Pod: T Cell Development And T Cell Mediated Immunity

Front 1

Which route(s) does the thymus receive T progenitor cells:
A. lymph
B. blood
C. both

Back 1

B

Front 2

Which route(s) do the nature T cells leave:
A. lymph
B. blood
C. both

Back 2

B

Front 3

Embryologic origin for the following cells in the thymus:
1. cortical epithelial cells
2. medullary epithelial cells
3. thymocytes
4. dendritic cells
5. macrophages

Back 3

1. ectoderm
2. endoderm
3. bone marrow
4. bone marrow
5. bone marrow

Front 4

What is the thymic analge composed of?

Back 4

1. cortical epithelial cells
2. medullary epithelial cells

Front 5

What happens in Hassall's corpuscle?

Back 5

site of thymic cell death

Front 6

What Ig is expressed by double negative thymocytes?

Back 6

CD2

Front 7

Where is IL7 produced and what's its function?

Back 7

IL-7 is made by the stromal cells of the red bone marrow and the thymus.

IL-7 is a hematopoietic growth factor capable of stimulating the proliferation of lymphoid progenitors

Front 8

What is the difference in DNA rearrangement between T cell and B cell development?

Back 8

T cell does multiple TCR rearrangements simultaneously whereas B cell does it sequentially.

Front 9

What are the two races in T cell DNA rearrangement?

Back 9

1. β and γ:δ compete
2. α and γ:δ compete

Front 10

What is α:β pre T cell receptor made of?

Back 10

β chain
surrogate α chain
CD3
ζ

Front 11

What is the function of pre T cell receptor?

Back 11

1. Triggers T cell proliferation
2. Halt β chain rearrangment.
3. Cells become permissive for TCR α chain locus rearrangement.
4. stimulates CD4 and CD8 co-receptors


Ensures a T cell express only one type of TCR β chain.

Front 12

TCR β chain is similiar to which chain in B cell?

What is the difference in the gene make up between these 2 chains?

Back 12

Heavy chain.

TCR β chain can undergo second rearrangements because there are two sets of DJ and C gene segments that are tandemly associated with V gene segments.

Front 13

Which event triggers thymocytes to becone double positive?

Back 13

Successful rearrangment of TCR β chain.

Front 14

Where are double positive thymocytes loacted in the thymus?

Back 14

inner cortex of the thymus

Front 15

Which type of T cells emerge first during embryonic development?
A. α:β T cells
B. γ:δ T cells

Back 15

B

Front 16

Where do the three waves of γ:δ T cells migrate to?

Back 16

1. epidermis
2. reproductive tract
3. diverse locations

Front 17

What are the dentritic epidermal T cells(dETC)?

Back 17

First wave of γ:δ T cells that migrate to the skin.

Front 18

Why do early γ:δ T cells express less diverse TCRs?

Back 18

No TdT expression
limited selection of V region.

Front 19

Which genes are shut down during Pre T cell proliferation?

Back 19

RAG1,2

Front 20

T/F: Signal joints can not be replicated and an excised coding joint can be found in γ:δ T cells and B cells.

Back 20

F.

Front 21

Which event stops α chain rearrangement in T cells?

Back 21

When T cell is positively seleced.

Front 22

Where does positive selection take place in T cell development?

What cells are involved in this process?

Back 22

Cortex of the thymus
cortical epithelial cells: express both MHC1 and MHCII.

Front 23

What causes bare lymphocyte syndrome?

Back 23

lack of expression of MHCI or MHCII by lymophocytes and thymic epithelial cells.

Front 24

Negative selection in T cells is mediated by what cells?

Back 24

dendritic cells.

Front 25

Naive T cells are mature in _____ area.

Back 25

T-cell rich area

Front 26

What cells does HIV infect?

Back 26

CD4 T cells

Front 27

What is a mixed lymphocyte reaction?

Back 27

Peripheral blood cells from one person are mixed in tissue culture with lethally irradiated cells from a second person of a disparate HLA type.

The magnitude of the alloreative response to nonself MHC provides an estimate of relative numbers of T cells that are negatively within the thymus of an individual.

Front 28

What percentage of the positively selected T cells is deleted in the thymus?

Back 28

1%

Front 29

Why is it not a good idea to increase the number of MHC molecules?

Back 29

Increase the load of nrgative relection, T cell repretiore decreases.

Front 30

Thymoma is a tumor of ____ cells.

