Chapter 8.2 quiz update Flashcards Preview

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Flashcards in Chapter 8.2 quiz update Deck (45):
1

Which of the following contributes to the activation of naive T cells?

a. neutrophils
b. B cells
c. macrophages
d. dendritic cells
e. basophils

d. dendritic cells

2

Macrophages exhibit all of the following characteristics except _____.

a. they trap and degrade pathogens in secondary lymphoid organs

b. they deliver co-stimulatory signals to naive T cells needed for T-cell priming

c. they migrate from sites of infection to nearby secondary lymphoid organs

d. they remove and degrade apoptotic lymphocytes from secondary lymphoid tissues

e. they donÕt migrate from sites of infection to nearby secondary lymphoid organs

c. they migrate from sites of infection to nearby secondary lymphoid organs

3

Which of the following describes an activated dendritic cell upon arriving in a lymph node?

a. located in follicles and medulla of the lymph node

b. associated mainly with antigen uptake and processing

c. bears highly elaborated finger-like processes called dendrites

d. expresses low levels of MHC class II molecules

e. carries out apoptosis of lymphocytes

c. bears highly elaborated finger-like processes called dendrites

4

Activated T cells express _____, which binds to B7 with 20 times higher affinity than CD28 and results in _____ of T-cell activity and proliferation.

a. high-affinity IL-2 receptor; stimulation

b. CD40L; suppression

c. VLA-4; stimulation

d. CTLA4; suppression

d. CTLA4; suppression

5

Which of the following is associated with immature dendritic cells in the skin before their activation?

a. Toll-like receptors

b. CTLA4

c. CCR7

d. DC-SIGN

e. ICAM-3

a. Toll-like receptors

6

All of the following are correctly matched except _____.

a. T1: T-bet

b. Treg: FoxP3

c. IL-12: dendritic cells

d. TH17: RORgammaT

e. TH2: Bcl6

e. TH2: Bcl6

7

. Naive lymphocytes homing to lymphoid tissue use _____ to bind to CD34 and GlyCAM-1 on high endothelial venules (HEV).

a. L-selectin

b. CD2 (LFA-2)

c. ICAM-1

d. CCL21

e. CD28

a. L-selectin

8

The co-stimulatory molecule _____ on professional antigen-presenting cells binds _____ on the surface of naive T cells.

a. DC-SIGN; ICAM-3

b. B7; CD28

c. ICAM-1; LFA-1

d. MHC class II; T-cell receptor

e. MHC class II; CD4

b. B7; CD28

9

An adhesion molecule called _____ is expressed exclusively on activated dendritic cells and binds to _____ on naive T cells in the T-cell areas of secondary lymphoid tissue.

a. DC-SIGN; ICAM-3

b. CD2; LFA-3

c. MHC class II; T-cell receptor

d. L-selectin; GlyCAM-1

e. ICAM-1; LFA-1

a. DC-SIGN; ICAM-3

10

The area of contact between membranes of a T cell and an antigen-presenting cell where a clustering of proteinÐprotein interactions occur is called a(n)___________.

a. immunoreceptor tyrosine-based activation motif (ITAM)

b. polarization

c. cross-presentation center

d. granuloma

e. immunological synapse

e. immunological synapse

11

All of the following are included in the central supramolecular activation complex (c-SMAC) except _____.

a. CD4 or CD8

b. ICAM-1

c. CD28

d. T-cell receptor

e. PKC-theta

b. ICAM-1

12

Talin is best described as a _____.

a. protein tyrosine kinase

b. transcriptional activator

c. cytoskeletal protein

d. pro-inflammatory cytokine

e. cytokine receptor that associates with Janus kinases (JAKs)

c. cytoskeletal protein

13

The primary effect of inositol trisphosphate (IP3) during T-cell activation is to _____.

