Exam 1: Antigen processing

Question 1

Present antigen to naive CD4 and CD8 t cells so they initiate t cell responses

Answer 1

Dendritic cells

Question 2

Present antigens to differentiated CD4 t cells in the effector phase of cell mediated immunity

Answer 2

Macrophages

Question 3

Present antigens to helper t cells (CD4) during humora immune resp.

Answer 3

B lymphocytes

Question 4

What are the two important functions of APCs?

Answer 4

1. Convert P antigens to peptides and display peptide-MHC complexes
2. Co-stimulation to T cells

Question 5

Processing of endocytosed antigens for MHC class II sequence of events:

Answer 5

1. Uptake into vesicular compartments
2. Processing in endosomal and lysosomal vesicles
3. biosynthesis and transport of MHC class 2 molecules
4. Asssociation with MHC class 2 molecules
5. Expression on the APC surface

Question 6

What are the 3 APCs?

Answer 6

1. DC
2. Macrophage
3. B cells

Question 7

What 3 things induce MHC II on macrophages?

Answer 7

1. PAMPS
2. DAMPS
3. Cytokines

Question 8

What are the 3 functions of APCs?

Answer 8

1. Capture
2. Digest
3. Display

Question 9

Antigen presentation begins with _____.

Answer 9

Antigen processing

Question 10

What do the pathways of Antigen processing do?

Answer 10

convert protein antigens into peptides and load them on MHC molecules to be displayed to lymphocytes

Question 11

antigens present in the acidic vesicular compartments of APCs generate _____ associated peptides.

Answer 11

MHC class II

Question 12

antigens present in the cytosol generate _____ associated peptides

Answer 12

MHC class I

Question 13

Acidic compartments that contain proteolytic enzymes

Answer 13

Endosomes

Question 14

What fuses with endosomes to form phagosomes?

Answer 14

Lysosomes

Question 15

The most important proteolytic enzymes involved in protein degredation

Answer 15

Cathepsins

Question 16

Association of processed peptides with class 2 MHC molecules takes place in:

a. Endosomal compartments
b. Endoplasmic reticulum
c. Golgi apparatus
d. Proteosome

Answer 16

a. Endosomal Compartments

Question 17

Which of the following statements is NOT true?

a. Exogenous acquired proteins will generate peptides that activate CD4T cells
b. Endogenously acquired proteins will generate peptides that activate CD8T cells
c. Cytotoxic cells are stimulated by B cells that present antigen through MHC

Answer 17

B.

Question 18

What are the steps for processing Cytosolic antigens for MHC class I:

Answer 18

1. Cytosol location
2. Proteolytic degradation in proteosome
3. Transport to ER
4. Assembly in ER
5. Surface expression

Question 19

T/F. Sometimes even endocytosed antigens may be presented through MHC class I molecules

Answer 19

T

Question 20

Proteins synthesized in the cytosol are ubiquitinated thus destined for ______

Answer 20

Proteosomal degradation

Question 21

What is the main transporting system to get peptides to the ER?

Answer 21

Transporter associated with antigen presentation TAP

Question 22

Where is TAP located?

Answer 22

Memb. of ER

Question 23

______ acquired proteins will generate peptides that activate CD4 T cells

Answer 23

Exogenously

Question 24

______ acquired proteins will generate peptides that activate CD8T cells

Answer 24

Endogenously

Question 25

Surface molecule found on T cells that recognizes antigen presented in the correct MHC complex

Answer 25

TCR

Question 26

What are the 2 types of TCR?

Answer 26

1. aB TCR | 2. yd TCR

Question 27

Which TCR is the most common?

Answer 27

aB TCR

Question 28

Which TCR is found on the T cells in lymphoid tissue

Answer 28

aB TCR

Question 29

Which TCR is found on T cells at mucosal surfaces?

Answer 29

yD TCR

Question 30

T/F. Each T cell contains TCRs of multiple specificities?

Answer 30

F. only one specificity

Question 31

T/F aB TCR is MHC Dependent

Answer 31

T

Question 32

T/F. yD TCR is MHC Dependent?

Answer 32

F. independent

Question 33

Group of proteins closely associated with TCR

Answer 33

CD3 Complex

Question 34

What function does the CD3 Complex have?

Answer 34

transduces activation signals to nucleus following antigen interaction with TCR

Question 35

When T cells from one individual recognize foreign peptides only when bound to and displayed by MHC molecules of that individual

Answer 35

Self MHC restriction

Question 36

CD4 T cells are MHC class ___ restricted

Answer 36

2

Question 37

CD8T cells are MHC class ___ restricted

Answer 37

1

Question 38

CD4 MHC class 2 restricted T cells recognize peptide antigens derived from ______ .

Answer 38

Extracellular/Exogenous P that are internalized into vesicles of APCs

Question 39

CD8 MHC class 1 restricted T cells recognize peptides derived from______.

Answer 39

Cytosolic/Endogenously synthesized proteins

Question 40

T/F. The BCR interacts with the MHC molecule

Answer 40

F.

Question 41

T/F. B cells can recognize soluble antigens as well as antigens exposed on cell surfaces

Answer 41

T

Question 42

Lipid antigens are presented by molecules called ____.

Answer 42

CD1

Question 43

Where are CD1 molecules found?

Answer 43

APCs and epithelial cells

Question 44

Who Do CD1 molecules present antigens to?

Answer 44

T cells that are not MHC restricted NKT-cells

Question 45

What is the first signal in co stimulatory signaling

Answer 45

Specific signal Generated by interaction of an antigenic peptide bound in the MHC cleft with the TCR-CD3 complex

Question 46

What is the second signal in co stimulatory signaling?

Answer 46

Co-stimulatory signal Provided by interaction b/t CD28 on T cells and members of B7 family on the APCs

Question 47

What happens when T lymphocytes are stimulated without a co-stimulatory signal?

Answer 47

clonal anergy

Question 48

A state of no responsiveness, which occurs when a co-stimulatory signal is absent

Answer 48

Clonal anergy

Question 49

presentation of antigens through class 1 pathway

Answer 49

cross-presentation