Back 30

thymic stromal cells or epithelial cells.

Front 31

CD1 is expressed in what type of cells?

Back 31

cortical thymocytes
intestinal epithelium

Front 32

CD1 is recognized by ____ cells.

Back 32

NKT cells

Front 33

Where do T cells encounter antigens?

Back 33

secondary lymphoid tissues

Front 34

T/F: Dendritic cells only triggers T cell response.

Back 34

T.

Front 35

Where do the pathogens enter our body through the following route end up:
1. through wound in skin
2. from gut
3. after entry into blood stream

Back 35

1. dendritic cells containing ingested pathogen carried to the nearest lymph node.
2. GALT (peyer's patches) though M cells.
3. Spleen.

Front 36

What is the cell surface glyprotein that distinguishes professional APC and is involved in co-stimulation?

Back 36

B7

Front 37

Which receptor does B7 bind to and what is the signal it produces?

Back 37

CD28 on a T cell.
Activates the T cell and signals it to proliferate.

Front 38

Absence of B7-CD28 binding would lead to ____.

Back 38

anergy

Front 39

What mechanism other than negative selection are selfreactive T cells eliminated?

Back 39

anergy: when self antigen is recognized, the lack of B7-CD28 interaction makes the cells inactive.

Front 40

What are the differences between immature dendritic cells and mature dendritic cells?

Back 40

immature: capture, uptake, and processing of antigens.
mature: develop fingerlike dendrites to interact with T cells.

Front 41

Immunological synapse is made between ____ and ____ cells.

Back 41

T cell and APC

Front 42

Immunological synapse is complosed of two regions: cental molecular activation complex(c-SMAC), and peripheral supramolecular complex(p-SMAC). What interations are specific in each region?

Back 42

c-SMAC: TCR:antigen:MHC:CD4/CD8, CD2:LFA3, CD28:B7
p-SMAC: LFA1:ICAM1, LFA1:ICAM2, ICAM3:DC-SIGN

Front 43

What is homing process?

Back 43

Movement of naive T cells into secondary lymphoid tissue.

Front 44

What molecules are involved in the homing process?

Back 44

T cell:endothelial cells
1. L-selectin:CD34 (addressin)
2. L-selectin:GlyCAM-1 (addressin)

3. LFA1:ICAM1
4. LFA1:ICAM2
5. CCR7:CCL21 (chemokines)

Front 45

LFA1 on T cell membrane is activated by ____.

Back 45

CCL21

Front 46

What adhesion molecules are involved in T cell and dendritic cell interaiton?

Back 46

T cell:dendritic cell
1. LFA1:ICAM1
2. LFA1:ICAM2
3. ICAM3:DC-SIGN
4. CD2:LFA3

Front 47

Which type of T cell leave the secondary lymphoid tissue?

Back 47

CD8 T cells

Front 48

What are the factors that contribute to the delay between initiation of infection and engagement of adaptive immune response? (3)

Back 48

1. antigen activation of T cells
2. availability of antigen-specific T cells
3. prolifration and differentiation of antigen-specific large clone of effector T cells

Front 49

What molecule is found on mucosal epithelium that functions like GlyCAM and CD34 on HEV?

Back 49

MadCAM-1

Front 50

Which other molecule also binds to B7, but dampens down T cell activation and proliferation?

Back 50

CTLA4

Front 51

What are the three APC in the secondary lymphoid tissue?

Where is each one located?

Back 51

1. dendritic cell: T-cell area
2. macrophage:throughout
3. B cell: B cell area

Front 52

T/F: Macrophages are involved in both innate and adaptive immunity.

Back 52

T

Front 53

When Langerhan's cells mature, they become ____.

Back 53

Interdigitaiting reticular cells.

Front 54

As APCs, marophage has what types of receptors?

Back 54

1. MHCs
2. mannose receptor
3. scavenger receptor
4. complement receptor
5. Toll like receptor

Front 55

As APCs, a B cell has what types of receptors?

Back 55

1. MHCs
2. Toll like receptors

Front 56

Naive T cells are able to squeeze through endothelium and enter the cortex of lymphoid tissue as a result of interation between:
A. CD2 and LFA3
B. CD4 and MHC molecule
C. LFA1 with ICAM1 and/or ICAM2
D. L-selectin and MadCAM-1
E. scavenger receptor and endothelium

Back 56

C.

Front 57

What type of agen does each of the three APC present?