a. cause an increase in cytosolic calcium concentration

b. activate phospholipase C-gamma

c. activate a MAP kinase cascade

d. facilitate the differentiation of immature effector T cells

e. align the microtubule-organizing center toward the antigen-presenting cell

a. cause an increase in cytosolic calcium concentration

14

Which of the following is not a transcription factor, a component of a transcription factor, or an activator of transcription?

a. Fos

b. AP-1

c. NFkappaB

d. NFAT

e. Janus kinases (JAKs)

e. Janus kinases (JAKs)

15

The enzyme that generates diacylglycerol (DAG) and inositol trisphosphate (IP3) from phosphatidylinositol bisphosphate (PIP2) is _____.

a. protein kinase C-theta (PKC-theta)

b. calcineurin

c. phospholipase C-gamma (PLC-gamma)

d. protein tyrosine kinase ZAP-70

e. protein tyrosine kinase Lck

c. phospholipase C-gamma (PLC-gamma)

16

All of the following statements regarding interleukin-2 (IL-2) or its receptor are true except _____.

a. The low-affinity IL-2 receptor is a membrane-bound heterodimer composed of alpha and beta chains.

b. IL-2 production increases approximately 100-fold if a co-stimulatory signal is delivered.

c. T-cell proliferation occurs upon binding of IL-2 to the high-affinity IL-2 receptor.

d. The high-affinity IL-2 receptor is assembled after T-cell activation.

e. Rapamycin is an immunosuppressive drug that inhibits signaling of IL-2 through the IL-2 receptor.

a. The low-affinity IL-2 receptor is a membrane-bound heterodimer composed of alpha and beta chains.

17

If a non-professional antigen-presenting cell that lacks co-stimulatory molecules presents peptide:MHC complexes to a T cell specific for that peptide, then _____.

a. the T cell delivers a signal to the non-professional antigen-presenting cell to activate the expression of co-stimulatory molecules.

b. the T cell begins to express the ? chain of the IL-2 receptor.

c. the T cell differentiates into a TH1 cell.

d. T-cell tolerance occurs as a result of anergy.

e. the T cell is more heavily reliant on signals transmitted through CD4 or CD8 in order to become activated.

a. the T cell delivers a signal to the non-professional antigen-presenting cell to activate the expression of co-stimulatory molecules.

18

Which of the following statements regarding leprosy is false?

a. It is caused by the bacterium Mycobacterium leprae.

b. Disease progression is influenced depending on whether the immune response is polarized toward either a TH1 or TH2 response.

c. The tuberculoid form of leprosy is associated with localized inflammation and granuloma formation.

d. In lepromatous leprosy, the patient makes a TH2 response that clears the mycobacteria from the body.

e. The less severe form of leprosy presents with high levels of IL-2 and IFN-? produced by responding T cells.

d. In lepromatous leprosy, the patient makes a TH2 response that clears the mycobacteria from the body.

19

Which of the following statements is false regarding CD8 T cells?

a. CD8 T cells have only one effector function, which is cytotoxicity.

b. Compared with naive CD4 T cells, naive CD8 T cells have more stringent requirements for co-stimulatory activity.

c. Effector CD8 cells require co-stimulation to kill their target cells.

d. The most potent antigen-presenting cell for naive CD8 T cells is the dendritic cell.

c. Effector CD8 cells require co-stimulation to kill their target cells.

20

An important way in which effector T cells differ from naive T cells is that _____.

a. the cell-surface level of LFA-1 is lower on effector T cells

b. L-selectin is upregulated during differentiation of effector T cells

c. cellular proliferation occurs after effector T cells leave the secondary lymphoid tissues

d. the provision of co-stimulatory signals is not required to induce a response by effector T cells

e. effector T cells do not recirculate between lymph, blood, and secondary lymphoid tissues.

d. the provision of co-stimulatory signals is not required to induce a response by effector T cells

21

All of the following indicate correct intermolecular associations except _____.

