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CHAPTER 10
The Body’s Defenses Against Infection
Questions
10–1
_____ microorganisms are microbes that colonize mucosal surfaces but under normal
circumstances do not cause disease.
a. Opportunistic
b. Commensal
c. Parasitic
d. Mesenteric
e. Pathogenic.
10–2
_____ makes up the membranes of connective tissue that help to anchor the gastrointestinal tract
and hold it in place.
a. The mesentery
b. Peyer’s patches
c. The lamina propria
d. The subepithelial dome
e. Waldeyer’s ring.
10–3
Waldeyer’s ring includes which of the following? (Select all that apply.)
a. Peyer’s patches
b. lingual tonsils
c. adenoids
d. mesenteric lymph nodes
e. palatine tonsils.
10–4
Which of the following describe M cells in the gut? (Select all that apply.)
a. They derive their name from mucus cells.
b. They are located in the dome of a Peyer’s patch.
c. They deliver antigens and pathogens from the lymphoid tissue to the luminal side of the
gut mucosa by transcytosis.
d. They are protected from digestive enzymes by a thick glycocalyx and a layer of mucus.
e. They do not directly participate in antigen processing or presentation.
10–5
Mucosae of a healthy intestinal tract _____. (Select all that apply.)
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a. have a large number of activated T and B cells
b. harbor T cells bearing a very wide diversity of antigen specificities
c. contain intraepithelial lymphocytes
d. have large numbers of resident neutrophils
e. are populated with both : and : CD8 effector T cells.
10–6
_____ is the vascular addressin found on endothelial cells of intestinal mucosa that binds to
integrins of gut-homing effector lymphocytes.
a. CCL25
b. C-cadherin
c. NOD1
d. MAdCAM-1
e. CCR9.
10–7
The dominant immunoglobulin synthesized at mucosal surfaces is _____.
a. IgA
b. IgD
c. IgE
d. IgG
e. IgM.
10–8
If a B cell has been activated by antigen in the mucosa of the respiratory tract then _____. (Select
all that apply.)
a. lactating mothers will provide antigen-specific natural IgA in breast milk.
b. secretory IgA will be synthesized in the lamina propria of all mucosae.
c. it does not enter the bloodstream, but instead remains in the mucosa and differentiates
into an effector B cell.
d. it will recirculate through all mucosal tissues including respiratory and gastrointestinal
mucosae.
e. monomeric IgA is secreted into the lamina propria.
10–9
In which of the following tissues is IgA2 produced at approximately twice the level as IgA1?
a. spleen
b. mammary glands
c. large intestine
d. gastric mucosa
e. upper small intestine.
10–10
Secretory IgA is best described as _____.
a. a non-inflammatory immunoglobulin that restricts the passage of antigens across mucosal
surfaces
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b. a complement-activating immunoglobulin that causes destruction of invasive microflora
through the membrane-attack complex
c. an opsonizing antibody that facilitates uptake by M cells through Fc receptors
d. an inflammatory immunoglobulin that stimulates the chemotaxis of neutrophils into
mucosal surfaces
e. a monomeric IgA that neutralizes antigen effectively at mucosal surfaces.
10–11
Secretory IgA and _____ can bind to the poly-Ig receptor and be transported into the lumen of
the gut or across other mucosal surfaces.
a. IgG
b. IgE
c. IgD
d. monomeric IgM
e. pentameric IgM.
10–12
Intracytoplasmic bacteria in enterocytes of the gastrointestinal tract are detected by _____.
a. poly-Ig receptor
b. major basic protein
c. MIC-A and MIC-B
d. NOD proteins
e. receptors for phosphoantigens.
10–13
NOD1 responds to _____, forms oligomers, and then activates the protein kinase _____.
a. muramyl dipeptide; RICK
b. muramyl dipeptide; NFB
c. defensins; RICK
d. muramyl tripeptide containing diaminopimelic acid: RICK
e. chemokines; NFB.
10–14
Ligand binding of NOD2 results in the activation of the _____ signaling pathway and the
production of defensins, chemokines, and cytokines.
a. NFB
b. NKG2D
c. Toll-like receptor
d. CD94:NKG2A
e. poly-Ig receptor.
10–15
Which of the following characterize MIC-A and MIC-B proteins? (Select all that apply.)
a. recognized by NKG2D receptors of NK cells and some CD8 T cells
b. activate the NFB signaling pathway
c. activate mast cells in the intestinal wall
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d. closely related to MHC class I heavy chains
e. bind to MHC class I molecules and activate CD8 T cells.
10–16
Which of the following types of immune responses are most beneficial in clearing helminth
infections in the intestinal tract? (Select all that apply.)
a. production of IgG2 antibodies
b. production of IgE antibodies
c. complement fixation
d. eosinophil activation
e. antibody-dependent cell-mediated cytotoxicity
f. IFN--induced production of mucus
g. TH1-derived cytokines.
10–17
Indicate whether the following questions are true (T) or false (F).
