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1
Q

Where doe all blood cells develop from?

A

common pluripotent stem cells.

2
Q

What is a primary lymphoid organ?

A

The thymus and bone marrow where starting from the 13th week, some stem cells migrate there.

3
Q

Where do T lymphocytes generate?

A

The thymus where they proliferate, differentiate, and complete their maturation.

4
Q

Where do B cells proliferate, differentiate, and complete their maturation?

A

The bone marrow

5
Q

Where are Ag specific receptors localized?

A

T and B cells

6
Q

The sturucture of these receptors vafies from one cell to another but they are all identicall…

A

on a single cell

7
Q

How long until a naive lymphocyte dies if they do not recognize an Ag?

A

1 to 3 months.

8
Q

Pluripotent stem cells, CD 34 + differentiate into

A

lyphoid progenitor and myeloid progenitor

9
Q

meloid progenitor become what 3 things?

A

mega karyocyte, myeloblast and erythroblast

10
Q

what 2 things do lymphoid progenitors become?

A

t cell precurser and b cell pre cursor

11
Q

CD stands for

A

cluster of differentiation, which indicates a defined subset of cellular surface receptors that identify cell type and stage of differentitation

12
Q

What is refered to as resting lymphoctyes?

A

naive and memory lymphocytes?

13
Q

Why is something a resting lymphocyte?

A

it is not deviding, nor are they performing effector functions

14
Q

Can a person distinguish btw B and T lymphoctes?

A

No, not morphologically.

15
Q

WHen observed on blood smears B and T lymphocytes are refered to as?

A

small lymphocytes (8 to 10 um)

16
Q

What state of rest are naive lymphocytes in?

A

the Go stage of the cell cycle

17
Q

What happens when stimulation occurs?

A

G1 stage of the cell cycle before dividing

18
Q

What are activated lyphoctes called?

A

large lymphoctyes or lymphoblasts 10 to 12 diameter

19
Q

What does the survival of naive lymphocytes depend on?

A

Signals generated by Ag receptors (TCR or BCR) and cytokines

20
Q

What generates survival signals even in the absence of Ag?

A

Ag receptor of naive B cells (BCR)

21
Q

What do naive T lymphocytes (TCR) recognize?

A

Various self Ags weakly, enough to generate surviavl signals but without triggering clonal expansion and differentiation into effecto cells.

22
Q

What is the most important cytokine for survaval of naive T cells? What does it do?

A

interleukin IL-7, which promotes low -level cycling of naive T cells

23
Q

What cytokine is required for B cell survival?

A

The cytokine in the TNF family, B cell-activating factor (BAFF)

24
Q

What doe T cells make contact with and where?

A

epithelial cells, DCs, and Mo in the thymus

25
Q

What provide mechanisms for the slection and differentition of T cells unful to the immune system?

A

cell-to cell interactions

26
Q

What serve as solube regulatory factors or messengers for the immune system ion general?

A

cytokines

27
Q

What 4 cytokines play an impotant role in T cell development?

A

IL-1, IL-2, IL-6, IL-7

28
Q

Where do most naive T cells go after migration from the thymus?

A

They are maintained in the periphery without proliferating.

29
Q

The number of naive T cells in the periphery remains fairly constat in youn adults,

A

despite continuouis output from thymus, suggesting balanced loss and replacmeent of peripheral naive T cells

30
Q

What are large numbers of Ag-specifice T cells procuded from?

A

T cell precursors

31
Q

Each T cell has receptors specific for only one Ag that is gnereated by…

A

gene rearrangement from multiple, inherited germline genes

32
Q

Why does T cells undergo selection?

A

to remove those that are highly self reactive

33
Q

What two types of cells are developed in the T cell process?

A

T helper cells and cytotoxic T lymphocytes (CTLs)

34
Q

What do T helper cells express?

A

CD4 and provide help for B cell growth and differentiation

35
Q

What do cytotoxic T lymphocytes express?

A

CD8 and recognize and kill virus- infected cells.

36
Q

Where do mature T cells migrate?

A

To secondary lymphoid tissues to mediate protection

37
Q

When do B cells start to develop?

A

Around the 14th week of gestation.

38
Q

WHere does differntiation into B cells occur?

A

The fetal liver, after birth in the bone marrow, which is the lifetime production.

39
Q

What two different kinds of B cells develop?