a. Janus kinases (JAKs): serglycin

b. L-selectin: GlyCAM-1

c. VLA-4: VCAM-1

d. JAKs: signal transducers and activators of transcription (STATs)

e. CD40: CD40 ligand

a. Janus kinases (JAKs): serglycin

22

During cytokine signaling, _____ translocate(s) to the nucleus and direct(s) the upregulation of gene expression.

a. perforin

b. STATs

c. CD40 ligand

d. TGF-beta

e. CXCL2

b. STATs

23

Which of the following cytokine(s) is(are) secreted by both CD8 T cells and TH1 cells?

a. IL-4

b. IL-5

c. IFN-gamma and lymphotoxin (LT)

d. TNF-alpha

e. IL-13

c. IFN-gamma and lymphotoxin (LT)

24

Which of the following cytokine(s) is not secreted by TH2 cells?

a. IFN-gamma and lymphotoxin (LT)

b. IL-4

c. IL-5

d. IL-10

e. TGF-beta

a. IFN-gamma and lymphotoxin (LT)

25

In a person with lepromatous leprosy, the lesions would contain mRNA for _____.

a. lymphotoxin (LT)

b. IL-2

c. IL-5

d. IFN-gamma

e. granulysin

c. IL-5

26

The release of lytic granules from cytotoxic T cells is aimed specifically at infected target cells while preserving the integrity of neighboring, uninfected cells. This is best explained by the observation that _____.

a. only target cells bearing appropriate peptide:MHC class I complexes are susceptible to necrosis

b. redistribution of lytic granules in the T cell delivers them to confined areas on the target cell in contact with the T cell

c. regulatory T cells deliver survival signals to uninfected neighboring cells that renders them resistant to cytotoxins

d. the amount of cytotoxins in a given cytotoxic T cell is so limited that only the cell closest to the T cell will succumb to the effects of perforin and granzyme

e. uninfected cells are highly resistant to the effects of cytotoxins.

b. redistribution of lytic granules in the T cell delivers them to confined areas on the target cell in contact with the T cell

27

All of the following statements refer to regulatory T cells except ____.

a. they produce anti-inflammatory cytokines

b. they express elevated levels of CD25

c. they express FoxP3

d. they enhance the production of new effector T cells

e. they suppress the function of existing T cells

d. they enhance the production of new effector T cells

28

Identify the mismatched pair:

a. TFH cells: Bcl6

b. TH1: GATA3

c. TH1 cells: IFN-gamma

d. TH2: IL-4

e. Treg: TGF-beta

b. TH1: GATA3

29

Which of the following is incorrect regarding sphingosine 1-phosphate (S1P) and its receptor?

a. It is a lipid that has chemotactic activity.

b. S1P gradients are established in lymph nodes with lowest concentrations in T-cell areas.

c. CD69 upregulates S1P receptor expression on the surface of naive T cells.

d. S1P is synthesized by all cells.

c. CD69 upregulates S1P receptor expression on the surface of naive T cells.

30

Which of the following is produced by CD8 T cells?

a. IL-10

b. TGF-beta

c. IFN-gamma

d. IL-4

e. IL-17

c. IFN-gamma

31

Which of the following is not produced by T follicular helper (TFH) cells?

a. CD4

b. IL-4

c. IFN-gamma

d. TNF-alpha

e. IL-21

d. TNF-alpha

32

Which of the following is not produced by TH17 cells?

a. ICOS (inducible T-cell co-stimulator)

b. IL-17

c. CD4

d. IL-21

e. STAT3

a. ICOS (inducible T-cell co-stimulator)

33

T cells failing to encounter specific antigen leave lymph nodes via the _________.

a. germinal center

b. bloodstream

c. high endothelial venules (HEV)

d. afferent lymph

e. efferent lymph

e. efferent lymph

34

Clonal expansion and differentiation of naive T cells to effector T cells depends on the activation of the transcription factor(s) _____ through a ZAP-70-mediated signal transduction pathway.

