A12A35
HLA-B115B200 HLA-C52C19. What do these letter and numbers describe?
a. The composition of the patient’s T cell repertoire
b. The composition of the patient’s B cell repertoire
c. The patient’s inherited haplotypes for MHC class I
d. none of the above
e. a and b
16. (3 points) Approximately 30 billion B cells are produced and leave the bone marrow
each day. Which of the following is/are TRUE regarding B cell development in the
bone marrow?
a. B cells mature in the bone marrow (i.e. differentiate from pro- B cells to mature B
cells) in the ABSENCE of DNA rearrangement
b. B cells maturing in the bone marrow need to rearrange the DNA for EITHER the
heavy chain of the BCR or the light chain of the BCR, but NOT both.
c. During B cell development, the heavy chain DNA must move a D region
segment next to a J region segment and move the DJ combined segment next
to a V region segment before the DNA for the light chain can rearrange
d. Regardless of whether the DNA rearrangement on the initial chromosome is
productive or not, the DNA on the second chromosome will NEVER rearrange
e. none of the above
17. (3 points) During B cell development in the bone morrow most of the developing B
cells will die. Which of the following is/are TRUE regarding B cell death in the bone
marrow?
a. B cells that FAIL to rearrange their heavy chain DNA on BOTH copies of the
chromosome will die by apoptosis
b. During B cell development, B cells that have rearranged their heavy chain, but
NOT their light chain are signaled to die if they encounter a self antigen
c. During B cell development, B cells that have rearranged their heavy chain, AND
their light chain are signaled to die if they encounter a self antigen
d. Developing B cells can not leave the bone marrow until the have successfully
rearranged BOTH the  and  chains of the T cell antigen receptor (TCR)
e. a and c
18. (3 points) Which of the following is/are TRUE regarding germinal centers in the
secondary lymphoid tissues?
a. They form during an immune response and contain among other cells,
centroblasts, centrocytes and follicular dendritic cells (FDCs)
b. Somatic hypermutation and affinity maturation occur in germinal centers
c. The switch from IgM synthesis to IgG or IgA or IgE synthesis occurs in the
germinal centers
d. all of the above
e. b and c
MCMP 422
SPRING 2004
FINAL EXAM A
19 (3 points) As T cells develop in the thymus they go through several stages of
maturation and migrate from the cortex to the medulla. Which of the following is/are
TRUE regarding T cell development?
a. T cells MUST rearrange their DNA for the  and  (or  and ) chains of the
TCR if they are to develop into mature T cells
b. During NEGATIVE selection, strong engagement of the TCR is a signal to
SURVIVE
c. During POSITIVE selection, T cells that recognize self MHC are signaled to DIE
by apoptosis
d. all of the above
e. none of the above
20 (3 points) A mouse of strain X undergoes whole body irradiation that destroys all bone
marrow cells, but all other cells and tissues remain healthy. The irradiated mouse is
given a bone marrow transplant from an UNRELATED strain Y mouse that shares
NO MHC alleles with strain X. Which of the following will occur in the transplanted
strain X animal?
a. T cells that arise from the strain Y mouse (strain Y T cells) will not develop in the
thymus of the irradiated strain X mouse because they will not recognize self MHC
molecules
b. Strain Y T cells will develop in the irradiated strain X mouse and those
passing positive selection will recognize strain X MHC as self
c. Macrophages that develop in the irradiated strain X mouse will express strain X
MHC molecules
d. None of the above
e. a and c
21. (3 points) Which of the follow is/are TRUE regarding either the expression or the
function of CD4 and CD8?
a. T cells undergoing positive selection in the thymus will express both CD4 and
CD8 on their surface (double positive T cells)
b. Both CD4 and CD8 bind MHC molecules, but the class of MHC molecule they
bind is different
c. Only T cells that express either CD4 or CD8, but not BOTH will leave the thymus
d. All of the above
e. a and b
22. (3 points) Mature, naive T cells that leave the thymus
a. circulate in the blood and lymph and congregate in the T cells enriched areas of
lymph nodes, spleen and mucosal tissue
b. encounter foreign peptides for the first time at the site of an infection
c. can survive for long periods of time in the absence of antigenic stimulation
d. all of the above
e. a and c
23. (3 points) Which of the following are professional antigen presenting cells (APCs).
