Deck 3: Tolerance

Question 1

Which of the following statements about induction or maintenance of T cell tolerance is NOT true?

A)Central tolerance is induced when immature developing T cells in bone marrow or thymus encounter self antigens.
B)Peripheral T cell tolerance results when mature naive T cells recognize antigens without adequate B7-1- or B7-2-mediated costimulation.
C)Peripheral T cell tolerance results when T cells recognize antigen in the setting of an innate immune response to the antigen.
D)Peripheral T cell tolerance to some antigens is induced when mature T cells recognize antigen and bind B7-1 or B7-2 via the inhibitory CTLA-4 receptor.
E)Peripheral T cell tolerance to an antigen may be induced by persistent and repeated stimulation of lymphocytes by that antigen in tissues.

Answer 1

Peripheral T cell tolerance results when T cells recognize antigen in the setting of an innate immune response to the antigen.

Question 2

For each feature of self-tolerance described in questions ,choose the term (letters A-K)that most closely matches it.
Tolerance-sensitive stage of T cell maturation

A)Immature (IgM+IgD-)
B)Thymic cortex
C)Bone marrow
D)Antigen recognition without T cell help
E)Receptor editing
F)Activation-induced cell death
G)Regulatory T cell-mediated suppression
H)Antigen recognition with costimulation
I)Double positive (CD4+CD8+)
J)Anergy
K)Thymic medulla

Answer 2

Double positive (CD4+CD8+)

Question 3

Failure of self-tolerance is the cause of which one of the following types of diseases?

A)Allograft rejection
B)Autoimmunity
C)Atopy
D)Anergy
E)Acne

Answer 3

Autoimmunity

Question 4

For each feature of self-tolerance described in questions ,choose the term (letters A-K)that most closely matches it.
Mechanism of peripheral tolerance induction of B cells but not T cells

A)Immature (IgM+IgD-)
B)Thymic cortex
C)Bone marrow
D)Antigen recognition without T cell help
E)Receptor editing
F)Activation-induced cell death
G)Regulatory T cell-mediated suppression
H)Antigen recognition with costimulation
I)Double positive (CD4+CD8+)
J)Anergy
K)Thymic medulla

Question 5

The AIRE protein is expressed by thymic medullary epithelial cells and is required for tolerance to many self-antigens.Which one of the following statements about how AIRE functions is correct?

A)AIRE is secreted by thymic medullary epithelial cells,and then binds and blocks the T cell receptors on developing T cells.
B)AIRE suppresses MHC expression by thymic medullary epithelial expression
C)AIRE is secreted by thymic medullary epithelial cells binds to soluble self antigens.
D)AIRE is required for thymic medullary epithelial expression of peripheral tissue antigens,which are then presented to immature T cells.
E)AIRE stimulates expression of immunosuppressive cytokines by thymic medullary epithelial cells.

Question 6

Immunologic tolerance is defined as:

A)The removal of an antigen,or the microbes expressing the antigen,by the immune system,so that the host can tolerate the infection
B)Activation of only B cells,and not T cells,on exposure to an antigen
C)Unresponsiveness of the immune system to an antigen,which is induced by previous exposure to that antigen
D)The production of memory B cells and T cells on primary exposure to an antigen,which allows the host to tolerate a secondary exposure to the antigen
E)Vaccination of individuals against particular pathogens to prevent subsequent infections

Question 7

For each feature of self-tolerance described in questions ,choose the term (letters A-K)that most closely matches it.
Site of central T cell tolerance induction

A)Immature (IgM+IgD-)
B)Thymic cortex
C)Bone marrow
D)Antigen recognition without T cell help
E)Receptor editing
F)Activation-induced cell death
G)Regulatory T cell-mediated suppression
H)Antigen recognition with costimulation
I)Double positive (CD4+CD8+)
J)Anergy
K)Thymic medulla

Question 8

For each feature of self-tolerance described in questions ,choose the term (letters A-K)that most closely matches it.
Mechanism of peripheral tolerance for T cells but not B cells

A)Immature (IgM+IgD-)
B)Thymic cortex
C)Bone marrow
D)Antigen recognition without T cell help
E)Receptor editing
F)Activation-induced cell death
G)Regulatory T cell-mediated suppression
H)Antigen recognition with costimulation
I)Double positive (CD4+CD8+)
J)Anergy
K)Thymic medulla

Question 9

CTLA-4,expressed by regulatory T cells and activated effector T cells,is crucial for self-tolerance as well as regulation of T cell responses of foreign antigens.Which of the following is a property of CTLA-4 that is important for its function?

A)CTLA-4 binds to CD28 and blocks its function.
B)CTLA-4 binds B7-1 and B7-2 with high affinity blocking their binding to CD28.
C)CTLA-4 binds class I MHC and blocks it ability to bind peptides.
D)CTLA-4 binds IL-2,preventing IL-2 binding to the IL-2 receptor.
E)CTLA-4 binds to IgG,preventing IgG biding to antigens.

Question 10

For each feature of self-tolerance described in questions ,choose the term (letters A-K)that most closely matches it.
Mechanism of peripheral tolerance of B cells and T cells

A)Immature (IgM+IgD-)
B)Thymic cortex
C)Bone marrow
D)Antigen recognition without T cell help
E)Receptor editing
F)Activation-induced cell death
G)Regulatory T cell-mediated suppression
H)Antigen recognition with costimulation
I)Double positive (CD4+CD8+)
J)Anergy
K)Thymic medulla

Question 11

For each feature of self-tolerance described in questions ,choose the term (letters A-K)that most closely matches it.
Mechanism of central tolerance of B cells

A)Immature (IgM+IgD-)
B)Thymic cortex
C)Bone marrow
D)Antigen recognition without T cell help
E)Receptor editing
F)Activation-induced cell death
G)Regulatory T cell-mediated suppression
H)Antigen recognition with costimulation
I)Double positive (CD4+CD8+)
J)Anergy
K)Thymic medulla

Question 12

Which of the following sets of proteins (among others)are typically expressed by most regulatory T cells ( Treg)?

A)CD8,CD3,Perforin,IL-2,T-bet
B)CD4,PD-1,IL-2,FoxP3
C)CD4,CD3,CD25 (IL-2 receptor),FoxP3
D)CD4,CD3,CLTA4,AIRE,
E)CD4,TGF-b,CD25 (IL-2 receptor),IL-2

Question 13

For each feature of self-tolerance described in questions ,choose the term (letters A-K)that most closely matches it.
Tolerance-sensitive stage of B cell maturation

A)Immature (IgM+IgD-)
B)Thymic cortex
C)Bone marrow
D)Antigen recognition without T cell help
E)Receptor editing
F)Activation-induced cell death
G)Regulatory T cell-mediated suppression
H)Antigen recognition with costimulation
I)Double positive (CD4+CD8+)
J)Anergy
K)Thymic medulla