Back 57

1. DC: all types, especially virus
2. macrophages: bacteria
3. B cells: peptides and protein antigens

Front 58

Which cell type never funcion as a professional antigen presenting cell?
A. B cell
B. dendritic cell
C. macrophages
D. mast cell

Back 58

D.

Front 59

An early result of the interaction between an antigen-presenting cell and a T cell is:
A. activation of complement
B. activation of macrophages
C. activation and proliferation of T cells
D. apoptosis of the APC
E. production of antibodies

Back 59

C.

Front 60

Which special adhesion molecule does activated dendritic cell expressed and bind tightly to ICAM3 on T cell?

Back 60

DC-SIGN

Front 61

Which specific chemokine is made by activated dendritic cell that attracts T cells toward them?

Back 61

CCL18

Front 62

Langerhans cells:
A. accumulate in and remain in lymphoid tissue.
B. express high levels of B7 molecules.
C. express more MHC molecules than interdigitating cells.
D. express a macrophage like morphology.
E. phagocytose efficiently.

Back 62

E.

Front 63

Why is adjuvants required for an effective vaccine?

Back 63

It induces co-stimulatory activity in dendritic cells, macrophages, and B cells.

Front 64

What's role of lipid rafts in cell signalling?

Back 64

organize signal transduction proteins in proper complexes.

Front 65

List three examples of lipid rafts.

Back 65

1. sphingolipid
2. cholecterol
3. GPI anchor

Front 66

The initial signal to activate a T cell is conducted by:
A. CD3
B. ITAM
C. ZAP70
D. Lck

Back 66

A.

Front 67

Once ITAMS get the signal from CD3, they are phosphorylated by ___.
A. Lck
B. Fyn
C. CD45
D. NFAT

Back 67

B.

Front 68

What is the role of Lck?

Back 68

It associates with CD4/CD8 and activate ZAP70.

Front 69

What is the role of CD45?

Back 69

It helps activate Lck , Fyn, and other kinases.

Front 70

What's the role of ZAP70?

Back 70

Binds to ITAM of ζchain and activate PLC-γ and GEF(guanine-exchange factors).

Front 71

What is the role of PLC-γ?

Back 71

It cleaves PIP2 into IP3 and DAG.

Front 72

What is the role of IP3?

Back 72

increase intracellular Ca level and activate calcineurin.

Front 73

What is the role of calcineurin?

Back 73

Activates NFAT.

Front 74

The combined action of what three molecules turn on the transcription of genes that direct T cell proliferation and differentiation?

Back 74

NFAT
NFkB
AP-1

Front 75

Signal transduction initiated by antigen-induced activation of either B or T cell receptors is mediated by:
A. chemokines
B. cytokines
C. ICAMs
D. ITAMs
E. VCAMs

Back 75

D.

Front 76

What is the role of DAG?

Back 76

Activate NFkB.

Front 77

AP-1 can be activated by____.

Back 77

GEF(guanine exchange factor) through G protein linked MAPK cascade.

Front 78

NFkB can be activated by ___.

Back 78

DAG which activate PKC.

Front 79

Which cytokine is responsible for proliferation and differentiation of activated T cells?

Back 79

IL-2

Front 80

Which of the following signal is needed to produce IL-2 by the activated T cell?
A. TCR:antigen:MHC signal
B. costimulatory signal
C. coreceptor signal
D. all the above

Back 80

D.

Front 81

What is the principle effect of the co-stimulatory signal?

Back 81

To increase the synthesis of IL-2 by the T cell by 100 fold.

Front 82

What does cyclosporin do?

Back 82

Inhibit IL-2 production by disrupting signals from TCR.

Front 83

What does rapamysin do?

Back 83

Inhibit signaling from IL-2 receptor.

Front 84

Cytokines made by Th1 cells lead to____.

Back 84

1. macrophage activation
2. inflammation
3. production of opsonsizing antibodies that enhances phagocytosis.

Front 85

Cytokines made by Th2 cells lead to____.

Back 85

1. B cell differentiation
2. production of neutalizing antibodies.

Front 86

How does autoreactive T cell aquire anergy?

Back 86

lack of costimulaiton of CD28-B7.

Front 87

What are the effector molecules of Th1 cells?

Back 87

IFN-γ
GM-CSF
TNF-α,β
CD40 ligand
IL3
Fas ligand

Front 88

What are the effector molecules of Th2 cells?

