L7:2

Question 1

CD4 facilitates binding of HLA class ___ molecules to the TCR

CD8 facilitates binding of HLA class ___ molecules to TCR

Answer 1

HLA Class II
HLA Class I

Question 2

True or False: CD4/CD8 are mutually exclusive on mature T cells

Answer 2

TRue

Question 3

In the role of co-receptors, CD4 and CD8 are ___ molecules and function in _____

Answer 3

As co-receptors, CD4/CD8 are adhesion molecules that function in signal transduction

Question 4

____ is present on all mature T-Lymphocytes and is a critical signaling molecule

Answer 4

CD3

Question 5

Which molecule is composed of an epsilon, gamma, and delta chain?

Answer 5

CD3

Question 6

True or False: HLA molecules have a conserved and variable domain

Answer 6

False - T Cell Receptors have conserved and variable domains (Va and Vb)

Question 7

TCR recognizes ___ and ___ (APC)

Answer 7

TCR recognizes antigen + HLA (APC)

Question 8

A processed antigen and HLA molecule are recognized and bound by the antigen binding site of the TCR. Which signal does this correspond to?

Answer 8

Signal 1

Question 9

True or False: Signal 2 leads to leads to activation of T cell, CD3, and zeta tyrosine kinases

Answer 9

False - Signal 1

Question 10

What part of the TCR forms the terminal antigen binding site?

Answer 10

Variable region domain (Va and Vb)

Question 11

What are the two functions of CD3?

Answer 11

1) TCR chaperone - transports newly made TCR molecule to cell surface
2) Cellular signaling molecules (transmembrane/cytoplasmic domain)

Question 12

True or False: CD3 molecules are closely associated with zeta chains

Answer 12

True

Question 13

True or False: Zeta chains are T-cell specific and located primarily extracellularly

Answer 13

False - zeta chains are NOT T-cell specific and are mostly intracellular

Question 14

True or False: Zeta chains are involves in transducing intracellular signal from TCR-CD3 complex

Answer 14

True

Question 15

T cells become activated when the
“immunological synapse” is formed between and ___ (usually a dendritic cell) and a __
cell.

Answer 15

APC ; T Cell

Question 16

A ___ is a disulfide-linked heterodimer glycoprotein belonging to the Ig
supergene family of molecules

Answer 16

TCR

Question 17

True or False: All members of the Ig Supergene Family bind and recognize foreign antigens (HLA, Ig, TCR)

Answer 17

True

Question 18

What type of chains do most TCR’s have?

Answer 18

alpha and beta

Question 19

True or False: TCR’s are clonally distributed (meaning each T cell bears a unique TCR)

Answer 19

True - allows for antigen specificity

Question 20

True or False: Positive co-stimulatory interactions are most commonly associated with Signal 1

Answer 20

False - Signal 2

Question 21

What are the two positive co-stimulatory interactions?

Answer 21

1) B7(CD80): CD28
2) CD40:CD40L

Question 22

True or False: Co-stimulatory reactions are critical for initial activation of memory T cells

Answer 22

False - Co-stimulatory reactions are critical for initial activation of NAIIVE T cell!!!!

Question 23

What are the two negative co-stimulatory interactions?

Answer 23

1) PD-L1: PD-1
2) B7:CTLA

Question 24

_____/_____ strongly inhibits T cells and induces T cell differentiation

Answer 24

PD-L1/PD-1

Question 25

What co-stimulatory interaction is essential for maintaining peripheral tolerance and limiting immune response?

Answer 25

PD-L1/PD-1

Question 26

Activation of T-Helper cells is associated with transcription of ______

Answer 26

IL-2

Question 27

_____: Autocrine growth factor for T-cells

Answer 27

IL-2

Question 28

What are the two functions of IL-2?

Answer 28

1) Induces proliferation 2) Induces differentiation to effector cell function (production of cytokines) or memory cell

Question 29

IL-2 Receptor is also known as ___

Answer 29

CD25

Question 30

True of False: Memory T cells have fewer activation requirements upon second antigen encounter

Answer 30

True

Question 31

True or False: Memory T cells are less easily activated, compared to native T cells

Answer 31

False - memory T cells are MORE easily activated than naive T cells

Question 32

Once activated in subsequent encounters with antigen, memory cells become either ___ or ___

Answer 32

effectors or more memory cells

Question 33

What co-stimulatory interaction is crucial for T cell activation?

Answer 33

B7:CD28

Question 34

Where does peripheral tolerance occur?

Answer 34

Lymph nodes

Question 35

True or False: Peripheral Tolerance occurs when T cells are stimulated with secondary stimulation (B7-CD28)

Answer 35

False - Peripheral Tolerance occurs when T cells are stimulated WITHOUT secondary stimulation (B7-CD28)

Question 36

The absence of this “second signal” can result in functional inactivation of the T cell called _____

Answer 36

clonal anergy

Question 37

True or False: Once T cells become anergic they cannot become activated even if they encounter their specific foreign peptide/MHC molecule

Answer 37

True

Question 38

repeated stimulation of activated T cells can cause the T cell to die by apoptosis, also known as ____

Answer 38

clonal deletion

Question 39

Regulatory T cells can inhibit the activation of T cells by _____

Answer 39

self-peptide/ MHC