MCMP 422
SPRING 2004
a.
b.
c.
d.
e.
FINAL EXAM A
dendritic cells
B cells
macrophages
all of the above
b and c
24. (3 points) The secondary lymphoid tissues are important places for immune function.
Which of the following is/are TRUE regarding secondary lymphoid tissues?
a. pathogens arrive in the lymph nodes by: 1) the lymph and 2) dendritic cells that
ingest the pathogen at the site of an infection and migrate to the lymph nodes
b. macrophages in the T cell area of the lymph nodes ingest pathogens that arrive by
the lymph and along with dendritic cells present foreign antigens to passing naïve
T cells
c. all the CD8+ T cells, but only a subset of the CD4+ T cells leave the lymph nodes
once they have encounted foreign peptide for the first time
d. all of the above
e. a and b
25. (3 points) “Co-stimulation” of T-cells is essential for the effective function of the
immune system. Which of the following is/are TRUE regarding co-stimulation?
a. developing T cells in the thymus require co-stimulation to progress from positive
selection to negative selection
b. developing T cells in the thymus require co-stimulation to progress from double
positive cells to single positive cells
c. naïve T cells that bind antigen in the ABSENCE of co-stimulation become
anergic
d. all of the above
e. a and c
26. (3 points) Naïve T cells stimulated by MHC molecules presenting foreign peptides on
cells that DO NOT also express B7 will
a. fail to synthesize and express BOTH interleukin 2 (IL-2) and the high affinity
receptor for IL-2 (IL-2R)
b. secrete cytokines that mediate inflammation
c. secrete cytokines that help B cells differentiate
d. none of the above
e. b and c
27. (3 points) Cyclosporin A and tacrolimus (FK506) are used in patients receiving
transplants to suppress the immune system. These drugs PRIMARILY inhibit
a. B cell development in the bone marrow
b. T cell growth (clonal expansion) in the periphery (circulation)
c. marcophage function
d. dendritic cell function
e. mast cell degranulation
MCMP 422
SPRING 2004
FINAL EXAM A
28. (3 points) The balance between different T cell subsets is critical to the outcome of an
immune response. Patients infected with Mycobacterium leprae for example can
have radically different outcomes depending on which set of T cells dominant the
immune response. Which of the following is/are TRUE regarding Mycobacterium
lepra.
a. Mycobacterium leprae is a bacterium that grows within the vesicular system of
macrophages and therefore escapes the immune system
b. If the immune system responds to Mycobacterium leprae by primarily producing
IFN-, TNF-, TNF- and IL-3 the patient’s macrophages will be activated to kill
the intracellular Mycobacterium leprae and the patient will likely survive
c. If the immune system responds to Mycobacterium leprae by primarily producing
IL-4 and IL-5, the patient’s B cells will be activated resulting in antibody
production, but these antibodies will be largely ineffective against the intracellular
Mycobacterium leprae and the patient will likely die
d. all of the above
e. a and c
29. (3 points) Effector T cells are T cells that previously have been primed (seen antigen
before). Which of the following is/are TRUE regarding effector T cells?
a. the next time an effector CD8+ cell sees foreign peptides properly presented, it
will kill the cells presenting those peptides
b. the next time an effector TH1 cell sees foreign peptides properly presented, it will
secrete inflammatory cytokines resulting in macrophage activation
c. effector T cells to not need co-stimulation to react to foreign peptide antigens
when properly presented
d. all of the above
e. a and b
30. (3 points) Individuals who know they are allergic to rag weed or pollen will respond
in seconds to the presence of the allergen. This quick response time results from
a. the fact that IgE is the most quickly synthesized Ab in the body and can be
produced and secreted almost instantaneously
b. the fact that mast cells and basophils have high affinity receptors for IgE so
that they continually have IgE on their surface
c. the fact that parasites are usually present within the body where they continuously
stimulate the production of IgE
d. the fact that the DNA for IgE does NOT have to be rearranged
e. the fact that IgE is the only immunoglobulin that does not require the presence of
a light chain to bind antigen
31. (3 points) Which of the following are greatly aided in “doing their job” by the
presence of IgG molecules that are specific for a pathogen?
