IMMUNOLOGY FIT BOARD REVIEW: ABBAS 8TH WITH 273
QUESTIONS AND ANSWERS
8. B, page 248.
On activation, helper T cells express CD40 ligand (CD40L) which engages its receptor, CD40, on antigen-
stimulated B cells and induces B cell proliferation and differentiation. Cytokines produced by the helper
T cells also contribute to B cell responses. - -The interaction of ____________ in T-Dependent B cell
activation stimulates B cell proliferation and differentiation.
a. CD40 on T cells and CD40 Ligand on B cells
b. CD 40 Ligand on T cells and CD40 on B cells
c. CD 40 on Both T cells and B cells
d. CD40 Ligand on Both T cells and B cells
-A, page 104.
After stimulation by an antigen, a single clone of B cells may produce antibodies with different isotypes
that nevertheless possess identical V domains and therefore identical antigen specificity. Naïve B cells
simultaneously express IgM and IgD that function as membrane receptors for antigens. When these B
cells are activated by foreign antigens, typically of microbial origin, they may undergo a process called
isotype switching - -A 23-year-old female presents with abdominal pain and diarrhea which is foul
smelling. She reports eating raw meat. A complete blood count reveals eosinophilia. Which of the
following can explain the increase in eosinophils?
a. Naïve +IgD and +IgM B cells recognize parasite antigen and thus switch to +IgE isotype to carry out the
process of antigen elimination.
b. B cells switching to the IgG isotype also prolongs the effectiveness of humoral responses.
c. +IgM B cells recognize linear determinants of parasites and IgM progeny rid the body of parasites.
-A, page 105.
"IgA can be secreted efficiently across mucosal epithelia and is the major class of antibody in mucosal
secretions and milk." - -9. Which antibody is efficiently secreted through mucosal epithelia and is the
major class of antibody in mucosal secretions and human milk?
a. IgA
b. IgE
c. IgM
d. IgG
-A, page 123.
"The association of peptides and MHC molecules is a saturable interaction with a very slow off rate...This
extraordinarily slow off rate of peptide dissociation from MHC molecules ensures that after an MHC
molecule has acquired a peptide, it will display the peptide long enough to maximize the chance that a
particular T cell will find the peptide it can recognize and initiate a response." - -What type of interaction
does a peptide and MHC molecule have?
a. Saturable, slow off
b. Saturable, fast off
c. Non saturable, slow off
d. Nonsaturable, fast off
,-A, page 125.
"Protein antigens that are present in the cytosol...generate class I associated peptides that are
recognized by CD8+ T cells." - -5. Listeria monocytogenes can resist microbiocidal mechanisms by
producing listeriolysin which allows the bacteria to escape from vesicles into the cytosol. What type of
molecule would then present the listeria microbial protein?
a. Class I MHC
b. Class II MHC
c. HLA DM
d. CIITA
-A, page 133.
"NKT cells recognize lipids and glycolipids displayed by the class I-like non-classical MHC molecule called
CD1." - -What molecule is structurally homologous to the class I MHC molecule and displays lipid
antigens for recognition by NKT cells?
a. CD1
b. CD2
c. CD3
d. CD4
-A, page 143, figure 7.6.
The T cell receptor complex consists of a collection of homodimers and heterodimers. The αβ
heterodimer serves as the binding site for a peptide-MHC complex. Each TCR complex also contains one
CD3 Ɣε heterodimer and one δε heterodimer, as well as a ζζ homodimer, all of which contain ITAMs on
their cytoplasmic tails. - -Which of the following components of the T cell receptor complex serve as the
binding site for a peptide-MHC complex?
a. αβ
b. εδ
c. εƔ
d. ζζ
-A, page 151.
