Deck 14: The Immune Response in Time and Space

Question 1

After production, naïve lymphocytes travel briefly through the blood to the

A)spleen.
B)peripheral lymph nodes.
C)mucosal associated lymphoid tissue.
D)All of the answers are correct.
E)None of the answers are correct.

Answer 1

D

Question 2

Continual lymphocyte circulation is needed because

A)antigen is usually present in large amounts.
B)lymphocytes have a small chance of recognizing a particular antigen.
C)the chance of a naïve cell encountering its target antigen is moderately high.
D)there are relatively few antigen-presenting cells in the lymph nodes compared to lymphocytes.
E)All of the answers are correct.

Answer 2

B

Question 3

Lymphocytes exit the blood and enter the lymph node by extravasating at the high-endothelial venules (HEVs) present in the lymph node cortex.Extravasation does NOT require which of the following?

A)Homing
B)Addressins
C)Chemokines
D)Dendritic cells
E)All of the answers are required.

Answer 3

D

Question 4

After extravasation, naïve lymphocytes enter the _____ to scan for antigen.

A)thymic cortex
B)lymph node medulla
C)lymph node cortex
D)high-endothelial venule
E)None of the answers are correct.

Question 5

Reticular networks in the lymph nodes

A)are made of fibroblasts.
B)guide T-cell movements.
C)guide B-cell movements.
D)regulate lymphocyte direction.
E)All of the answers are correct.

Question 6

Naïve B cells do NOT depend on which of the following as they move through a lymph node?

A)Follicular dendritic cells
B)Fibroblastic reticular fibers
C)Chemokines CCL21 and CCL19
D)The chemokine CXCL13
E)Naïve B cells do not depend on any of the answer choices provided.

Question 7

S1P1 receptor is upregulated by naïve T cells and B cells after 12-18 hours if they fail to encounter antigen in the lymph node.This means all of the following EXCEPT

A)the naïve cells have not been activated.
B)the naïve cells have not encountered antigen.
C)the naïve cells will exit the lymph node.
D)space will be made for other cells to enter the lymph node.
E)the naïve cells will die by apoptosis.

Question 8

Pattern-recognition receptors on innate immune cells

A)coordinate killing of pathogens.
B)alert the adaptive immune system of an infection.
C)recognize specific pathogen.
D)both coordinate killing of pathogens and alert the adaptive immune system of an infection.
E)both coordinate killing of pathogens and recognize specific pathogens.

Question 9

Early in an infection, antigen-presenting cells

A)become less effective at phagocytosis.
B)become more effective at antigen processing.
C)become less effective at cross presentation.
D)recruit more adaptive immune cells than innate immune cells.
E)remain at the site of infection.

Question 10

Which of the following is the CORRECT sequence of events?

A)Antigen uptake > antigen processing > APC migration to lymph nodes > antigen presentation
B)APC migration to lymph nodes > antigen uptake > antigen processing > antigen presentation
C)APC migration to lymph nodes > antigen presentation > antigen uptake > antigen processing
D)Antigen uptake > antigen processing > antigen presentation > APC migration to lymph nodes
E)APC migration to lymph nodes > antigen uptake > antigen presentation > antigen processing

Question 11

As antigen is picked up in peripheral tissues by antigen-presenting cells, it is

A)processed for presentation to B cells.
B)processed for presentation to T cells.
C)moved without processing over several hours to the lymph nodes.
D)taken in unprocessed form for presentation to T cells.
E)All of the answers are correct.

Question 12

Which of the following mechanisms of travel to lymph nodes by unprocessed antigen is CORRECT?

A)Small and soluble antigens travel through afferent lymphatics as opsonized particles.
B)Small and soluble antigens travel directly through the bloodstream.
C)Large particles and pathogens travel directly through the bloodstream.
D)Opsonized pathogens travel directly through the bloodstream.
E)Small particles are carried by macrophages.

Question 13

Which of the following is the proper order of transfer for opsonized antigens?

A)CD169⁺ macrophages > follicular dendritic cells > antigen nonspecific B cells
B)Antigen nonspecific B cells > CD169⁺ macrophages > follicular dendritic cells
C)CD169⁺ macrophages > antigen nonspecific B cells > follicular dendritic cells
D)Antigen nonspecific B cells > follicular dendritic cells > CD169⁺ macrophages
E)None of the answers are correct.

Question 14

The use of complement receptor deficient cells has shown that

A)normal B cells sample antigen on macrophages and leave it intact.
B)normal B cells sample antigen on macrophages and take part of it.
C)complement receptor-deficient B cells do not sample antigen on macrophages.
D)complement receptor-deficient B cells sample antigen on macrophages and take part of it.
E)None of the answers are correct.

Question 15

Which of the following cell types is NOT likely to be present early on in an infection?

A)Granulocytes
B)Antigen-presenting cells
C)Cytotoxic T cells
D)Dendritic cells
E)Neutrophils

Question 16

During activation, naïve CD4⁺ T cells

A)interact with antigen-presenting cells.
B)reduce movement.
C)begin to divide.
D)move to interact with B cells.
E)All of the answers are correct.

Question 17

Although our understanding of the kinetics of T-cell activation has changed over time, we now believe that

A)antigen availability does not affect T-cell/APC interactions.
B)antigen quantity does not affect T-cell/APC interactions.
C)optimal proliferation of helper T cells requires only relatively brief APC exposure.
D)optimal proliferation of helper T cells requires several hours of APC exposure.
E)dendritic cell activation does not affect T-cell activation.

Question 18

B cells have been shown to need two signals for activation.Absent T-cell help, they will NOT activate because

A)T cells provide signal 1 through the B-cell receptor.
B)T cells provide signal 2 through the B-cell receptor.
C)T cells activate B cells indirectly by activating follicular dendritic cells.
D)T cells activate B cells through CD40 signaling.
E)B cells will still activate because of dendritic cells.