a. macrophages
b. natural killer (NK) cells
c. complement
d. all of the above
MCMP 422
SPRING 2004
FINAL EXAM A
e. b and c
32. (3 points) Which of the following statements is/are TRUE?
a. Thymus independent antigens (TI antigens) cause the production of ONLY IgM
and not other isotypes of immunoglobulins
b. a “B cell response” (i.e., the ultimate production of antibodies) is more effective
against a bacterial infection than a “ T cell response”
c. a “B cell response” (i.e., the ultimate production of antibodies) is more effective
against a viral infection than a “ T cell response”
d. a and b
e. a and c
33. (3 points) Complement is very important to the effective elimination of pathogenic
bacteria in the body. There are three complement pathways that are initiated
differently but converge at a similar step. Which of the following would occur if the
enzyme C3 convertase (C2b/C4b) was PREVENTED from functioning?
a. complement would be ineffective at opsonizing bacteria for engulfment by
macrophages and neutrophils
b. Ab/Ag complexes would not effectively be removed from the blood resulting in
kidney damage
c. the MAC (membrane attack complex) would fail to form on the surface of
bacteria and would avoid complement mediated lysis
d. all of the above
e. b and c
34. (3 points) Pattern recognition receptors
a.
are receptors that bind only proteins on the surface of infectious
microorganisms
b.
stimulate endocytosis of microorganisms by macrophages, but not
cytokine release
c.
undergo gene rearrangements and affinity maturation to enhance
recognition of specific pathogen-associated molecular patterns
d.
stimulate cytokine release by macrophages, but not endocytosis of
microorganisms
e.
are unlike antigen receptors in that they are encoded in the germline
of an organism and do not undergo rearrangements
35. (3 points) Polymorphonuclear leukocytes, the first cells recruited from the
bloodstream in response to an infection, are also known as
a.
neutrophils
b.
eosinophils
c.
basophils
d.
lymphocytes
e.
macrophages
36. (3 points) IL-8
MCMP 422
SPRING 2004
a.
b.
c.
d.
e.
FINAL EXAM A
is a chemokine
is a chemoattractant for neutrophils
binds to a CXCR on the surfaces of cells
stimulates the activation of integrins like LFA-1
all the above
Questions 37 and 38 refer to the following paragraph:
In a recent report in the April 21 issue of The Journal of the American Medical
Association, Researchers at The Hospital for Sick Children in Toronto examined a
possible relationship between the development of multiple sclerosis (MS) and early
infection with Epstein-Barr virus (EBV). The research team found that 83 per cent of the
pediatric MS patients showed evidence of a past EBV infection, compared with 42 per
cent for the healthy control group. This suggested a possible relationship between the
sequence and timing of viral exposure and the onset of MS.
37. (3 points) Interestingly, genes have been found in EBV that encode for proteins with
sequences that are identical to those found in myelin basic protein (MBP), a protein
found in the myelin sheath surrounding nerve cells. The onset of MS following an
EBV infection might have resulted from
a.
production of MBP-specific IgE that triggered mast cell degranulation in
the CNS
b.
generation of IgG that cross-reacted with MBP in the CNS
c.
generation of MBP-specific TH1 cells that infiltrated the CNS
d.
generation of CD8 T cells that infiltrated the CNS and killed nerve cells
presenting MBP-derived peptides on MHCI molecules
e.
none of the above responses is associated with development of MS
38. (3 points) This study could not have been done in adult MS patients because nearly
90% of the adult population in Western countries has been exposed to EBV. EBV
a.
initially infects epithelial cells before moving along neurons into the basal
ganglia where MHCI levels are low
b.
is rapidly cleared from an infected patient due to humoral immune
responses that generate neutralizing antibodies
c.
does not produce obvious symptoms when it affects young adults, unlike
the severe symptoms seen with infected children
d.
persists in an infected patient due to its ability to exist in a latent state
in B cells
39. (3 points) The graph below is redrawn from a report published in 1910, by Ross and
Thomson, of the progress of a human infection with Trypanosoma gambiense.