During TCR activation, ZAP-70 phosphorylates LAT, allowing Grb-2 to dock. SOS is then recruited to a site
on Grb-2, which exchanges GTP for GDP on the Rac molecule, resulting in Rac-GTP. Rac-GTP activates
Raf, which activates MEK-1, which activates the MAP kinase ERK. - -Which of the following MAP kinases
is activated through the Ras G protein pathway?
a. ERK
b. JAK
c. JNK
d. STAT
-A, page 172.
Precursors of T lymphocytes leave the fetal liver before birth and bone marrow later in life and complete
their maturation in the thymus. - -Precursors of T lymphocytes leave the fetal liver before birth and bone
marrow later in life and complete their maturation in the
a. Thymus.
b. Liver.
c. Bone marrow.
d. Generative lymphoid organs.
,-A, page 176.
The assembled pre-BCR and pre-TCR complexes provide signals for survival, for proliferation, for the
phenomenon of allelic exclusion and for the further development of early B and T lineage cells. Thus
expression of the pre antigen receptor is the first checkpoint during lymphocyte development. - -
Lymphocyte development is a stepwise process guided by 2 check points before the lymphocyte can be
selected to "mature." What is the first check point during lymphocyte development?
a. Expression of the pre-B/T antigen receptor.
b. Positive selection.
c. Negative selection.
d. Clonal deletion and receptor editing.
-A, page 208.
Of the three chains, only IL-2α is unique to the IL-2R. IL-2 binds to the alpha chain alone with low
affinity, and this does not lead to any detectable cytoplasmic signaling or biologic response. The beta
chain is also part of the IL-15 receptor. The gamma chain is shared by multiple cytokine receptors
involving those for IL-4, IL-7, IL-9, IL-15, and IL-21. The IL-2 receptor has no delta chain. - -Which of the
following chains is unique to the IL-2receptor?
a. α
b. β
c. γ
d. δ
-A, page 211.
Central memory T cells express CCR7 and L-selectin and home mainly to lymph nodes. Effector memory
T cells do not express CCR7 or L-selectin and home to peripheral sites, especially mucosal tissues.
On antigenic stimulation, effector memory T cells produce effector cytokines such as IFN-γ or rapidly
become cytotoxic, but they do not proliferate much.
The most reliable markers for memory T cells are IL7R and CD27.
Maintenance of memory T cells is dependent on cytokines but does not require antigen recognition. - -
Identify the correct statement regarding memory T cells.
a. Central memory T cells express CCR7 and L-selectin and home mainly to lymph nodes.
b. Central memory T cells home to mucosal tissues and produce IFN-γ in response to antigenic
stimulation.
c. The most reliable phenotype markers for memory T cells appear to be the surface expression of the IL-
7 receptor and CD28.
d. The maintenance of memory T cells requires cytokines and antigen recognition.
-A, page 217.
The signature cytokines produced by T cell subsets determine their effector functions and roles in
disease. The signature cytokine produced by TH1 CD4+ T cells is INF-γ which occurs in response to
intracellular microbes that activate dendritic cells, macrophages, and NK cells. - -What is the signature
cytokine produced by the TH1 subset of CD4+ effector T cells?
a. INF-γ
b. TNF-α
c. IL-4
d. IL-22
, -A, page 224.
IL-4 stimulates B cell Ig heavy chain class switching to the IgE isotype and also enhances switching to
IgG4 (in humans) and inhibits switching to the IgG2a and IgG2c isotypes (in mice), both of which are
stimulated by IFN-γ.
IL-13 can also contribute to switching to the IgE isotype. - -Which of the following cytokines is
responsible for B cell Ig heavy chain class switching to both the IgE and IgG4 isotypes?
a. IL-4
b. IL-5
c. IL-12
d. IFN-γ
-A, page 231.
The function of CD8+ cytotoxic T lymphocytes include elimination of a variety of intracellular microbes,
eradication of tumor cells and play critical roles in the acute rejection of organ allografts. - -CD8+ T
lymphocytes are effector T cells responsible for the following functions:
a. Elimination of intracellular microbes, tumor cells and acute organ allograft rejection.
b. Elimination of extracellular microbes and tumor cells.
c. Elimination of intracellular microbes, tumor cells and chronic organ allograft rejection.
d. Elimination of extracellular microbes, tumor cells and chronic organ allograft rejection.