a. AP-1, NFkappaB, and NFAT

b. IL-2 and AP-1

c. NFkappaB and Ras

d. NFAT and IL-2

e. Ras and IL-4

a. AP-1, NFkappaB, and NFAT

35

Fos, a component of the transcription factor AP-1, is activated during T-cell signaling by a process involving a GTP-binding protein called _____.

a. inositol trisphosphate

b. Ras

c. protein kinase C-theta

d. Lck

e. ZAP-70

b. Ras

36

_____ is a second messenger in the T-cell signaling pathway leading to the activation of NFAT.

a. diacylglycerol (DAG)

b. NFkappaB

c. inositol trisphosphate (IP3)

d. Fos

e. Ras

c. inositol trisphosphate (IP3)

37

Which of the following is a protein tyrosine kinase involved in T-cell activation culminating in T-cell proliferation and differentiation?

a. AP-1

b. ZAP-70

c. NFkappaB

d. NFAT

e. calcineurin

b. ZAP-70

38

Binding of _____ to _____ induces T-cell proliferation and differentiation of activated T cells.

a. CD4; MHC class II

b. CD28; B7

c. LFA-1; ICAM-1

d. IL-2; the high-affinity IL-2 receptor

e. IL-2; the low-affinity IL-2 receptor

d. IL-2; the high-affinity IL-2 receptor

39

Expression of IFN-gamma is induced in a CD4 TH1 cell under the direction of the transcription factor ______.

a. T-bet

b. FoxP3

c. AP-1

d. GATA-3

e. NFAT

a. T-bet

40

IL-4 is induced in a CD4 TH2 cell under the direction of the transcription factor _____.

a. T-bet

b. FoxP3

c. AP-1

d. GATA-3

e. NFAT

d. GATA-3

41

Tuberculoid leprosy is characterized by a ______-type response in which patients _____.

a. TH2; usually survive

b. TH2; eventually die

c. TH1; usually survive

d. TH1; eventually die

e. Treg; eventually die

c. TH1; usually survive

42

Many cytokine receptors are associated with cytoplasmic protein kinases called _____, which become activated when the cytokine receptors bind to their respective cytokines.

a. ZAP-70

b. STATs

c. Lck

d. ITAMS

e. JAKs

e. JAKs

43

Signal transducers and activators of transcription (STATs) are _____ that are phosphorylated by _____.

a. transcription factors; JAKs

b. protein kinases; other STATs

c. cytokine receptors; JAKs

d. cytokines; cytokine receptors

e. transcription factors; Lck

a. transcription factors; JAKs

44

Which of the following characteristics permits activated CD8 T cells to destroy any cell type harboring viable and replicating pathogens such as viruses?

a. The pathogen is located in extracellular spaces.

b. CD8 T cells enable macrophages to kill intracellular pathogens.

c. Pathogen-derived peptides bind MHC class I molecules in endocytic vesicles found ubiquitously in most cell types.

d. MHC class II molecules are expressed ubiquitously by most nucleated cells.

e. MHC class I molecules are expressed ubiquitously by most nucleated cells.

e. MHC class I molecules are expressed ubiquitously by most nucleated cells.

45

Cytotoxic T cells focus their killing machinery on target cells through a process called polarization. The cytoskeleton and the cytoplasmic vesicles containing lytic granules are oriented toward the area on the target cell where peptide:MHC class I complexes are engaging T-cell receptors. In the T cell, the microtubule-organizing center (MTOC), Golgi apparatus (GA), and lytic granules, which contain cytotoxins, align toward the target cells. The lytic granules then fuse with the cell membrane, releasing their contents into the small gap between the T cell and the target cell, resulting in the deposition of cytotoxins on the surface of the target cell. The cytotoxic T cell is not killed in this process and will continue to make cytotoxins for release onto other target cells, thereby killing numerous target cells in a localized area in succession. The cytotoxins include perforin, granzymes, and granulysin, molecules that induce apoptosis (programmed cell death) of the target cell.

a. True

b. False

a. True