How can you account for this periodic rise and fall in numbers of circulating
trypanosomes?
MCMP 422
SPRING 2004
a.
b.
c.
d.
FINAL EXAM A
trypanosomes establish a latent infection and their reproduction is
reactivated periodically after each immune response has died down
a high mutation rate due to error-prone replication changes the epitopes on
the major cell surface antigen
the existence of multiple trypanosome serotypes allows low abundance
strains to gain a competitive advantage and proliferate each time the more
abundant serotypes are killed by the immune response
a repeating series of gene conversions that result in the production of
different form of a major cell surface antigen on the parasite
40. (3 points) There is an immunodeficiency disease called “bare lymphocyte syndrome”
in which patients lack expression of all MCH II gene products. As a consequence,
positive selection of CD4 T cells in the thymus does not occur. These patients likely
suffer from
a.
recurrent infections consisting almost exclusively of encapsulated,
pyogenic bacteria
b.
recurrent infections by multiple microorganisms including bacteria,
viruses, fungi and protozoans
c.
recurrent infections limited to viruses
d.
no apparent or visible disorders since CD4 T cells are not critical
components of the adaptive immune response
41. (3 points) Following the initial infection with HIV, adult patients typically exhibit a
prolonged latent or asymptomatic phase that can last for several years where they do
not suffer from any outward signs of infection. This phase is characterized by
a.
a period of rapid viral replication, infection and elimination of CD4 T
cells balanced by the rapid generation of new CD4 T cells.
b.
a period in which the adaptive immune response has eliminated most
actively replicating virus, but some virus remains “hidden” in a latent
infection to reappear at a later time when the immune response has
subsided.
c.
the successful elimination of the initial strain of HIV with which the
patient was infected followed by the eventual reappearance of mutant
strains that present peptides that are not recognized by CD8 T cells.
MCMP 422
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d.
FINAL EXAM A
the elimination of all CCR5 positive CD4 T cells leaving only CXCR4
positive cells that eventually become targets for reinfection when new
viral variants arise that can use different chemokine receptors.
42. (3 points) Despite the efficacy of HIV protease inhibitors, they are never given
alone, but are administered in combination with nucleoside reverse transcriptase
inhibitors because
a.
protease inhibitors are effective only against circulating virus particles and
have no effect on the replication of viruses already integrated into the host
DNA.
b.
resistance to single therapeutic agents arises rapidly due to the high
mutation rates associated with viral replication.
c.
protease inhibitors actually stimulate rates of viral RNA reverse
transcription unless a transcriptase inhibitor is also provided.
d.
protease inhibitors can block the fusion of viral envelopes with CD4 T
cells, but do not prevent the assembly of new virions.
e.
all the above
43. (3 points) Which of the following cells is/are a major contributor to type I
hypersensitivity reactions?
a.
NK (natural killer) cells
b.
CD4 TH1 cells
c.
CD4 TH2 cells
d.
CD8 cells
e.
red blood cells
44. (3 points) Which type of hypersensitivity reaction is most likely to cause rapid death
by anaphylactic shock?
a.
reactions mediated by T cells
b.
reactions mediated by soluble immune complexes
c.
reactions mediated by IgE
d.
a and b
e.
none of the above
45. (3 points) Successful recovery from a bacterial infection through an adaptive
immune response generally protects the patient from a second infection by the same
organism. However, successful recovery from an infection with Streptococcus
pneumoniae does not necessarily guarantee that a patient will not become re-infected
with Streptococcus pneumoniae at a later date. This is likely due to
a.