A

B1 and B2

40
Q

WHat is the first antibody express on B cells/

A

IgM

41
Q

What is expressed after IgM on B cells?

A

IgD

42
Q

B cells protliferate into … with T cells help.

A

memory cells or inot plasma cells

43
Q

What produce and secrete large amounts of Abs?

A

plasma cells

44
Q

Who do B cells present Ags to?

A

helper T cells, which is a key step in the cooperation of Th cells with B cells for Ab responses to protein Ags

45
Q

What are generatie lymphoid organs?

A

bone marrow and thymu

46
Q

What are secondary lymphoid organs?

A

lymph nodes, spleen, regional lymphoid tissues such as mucosa-associated lymphoid tissue

47
Q

What is peripheral lymphoid organs?

A

lymph nodes, spleen, mucosal and cutaneous lymphoid tissues

48
Q

What parts of the body do lymphocytes not make it to?

A

eye, brain, and testicles

49
Q

What specialized venules do the lymphoctes use to get to the lymph nodes, skin, and intestines?

A

High Endothelium Venules(HEVs)

50
Q

What is not requried for the proliferation of B cells?

A

IL 2

51
Q

Cells of HEVs are much higher than normal endothelial cells and express much high levels of?

A

adhesion molecules that serve as homing receptors for lymphocytes

52
Q

What is diapesis?

A

the passage of blood cells through the intact walls of the capillaries, typically accompanyging inflammation

53
Q

Why do lymphocytes migrate by diapediesis into the tissue/

A

In response to chemokines

54
Q

How do lymphocytes renter the ciculations/

A

Efferent lymph vessels that merge into the thoracic duct

55
Q

What are the most important for activation of naive T cells?

A

Dendritic cells

56
Q

What is maturation of Dcs dependent on?

A

The cytokine Flt3, which binds to the Flt3 tyrosine kinase receptor on the precursor cells

57
Q

What recognize Ags typically made by microbes and not mammalian cells/

A

Mo and DCs

58
Q

Where do classical DCs resdie?

A

in skin, mucosa, and organ parenchyma

59
Q

What responds to viral infections/

A

plasmacytoid DCs

60
Q

What is important contacts for B cells development?

A

stromal cells and ctyokines IL1, IL6, and IL7

61
Q

What is not required for the development of B cells, but is needed for the development of T cells?

A

IL2

62
Q

How does recognition of Ag occur for B cells?

A

The B cell precursors rearrange multiple, inherited, germline genes that encode B cell receptors

63
Q

What is a terminally differentiated B cell which produces and secretes lg amounts of Abs?

A

plasma cells

64
Q

B cells present Ags to?

A

T helper cells

65
Q

What is the function of a plasma cell?

A

secretion of Abs

66
Q

What do lymphocytes develop from?

A

bone marrow stem cells and then mature in the genrative lymphoid organ

67
Q

What parts of the body do lymphocytes no reach?

A

eye, brain, testicles

68
Q

What area does lymphocytes reach via high endothelum venules (HEV)?

A

LN, skin and intestines, bc they are much higher than normal endothelial cells and their express high levesl of adhesion molecles that serve as homing receptors for lymphocytes

69
Q

How do lymphocytes respond to chemokines??

A

migrate by diapedis into the tissue

70
Q

How do lymphocytes reenter circulation?

A

efferent lymph vessels that merge into the thoracic duct

71
Q

Antigens are captured from a site of infections and transported to?

A

the draining lymph node, where the immune response is initiated

72
Q

Where do fully mature naive T cells and immature B cells migrate ?

A

into lymphoid organs such as LNs and the spleen

73
Q

Where doe B cells complete there maturation?

A

LNs and spleen

74
Q

What do naive B and T cells actived by Ags differentiate into?

A

effector or memory lymphoctes

75
Q

WHere do some effector and memory lymphocytes migrate to?

A

periperhal tissue sites of infection

76
Q

Abs secreted by effector B cells in LNs, spleen and bone marrow enter?

A

The blood and are deleivered to sites of infection

77
Q

What are antigen presenting cells???(APCs)

A

Cells that capture, process, display microbial Ags to lymphocytes and provide signals that stimulate the proliferation and differentation of the lymphocytes

78
Q

What do APC usually refer to ?

