Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Immuno > Chapter 9 > Flashcards

Chapter 9 Flashcards

1
Q

Which of the following is not a function of antibodies?

a. They neutralize pathogens by masking their surface.
b. They act as molecular adaptors that bridge together pathogen and phagocyte surfaces.
c. They exert toxic effects directly.
d. They act as opsonins that mediate phagocytosis.
e. They activate complement fixation

A

They exert toxic effects directly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

To mount the most effective antibody response that results in the synthesis of high-affinity antibodies, which of the following must occur? (Select all that apply.)

a. recognition of thymus-independent (TI) antigens
b. isotype switching
c. increased expression of TLR9 by B cells
d. affinity maturation
e. decreased expression of CD40 by B cells

A

b. isotype switching

d. affinity maturation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Immunoreceptor tyrosine-based activation motifs (ITAMs) are located on _____.

a. the cytoplasmic tails of IgM
b. tyrosine kinases Blk, Fyn, and Lyn
c. the cytoplasmic tails of Igα and Igβ
d. breakdown products of C3b deposited on pathogen surfaces
e. thymus-independent antigens

A

the cytoplasmic tails of Igα and Igβ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Identify the mismatched association.

a. Syk: Igβ cytoplasmic tails
b. tyrosine kinase Lyn: CD81
c. B-cell co-receptor: CD21/CD19/CD81
d. C3b fragments: C3d and iC3b
e. C3b/CR1: factor I
f. hyper-IgM syndrome: CD40 ligand deficiency

A

tyrosine kinase Lyn: CD81

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

A primary focus of clonal expansion is best described as _____.

a. the location in the B-cell zone where conjugate pairs of B and T cells undergo cellular proliferation, isotype switching, and somatic hypermutation
b. the location in the medullary cords where conjugate pairs of B cells and T cells undergo cellular proliferation and IgM is secreted
c. the dark zone of the germinal center where centroblasts divide and pack closely together
d. the initial wave of B-cell proliferation induced by T-independent antigens

A

the location in the medullary cords where conjugate pairs of B cells and T cells undergo cellular proliferation and IgM is secreted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

A primary focus forms after a circulating naive B cell forms a conjugate pair with _____ in the _____ of a lymph node.

a. TH1 cell; B-cell zone
b. cytotoxic T cell; T-cell zone
c. follicular dendritic cell; germinal center
d. TFH; medullary cords
e. CD40 ligand; T-cell zone

A

TFH; medullary cords

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which of the following do not bind to components found on the surface of an activated B cell? (Select all that apply.)

a. MHC class II
b. T-cell receptor
c. antigen
d. CD40
e. C3d
f. IL-4
g. CD4
h. LFA-1
i. CD40 ligand

A

a. MHC class II

d. CD40

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

B cells migrating directly from a primary focus to the medullary cords in a lymph node after activation with a T-dependent antigen differentiate into plasma cells that secrete predominantly _____.

a. IgD
b. IgE
c. sIgA
d. IgG
e. IgM

A

IgM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Lymphoblasts upregulate a transcription factor called _____ when they terminally differentiate into plasma cells.

a. NFκB
b. Bcl-xL
c. B-lymphocyte induced maturation protein 1 (BLIMP-1)
d. CD40
e. ICAM-1

A

B-lymphocyte induced maturation protein 1 (BLIMP-1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The primary focus of B-cell expansion forms in the _____, whereas a secondary focus of B-cell expansion creates the _____.

a. T-cell area; medullary cords
b. medullary cords; T-cell area
c. T-cell area; B-cell area
d. medullary cords; germinal center
e. light zone; dark zone

A

medullary cords; germinal center

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Proliferating centroblasts use the DNA-modifying enzyme activation-induced cytidine deaminase for ________. (Select all that apply.)

a. cell proliferation
b. somatic hypermutation
c. apoptosis
d. upregulation of CD40
e. isotype switching

A

b. somatic hypermutation

e. isotype switching

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the fate of centrocytes in which somatic hypermutation has resulted in high-affinity receptors for antigen? (Select all that apply.)

a. They die by apoptosis.
b. They express Bcl-xL.
c. They process antigen and present it to TFH cells.
d. CD40 on the centrocyte engages with CD40 ligand on TFH cells.
e. They undergo phagocytosis by tingible body macrophages

A

b. They express Bcl-xL.
c. They process antigen and present it to TFH cells.
d. CD40 on the centrocyte engages with CD40 ligand on TFH cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The main function of Bcl-xL is to _____ in the centrocyte.

a. provide death signals
b. induce somatic hypermutation
c. upregulate the expression of activation-induced cytidine deaminase
d. prevent apoptosis
e. induce isotype switching

A

prevent apoptosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Engulfment of apoptotic centrocytes is facilitated by _____ in germinal centers.

a. follicular dendritic cells
b. immune-complex coated bodies (iccosomes)
c. tingible body macrophages
d. antigen-specific B cells
e. antigen-specific TFH cells

A

tingible body macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which of the following is an accurate description of how centroblasts differ from centrocytes?

a. Centroblasts cease their expression of cell-surface immunoglobulins.
b. Centroblasts divide more slowly than centrocytes.
c. Centroblasts express CD44 but centrocytes do not.
d. Centrocytes, but not centroblasts, initiate the process of isotype switching.
e. Centroblasts participate in affinity maturation.