Question 19

Several types of T cells have been shown to be able to provide help for B cells during activation.Which of the following statements is TRUE?

A)All produce the same chemokine to activate but provide different CD40 signals.
B)All produce the same chemokine and the same CD40 signal as well.
C)All provide CD40 signaling but produce different chemokines.
D)All provide CD40 signaling but trigger distinct class switching.
E)All provide CD40 signaling but produce different chemokines and trigger distinct class switching.

Question 20

Activation of naïve B cells is a two-step process, during which

A)antigen triggers B-cell production of CCR7, which leads it to interact with T cells.
B)antigen triggers T-cell production of CCR7, which recruits B cells.
C)T-cell help stimulates B cells to produce CCR7, then divide.
D)macrophages trigger B-cell production of CCR7, which leads it to interact with T cells.
E)None of the answers are correct.

Question 21

T-cell help of B cells will be impaired if the T cells lack CD28 because

A)CD28 is needed to activate class switching by turning on AICD.
B)CD28 is needed to interact with CD40 on the B cell.
C)CD28 is needed to signal through the B-cell receptor.
D)CD28 is needed to signal through the T-cell receptor.
E)None of the answers are correct.

Question 22

Visualization of B-cell traffic between the light and dark zones of the germinal center has shown that they migrate far less than had been predicted.This demonstrates that

A)the traditional model of trafficking is inaccurate.
B)the rate of hypermutation and selection does not require extensive movement.
C)only brief contacts by the B cells with helper T cells are needed.
D)both the traditional model of trafficking is inaccurate and only brief contacts by the B cells with helper T cells are needed.
E)both the rate of hypermutation and selection does not require extensive movement and only brief contacts by the B cells with helper T cells are needed.

Question 23

A major difference between naïve and effector lymphocytes is that effector lymphocytes

A)follow chemokine trails.
B)do not home in to the lymph nodes.
C)do not require co-stimulation.
D)All of the answers are correct.
E)None of the answers are correct.

Question 24

In tissues, B cells seek out T cell help in

A)bone marrow.
B)afferent lymphatics.
C)the follicle border of lymph nodes.
D)the red pulp of the spleen.
E)All of the answers are correct.

Question 25

To avoid returning to the lymph nodes, effector cells

A)up-regulate chemokine receptors to allow them to home in to site of infection.
B)down-regulate L-selectin, so they do not enter the high-endothelial venules (HEVs).
C)down-regulate chemokine receptors, so they do not enter the high-endothelial venules (HEVs).
D)up-regulate chemokine receptors and downregulate L-selectin.
E)down-regulate both L-selectin and chemokine receptors.

Question 26

Tracking of responses to a transgenic pathogen (toxoplasma) has shown that

A)T-cell behavior followed patterns predicted by previous studies.
B)dendritic cell behavior followed patterns predicted by previous studies.
C)lymph-node architecture changed due to inflammation.
D)T cells divided at the site of infection.
E)All of the answers are correct.

Question 27

Which of the following adaptive cell types' response is MOST similar to innate immunity?

A)Central memory T cells.
B)Effector memory T cells.
C)Tissue-resident memory T cells.
D)Memory B cells.
E)None of the answers are correct.

Question 28

Studies of graft rejection using cells labeled with fluorescent markers demonstrate that

A)any infiltration of a skin graft depends on MHC mismatch.
B)deep infiltration of a skin graft depends on MHC mismatch.
C)host antigen-presenting cells enter the skin graft before migrating to lymph nodes.
D)both any infiltration of a skin graft depends on MHC mismatch, and host antigen-presenting cells enter the skin graft before migrating to lymph nodes.
E)both any infiltration of a skin graft depends on MHC mismatch and host antigen-presenting cells enter the skin graft before migrating to lymph nodes.

Question 29

Listeria is able to persist in an infection because it

A)avoids being broken down and presented as antigen.
B)localizes quickly to lymph nodes and persists there.
C)reproduces inside macrophages.
D)is passed by dendritic cells to monocytes.
E)None of the answers are correct.

Question 30

The failure of cytotoxic T cells to eliminate tumors can be attributed to

A)failure of tumor antigen presentation.
B)failure of activation of tumor-specific T cells.
C)failure of recruitment of T cells to the tumor.
D)failure of the T cells to produce cytotoxic effector molecules.
E)All of the answers are correct.

Question 31

Immune responses are often ineffective - in some cases, these responses can contribute to disease through which of the following conditions?

A)Listeria
B)Tissue grafts
C)Solid tumors
D)Type 1 diabetes
E)All of the conditions are contributed to by immune responses.

Question 32

What is extravasation, and what are its four primary steps?

Question 33

A line of mice develops wherein the S1P1 gene is excised following lymphocyte development.What effect would this have on the immune response?

Question 34

Explain the function of nonantigen-specific B cells during the early phases of the adaptive immune response.

Question 35

Compare and contrast how a soluble toxin subunit and a malarial parasite (sporozoite) would travel through the body.How would each be recognized by the immune system?

Question 36

How do CD4⁺ T cells provide physical help to CD8 T cells, given that they interact with different classes of MHC molecules?

Question 37

What are the steps required for a naïve B cell to achieve activation in vivo? Explain the significance of each step.

Question 38

What are the three types of memory cells in the body? Where is each type located?

Question 39

Explain how the immune system both responds to and controls Toxoplasma gondii infection in the brain.

Question 40

Provide an example of the immune system helping to spread an infection throughout the body, including an analysis of how the infection is able to circulate.

Question 41

What is one component, activity, or interaction in the immune system of which you would want high-quality video? What might it assist you in evaluating? How would you apply this to your studies? Explain.