A

A cell that displays Ag to T lyphocytes bc B lymphocytes do not need PAC for their activation

79
Q

What is the major type of APC involved in intitaiting T cell response?

A

dendrictic cells

80
Q

What are other types of APCs?

A

macrophages and B cells, both present Ags to T lymphocytes in cell mediated and humoral immune responses

81
Q

What does follicular DC display?

A

Ags to B lymphocytes during particular phases of humor immune repsonses

82
Q

What provide link btw innate and adaptive immunity?

A

DCs and Mo

83
Q

What are the most important for the activation of Naive T cells?

A

dendritic cells

84
Q

What have long membranous projections and phagocytic capabilites?

A

dendritic cells

85
Q

What linease are DCs from?

A

myeloid lineage and arise from a precursor that can also differentiate into monocytes

86
Q

What is matturation of DCs dependent on?

A

cytokine Flt3 ligand, which binds to Flt3 tyrosine kinase receptor on the precursos cells

87
Q

Do activated DCs secrete cytokines?

A

Yes

88
Q

Fetal hemapoietic stem cells create??

A

langerhans cells

89
Q

Adult dendritic precursors create?

A

classical Dcs, plamacytoid Dcs, and inflammatory DCs

90
Q

Where do classical DCs reside?

A

skin, mucosa, and organ parnechyma

91
Q

Upon activation by microbes, DC migrate to?

A

LNs where they display microbial protein Ags to T lyphocytes

92
Q

What do plamacytoid DCs respond to?

A

viral infections

93
Q

What does plamacytoid DCs recognize and produe?

A

nucleic acids of intracellular viruses and soluble proteins type I interferons, aka IFN-alpha/beta

94
Q

What circulating thing can DCs be derived from?

A

monocytes

95
Q

Where are FDCs found?

A

in collection of activated B cells with membranous projections

96
Q

Where do FDCs reside?

A

LNs, spleen, and mucosal lyphoid tissues

97
Q

What are unrelated to DCs that present Ags to T lymphocytes?

A

follicular dendirtic cells (FDCs)

98
Q

What do FDCs bind and display? Why?

A

protein Ags, for recognition by B lymphocytes

99
Q

FDCs have the remakable ability to?

A

retain complement- fixed Ags on tehirf cell surface for extended periods of time

100
Q

What do FDC immune complexes provide?

A

antigenic stimulus that drives Ab affinity maturation

101
Q

What are innate lymphoid cells? (ILCs)

A

several subsets of bone marrow- derived cells w lymphoid morphology

102
Q

ILCs functions?

A

similar to T cells, but lack T cell antigen receptors

103
Q

What are the 3 major functions of ILCs?

A
  1. provide early defense against infectious pahtogens
  2. recognize stressed and damaged host cells and help to elminate these cells
  3. influence the nature of the subsequent adaptive immune resposnee
104
Q

What are the first and best characterized innate lyphoid cells?

A

natural killer cells

105
Q

What doe NK cells sectreet?

A

IFN-gamma and kill infected and damaged cells

106
Q

What is the HSC nich?

A

in the bone marrow where there are regions of support for functions of hematopoietic stem cells and other types of hematopoeitic cells (progenitors)

107
Q

What does the HSC nich contribute too?

A

HSC quience, proliferation, self-renewal and differentiation

108
Q

What does the nich consist of?

A

A network of vessels, nerve fibers, bone remodeling cells and subpopulations of hematopoietic cells, which reslut in a complex three demential architechture

109
Q

The thymus is made of of??

A

The cortex and the medulla

110
Q

What is teh Hassal’s corpuscle in teh thymus?

A

part of the medulla whose fuction is poorly understood

111
Q

What makes up the white pulp of the spleen?

A

the T cell and B cell zones

112
Q

Naive lymphocytes enter the LN through?

A

an artery, leave the circulation by moving across the wall of high endothelial venule

113
Q

How do B and T cells migrate in the LN?

A

chemokines that are produced in these areas

114
Q

Where do DC migrate too in the LN?

A

T cell rich arease

115
Q

activated to be killing microbes

A

classical activation

116
Q

activated to repair and remodel?

A

alternative activation

117
Q

What type of receptors to mast cells and baosphils express?

A

IgE

118
Q

What promote the maturation of eosinophils in myeloid precursors?

A

GM-CSF, IL-3, IL-5