A

Centroblasts cease their expression of cell-surface immunoglobulins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

If a centrocyte does not interact with antigen and engage CD40 shortly after its derivation, then _____.

a. it recommences somatic hypermutation
b. it undergoes apoptosis
c. it moves back into the dark zone of the germinal center and switches its isotype
d. its surface immunogloblulin levels decrease and proliferation recommences

A

it undergoes apoptosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

_____ is a mechanism that drives the preferential selection of immunoglobulins with the highest affinity for antigen.

a. Anergy
b. Isotype-switching
c. Affinity maturation
d. Antibody-dependent cell-mediated cytotoxicity
e. Transcytosis

A

Affinity maturation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

_____ in the switch regions positioned 5′ to each heavy-chain C gene is induced by _____.

a. Somatic hypermutation; TI antigens
b. Chromatin remodeling; B-cell co-receptor signaling
c. Recombination; survival signals received from follicular dendritic cells
d. Transcription; helper T-cell cytokines
e. Gene repression; apoptotic signals received from tingible body macrophages

A

Transcription; helper T-cell cytokines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Plasma cells and memory B cells differentiate most immediately from _____.

a. centrocytes
b. centroblasts
c. B-1 cells
d. IgG-secreting B cells

A

centrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Which of the following statements is true regarding the complement component C4B?

a. Deficiency of C4B is associated with systemic lupus erythematosus (SLE).
b. C4B has similar properties to those of C4A.
c. The thioester bond of C4B is preferentially acted upon by amino groups of macromolecules.
d. C4B is encoded in the class II region of the MHC.
e. The gene for C4B is duplicated or deleted in some individuals.

A

The gene for C4B is duplicated or deleted in some individuals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which of the following is able to bind to C1q? (Select all that apply.)

a. bacterial adhesins
b. toxoids
c. IgM
d. C-reactive protein
e. hemagglutinin
f. lipopolysaccharide
g. classical C3 convertase

A

c. IgM

d. C-reactive protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

IgM is particularly efficient at fixing complement because it _____.

a. is a much larger antibody than the other isotypes
b. has an extra CH domain
c. is made first in an immune response and therefore has first access to C1q
d. has five binding sites for C1q
e. has easy access to extravascular areas

A

has five binding sites for C1q

23
Q

C3 convertase of the classical pathway is _____, whereas C3 convertase of the alternative pathway is _____.

a. C1a; C3bBb
b. C4bC2a; C3bBb
c. C3bCR1; C3bBb
d. C4bC2a; C3bCR1
e. C1a; C3bCR1

A

C4bC2a; C3bBb

24
Q

Which of the following statements are true regarding C4? (Select all that apply.)

a. There are two forms of C4 encoded by separate genes residing in the class II region of the MHC.
b. Evolution of the different forms of C4 probably occurred as a result of gene duplication and diversification.
c. Because there are two forms of C4, C4 deficiency is the least common human immunodeficiency.
d. More than 30% of the human population lacks either C4A or C4B.
e. C4A and C4B have identical properties.
f. C4B deficiency is associated with increased susceptibility to systemic lupus erythematosus.
g. C4A and C4B are monomorphic.

A

b. Evolution of the different forms of C4 probably occurred as a result of gene duplication and diversification.
d. More than 30% of the human population lacks either C4A or C4B.

25
Q

Complexes of IgG bound to soluble multivalent antigens can activate the classical pathway of complement, resulting in the deposition of _____ on the complex, targeting it for endocytic uptake by cells bearing _____.

a. C4b; CR2 and Fc receptors
b. C3b; CR2 and Toll-like receptors
c. C5-9; CR1 and Fc receptors
d. C3b; CR1 and Fc receptors
e. C2a; CR2 and Toll-like receptors

A

C3b; CR1 and Fc receptors

26
Q

A distinguishing feature of FcγRIIB1 compared with FcγRIIA is _____.

a. its ability to activate cells and induce endocytosis
b. the existence of ITIMs in its cytoplasmic tails
c. its inability to bind to IgG1
d. its expression on NK cells