Back 88

IL3,4,5,10,15
TGF-β
CD40 ligand
GM-CSF

Front 89

What effector molecules of cytotoxic T cells?

Back 89

perforin
granzymes
granulysin
Fas ligand

IFN-γ
TNF-α,β

Front 90

Th1 cells recognized antigens bound to which class MHCs?

Back 90

MHCII

Front 91

Cytotoxic cells recognized antigens bound to which class MHCs?

Back 91

MHCI

Front 92

APCs that activate helper T cells express:
A. CD8
B. MHCI
C. MHCII
D. IgE

Back 92

C.

Front 93

Helper T cells
A. are involved in production of IgA but not other isotypes.
B. can differentiate into cytotoxic T cells
C. interact with macrophages and B cells
D. make it possible for macrophages to phagocytose antigen
E. mediate immune responses to large polysaccharide antigens.

Back 93

C.

Front 94

What are the three ways to activate a naive CD8 T cell?

Back 94

1. activated dendritic cell
2. naive CD4 cell activate APC to make B7.
3. effector CD4 cell secrete IL-2

Front 95

Which of the following events determines whether cytotoxic T cells rather than antibodies are produced during an immune response?
A. activation of T helper cells by APC.
B. activation of macrophages to produce a stronger oxidative burst
C. binding of CD4 to macrophage surface protein
D. presentation of antigen on MHCI molecule
E. whether antigen is degraded by macrophages.

Back 95

D.

Front 96

What is a major difference between activated naive T cell and a effector T cell in stimulaiton?

Back 96

no co-stimulation is needed for effector T cells.

Front 97

Cytoplasmic tails of cytokine receptors are often associated with____.

Back 97

JAK: Janus kinases

Front 98

What is the signaling pathway of gene transription induced by cytokine binding with its receptor?

Back 98

upon binding:
cytokine receptos domerize
JAK phosphorylates STAT
STAT dimerize, move to the neucleus to initiate gene transcription.

Front 99

Myelopoieses can be stimulated by which two cytokines?

Back 99

GM-CSP and IL3

Front 100

T/F: A coomon pattern is for a membrane associated cytokine and a secreted cytokine to work synergistically within a local area to fight infection.

Back 100

T.

Front 101

What is the main effect to IFNγ secreted by cytotoxic T cells?

Back 101

inhibit viral replication

Front 102

What are the 2 different ways of inducing apoptosis in infected cells by cytotoxic T cells?

Back 102

1. perforin, granzymes, granulysin
2. Fas ligand

Front 103

Cytotoxic T cells:
A. are elicited pro=imarily by protozoan infections.
B. kill by antibody-dependent cytotoxicity.
C. kill virus-infected host cells.
D. stimulate B cells to make antibody.
E. stimulate neutrophils to attack bacteria.

Back 103

C.

Front 104

Macrophages require 2 signals for activation:______.

Back 104

1. IFN-γ
2. CD40L(T cell):CD40(macrophage)

Front 105

What cytokines inhibit macrophage activation?

Back 105

TGF-β
IL-4
IL-10
IL-13

Front 106

How does Th1 cells coordinate host responses to intravesicular pathogens?

Back 106

1. IFN-γ, CD40L activates macrophages
2. Fas ligand or TNF-β to induces apoptosis of macrophages
3. bacteria released
4. bacteria killed by new macrophages

Front 107

What is the function of TNFα,β?

Back 107

induces vascular endothelial cells to change adhesion molecules.

Front 108

Granuloma contains ___ in the center area.

Back 108

large macrophages(epitheloid cells): fusion of multiple infected macrophages

Front 109

Granuloma contains ___ in the peripheral area.

Back 109

activated T cells

Front 110

What types of infection can lead to granuloma?

Back 110

chronic infections resistant to macrophage killing mechanisms.

Front 111

What is the benefit of granuloma?

Back 111

shield infected area from vasular supply, cause the core to die.

Front 112

What is caseation necrosis?

Back 112

core of the glonuloma die because of lack of blood supply.

Front 113

What is cognate interaction?

Back 113

B cell and T helper cells recognize the same antigen but bind to different epitopes.

Front 114

Which of the following cytokine stimulate B cell proliferation:
A. IL4
B. IL5
C. IL6
D. IL10

Back 114

A.

Front 115

What does regulatory(suppressor) T cell do?

Back 115

release IL-4, 10, and TGF-β, CD25.

Regulate Th1 pathway.