Deck 1: Activation of T Lymphocytes

Question 1

Which one of the following statements about MHC-TCR interactions is NOT true?

A) Antigen receptors on T cells bind to MHC molecules for only brief periods of time.
B) The affinity of most TCRs for peptide-MHC complexes is similar to the affinity of antibodies for their antigens.
C) Only 1% or less of the MHC molecules on any antigen-presenting cell (APC) display a peptide recognized by a particular T cell.
D) T cells usually require multiple engagements with an APC before a threshold of activation is reached.
E) A subthreshold number of MHC-TCR interactions can lead to T cell inactivation.

Answer 1

The affinity of most TCRs for peptide-MHC complexes is similar to the affinity of antibodies for their antigens.

Question 2

All of the following protein-protein interactions are involved in activation of naive helper T cells by antigen-presenting cells (APCs) EXCEPT binding of:

A) Peptide-MHC complexes on the APC to the TCR on the T cell
B) CD4 on the T cell to nonpolymorphic regions of class II MHC molecules on the APC
C) Integrins on the T cell with adhesion ligands on the APC
D) B7-2 on the APC with CD28 on the T cell
E) CD40L on the T cell with CD40 on the APC

Answer 2

CD40L on the T cell with CD40 on the APC

Question 3

For each of the descriptions in questions , choose the T cell signaling molecule that best matches it from the list below (A-O).
This is a transcription factor that exists in the phosphorylated form within the nucleus.

A)CD3
B)Lck
C)Zap-70
D)LAT
E)Ras
F)PLCγ
G)PIP2
H)PIP3
I)IP3
J)DAG
K)Calcineurin
L)NFAT
M)Jun
N)Fos
O)NF-γB

Answer 3

Jun

Question 4

For each of the descriptions in questions , choose the T cell signaling molecule that best matches it from the list below (A-O).
This molecule binds to a receptor on the endoplasmic reticulum and stimulates release of calcium into the cytosol.

A)CD3
B)Lck
C)Zap-70
D)LAT
E)Ras
F)PLCγ
G)PIP2
H)PIP3
I)IP3
J)DAG
K)Calcineurin
L)NFAT
M)Jun
N)Fos
O)NF-γB

Question 5

For each of the descriptions in questions , choose the T cell signaling molecule that best matches it from the list below (A-O).
This molecule becomes an active transcription factor on dephosphorylation.

A)CD3
B)Lck
C)Zap-70
D)LAT
E)Ras
F)PLCγ
G)PIP2
H)PIP3
I)IP3
J)DAG
K)Calcineurin
L)NFAT
M)Jun
N)Fos
O)NF-γB

Question 6

For each of the descriptions in questions , choose the T cell signaling molecule that best matches it from the list below (A-O).
Binding of this molecule to Jun is needed for transcriptional activation of the IL-2 gene.

A)CD3
B)Lck
C)Zap-70
D)LAT
E)Ras
F)PLCγ
G)PIP2
H)PIP3
I)IP3
J)DAG
K)Calcineurin
L)NFAT
M)Jun
N)Fos
O)NF-γB

Question 7

For each of the descriptions in questions , choose the T cell signaling molecule that best matches it from the list below (A-O).
Immunosuppressive therapy with the drugs cyclosporine and FK506 inhibits T cell activation by blocking the protein phosphatase activity of this molecule.

A)CD3
B)Lck
C)Zap-70
D)LAT
E)Ras
F)PLCγ
G)PIP2
H)PIP3
I)IP3
J)DAG
K)Calcineurin
L)NFAT
M)Jun
N)Fos
O)NF-γB

Question 8

For each of the descriptions in questions , choose the T cell signaling molecule that best matches it from the list below (A-O).
This molecule has the same downstream effect as addition of the drug phorbol myristate acetate (PMA) to T cells.

A)CD3
B)Lck
C)Zap-70
D)LAT
E)Ras
F)PLCγ
G)PIP2
H)PIP3
I)IP3
J)DAG
K)Calcineurin
L)NFAT
M)Jun
N)Fos
O)NF-γB

Question 9

For each of the descriptions in questions , choose the T cell signaling molecule that best matches it from the list below (A-O).
This molecule is a transcription factor involved in the expression of several T cell activation genes activated when its bound inhibitor is phosphorylated.

A)CD3
B)Lck
C)Zap-70
D)LAT
E)Ras
F)PLCγ
G)PIP2
H)PIP3
I)IP3
J)DAG
K)Calcineurin
L)NFAT
M)Jun
N)Fos
O)NF-γB

Question 10

For each of the descriptions in questions , choose the T cell signaling molecule that best matches it from the list below (A-O).
This protein is a well-characterized proto-oncogene product that on mutation to a constitutively active form has been associated with multiple neoplasms.

A)CD3
B)Lck
C)Zap-70
D)LAT
E)Ras
F)PLCγ
G)PIP2
H)PIP3
I)IP3
J)DAG
K)Calcineurin
L)NFAT
M)Jun
N)Fos
O)NF-γB