-A, page 232.
Specialized dendritic cells ingest infected cells, transfer the protein to the cytosol and process the
antigen to enter the class I MHC presentation pathway for recognition by CD8+ T cells. See Fig. 6.20. - -
Cross presentation is a critical step in the antigen presentation to CD8+ T cells. Which of the following
best explains this process?
a. Specialized dendritic cells ingest infected cells, transfer the protein to the cytosol and process the
antigen to enter the class I MHC presentation pathway for recognition by CD8+ T cells.
b. Specialized B cells ingest infected cells, transfer the protein to the cytosol and process the antigen to
enter the class I MHC presentation pathway for recognition by CD8+ T cells.
c. Specialized dendritic cells ingest infected cells, transfer the protein to the cytosol and process the
antigen to enter the class II MHC presentation pathway for recognition by CD8+ T cells.
d. Specialized dendritic cells ingest infected cells, transfer the protein to the cytosol and process the
antigen to enter the class I MHC presentation pathway for recognition by CD4+ T cells.
-A, page 234.
Exhausted CD8+ T cells demonstrate decreased INFγ and increased expression of inhibitory receptors
such as PD-1. Presence of IL-21 helps prevent exhaustion from occurring and antibodies directed against
PD-1 are being considered therapeutically in the treatment of tumors ad chronic viral infections. - -What
functional and phenotypic changes are found in exhausted CD8+ T cells?
a. Decreased production of INFγ
b. Decreased expression of PD-1
c. Increased production of IL-21
d. Presence of natural antibodies that block PD-1
-A, page 241, Figure 12-2.
The secondary response has an antibody isotype with a relative increase in IgG and under certain
situations an increase in IgA or IgE, compared to IgM, the antibody isotype that predominates in the
primary antibody response. - -The primary antibody immune response is different from the secondary
QUESTIONS AND ANSWERS
8. B, page 248.
On activation, helper T cells express CD40 ligand (CD40L) which engages its receptor, CD40, on antigen-
stimulated B cells and induces B cell proliferation and differentiation. Cytokines produced by the helper
T cells also contribute to B cell responses. - -The interaction of ____________ in T-Dependent B cell
activation stimulates B cell proliferation and differentiation.
a. CD40 on T cells and CD40 Ligand on B cells
b. CD 40 Ligand on T cells and CD40 on B cells
c. CD 40 on Both T cells and B cells
d. CD40 Ligand on Both T cells and B cells
-A, page 104.
After stimulation by an antigen, a single clone of B cells may produce antibodies with different isotypes
that nevertheless possess identical V domains and therefore identical antigen specificity. Naïve B cells
simultaneously express IgM and IgD that function as membrane receptors for antigens. When these B
cells are activated by foreign antigens, typically of microbial origin, they may undergo a process called
isotype switching - -A 23-year-old female presents with abdominal pain and diarrhea which is foul
smelling. She reports eating raw meat. A complete blood count reveals eosinophilia. Which of the
following can explain the increase in eosinophils?
a. Naïve +IgD and +IgM B cells recognize parasite antigen and thus switch to +IgE isotype to carry out the
process of antigen elimination.
b. B cells switching to the IgG isotype also prolongs the effectiveness of humoral responses.
c. +IgM B cells recognize linear determinants of parasites and IgM progeny rid the body of parasites.
-A, page 105.
"IgA can be secreted efficiently across mucosal epithelia and is the major class of antibody in mucosal
secretions and milk." - -9. Which antibody is efficiently secreted through mucosal epithelia and is the
major class of antibody in mucosal secretions and human milk?
a. IgA
b. IgE
c. IgM
d. IgG
-A, page 123.