A

the existence of ITIMs in its cytoplasmic tails

27
Q

For IgG2 to be effective at stimulating uptake of IgG2-coated bacteria, _____.

a. an individual must express allotype H131 of FcγRIIA
b. an individual must express allotype R131 of FcγRIIA
c. the ITIMs of FcγRIIB2 must be non-functional
d. complement must be fixed on the surface of the bacterium

A

an individual must express allotype H131 of FcγRIIA

28
Q

Naive B cells search for specific antigen displayed by follicular dendritic cells in primary follicles. Naive T cells, however, search for specific antigen presented by ______.

a. dendritic cells
b. subcapsular sinus macrophages
c. medullary sinus macrophages
d. centrocytes
e. tingible body macrophages

A

dendritic cells

29
Q

Which of the following is consistent with a recently antigen-activated mast cell?

a. high levels of MHC class II molecules on the cell surface
b. the absence of prepackaged granules
c. the absence of IgE on the cell surface
d. high concentrations of C3b on the cell surface
e. the induction of antibody-dependent cell-mediated cytotoxicity

A

the absence of prepackaged granules

30
Q

Some types of B-cell tumor have been treated with rituximab, an anti-CD20 monoclonal antibody, which exerts its effect through a mechanism known as ______ involving the participation of NK cells.

a. degranulation
b. neutralization
c. opsonization
d. antibody-dependent cell-mediated cytoxicity
e. receptor-mediated endocytosis

A

antibody-dependent cell-mediated cytoxicity

31
Q

Which of the following is a characteristic of follicular dendritic cells in the primary follicles of secondary lymphoid tissues? (Select all that apply.)

a. They are bone marrow derived hematopoietic cells.
b. They provide a stable depository of intact antigens able to bind to B-cell receptors.
c. They have a large surface area as a result of forming dendrites.
d. They internalize immune complexes through CR2 receptor cross-linking.
e. They produce cytokines that induce B cells to proliferate and become centroblasts.

A

b. They provide a stable depository of intact antigens able to bind to B-cell receptors.
c. They have a large surface area as a result of forming dendrites.

32
Q

The B-cell co-receptor is composed of

a. Igα; Igβ; CD19
b. Igα; Igβ; Lyn tyrosine kinase
c. CR2 (CD21); CD19; CD81
d. CD14; CD19; CD81
e. CD40; MHC class II; CED19

A

CR2 (CD21); CD19; CD81

33
Q

C3d and iC3b are breakdown products of _____, which binds to _____ of the B-cell co-receptor.

a. C3a; CR2
b. C3b; CR2
c. C3c; CD81
d. C3c; CD19
e. C3b; CD19

A

C3b; CR2

34
Q

When bound to CR1, C3b is cleaved by _____, generating pathogen-associated B-cell co-receptor ligands.

a. factor I
b. CR2
c. C3d
d. CD19
e. Lyn

A

factor I

35
Q

The Igα-associated tyrosine kinase _____ phosphorylates the cytoplasmic tail of CD19, which mediates signal transduction in activated B cells.

a. CD81
b. Blk
c. Fyn
d. Lyn
e. Syk

A

Lyn

36
Q

48 A B cell’s sensitivity to antigen can be increased 1000–10,0000-fold by

a. simultaneously ligating the B-cell receptor and co-receptor
b. simultaneously ligating the B-cell receptor and Toll-like receptor
c. ligating the B-cell co-receptor and phosphorylating Ig-α ITAMs
d. increasing levels of Syk proteins in the vicinity of co-receptor ligation
e. ligating cytokine receptors on the B-cell surface

A

simultaneously ligating the B-cell receptor and co-receptor

37
Q

The process that drives an increase in antibody affinity for antigen is known as _____.

a. apoptosis
b. affinity maturation
c. antibody-dependent cell-mediated cytotoxicity
d. opsonization
e. clonal expansion

A

affinity maturation

38
Q

FcRn has which of the following characteristics? (Select all that apply.)

a. It binds to monomeric IgA in acidified endocytic vesicles.
b. It transports IgG out of the blood into tissue across the endothelium.
c. It is similar in structure to an MHC class II molecule.
d. It protects IgA from degradation by plasma proteases.
e. Two molecules of FcRn are required to bind to each Fc region.

A

b. It transports IgG out of the blood into tissue across the endothelium.
e. Two molecules of FcRn are required to bind to each Fc region.

