L8 T and B cell development - Hudig Flashcards
1
Q
Where are the pluripotent cells?
A
bone marrow
2
Q
Where are the B cells made?
A
bone marrow
3
Q
Are all self-reactive B cells destroyed in the bone marrow?
A
no, but MOST of them
4
Q
T cell made in the (blank) and mature in the (blank)
A
bone marrow, thymus
5
Q
In the thymus, T cells are selected positively for (blank) then negatively for (blank)
A
positive for weak MHC binding, then negative for strong self MHC binding
6
Q
Where do NK cells develop?
A
bone marrow
7
Q
What three enzyme mutations are involved in SCID?
A
RAG1
RAG2
TdT
8
Q
What is central tolerance?
A
deletion of anti-self T cells in the thymus
9
Q
SCID mutations effect (t/b) cell dev?
A
both of them!
10
Q
preT stem cells from bone marrow lack what markers?
A
Cd3,/4/8
11
Q
preT’s in the thymus express CD25 to divide which allows them to bind what?
A
IL2
12
Q
Where do T cells get their tCRS
A
in the thymus
13
Q
Can the tCR still bind the MHC without it holding a peptide
A
yes, it is just a weak bind
14
Q
Why is the first positive selection for T cells for those that can bind to self-MHC?
A
so all the binding strength during recognition doesnt have to come from the peptide alone
15
Q
Why is the second negative selection for T cells those that bind self-MHC strongly?
A
Want the TCR to be able to bind the MHC, but not trigger activation if it is not holding a protein
16
Q
what percent of thymocytes survive selection?
A
1%
17
Q
By what method are the rejected T cells killed?
A
apoptosis
18
Q
(blank)Induces Expression of Organ-Specific Proteins in the Thymus to Support Deletion of “Self”-Reacting T Cells
A
AIRE (Autoimmune Regulator)
19
Q
AIRE is found in the (blank)
A
thymic medullary epithelial cells
20
Q
AIRE protein interacts with multiple (blanks)
A
transcription factors
21
Q
T/F: AIRE induced organ specific proteins can be secreted or remain in the cytoplasm, allowing both CD4 and CD8 recogntion
A
true
22
Q
at what age does the thymus begin to regress?
A
puberty
23
Q
bone marrow contains stem cells for what cell lines?
A
preT, B, NK, and RBCs, granulocytes, macrophages and platelets
24
Q
What are the primary lymphoid organs?
A
thymus and bone marrow
25
what are the peripheral lymphoid organs?
lymph nodes
spleen
GALT, MALT
26
does the thymus completely disappear with age?
no, just atrophies
27
the spleen clears blood infections of (blanked) bacteria, such as strep pneumoniae
encapsulated
28
Where does central tolerance occur?
central lymphoid organs: bone marrow and thymus
29
Where does peripheral tolerance occur?
in circulation
30
What happens if a t or b cell sees a self antigen without signal 2?
they will die or become anergic
31
Is T cell or B cell self-tolerance easier to break?
b cell
32
why do b cells break self tolerance?
affinity maturation which reacts with self
33
B cells will express MHC II if triggered by (blank)
IFNg
34
Why are B cells more likely to break tolerance?
NO AIRE in the bone!
35
How do B cells commonly break tolerance?
a true antigen gets stuck to something self; the whole complex is internalized and is all recognized as Ag
36
Does the thymus contain germinal centers?
no
37
Does the thymus contain B cells?
only a few
38
Where in the thymus is T cell proliferation?
cortex
39
What is the effect of glucocorticoid hormones on thymocyte proliferation?
depresses cortical proliferation
40
Do glucocorticoid hormones deplete T cell levels in the thymic medulla?
no
41
Where are Ab generating plasma cells originally formed?
in lymph nodes, peyer's patches, and the spleen
42
Do plasma cells travel?
to the bone marrow
43
T/F: the thymus has only Efferent lymphatics
true
44
where does the lymph from the thymus drain?
thoracic duct
45
Do T and B cell interactions occur in the blood?
NO, almost exclusively in lymphoid organs
46
Lymph fluid lacks what two cell types?
RBCs and granulocytes
47
T/F: lymph contains the same proteins as plasma
true
48
T/F: there is lower IgM and C1q in lymph than plasma
true
49
Soluble antigens, macrophages, and other APCs will enter lymph nodes via (blank)
afferent lymphatics into the subcaspuslar sinusoids
50
What cells are in the lymph node cortex?
B cells
51
What cells are in the lymph node paracortex?
T cells
52
Are B cells dividing in primary follicles?
no
53
What follicles are B cells dividing in?
secondary/germinal follicles
54
Are there T cells in the primary follicles of lymph node?
no
55
Are there T cells in the germinal centers>?
only a select few
56
Where are dendritic cells found in the lymph node?
Cortex and paracortex
57
Where are the plasma cells in the lymph node?
in the medullary cords; NOT IN THE B FOLLICLES
58
Is there cellular movement within the lymph node?
yes
59
What does it take to activate a b cell in the lymph node?
