Question 1

Which type of T cell directs and regulates B-cell activity and differentiation?

Accepted Answer

A)  Memory T
B)  NK
C)  TC
D)  TH1
E)  TH2 E

Question 2

True or False? The sole purpose of CD4 and CD8 molecules is to provide immunologists a means of differentiating between T-cell populations.Explain.

Accepted Answer

False, they have defined biological functions.First, during T-cell activation, they help stabilize the interaction between TCRs and antigen-loaded MHC.Second, the cytoplasmic tails of CD4 and CD8 help trigger the signal transduction events needed to fully activate the T cell.

Question 3

Which type of T helper cell inhibits inflammation?

Accepted Answer

A)  TH1
B)  TH2
C)  TH17
D)  TREG
E)  TFH D

Question 4

Which cells are capable of providing both signal 1 and signal 2 to a naïve T cell?

Accepted Answer

A)  Dendritic cell
B)  Macrophage
C)  B cells
D)  All of the answers are correct.
E)  None of the answers are correct.

Question 5

TSST-1 is a protein produced by some species of bacteria that acts as a superantigen.What ligand does TSST-1 bind?

Accepted Answer

A)  T-cell receptor
B)  MHC class I
C)  MHC class II
D)  Both T-cell receptor and MHC class I
E)  Both T-cell receptor and MHC class II

Question 6

CD8+ T cells exposed to MHC class I peptides are

Accepted Answer

A)  cytotoxic T cells.
B)  helper T cells.
C)  natural killer cells.
D)  dendritic T cells.
E)  both cytotoxic T cells and helper T cells.

Question 7

Naïve CD4+ and CD8+ T-cells leave the _____ and enter circulation.

Accepted Answer

A)  bone marrow
B)  liver
C)  lymph node
D)  spleen
E)  thymus

Question 8

CTLA-4 is a costimulatory receptor on T cells that belongs to the same family as the CD28 costimulatory receptor.However, CTLA-4 is antagonistic to CD28.Which of the following could be a functional advantage of CTLA-4 expression within the immune response?

Accepted Answer

A)  CTLA-4 competes with CD28 for ligand binding so that, if CD28 binds to its ligand, the response will be magnified.
B)  CTLA-4 is often given to immunosuppressed individuals to trigger an immune response.
C)  CTLA-4 limits the immune response of TC and TH cells after an infection has been cleared.
D)  CTLA-4 limits TC activity in healthy individuals during a viral infection.
E)  CTLA-4 reduces the lag time between antigen presentation to a TH cell and B-cell activation.

Question 9

You have just been infected with an intracellular bacterial pathogen (such as Listeria monocytogenes).In mounting an immune response against the pathogen, which subset of CD4⁺ T cells will be produced preferentially? What polarizing cytokine will favor the production of this subset? What effector cytokine will be produced by this subset?

Accepted Answer

The answer of You have just been infected with an...

Question 10

Bonds formed between the T cell and a dendritic cell are relatively weak.Which of the following help to strengthen this association so that a T cell can see which antigen is being presented by a dendritic cell?

Accepted Answer

A)  CD28/LFA-5
B)  CD 28
C)  ICAM-1/LFA-1
D)  IL-2R
E)  Pattern-recognition molecules

Question 11

Compare costimulatory and co-inhibitory molecules.What are the two major roles of co-inhibitory molecules?

Accepted Answer

The answer of Compare costimulatory and co-inhibitory molecules.What are the...

Question 12

With respect to T-cell activation, effector molecules trigger all of the following functions EXCEPT

Accepted Answer

A)  cell-cycle entry.
B)  cell division to produce additional T cells.
C)  cell differentiation into various types of T cells.
D)  cell stimulation of B cells.
E)  cell survival.

Question 13

Mycobacterium leprae, the causative agent of leprosy in humans, is an intracellular pathogen that resides in the phagosome of macrophages.Leprosy presents in two main clinical manifestations.Tuberculoid leprosy results in the formation of granulomas and a cell-mediated immune response, whereas lepromatous leprosy results in the production of high levels of IgG (hypergammaglobulinemia).If TH2 is produced in high levels during an M.leprae infection, which type of leprosy would result?

Accepted Answer

A)  Lepromatous leprosy
B)  Tuberculoid leprosy
C)  Either lepromatous leprosy or tuberculoid leprosy
D)  Neither; leprosy depends on the expression of TREG cells
E)  Cannot determine; insufficient clinical evidence to support either outcome

Question 14

For pathogen peptides to be seen as foreign, they must be displayed on a T cell in the context of a(an)

Accepted Answer

A)  B-cell marker.
B)  CD molecule.
C)  IgM molecule.
D)  MHC peptide.
E)  Pattern-recognition receptor molecule.

Question 15

What is the function of a memory T cell?

Accepted Answer

A)  To activate TC and TH cells during an active primary infection
B)  To avoid autoimmune disorders by producing memory for self-antigens during T-cell development
C)  To maintain an active T-cell response (TC or TH)  after an infection is cleared
D)  To provide an almost immediate response upon subsequent exposure to a specific pathogen
E)  To suppress TC activity after a pathogen is cleared

Question 16

Which of the following are characteristics of naïve CD4+ and CD8+ T cells as they leave the thymus and enter the circulation (prior to antigen stimulation)?