39
Q

The process involving receptor-mediated transport of macromolecules from one side of a cell to the other is called

a. phagocytosis
b. exocytosis
c. transcytosis
d. signal transduction
e. opsonization

A

transcytosis

40
Q

52 Of the following, which group of children is the most vulnerable to infection?

a. babies born at term
b. babies born prematurely
c. infants of 3–6 months
d. infants receiving first vaccination
e. babies receiving formula and not breast milk

A

babies born prematurely

41
Q

_____ occurs as a result of influenza virus binding to oligosaccharide components on erythrocyte surfaces causing them to clump together.

a. Passive immunization
b. Opsonization
c. Hemagglutination
d. Neutralization
e. Complement activation

A

Hemagglutination

42
Q

Which of the following are correctly matched? (Select all that apply.)

a. protein F; fibronectin
b. neutralization; IgE
c. breast milk; IgG
d. influenza; hemagglutinin
e. mucosal epithelium; IgA

A

a. protein F; fibronectin
d. influenza; hemagglutinin
e. mucosal epithelium; IgA

43
Q

55 Bacteria use _____ to attach to the surface of cells during colonization.

a. hemagglutinins
b. toxins
c. breakdown products
d. anti-inflammatory molecules
e. adhesins

A

adhesins

44
Q

Denatured toxin molecules called _____ are used to vaccinate individuals to stimulate the production of _____.

a. toxoids; neutralizing IgG antibodies
b. adhesins; neutralizing antibodies
c. toxoids; passive immunity
d. adhesins; complement proteins
e. toxoids; C-reactive protein

A

toxoids; neutralizing IgG antibodies

45
Q

Which of the following are characteristics of systemic lupus erythematosus? (Select all that apply.)

a. It is an autoimmune disease.
b. It is associated with a deficiency of C4A.
c. Increased levels of immune complexes are detected in the blood.
d. CR1 receptor levels are decreased.
e. Immune complexes are deposited on the kidney glomeruli, which can lead to kidney complications.

A

a. It is an autoimmune disease.
b. It is associated with a deficiency of C4A.
c. Increased levels of immune complexes are detected in the blood.
e. Immune complexes are deposited on the kidney glomeruli, which can lead to kidney complications.

46
Q

The disadvantage of having a longer hinge region in IgG3 compared with the other IgG subclasses is a reduction in its serum half-life because of its susceptibility to _____.

a. increased proteolysis by serum proteases
b. clearance by erythrocytes via FcR binding
c. immune complex formation and deposition in kidney glomeruli
d. complement fixation and uptake by cells bearing receptor CR1
e. opsonization by neutrophils

A

increased proteolysis by serum proteases

47
Q

Which of the following antibodies activate the classical pathway of complement? (Select all that apply.)

a. IgM
b. IgG1
c. IgD
d. IgG3
e. IgE

A

a. IgM
b. IgG1
d. IgG3

48
Q

The γ chain of the FcγRI receptor is closely related to the _____, which contains _____.

a. FcRn; MHC class I-like structure
b. ζ chain of the T-cell receptor complex; ITAM motifs
c. γ chain of the FcγRIII receptor; ITIM motifs
d. γ chain of the FcαRI receptor; ITIM motifs
e. γ chain of the FcεRI receptor; ITIM motifs

A

ζ chain of the T-cell receptor complex; ITAM motifs

49
Q

Of the Fc receptors for IgG, which one is similar to FcεRI in its ability to bind antibody in the absence of antigen but does not transduce an activating signal until antigen cross-linking occurs?

a. FcγRI
b. FcγRIIA
c. FcγRIIB2
d. FcγRIIB1
e. FcγRIII

A

FcγRI

50
Q

Which of the following individuals would be most susceptible to fulminant meningococcal disease or septic shock when infected with Neisseria meningitidis?

a. homozygous for allotype H131 of IgG2
b. heterozygous for allotype H131 of IgG2
c. homozygous for allotype R131 of IgG2
d. heterozygous for allotype R131 of IgG2
e. all of the above would be equally susceptible to infections with Neisseria meningitidis

A

homozygous for allotype R131 of IgG2

51
Q

Antibody-dependent cell-mediated cytotoxicity (ADCC) is carried out by _____ after cross-linking of IgG1 or IgG3 antibodies on _____ receptors.

a. NK cells; FcγRI
b. neutrophils; FcγRI
c. NK cells; FcγRIII
d. macrophages; FcγRIIB2
e. mast cells; FcεRI

A

NK cells; FcγRIII

52
Q

The symptoms of allergy and asthma are induced after cross-linking of IgE antibody on FcεRI receptors found on the surface of _____. (Select all that apply.)

a. basophils
b. eosinophils
c. macrophages
d. mast cells
e. neutrophils

A

a. basophils
b. eosinophils
d. mast cells

53
Q

The FcαRI receptor binds to _____:antigen complexes and facilitates the phagocytosis of opsonized antigens.

a. dimeric IgA
b. IgM
c. IgE
d. IgG
e. monomeric IgA

A

monomeric IgA

Immuno (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions