Question 1

During B-cell development,antibody production switches from membrane-bound IgM to secreted antibody production.How does this switch occur?

Accepted Answer

Somatic recombination of the immunoglobulin heavy-gene locus first creates a rearranged gene that can express a membrane-bound μ chain.Antigen binding is required before the B cell can switch to secreted antibody production.The choice between membrane-bound versus secreted IgM depends on differential use of polyadenylation sites in the μ transcript.The μ transcript has two potential polyadenylation sites.If the downstream site is chosen,the resulting protein includes a C-terminal membrane anchor,which yields a membrane-bound form of μ .If the upstream polyadenylation site is used,the membrane anchor is bypassed,and the transcript is processed to yield the secreted version of the μ chain.

Question 2

During the early stages of B cell differentiation,heavy chains are complexed with:

Accepted Answer

A)  light chains. 
B)  light chains 
C) surrogate light chains. 
D) none of the above 
A)  light chains. 
B)  light chains 
C) surrogate light chains. 
D) none of the above C

Question 3

Which of the following would occur from B-cell class switching?

Accepted Answer

A) rearrangement of the light chain 
B) new VDJ recombination that still retains antigen specificity 
C) production of IgA secreted into the bloodstream with the same antigen specificity 
D) production of IgG γ2 with the same antigen specificity 
A) rearrangement of the light chain 
B) new VDJ recombination that still retains antigen specificity 
C) production of IgA secreted into the bloodstream with the same antigen specificity 
D) production of IgG γ2 with the same antigen specificity D

Question 4

ITAMs are part of:

Accepted Answer

A) Igα and Igβ 
B) heavy chains. 
C) light chains. 
D) surrogate light chains. 
A) Igα and Igβ 
B) heavy chains. 
C) light chains. 
D) surrogate light chains.

Question 5

Explain why Bence-Jones proteins are different for different B-cell tumors from different patients but identical when isolated from a single tumor.

Accepted Answer

B-cell tumors are clonal expansions of i

Question 6

Which of the following is NOT a way that MHC proteins play a role in the immune response?

Accepted Answer

A) presentation of antigen by class II MHCs on T-cells 
B) restrict cytotoxic T-cell killing of virally-infected cells 
C) allow lymphocytes to distinguish between "self" and "non-self" 
D) presentation of antigen by class II MHCs on B-cells 
A) presentation of antigen by class II MHCs on T-cells 
B) restrict cytotoxic T-cell killing of virally-infected cells 
C) allow lymphocytes to distinguish between "self" and "non-self" 
D) presentation of antigen by class II MHCs on B-cells

Question 7

Which complement components show chemoattractant activity and help recruit neutrophils to sites of complement activation?

Accepted Answer

A) C1q 
B) C1rC1s complexes 
C) C2C4 complexes 
D) small fragments released from C3 
A) C1q 
B) C1rC1s complexes 
C) C2C4 complexes 
D) small fragments released from C3

Question 8

Somatic recombination is catalyzed by RAG1 and RAG2 recombinases.How does the RAG1-RAG2 complex recognize the cleavage site at the exact boundary of the coding and signal sequences in the variable regions of immunoglobulin genes?

Accepted Answer

At the 3´ end of each light-chain V gene

Question 9

Why has the live-attenuated polio vaccine been recently discontinued?

Accepted Answer

The risk of re-emergence of mo

Question 10

Which class of immunoglobulins is made first?

Accepted Answer

A) IgA 
B) IgE 
C) IgG 
D) IgM 
A) IgA 
B) IgE 
C) IgG 
D) IgM

Question 11

Which cells can activate macrophages and stimulate an inflammatory response through the production of IFNγ?

Accepted Answer

A) CD4 Th1 T cells 
B) CD8 T cells 
C) regulatory T cells 
D) plasma cells 
A) CD4 Th1 T cells 
B) CD8 T cells 
C) regulatory T cells 
D) plasma cells

Question 12

Patients with an X-linked inherited disease called Hyper IgM (XHIGM)syndrome have a deficiency in CD40 ligand,a protein found on the surface of T lymphocytes.Patients with XHIGM are unable to make the class switch between IgM and either IgA or IgG.From this information,you could conclude that:

Accepted Answer

A) B-cell production of IgM does not depend on the CD40 ligand. 
B) the class switch between IgM and either IgA or IgG requires T cells. 
C) the switch between membrane-bound IgM and secreted IgM requires T cells. 
D) B-cell production of IgM does not depend on the CD40 ligand,and the class switch between IgM and either IgA or IgG requires T cells. 
A) B-cell production of IgM does not depend on the CD40 ligand. 
B) the class switch between IgM and either IgA or IgG requires T cells. 
C) the switch between membrane-bound IgM and secreted IgM requires T cells. 
D) B-cell production of IgM does not depend on the CD40 ligand,and the class switch between IgM and either IgA or IgG requires T cells.

Question 13

What roles do natural killer cells play in the innate immune response?

Accepted Answer

Natural killer cells seek out viral infe

Question 14

Treatment of IgG antibodies with the protease pepsin yields:

Accepted Answer

A) fragments that retain antigen-binding capacity but are monovalent. 
B) separated heavy and light chains. 
C) single chain antibodies similar to those made by camelids. 
D) bivalent fragments called F(ab)s. 
A) fragments that retain antigen-binding capacity but are monovalent. 
B) separated heavy and light chains. 
C) single chain antibodies similar to those made by camelids. 
D) bivalent fragments called F(ab)s.

Question 15

In cells with mutations in either TAP1 or TAP2:

Accepted Answer

A) ubiquitin conjugation would be disrupted and antigen proteins would not be tagged for destruction. 
B) ubiquitin-conjugated proteins would not be destroyed by proteasomal proteolysis. 
C) peptides generated by proteasomal proteolysis would not be complexed with class I MHC molecules. 
D) class I MHC-antigen complexes would be unable to cross the ER membrane. 
A) ubiquitin conjugation would be disrupted and antigen proteins would not be tagged for destruction. 
B) ubiquitin-conjugated proteins would not be destroyed by proteasomal proteolysis. 
C) peptides generated by proteasomal proteolysis would not be complexed with class I MHC molecules. 
D) class I MHC-antigen complexes would be unable to cross the ER membrane.

Question 16

Compare the class I and class II pathways of antigen processing and presentation.What kinds of antigens are involved? Which types of T cells recognize the antigen-MHC protein complexes?

Accepted Answer

In both pathways,host cells acquire anti

Question 17

Where do most of the interactions between the cells and molecules required for the immune response occur?

Accepted Answer

A) in the bloodstream 
B) in endothelial tissues 
C) in lymph nodes 
D) in the thymus 
A) in the bloodstream 
B) in endothelial tissues 
C) in lymph nodes 
D) in the thymus

Question 18

Activated CD4 T cells recognize an antigen-experienced B cell by means of:

Accepted Answer

A) the class I MHC-peptide complexes displayed by the B cell. 
B) the class II MHC-peptide complexes displayed by the B cell. 
C) both the class I and class II MHC-peptide complexes displayed by the B cells. 
D) none of the above 
A) the class I MHC-peptide complexes displayed by the B cell. 
B) the class II MHC-peptide complexes displayed by the B cell. 
C) both the class I and class II MHC-peptide complexes displayed by the B cells. 
D) none of the above

Question 19

Some Toll-like receptor proteins recognize and destroy CpG-containing bacterial DNA.How do these receptors differentiate between host DNA and DNA from invading bacteria?

Accepted Answer

Mammalian genomes show an underrepresent

Question 20

When tissue damage occurs,what attracts neutrophils to the site of damage?

Accepted Answer

Resident fibroblasts

Exam 22: Immunology

During B-cell development,antibody production switches from membrane-bound IgM to secreted antibody production.How does this switch occur?

During the early stages of B cell differentiation,heavy chains are complexed with:

Which of the following would occur from B-cell class switching?

ITAMs are part of:

Explain why Bence-Jones proteins are different for different B-cell tumors from different patients but identical when isolated from a single tumor.

Which of the following is NOT a way that MHC proteins play a role in the immune response?

Which complement components show chemoattractant activity and help recruit neutrophils to sites of complement activation?

Somatic recombination is catalyzed by RAG1 and RAG2 recombinases.How does the RAG1-RAG2 complex recognize the cleavage site at the exact boundary of the coding and signal sequences in the variable regions of immunoglobulin genes?

Why has the live-attenuated polio vaccine been recently discontinued?

Which class of immunoglobulins is made first?

Which cells can activate macrophages and stimulate an inflammatory response through the production of IFNγ?

Patients with an X-linked inherited disease called Hyper IgM (XHIGM)syndrome have a deficiency in CD40 ligand,a protein found on the surface of T lymphocytes.Patients with XHIGM are unable to make the class switch between IgM and either IgA or IgG.From this information,you could conclude that:

What roles do natural killer cells play in the innate immune response?

Treatment of IgG antibodies with the protease pepsin yields:

In cells with mutations in either TAP1 or TAP2:

Compare the class I and class II pathways of antigen processing and presentation.What kinds of antigens are involved? Which types of T cells recognize the antigen-MHC protein complexes?

Where do most of the interactions between the cells and molecules required for the immune response occur?

Activated CD4 T cells recognize an antigen-experienced B cell by means of:

Some Toll-like receptor proteins recognize and destroy CpG-containing bacterial DNA.How do these receptors differentiate between host DNA and DNA from invading bacteria?

When tissue damage occurs,what attracts neutrophils to the site of damage?

Chemical Foundations

Molecular Genetic Techniques

Protein Structure and Function

Culturing and Visualizing Cells

Fundamental Molecular Genetic Mechanisms

Bio-membrane Structure

Genes Genomics and Chromosomes

Transcriptional Control of Gene Expression

Post-Transcriptional Gene Control

Transmembrane Transport of Ions and Small Molecules

Cellular Energetics

Moving Proteins Into Membranes and Organelles

Vesicular Traffic, Secretion, and Endocytosis

Signal Transduction and G-Protein Coupled Receptors

Signaling Pathways That Control Gene Activity

Cell Organization and Movement I: Microfilaments

Cell Organization and Movement II: Microtubules and Intermediate Filaments

Regulating the Eukaryotic Cell Cycle

Integrating Cells Into Tissues

Cell Birth, Lineage, and Death

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