The ability of Streptococcus pneumoniae to hide from the immune system
in an intracellular compartment within a macrophage where it is protected
from proteolysis and from the presentation of bacterial peptides by MHC
molecules.
b.
The ability of Streptococcus pneumoniae to rapidly undergo mutations
leading to changes in epitopes on cell surface antigens.
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c.
d.
FINAL EXAM A
The existence of multiple strains of Streptococcus pneumoniae bearing
different cell surface antigens.
The presence of multiple genes for cell surface antigens allows
Streptococcus pneumoniae to switch expression from one gene to another
through gene conversion.
46. (3 points) Knowledge of the immune response can guide the development of proper
vaccine strategies. Many bacteria surrounded by capsular polysaccharide coats are
pathogens that can infect young children. To immunize children against such
infections, what common strategy is employed to create a vaccine?
a.
Isolate the capsular polysaccharide and use this to immunize children so
that they will produce a memory B cell response that will rapidly protect
them from any subsequent infection
b.
Couple the capsular polysaccharide to a protein that can provide
antigenic peptides for stimulating a CD4 T cell response and inject the
complex
c.
Inactivate the intact bacterium by treatment with formalin to create a
whole, killed cell preparation that can be sterilized and used for
immunization.
d.
clone the polysaccharide gene and insert this into a naked DNA plasmid
for injection directly into muscle (or via gene gun into skin cells) to induce
both humoral and cellular immune responses.
e.
prepare a subunit vaccine in which the capsular polysaccharide gene is
inserted into yeast and the resulting gene product is isolated, mixed with
an adjuvant and injected.
47. (3 points) A single vaccine is administered for immunization of children against
mumps, measles and rubella. This vaccine is composed of
a.
three different live, attenuated viruses
b.
three denatured toxins (toxoids) and a mixture of surface antigens
c.
conjugates between three different capsular polysaccharides linked to one
toxoid (either diphtheria or tetanus)
d.
three inactivated or killed viruses
e.
recombinant surface antigens expressed in yeast or bacteria and combined
with alum
48. (3 points) Individuals traveling to certain countries must be vaccinated against
yellow fever, which is caused by a mosquito borne virus. A single administration of
the vaccine affords long term protection. What is the most likely type of vaccine that
is administered?
a.
a live, attenuated virus
b.
an inactivated (killed) virus
c.
a conjugate vaccine
d.
a subunit vaccine
MCMP 422
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FINAL EXAM A
49. (3 points) Immunization has proven to be an effective way to prevent disease. The
mechanism underlying immunization is the generation of “memory” cells. Which of
the following are characteristics of “memory” B cells?
a.
they secrete only IgE
b.
they have undergone isotype switching
c.
they have undergone somatic hypermutation and affinity maturation
d.
b and c
e.
none of the above
50. (3 points) Influenza viruses cause epidemics in humans every couple of years.
Which of the following are true regarding these epidemics
a.
Frequent epidemics occur due to gene rearrangements resulting in the
placement of a new viral epitope gene into a transcriptionally active region
of the viral RNA.
b.
Frequent epidemics occur due to the rise of a new virus formed by genetic
recombinations between viral strains that normally infect different species
c.
Frequent epidemics occur due to the rise of new viral strains with
altered epitopes as a consequence of mutations due to error-prone
replication
d.
Frequent epidemics occur due to the re-activation of viruses that have
established latent infections in the nervous system
51. (3 points) The possible involvement of the immune system in the detection and
elimination of tumor cells has been examined using mouse models. In which of the
following scenarios would the recipient mice (mice B) form the FEWEST tumors?
a.
Immunocompetent mice (mice A) are treated with a carcinogen and
develop tumors. The tumor cells are removed and injected into
immunocompetent syngeneic mice (mice B).
b.
Rag1-/-, immune-deficient mice (mice A) are treated with a carcinogen and
develop tumors. The tumor cells are removed and injected into
immunocompetent syngeneic mice (mice B).
c.