Ag presentation by DC and signal 2
60
What do b cells in the lymph node do when they are activated?
become APCs and show the antigen to Thelper cells, and brings it back to a germinal follicle
61
The spleen clears (blank) infections
intravascular
62
T/F: the spleen has both types of lymphatics
false, IT LACKS AFFERENT AND EFFERENT; served entirely by blood stream
63
Where are plasma cells in the spleen?
marginal zone between the white pulp and red pulp
64
where are the T cells in the spleen?
periarteriolar sheath
65
Where are the B cells in the spleen?
primary and germinal follicles
66
After trauma, should you save even a part of the spleen?
yes, save as much as you can
67
What is the primary product of GALT?
IgA
68
what carries Ags from the lumen of the gut to PPs?
M cells--specialized epithelial APCs
69
Plasma cells in GALT secrete (blank)
dimers of IgA with a J chain
70
What are the three major areas of GALT?
tonsillar rings, Peyer's patches, and the appendix
71
Do tonsils have lypmhatic vessles?
no
72
Describe B cell architecture in the tonsil?
germinal centers and IgA-secreting plasma cells
73
What type of epithelium lies of PP's?
flat (thin), not columnar epithelium without goblet cells or microvilli
74
What two things are released into the draining lymph from PP's?
IgA blast cells and Ag
75
What lymph nodes drain PP's?
mesenteric nodes
76
What is the fate of the IgA blast cells released from PPs?
they go to other secretory sites throughout the gut, AND salivary, lacrimal, and lactating mammary glands, become plasma cells and secrete IgA
77
what type of MHC do M cells have?
MHCII
78
where is the germinal center in PPs?
central
79
where are the T cells in PPs?
peripherally ringing the germinal center
80
Where else are M cells located besides PPs?
respiratory and GU tract
81
What three things control gut microbiota?
GALT, PPs, and mesenteric lymph nodes
82
What functions to limit bacterial-epithelial contact in the gut?
mucus layer, epithelial antibacterial proteins, and IgA secreted by lamina propriia plasma cells
83
Defensins (blank) bacteria
kill
84
IgA (blanks) bacterial adhesion
blocks
85
RegIIIg is an antibacterial lectin that secreted by (blank) and limits bacterial peentration of the mucus layer
epithelial cells
86
Where do Ag loaded DCs from the gut travel to?
PPs or mesenteric lymph nodes, BUT NO FARTHER
87
IgA secreting plasma cells are found throughout the (blank) of thegut
lamina propria
88
T/F: the appendix is part of the GALT
true!
89
Does the appendix have lymphatics?
yes, both
90
where are the germinal centers located in the appendix?
cortex
91
what types of lymphocytes are found in the lamina propria of MALT?
plasma cells, T helper cells, and CTLs
92
The mucosa of the lacrimal glands, vagina, the bladder, mammary glands is (blank)
MALT
93
what is the first barrier to infection for HIV?
secretory immune system
94
Dexamethasone and cortisone (blank) dividing T cells in thymic cortex
KILLLLLL
95
T/F: local and endocrine hormones signal thymic cells to differentiate
true
96
Thymopoietin and thymosin come from (blank)
Hassal's corpuscles
97
T stem cells are found in the ?
bone marrow
98
Pro-T, pre-T, double pos T, and single positive T are found in the?
thymus
99
naive mature T cells are found in the?
periphery
100
At what point in differentiation does the T cells gain a/BTCR?
double positive
101
Where does T cell germline rearrangement occur?
thymic cortex
102
where is the second negative selection in T cell screeining?
the medulla
103
Do T cells die naturally of necrosis or apoptosis
apoptosis if everything goes according to plan
104
When is CD3 expressed on T cells?
AFTER t cells are presenting TCRs on their membrane
105
What is the co-receptor for antigen recognition by CTLs?
CD8 itself!
106
If not in the blood and you're not a Treg, where would you find CD25 T cells and what are they doing?
lymph nodes and spleen and are dividing post Ag exposure
107
What will trigger mature T cell division?
specific ags, T cell reactive lectins, or Abs to CD2 or 3
108
Ag-specific proliferative assays measure the activity of what cell type?
T memory cells
109
what are lectins?
proteins that bind sugars
110
what are the two lectins that are T cell mitogens?
Con A and PHA
111
Do conA and pHA stimulate B cells?
no
112
Can mAbs to CD3 stim t cell division?
yes
113
what radioactive method can measure T cell activity?
3H-TdR incorporation
114
How do you measure T cell activity in VIVO?
ability to respond to a DTH to chemicals like DNCB upon SECONDARY skin application
115
Where do you find pro and pre b cells?
bone marrow
116
where do you find immature and mature b cells?
periphery
117
The committed dividing B cells first only express Ig mu heavy chains and NO LIGHT chains in their (blank)
cytoplasm
118
Where do B cells divide once they have encountered antigen?
in a germinal follicle in lymphoid tissue
119
Where do B cells go to become plasma cells?
medullary cords of lymph nodes, marginal areas of the spleen, or PPs
120
Where do memory B cells hang out?
blood circulation
121
How do you measure B cell activity in vitro?
radioactive thymidine uptake
122
What are the B cell polyclonal mitogens? What do they do?
protein A of Staph Aureus (binds Fc of IgG), LPS of gram neg bacteria, and EBV virions; stimulate ALL B cells to divide
123
What cytokine stimulates B cell IgG1/3 production?
IFNg
124
What cytokine stimulates B cell IgE production?
IL4
125
What cytokine stimulates B cell IgA production?
TGF-b
