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Flashcards in Ch 9 Deck (79):
1

what are randomly generated by gene rearrangement

epitope-specific TCRs and BCRs

2

self-reactive lymphocytes undergo what

apoptosis

3

what is included in the B cell lineage

B 1 and B 2 cells

4

what is included in the T cell lineage

alpha-beta TCRs
gamma-delta TCRs
NKT cells

5

what cells are transitional

gamma-delta TCRs and B 1 cells

6

what cells are adaptive

alpha-beta TCRs and B2 cells

7

precursors of the T cell lineage

prothymocytes

8

migrate from bone marrow to the thymus

prothymocytes

9

enter at cortical region and lacks TCRs, CD3, CD4, CD8 molecules

thymocytes

10

how much percent of thymocytes become T cells

5%

11

remainder of thymocytes leaves what

thymus before selection or die by apoptosis

12

When cells arrive at the thymus, they can become what

NK cells, dendritic cells, B cells and even myeloid cells

13

a receptor on cells commits them to the T lineage

notch

14

can commit cells to T lineage even without the thymus being present

notch binding

15

dense outer region

cortex

16

looser inner region

medulla

17

connective tissue capsule with

trabeculae

18

arrive from the bone marrow as double negative cells that do not express CD4, CD8, CD3, or TCR

precursor cells

19

proliferate and differentiate into double positive thymocytes that express both CD4 and CD8 in addition to CD3 and TCR

double negative cells

20

die within 3-4 days unless they recognize pMHC I or pMHC II on cortical epithelial cells in the cortical region

double positive cells
this is also known as positive selection

21

surviving positive selection express only CD4 or only CD8 in addition to CD3 or TCRs

thymocytes

22

interact strongly with self peptides on MHC I or pMHC II of antigen presenting cells undergo apoptotic death

medullary thymocytes
this is also known as negative seletion

23

cross the endothelium of a venule and exit they thymus as T cells

mature single positive thymocytes

24

very early thymocyte development occurs in the bone marrow

alpha-beta T cell

25

Different stages of alpha-beta T cell (five)

double negative
double positive
positive/negative selection to become a single positive
final screening to remove autoreactive cells
release into the peripheral bloodstream

26

recombination of TCR gene segments occurs in the double negative stages, yielding what

either an alpha-beta or a gamma-delta T cell

27

selection must bind to MHC

positive

28

selection removal of cells that interact with antigen-presenting cells

negative

29

if a cell passes both negative and positive selection is will what

leave the thymus and become T cells

30

what percent of cells fail positive selection and fail to receive needed survival signals

95

31

selects thymocytes bearing receptors capable of binding self-MHC molecules, resulting in MHC restriction

positive selection

32

selects against thymocytes bearing high-affinity receptors for self-MHC/peptide complexes, resulting in self-tolerance

negative selection

33

what cells make up 80% of thymic cells

double positive thymocytes

34

migrate preferentially to respiratory organs, skin, peritoneal cavity

gamma-delta T cells

35

leave the thymus shortly after receiving TCRs and CD3

gamma-delta T cells

36

have limited variability, respond quickly, and no memory

gamma-delta T cells

37

Very early thymocyte development occurs in the bone marrow
Cells migrate to the thymus for further development

Alpha beta T cell

38

Recombination of TCR gene segments also occurs in the double negative stages yielding what

Alpha beta T cell
Gamma delta T cell

39

What are the different stages that cells migrate for further development

Double negative
Double positive
Positive or negative selection become a single positive
Final screening to remove auto reactive cells
Release into the peripheral bloodstream

40

Must bind to MHC

Positive selection

41

Removal of cells that interact with antigen presenting cells and it is potentially auto reactive

Negative selection

42

If this passes both negative and positive selection what happens

Becomes a T cell and leaves the thymus

43

Double positive thymocyte a make up what percent of thymocyte cells

80

44

Selects thymocyte said bearing receptors capable of binding self-MHC molecules, resulting in MHC restriction

Positive selection

45

Selects against thymocyte a bearing high-affinity receptors for self-MHC/peptide complexes, resulting in self-tolerance

Negative selection

46

What percent of cells fail positive selection and fail to receive needed survival signals

95

47

What cortical thymocyte a express alpha beta TCR and only later express CD4 and CD8 to become what type of thymocyte

Double negative
Double positive

48

What type of cells attempt to bind with pMHC I or pMHC II on cortical epithelial cells

Double positive

49

Double positive thymocytes that bind pMHC II cease what

CD8 expression

50

Double positive thymocytes that fail to bind to either pMHC I or pMHC II will do what

Die

51

Double positive thymocytes that bind pMHC I cease to do what

CD4 expression

52

What type of thymocytes migrate to the thymus medulla

Single positive

53

Do not undergo same selection process
Leave thymus shortly after receiving TCRs and CD3
Limited variability
Respond quickly
No memory

Gamma delta T cell

54

What type of T cell migrates preferentially to respiratory organs, skin, peritoneal cavity

Gamma delta T cell

55

Express several markers and receptors
Undergo some development in thymus
Express TCRs
Limited in repertoire to lipids, glycolipids, and some specialized peptides
Either CD4 or CD4CD8
Recognize nonclassical MHC I molecules

NK T cell

56

Cell death without triggering inflammation
Programmed cell death

Apoptosis

57

Results from injury and it is the release of cell contents meaning inflammation

Necrosis

58

The site of what generation changes during gestation

B cell

59

Blood cell development changes locations until bone marrow is formed and can take over

B cell

60

What doesn't exist at fertilization

Bone marrow

61

Contains connective tissue, blood vessels, fat, and cells and has vascular importance

Bone marrow

62

Give rise to myeloid, granuloid, erythroid, and lymphoid cells

Hematopoietic stem cells

63

Stem cells within this differentiate into many cell types
Stromal cells provide support and growth factors to developing cells
Structure is dynamic and complex

Bone marrow

64

Conventional and widely distributed
Require interaction with T cells for activation and proliferation
Continually replace from bone marrow
Vast repertoire
Repeated antigen exposure meaning stronger, faster response
Often accompanied by class switching
Immunologic memory
More IgD expressed gotten IgM

B2 cells

65

Arise from fetal liver
Importance in innate and autoimmunity
Limited repertoire
Often directed against conserved microbial antigens
Most natural antibodies
Predominantly in areas of microbial entry
Self renewing

B1 cells

66

What is different in the fetal liver from that in the adult bone marrow

Hematopoietic

67

What are the major sites of B1 cells vs the B2 cells

B1 peritoneal and pleural cavities
B2 secondary lymphoid organs

68

How does b1 cells get new cells vs b2

B1 self renewing
B2 precursors in the bone marrow

69

How diverse is b1 vs b2

B1 restricted diversity
B2 highly diverse

70

Which B cell 1 or 2 has somatic hyper mutation

B2

71

Which types of Ig is produced in b1 and b2

B1 IgM
B2 IgG

72

Which B cell responds to carbohydrate antigens

B1

73

Which B cell responds to protein antigens

B2

74

Which B cell has memory

B2

75

Hematopoiesis stages are defined by what three things

Cell-surface markers
Transcription factor expression
Ig gene rearrangements

76

What does both b and T cell developmental pathways share
Four things

Rearrangement of gene segments
Screening processes to avoid self-reactivity
Production of small subsets with discrete functions
Production of larger general purpose subsets

77

What screening processes are used in B cells and T cells

T cells positive and negative selection
B cells negative selection

78

B cells require what to hell and secrete antibodies

T cells

79

T cells require what for helper and killer subsets

Presentation and differentiate