Immunocompetent mice (mice A) are treated with a carcinogen and
develop tumors. The tumor cells are removed and irradiated (so that
they cannot proliferate) and used to immunize immunocompetent,
syngeneic mice (mice B). Two weeks later, the immunized mice B are
then injected with live tumor cells of the same type.
d.
Immunocompetent mice (mice A) are treated with a carcinogen and
develop tumors. The tumor cells are removed and injected into syngeniec,
Rag1-/-, immune-deficient mice (mice B).
52. (3 points) In which of the following scenarios would the recipient mice (mice B) form
the MOST tumors?
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a.
b.
c.
d.
FINAL EXAM A
Immunocompetent mice (mice A) are treated with a carcinogen and
develop tumors. The tumor cells are removed and injected into
immunocompetent syngeneic mice (mice B).
Rag1-/-, immune-deficient mice (mice A) are treated with a carcinogen and
develop tumors. The tumor cells are removed and injected into
immunocompetent syngeneic mice (mice B).
Immunocompetent mice (mice A) are treated with a carcinogen and
develop tumors. The tumor cells are removed and irradiated (so that they
cannot proliferate) and used to immunize immunocompetent, syngeneic
mice (mice B). Two weeks later, the immunized mice B are then injected
with live tumor cells of the same type.
Immunocompetent mice (mice A) are treated with a carcinogen and
develop tumors. The tumor cells are removed and injected into
immunocompetent allogeneic mice (mice B).
53. (3 points) Which of the following would be a TUMOR-ASSOCIATED antigen (as
opposed to a tumor-specific antigen)?
a.
An antigen (e.g., peptide presented on MHCI) found only on tumor cells
and not on normal cells
b.
An antigen (e.g., peptide presented on MHCI) found at higher levels on
tumor cells than on normal cells of the same cell type
c.
An antigen (e.g., peptide presented on MHCI) found on tumor cells and on
embryonic cells, but not on normal adult cells
d.
All of the above
e.
b and c
A recent gene therapy clinical trial to treat young children with X-SCID was carried out
in France. Questions 54-56 refer to this trial.
54. (3 points) The most common form of X-linked SCID arises due to
a.
a genetic deficiency in Bruton’s tyrosine kinase
b.
a genetic deficiency in adenosime deaminase
c.
a genetic deficiency in CD40L
d.
a genetic deficiency in the  chain common to many interleukin
receptors
e.
a genetic deficiency in the CD18 integrin subunit
55. (3 points) The retroviral vector based on Moloney murine leukemia virus that was
used in this study was used based on its ability to
a.
infect multiple dividing or nondividing cell types
b.
permanently introduce a replacement gene into a host cell genome
c.
replicate in the nucleus of an infected cell as an independent piece of DNA
known as an episome
d.
proliferate and spread throughout the body since it contained all the
genetic information required for viral replication
MCMP 422
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FINAL EXAM A
56. (3 points) While the treatment protocol led to the restoration of immune function in 9
of the 11 patients, 2 developed a serious complication (leukemia) that was a direct
consequence of the gene therapy approach. This resulted from
a.
insertion of a viral promoter near a cellular oncogene
b.
inflammation due to immune responses against viral antigens presented on
infected cells
c.
excessive proliferation of viruses in an immunoincompetent host
d.
autoimmune disease resulting from inappropriate activation of T cells
57. (3 points) Transfusions with blood donated by family or close relatives use blood cell
preparations that have been -irradiated in order to prevent transfusion-related graft
versus host reactions, which can be fatal. These reactions result from
a.
failure of the host immune system to destroy donor T cells due to shared
similarities in HLA haplotypes
b.
attack of host cells by donor T cells activated by host-specific peptides
presented by host APC’s
c.
attack of donor red blood cells by host T cells recognizing peptides
presented by donor APC’s
d.
all the above
e.
a and b
58. (3 points) The type of immune response required to combat an infection depends on
where the pathogen lives and replicates in the host. Which of the following responses
would be appropriate for the type of pathogen listed?
a.
extracellular pathogens are killed primarily by CD8 and NK cells
b.
pathogens that replicate in the cytosols of host cells are killed primarily by
antibodies and complement
c.
pathogens that replicate in macrophage vesicles are killed by TH1 and
NK cell-mediated macrophage activation
d.
all the above
e.
none of the above
59. (3 points) In order to prepare one unit of packed red blood cells, you would have to
start with how many units of whole blood?
a.
one
b.
two
c.
just a little over two (about 2.2)
d.
four
e.
ten
60. (3 points) For patients suffering from hemophilia A, the preferred method for
replacing the missing clotting factor is
a.