Accepted Answer

A)  Condensed chromatin
B)  Exhibit little transcriptional activity
C)  High mobility
D)  Very little cytoplasm relative to nucleus
E)  All of the answers are correct.

Question 17

T-cell activation requires antigen being displayed in the context of an APC and interaction between costimulatory molecules on the APC and the T cell.In addition to these two signals, T-cell activity is often influenced by cytokines.Which of the following is an example of how cytokines can influence T-cell activity in the presence of MHC presentation and costimulatory ligand interaction?

Accepted Answer

A)  CD28 causes memory NK cells to be produced.
B)  CD8 triggers apoptosis in T cells that recognize self-antigens.
C)  IL-2 triggers T-cell proliferation.
D)  Opsonins recruit eosinophils to present carbohydrate antibodies to naïve TC cells.
E)  TNF- ? increases the production of IgM by activated T cells.

Question 18

CD4+ T cells recognize

Accepted Answer

A)  CD8+ markers.
B)  IgM.
C)  MHC class I peptides.
D)  MHC class II peptides.
E)  both MHC class I and class II peptides.

Question 19

CTLA-4 is not constantly expressed on naïve T cells.Is this logical? Explain.

Accepted Answer

The answer of CTLA-4 is not constantly expressed on naïve...

Question 20

Which type of professional antigen-presenting cells is a naïve T cell MOST likely to encounter?

Accepted Answer

A)  B cell
B)  Dendritic cell
C)  Macrophage
D)  Either B cell or dendritic cell
E)  Either dendritic cell or macrophage

Exam 10: T-Cell Activation, Differentiation, and Memory

Which type of T cell directs and regulates B-cell activity and differentiation?

True or False? The sole purpose of CD4 and CD8 molecules is to provide immunologists a means of differentiating between T-cell populations.Explain.

Which type of T helper cell inhibits inflammation?

Which cells are capable of providing both signal 1 and signal 2 to a naïve T cell?

TSST-1 is a protein produced by some species of bacteria that acts as a superantigen.What ligand does TSST-1 bind?

CD8⁺ T cells exposed to MHC class I peptides are

Naïve CD4⁺ and CD8⁺ T-cells leave the _____ and enter circulation.

CTLA-4 is a costimulatory receptor on T cells that belongs to the same family as the CD28 costimulatory receptor.However, CTLA-4 is antagonistic to CD28.Which of the following could be a functional advantage of CTLA-4 expression within the immune response?

Bonds formed between the T cell and a dendritic cell are relatively weak.Which of the following help to strengthen this association so that a T cell can see which antigen is being presented by a dendritic cell?

Compare costimulatory and co-inhibitory molecules.What are the two major roles of co-inhibitory molecules?

With respect to T-cell activation, effector molecules trigger all of the following functions EXCEPT

For pathogen peptides to be seen as foreign, they must be displayed on a T cell in the context of a(an)

What is the function of a memory T cell?

Which of the following are characteristics of naïve CD4⁺ and CD8⁺ T cells as they leave the thymus and enter the circulation (prior to antigen stimulation) ?

CD4⁺ T cells recognize

CTLA-4 is not constantly expressed on naïve T cells.Is this logical? Explain.

Which type of professional antigen-presenting cells is a naïve T cell MOST likely to encounter?

Exam 10: T-Cell Activation, Differentiation, and Memory

Which type of T cell directs and regulates B-cell activity and differentiation?

True or False? The sole purpose of CD4 and CD8 molecules is to provide immunologists a means of differentiating between T-cell populations.Explain.

Which type of T helper cell inhibits inflammation?

Which cells are capable of providing both signal 1 and signal 2 to a naïve T cell?

TSST-1 is a protein produced by some species of bacteria that acts as a superantigen.What ligand does TSST-1 bind?

CD8+ T cells exposed to MHC class I peptides are

Naïve CD4+ and CD8+ T-cells leave the _____ and enter circulation.

CTLA-4 is a costimulatory receptor on T cells that belongs to the same family as the CD28 costimulatory receptor.However, CTLA-4 is antagonistic to CD28.Which of the following could be a functional advantage of CTLA-4 expression within the immune response?

Bonds formed between the T cell and a dendritic cell are relatively weak.Which of the following help to strengthen this association so that a T cell can see which antigen is being presented by a dendritic cell?

Compare costimulatory and co-inhibitory molecules.What are the two major roles of co-inhibitory molecules?

With respect to T-cell activation, effector molecules trigger all of the following functions EXCEPT

For pathogen peptides to be seen as foreign, they must be displayed on a T cell in the context of a(an)

What is the function of a memory T cell?

Which of the following are characteristics of naïve CD4+ and CD8+ T cells as they leave the thymus and enter the circulation (prior to antigen stimulation) ?

CD4+ T cells recognize

CTLA-4 is not constantly expressed on naïve T cells.Is this logical? Explain.

Which type of professional antigen-presenting cells is a naïve T cell MOST likely to encounter?

CD8⁺ T cells exposed to MHC class I peptides are

Naïve CD4⁺ and CD8⁺ T-cells leave the _____ and enter circulation.

Which of the following are characteristics of naïve CD4⁺ and CD8⁺ T cells as they leave the thymus and enter the circulation (prior to antigen stimulation) ?

CD4⁺ T cells recognize