Question 1

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

Accepted Answer

The primary focus of B-cell expansion forms in the medullary cords, whereas a secondary focus of B-cell expansion creates the germinal center.

Question 2

Which of the following is not a function of antibodies?

Accepted Answer

Antibodies do not exert toxic effects directly. They instead work to facilitate immune responses and provide protection against pathogens through the functions listed in choices A, B, D, and E.

Question 3

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

Accepted Answer

Centroblasts are large, rapidly dividing cells found in the germinal centers of lymph nodes that do not express cell-surface immunoglobulins, unlike centrocytes, which are smaller, less rapidly dividing cells that do express cell-surface immunoglobulins and participate in processes such as affinity maturation and isotype switching.

Question 4

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

Accepted Answer

Tingible body macrophages are responsible for the engulfment of apoptotic cells (centrocytes) in germinal centers, helping to clear out cells that have undergone apoptosis during the immune response.

Question 5

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.)

Accepted Answer

Isotype switching and affinity maturation are both essential for the synthesis of high-affinity antibodies. Recognition of thymus-independent antigens (A) may result in a weak antibody response, while increased expression of TLR9 by B cells (C) would enhance their response to DNA-containing antigens but not necessarily result in high-affinity antibodies. Decreased expression of CD40 by B cells (E) would inhibit their activation and differentiation, but alone would not lead to the synthesis of high-affinity antibodies.

Question 6

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

After activation with a T-dependent antigen, B cells that migrate to the medullary cords differentiate into plasma cells that predominantly secrete IgM, which is the first antibody isotype produced in a primary immune response.

Question 7

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

Accepted Answer

ITAMs are located on the cytoplasmic tails of Igα and Igβ, which are signaling subunits associated with the B cell receptor. When the B cell receptor binds to an antigen, it activates these ITAMs and initiates downstream signaling pathways that lead to B cell activation and proliferation.

Question 8

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

Accepted Answer

The gene for C4B is known to be duplicated or deleted in some individuals, leading to variations in C4B levels. Deficiency of C4B is not specifically associated with SLE, but complement deficiencies in general have been implicated in the development of autoimmune diseases like SLE. While C4B has some structural and functional similarities to C4A, they are not identical. The thioester bond of C4B can react with a variety of nucleophiles, not just amino groups. C4B is encoded in the class III region, not class II region, of the MHC.

Question 9

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

Accepted Answer

Centrocytes with high-affinity receptors express Bcl-xL to avoid apoptosis, process and present antigen to T_FH cells, and engage CD40 with CD40 ligand on T_FH cells for survival and differentiation signals.

Question 10

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

Accepted Answer

If a centrocyte does not interact with antigen and engage CD40 shortly after its derivation, it is unlikely to receive signals for survival and proliferation, leading to apoptosis.

Question 11

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

Accepted Answer

Lymphoblasts upregulate the transcription factor called B-lymphocyte induced maturation protein 1 (BLIMP-1) when they terminally differentiate into plasma cells.

Question 12

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

Accepted Answer

The answer of A primary focus of clonal expansion is...

Question 13

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

Accepted Answer

Plasma cells and memory B cells most immediately differentiate from centrocytes, which are found in the germinal centers of secondary lymphoid organs. Centrocytes are mature B cells that have undergone somatic hypermutation and are selected for high-affinity antibodies against antigens.

Question 14

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

Accepted Answer

Transcription in the switch regions positioned 5′ to each heavy-chain C gene is induced by helper T-cell cytokines.

Question 15

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

Accepted Answer

Proliferating centroblasts use the DNA-modifying enzyme activation-induced cytidine deaminase for somatic hypermutation and isotype switching. This enzyme plays a crucial role in these processes, allowing for the generation of a diverse repertoire of immunoglobulins with high affinity for specific antigens. AID is not involved in cell proliferation, apoptosis, or upregulation of CD40.

Question 16

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

Accepted Answer

Bcl-x_L is a member of the Bcl-2 family of proteins, which are known for their role in regulating apoptosis. Specifically, Bcl-x_L functions to prevent apoptosis in the centrocyte.

Question 17

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

Accepted Answer

Affinity maturation is a process by which B cells produce immunoglobulins with higher affinity for antigen. This is achieved through somatic hypermutation of the variable region of the antibody gene, followed by selection of B cells that produce antibodies with the highest affinity for antigen.

Question 18

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

Accepted Answer

A primary focus forms after a naive B cell pairs with a T_FH cell in the medullary cords of a lymph node, where initial B cell proliferation occurs.

Question 19

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

Accepted Answer

The answer of Describe the ways in which follicular dendritic...

Question 20

Explain why expression of CD40 ligand by T_FH cells is important in the boundary area of primary follicles in secondary lymphoid tissue as it relates to the targeted delivery of secreted cytokines to the B-cell surface.

Accepted Answer

The answer of Explain why expression of CD40 ligand by...

Quiz 9: Immunity Mediated by B Cells and Antibodies

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

Which of the following is not a function of antibodies?

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

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

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.)

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 _____.

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

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

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

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

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

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

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

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

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

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

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

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

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

Explain why expression of CD40 ligand by T_FH cells is important in the boundary area of primary follicles in secondary lymphoid tissue as it relates to the targeted delivery of secreted cytokines to the B-cell surface.

Quiz 9: Immunity Mediated by B Cells and Antibodies

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

Which of the following is not a function of antibodies?

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

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

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.)

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 _____.

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

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

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

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

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

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

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

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

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

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

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

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

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

Explain why expression of CD40 ligand by TFH cells is important in the boundary area of primary follicles in secondary lymphoid tissue as it relates to the targeted delivery of secreted cytokines to the B-cell surface.

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

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

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

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

Explain why expression of CD40 ligand by T_FH cells is important in the boundary area of primary follicles in secondary lymphoid tissue as it relates to the targeted delivery of secreted cytokines to the B-cell surface.