Factor VIII concentrate prepared from plasma
b.
cryoprecipitated antihemophilic factor (cryoprecipitate)
c.
fresh frozen plasma
d.
synthetic or recombinant Factor VIII
MCMP 422
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e.
FINAL EXAM A
whole blood
61. (3 points) Immune globulins are frequently isolated from donated (or purchased)
plasma. These fractions are used for
a.
fluid replacement in cases of trauma or excessive bleeding
b.
prophylaxis and treatment of bleeding disorders
c.
passive immunization of patients against infectious diseases
d.
treatment of thrombocytopenia
e.
all the above
62. (3 points) The preparation of monoclonal antibodies requires a method to generate
large amounts of a single antibody molecule. This is accomplished by
a.
fusing spleen cells from immunized mice with immortalized myeloma
cells and cloning the resulting hybrids that produce the appropriate
antibody
b.
isolating individual B cells producing specific antibodies and growing
these in culture in the presence of IL-2
c.
injecting mice with a single antigenic epitope so that only a single clone of
B cells will become activated and isolating the antibody from the serum
d.
injecting mice with the antigen and then fractionating the serum into
individual antibody molecules using a procedure known as HAT
63. (3 points)
a.
b.
c.
d.
e.
Which of the following would result in a second set rejection?
mouse A receives a skin graft from syngeneic mouse B
mouse A receives a skin graft from allogeneic mouse C
mouse A received a skin graft from syngeneic mouse B and then receives
a graft from allogeneic mouse C
mouse A received a skin graft from allogeneic mouse C and then
receives another graft from mouse C
athymic mouse A receives a skin graft from allogeneic mouse C
64. (3 points) Xolair, a monoclonal antibody, is a relatively new treatment for
individuals with severe allergic asthma that is injected once or twice a month. Xolair
is a “humanized” monoclonal antibody. This means
a.
a series of mouse monoclonal antibodies were screened in a number of
human patients to find one that did not elicit an immune response
b.
constant region sequences of the mouse monoclonal antibody were
replaced by human immunoglobulin sequences
c.
all of the mouse antibody except the complementarity determining
regions were replaced by human immunoglobulin sequences
d.
the monoclonal antibody was generated from human B cells isolated from
immunized patients
65. (3 points) Organ transplants between HLA-identical siblings (sisters/brothers) are
a.
less susceptible to rejection because HLA antigens are major contributors
to acute rejection responses
MCMP 422
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b.
c.
d.
e.
FINAL EXAM A
still in danger of being rejected by acute rejection reactions due to
differences at various minor histocompatibility loci
in greater danger of rejection due to a failure of the host to recognize
donor tissue as foreign
not susceptible to rejection due to the shared HLA antigens, which are
wholly responsible for acute rejection reactions
a and b
66. (3 points) Cyclosporine A and tacrolimus (FK506) are drugs that prevent transplant
rejection by inhibiting T cell activation. They are used as alternatives to one another
and are not typically given together. This is because
a.
they bind directly to the same protein (known as immunophilin) in T cells
b.
they bind to different immunophilins, but both drug-protein
complexes target the same intracellular enzyme in T cells
c.
one inhibits IL-2 production while the other inhibits IL-2 action, thus they
have similar effects on T cells
d.
they both induce rapid depletion of T cells from the circulation probably
through phagocytosis by cells with Fc receptors
e.
none of the above
67. (2 points) Who is buried in John Purdue’s grave?
a.
John Purdue
b.
Orville Redenbacher
c.
Neil Armstrong
d.
Otis Chalmers