"The association of peptides and MHC molecules is a saturable interaction with a very slow off rate...This
extraordinarily slow off rate of peptide dissociation from MHC molecules ensures that after an MHC
molecule has acquired a peptide, it will display the peptide long enough to maximize the chance that a
particular T cell will find the peptide it can recognize and initiate a response." - -What type of interaction
does a peptide and MHC molecule have?
a. Saturable, slow off
b. Saturable, fast off
c. Non saturable, slow off
d. Nonsaturable, fast off
,-A, page 125.
"Protein antigens that are present in the cytosol...generate class I associated peptides that are
recognized by CD8+ T cells." - -5. Listeria monocytogenes can resist microbiocidal mechanisms by
producing listeriolysin which allows the bacteria to escape from vesicles into the cytosol. What type of
molecule would then present the listeria microbial protein?
a. Class I MHC
b. Class II MHC
c. HLA DM
d. CIITA
-A, page 133.
"NKT cells recognize lipids and glycolipids displayed by the class I-like non-classical MHC molecule called
CD1." - -What molecule is structurally homologous to the class I MHC molecule and displays lipid
antigens for recognition by NKT cells?
a. CD1
b. CD2
c. CD3
d. CD4
-A, page 143, figure 7.6.
The T cell receptor complex consists of a collection of homodimers and heterodimers. The αβ
heterodimer serves as the binding site for a peptide-MHC complex. Each TCR complex also contains one
CD3 Ɣε heterodimer and one δε heterodimer, as well as a ζζ homodimer, all of which contain ITAMs on
their cytoplasmic tails. - -Which of the following components of the T cell receptor complex serve as the
binding site for a peptide-MHC complex?
a. αβ
b. εδ
c. εƔ
d. ζζ
-A, page 151.
During TCR activation, ZAP-70 phosphorylates LAT, allowing Grb-2 to dock. SOS is then recruited to a site
on Grb-2, which exchanges GTP for GDP on the Rac molecule, resulting in Rac-GTP. Rac-GTP activates
Raf, which activates MEK-1, which activates the MAP kinase ERK. - -Which of the following MAP kinases
is activated through the Ras G protein pathway?
a. ERK
b. JAK
c. JNK
d. STAT
-A, page 172.
Precursors of T lymphocytes leave the fetal liver before birth and bone marrow later in life and complete
their maturation in the thymus. - -Precursors of T lymphocytes leave the fetal liver before birth and bone
marrow later in life and complete their maturation in the
a. Thymus.
b. Liver.
c. Bone marrow.
d. Generative lymphoid organs.
,-A, page 176.
The assembled pre-BCR and pre-TCR complexes provide signals for survival, for proliferation, for the
phenomenon of allelic exclusion and for the further development of early B and T lineage cells. Thus
expression of the pre antigen receptor is the first checkpoint during lymphocyte development. - -
Lymphocyte development is a stepwise process guided by 2 check points before the lymphocyte can be
selected to "mature." What is the first check point during lymphocyte development?
a. Expression of the pre-B/T antigen receptor.
b. Positive selection.
c. Negative selection.
d. Clonal deletion and receptor editing.
-A, page 208.
Of the three chains, only IL-2α is unique to the IL-2R. IL-2 binds to the alpha chain alone with low
affinity, and this does not lead to any detectable cytoplasmic signaling or biologic response. The beta
chain is also part of the IL-15 receptor. The gamma chain is shared by multiple cytokine receptors
involving those for IL-4, IL-7, IL-9, IL-15, and IL-21. The IL-2 receptor has no delta chain. - -Which of the
following chains is unique to the IL-2receptor?
a. α
b. β
c. γ
d. δ
-A, page 211.
Central memory T cells express CCR7 and L-selectin and home mainly to lymph nodes. Effector memory
T cells do not express CCR7 or L-selectin and home to peripheral sites, especially mucosal tissues.
On antigenic stimulation, effector memory T cells produce effector cytokines such as IFN-γ or rapidly
become cytotoxic, but they do not proliferate much.
The most reliable markers for memory T cells are IL7R and CD27.
Maintenance of memory T cells is dependent on cytokines but does not require antigen recognition. - -
Identify the correct statement regarding memory T cells.
a. Central memory T cells express CCR7 and L-selectin and home mainly to lymph nodes.
b. Central memory T cells home to mucosal tissues and produce IFN-γ in response to antigenic
stimulation.
c. The most reliable phenotype markers for memory T cells appear to be the surface expression of the IL-
7 receptor and CD28.
d. The maintenance of memory T cells requires cytokines and antigen recognition.
-A, page 217.
The signature cytokines produced by T cell subsets determine their effector functions and roles in
disease. The signature cytokine produced by TH1 CD4+ T cells is INF-γ which occurs in response to
intracellular microbes that activate dendritic cells, macrophages, and NK cells. - -What is the signature
cytokine produced by the TH1 subset of CD4+ effector T cells?
a. INF-γ
b. TNF-α
c. IL-4
d. IL-22
, -A, page 224.
IL-4 stimulates B cell Ig heavy chain class switching to the IgE isotype and also enhances switching to
IgG4 (in humans) and inhibits switching to the IgG2a and IgG2c isotypes (in mice), both of which are
stimulated by IFN-γ.
IL-13 can also contribute to switching to the IgE isotype. - -Which of the following cytokines is
responsible for B cell Ig heavy chain class switching to both the IgE and IgG4 isotypes?
a. IL-4
b. IL-5
c. IL-12
d. IFN-γ
-A, page 231.
The function of CD8+ cytotoxic T lymphocytes include elimination of a variety of intracellular microbes,
eradication of tumor cells and play critical roles in the acute rejection of organ allografts. - -CD8+ T
lymphocytes are effector T cells responsible for the following functions:
a. Elimination of intracellular microbes, tumor cells and acute organ allograft rejection.
b. Elimination of extracellular microbes and tumor cells.
c. Elimination of intracellular microbes, tumor cells and chronic organ allograft rejection.
d. Elimination of extracellular microbes, tumor cells and chronic organ allograft rejection.
-A, page 232.
Specialized dendritic cells ingest infected cells, transfer the protein to the cytosol and process the
antigen to enter the class I MHC presentation pathway for recognition by CD8+ T cells. See Fig. 6.20. - -
Cross presentation is a critical step in the antigen presentation to CD8+ T cells. Which of the following
best explains this process?
a. Specialized dendritic cells ingest infected cells, transfer the protein to the cytosol and process the
antigen to enter the class I MHC presentation pathway for recognition by CD8+ T cells.
b. Specialized B cells ingest infected cells, transfer the protein to the cytosol and process the antigen to
enter the class I MHC presentation pathway for recognition by CD8+ T cells.
c. Specialized dendritic cells ingest infected cells, transfer the protein to the cytosol and process the
antigen to enter the class II MHC presentation pathway for recognition by CD8+ T cells.
d. Specialized dendritic cells ingest infected cells, transfer the protein to the cytosol and process the
antigen to enter the class I MHC presentation pathway for recognition by CD4+ T cells.
-A, page 234.
Exhausted CD8+ T cells demonstrate decreased INFγ and increased expression of inhibitory receptors
such as PD-1. Presence of IL-21 helps prevent exhaustion from occurring and antibodies directed against
PD-1 are being considered therapeutically in the treatment of tumors ad chronic viral infections. - -What
functional and phenotypic changes are found in exhausted CD8+ T cells?
a. Decreased production of INFγ
b. Decreased expression of PD-1
c. Increased production of IL-21
d. Presence of natural antibodies that block PD-1
-A, page 241, Figure 12-2.
The secondary response has an antibody isotype with a relative increase in IgG and under certain
situations an increase in IgA or IgE, compared to IgM, the antibody isotype that predominates in the
primary antibody response. - -The primary antibody immune response is different from the secondary
