Question 1

Explain the origin of the secretory component and its significance after the release of dimeric IgA from the apical face of the gut epithelium.

Accepted Answer

During transcytosis the poly-Ig receptor is cleaved by a protease,leaving a small piece of the original receptor,called the secretory component,still bound to the J chain via disulfide bonds.Once dimeric IgA is released at the apical face,the carbohydrate moieties of the secretory component anchor the antibody to mucins of the mucus,enabling the antibodies to bind subsequently to microbes in the mucus and inhibit the ability of microbes to bind to and invade the mucosal epithelium of the gut.Instead,the microbe is expelled from the body via mucosal secretions in the feces.

Question 2

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

Accepted Answer

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 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. B

Question 3

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

Accepted Answer

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 
B) adhesins; neutralizing antibodies 
C) toxoids; passive immunity 
D) adhesins; complement proteins 
E) toxoids; C-reactive protein. A

Question 4

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

Accepted Answer

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) 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.

Question 5

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

Accepted Answer

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) 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.

Question 6

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

Accepted Answer

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 
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.

Question 7

Which of the following is not a function of antibodies?

Accepted Answer

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 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.

Question 8

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

Accepted Answer

A) phagocytosis 
B) exocytosis 
C) transcytosis 
D) signal transduction 
E) opsonization. 
A) phagocytosis 
B) exocytosis 
C) transcytosis 
D) signal transduction 
E) opsonization.

Question 9

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

Accepted Answer

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) 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.

Question 10

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

Accepted Answer

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 
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.

Question 11

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.)

Accepted Answer

A) basophils 
B) eosinophils 
C) macrophages 
D) mast cells 
E) neutrophils. 
A) basophils 
B) eosinophils 
C) macrophages 
D) mast cells 
E) neutrophils.

Question 12

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

Accepted Answer

A) NK cells; FcγRI 
B) neutrophils; FcγRI 
C) NK cells; FcγRIII 
D) macrophages; FcγRIIB2 
E) mast cells; FcεRI. 
A) NK cells; FcγRI 
B) neutrophils; FcγRI 
C) NK cells; FcγRIII 
D) macrophages; FcγRIIB2 
E) mast cells; FcεRI.

Question 13

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

Accepted Answer

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 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.

Question 14

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?

Accepted Answer

A) FcγRI 
B) FcγRIIA 
C) FcγRIIB2 
D) FcγRIIB1 
E) FcγRIII. 
A) FcγRI 
B) FcγRIIA 
C) FcγRIIB2 
D) FcγRIIB1 
E) FcγRIII.

Question 15

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 _____.

Accepted Answer

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 
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.

Question 16

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 _____.

Accepted Answer

A) IgD 
B) IgE 
C) sIgA 
D) IgG 
E) IgM. 
A) IgD 
B) IgE 
C) sIgA 
D) IgG 
E) IgM.

Question 17

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

Accepted Answer

A) factor I 
B) CR2 
C) C3d 
D) CD19 
E) Lyn. 
A) factor I 
B) CR2 
C) C3d 
D) CD19 
E) Lyn.

Question 18

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

Accepted Answer

A) apoptosis 
B) affinity maturation 
C) antibody-dependent cell-mediated cytotoxicity 
D) opsonization 
E) clonal expansion. 
A) apoptosis 
B) affinity maturation 
C) antibody-dependent cell-mediated cytotoxicity 
D) opsonization 
E) clonal expansion.

Question 19

A.What are the similarities between the activation of mast cells and NK cells via FcεRI and FcγRIII,respectively? Be specific.
B.What are the differences? Again,be specific.

Accepted Answer

A.Similarities: (1)Activation of both ma

Question 20

Describe the ways in which follicular dendritic cells (FDCs)are similar to subcapsular sinus macrophages.

Accepted Answer

FDCs and subcapsular macrophages use the

Explain the origin of the secretory component and its significance after the release of dimeric IgA from the apical face of the gut epithelium.

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

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

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

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

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

Which of the following is not a function of antibodies?

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

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

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

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.)

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

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

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?

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 _____.

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 _____.

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

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

A.What are the similarities between the activation of mast cells and NK cells via FcεRI and FcγRIII,respectively? Be specific. B.What are the differences? Again,be specific.

Describe the ways in which follicular dendritic cells (FDCs)are similar to subcapsular sinus macrophages.

Elements of the Immune System and Their Roles in Defense

Innate Immunity: the Immediate Response to Infection

Innate Immunity: the Induced Response to Infection

Antibody Structure and the Generation of B-Cell Diversity

Antigen Recognition by T Lymphocytes

The Development of B Lymphocytes

The Development of T Lymphocytes

T Cell-Mediated Immunity

Preventing Infection at Mucosal Surfaces

Immunological Memory and Vaccination

Coevolution of Innate and Adaptive Immunity

Failures of the Bodys Defenses

Ige-Mediated Immunity and Allergy

Transplantation of Tissues and Organs

Disruption of Healthy Tissue by the Adaptive Immune Response

Cancer and Its Interactions With the Immune System

Filters

Exam 9: Immunity Mediated by B Cells and Antibodies

Explain the origin of the secretory component and its significance after the release of dimeric IgA from the apical face of the gut epithelium.

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

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

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

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

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

Which of the following is not a function of antibodies?

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

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

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

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.)

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

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

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?

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 _____.

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 _____.

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

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

A.What are the similarities between the activation of mast cells and NK cells via FcεRI and FcγRIII,respectively? Be specific. B.What are the differences? Again,be specific.

Describe the ways in which follicular dendritic cells (FDCs)are similar to subcapsular sinus macrophages.

Elements of the Immune System and Their Roles in Defense

Innate Immunity: the Immediate Response to Infection

Innate Immunity: the Induced Response to Infection

Antibody Structure and the Generation of B-Cell Diversity

Antigen Recognition by T Lymphocytes

The Development of B Lymphocytes

The Development of T Lymphocytes

T Cell-Mediated Immunity

Preventing Infection at Mucosal Surfaces

Immunological Memory and Vaccination

Coevolution of Innate and Adaptive Immunity

Failures of the Bodys Defenses

Ige-Mediated Immunity and Allergy

Transplantation of Tissues and Organs

Disruption of Healthy Tissue by the Adaptive Immune Response

Cancer and Its Interactions With the Immune System

Filters

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

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

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