__ a. Secondary immune responses take the same amount of time as primary immune
responses to become effective.
__ b. On secondary exposure to an infectious agent there is reduced mortality.
__ c. Only immune responses made in mucosal secondary lymphoid tissues can provide
protective immunity.
__ d. If an individual acquires a second cold in the same season it will most likely be caused by
a different type of cold virus.
__ e. Plasma cells generated in a secondary immune response have longer life-spans than those
made during a primary immune response.
__ f. During a primary immune response, only memory B cells are generated.
10–18
In which ways do memory B cells active in a secondary immune response differ from the naive
B-cell population activated in a primary immune response? (Select all that apply.)
a. The antibody produced is of higher affinity in a secondary immune response.
b. The frequency of antigen-specific B cells is lower in a secondary immune response.
c. The level of somatic hypermutation is higher in a secondary immune response.
d. Higher levels of IgM are produced in secondary immune responses.
e. B cells do not require T-cell help in secondary immune responses.
f. Memory B cells express higher levels of MHC class II molecules.
g. Naive B cells express higher levels of co-stimulatory molecules.
10–19
Which of the following characterizes immunological memory? (Select all that apply.)
a. The host retains the capacity to mount a secondary immune response.
b. The host retains the ability to respond to pathogen many years after primary exposure.
c. Naive T cells are activated more quickly when exposed to pathogen.
d. Memory B cells produce higher-affinity antibody than naive B cells.
e. Memory T cells undergo somatic hypermutation.
f. Memory T cells express CD45RA.
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10–20
What would be the outcome if a naive B cell were to simultaneously bind to pathogen coated
with specific antibody made by an effector B cell in a primary immune response using FcRIIB1,
and bind to the same pathogen using its B-cell receptor?
a. a positive signal leading to the production of low-affinity IgM antibodies
b. a positive signal leading to isotype switching and production of IgG, IgA, or IgE
antibodies
c. a positive signal leading to somatic hypermutation and production of high-affinity IgM
antibodies
d. a negative signal leading to inhibition of the production of low-affinity IgM antibodies
e. a negative signal leading to apoptosis.
10–21
Which of the following explains why the first baby born to a Rh– mother and a Rh+ father does
not develop hemolytic disease of the newborn?
a. Fetal erythrocytes do not cross the placenta and therefore do not stimulate an antibody
response.
b. The antibodies made by the Rh– mother during the first pregnancy are predominantly
IgM and have low affinity for the rhesus antigen.
c. Maternal macrophages in the placenta bind to anti-rhesus antibodies and prevent their
transfer to the fetus.
d. Hemolytic disease of the newborn is a T-cell-mediated disease and maternal T cells do
not cross the placenta during pregnancy.
e. The rhesus antigen is not immunogenic and does not stimulate an antibody response.
10–22
By which process are fetal erythrocytes destroyed in hemolytic anemia of the newborn?
a. lysis of erythrocytes by cytotoxic T cells
b. lysis of erythrocytes by complement activation
c. clearance of antibody-coated erythrocytes by macrophages in the fetal spleen
d. lysis of erythrocytes by NK cells via antibody-dependent cell-mediated cytotoxicity
e. cytotoxicity caused by major basic protein released from eosinophils.
10–23
Which of the following explain why infections with influenza virus erode immunological
memory over time? (Select all that apply.)
a. Influenza is a highly mutable virus that changes its epitope composition.
b. A compensatory immune response to new epitope variants is suppressed in naive B cells.
c. The antibody response is only directed toward new epitope variants, resulting in a
decreased memory response.
d. Cross-linking of B-cell receptor and FcRIIB1 on memory B cells induces anergy.
e. Naive B cells are suppressed by cytokines made by memory B cells.
10–24
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A memory T cell can be distinguished from a naive T cell on the basis of elevated levels of
_____. (Select all that apply.)
a. MHC class I
b. CD44
c. CD3
d. CD69
e. CD45RO.
10–25
Naive T cells do not express _____. (Select all that apply.)
a. CD25
b. CD45RA
c. CCR7
d. IFN-
e. FasL.
10–26
The production of CD45RO results from the removal of _____ during _____ processing.
a. domain A; post-translational
b. domain A; post-transcriptional
c. exons A, B and C; post-translational
d. exons A, B and C; post-transcriptional
e. exon A; post-transcriptional.
10–27
Effector memory cells enter _____, whereas central memory cells enter _____.
a. B-cell follicles; T-cell zones of secondary lymphoid tissues
b. T-cell zones of secondary lymphoid tissues; B-cell follicles
c. secondary lymphoid tissues; primary lymphoid tissues
d. T-cell zones of secondary lymphoid tissues; inflamed tissues
e. inflamed tissues; T-cell zones of secondary lymphoid tissues.
10–28
Central memory cells, but not effector memory cells, express _____. (Select all that apply.)
a. CCR7
b. IFN-
c. CD45RO
d. CD40L
e. IL-4.
10–29
Indicate whether each of the following statements is true (T) or false (F).
___ a. Memory T cells can persist in the absence of antigen.
___ b. The CD45RA isoform is associated with stronger signals in response to antigen.
___ c. T-cell survival is dependent on the cytokines IL-7 and IL-15.
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___ d. Naive B cells are more sensitive to specific antigen than memory B cells because they
express higher levels of co-stimulatory molecules.
___ e. Elderly people respond only to antigens encountered in childhood.
10–30
Fill in the blanks.
A. Cross-linking ________ and ________ on a ______ B cell by a specific antigen:IgG
complex renders the B cell anergic.
B. Treatment based on the above phenomenon is used to prevent hemolytic disease of the
newborn, which can occur in families where the mother is ______ and the father
_______.
10–31
V9:V2 T cells differ from : T cells in that they _____. (Select all that apply.)
a. respond to phosphorylated metabolic intermediates (phosphoantigens) of isoprenoid
biosynthesis pathways
b. bind to lipid antigens presented by CD1
c. do not carry out gene rearrangement
d. are not subject to positive and negative selection in the thymus
e. have limited diversity of V gene rearrangement.
10–32
Which of the following are expressed by V9:V2 T cells? (Select all that apply.)
a. IFN-
b. MHC class I
c. granulysin
d. CD56
e. CCR5
f. IL-4
g. CD40L
h. CD28.
10–33
_____ binds to MIC-A and MIC-B, which are synthesized in response to infection in gut
epithelium. (Select all that apply.)
a. MHC class I
b. NKG2D
c. V:V1
d. fibroblast growth factor
e. CD1.
10–34
_____ express a limited range of diversity in their antigen receptors yet can still bind to large
groups of pathogens expressing common chemical entities. (Select all that apply.)
a. : T cells
b. : T cells
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c. NK cells
d. NKT cells
e. B-1 cells.
10–35
Explain the path taken by CD1 molecules that eventually bind to pathogen-derived lipids inside
endosomes of the MHC class II compartment.
10–36
All NK cells express _____. (Select all that apply.)
a. CD3
b. MIC
c. NKG2D
d. KIR2DL1
e. CD56.
10–37
Which of the following describe the characteristics of CD94:NKG2A? (Select all that apply.)
a. It is an activating receptor of NK cells.
b. It is an inhibitory receptor of NK cells.
c. It binds to specific allotypes of HLA-A, -B, and –C heavy chains.
d. It binds to complexes of leader sequences of HLA-A, -B, and –C heavy chains bound to
HLA-E.
e. It is a member of the killer-cell immunoglobulin-like receptor (KIR) family.
10–38
In regard to killer-cell immunoglobulin-like receptors (KIRs) indicate which of the following
statements is true (T) or false (F).
___ a. KIRs have a broader range of specificity for HLA class I compared with CD94:NKG2A.
___ b. KIRs are activating receptors of NK cells and stimulate the release of perforin and
granzyme.
___ c. KIRs bind to monomorphic determinants on HLA-A, -B, and -C molecules.
___ d. All HLA-C allotypes are suitable ligands for KIRs.
___ e. KIRs are encoded in the leukocyte receptor complex (LRC) on chromosome 19.
___ f. MIC-A and MIC-B are suitable ligands for KIRs.
10–39
Match the molecule in column A with its appropriate ligand in column B. (Answers may be used
more than once.)
Column A
Column B
___ a. V:V T-cell receptor
1. HLA-A
___ b. CD94:NKG2A
2. FasL
___ c. NKG2D
3. phosphoantigen
___ d. LILRBI
4. HLA-E
___ e. FAS
5. MIC-A and MIC-B
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___ f. V9:V2 T-cell receptor
6. HLA-C
___ g. KIR2DL1
7. glycolipid antigen
___ h. CD1
10–40
_____ is a molecule expressed on NK cells and V:V1 T cells.
a. CD3
b. MIC-A
c. NKG2D
d. CD94:NKG2A
e. killer-cell immunoglobulin-like receptor (KIR).
10–41
If during development, none of the KIRs expressed by a NK cell are able to interact with self-
MHC class I molecules, then the NK cell retains expression of _____.
a. LILRBI
b. KIR2DL1
c. KIR2DL2/3
d. KIR3DL1
e. CD94:NKG2A.
10–42
CD1a, CD1b, and CD1c _____. (Select all that apply.)
a. are highly polymorphic and bind to a variety of pathogen-specific lipids
b. are encoded within the MHC on chromosome 6
c. express antigen-binding sites distinct from classical MHC class I molecules
d. are associated with 2-microglobulin at the surface of antigen-presenting cells
e. can bind to lipids in the endoplasmic reticulum or in endocytic vesicles.
10–43
CD1d differs from CD1a, CD1b, and CD1c in that _____. (Select all that apply.)
a. CD1d does not present lipid antigens.
b. CD1d is expressed in a variety of epithelial tissues.
c. CD1d presents antigen to NK T cells.
d. strong memory responses are generated by CD1d.
e. CD1d has a restricted receptor repertoire.
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Answers
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