Week 1 Flashcards
(144 cards)
1
Q
What are the primary lymph organs
A
red bone marrow and thymus
2
Q
What are the secondary lymph organs
A
lymph nodes, spleen, MALTs (tonsils, peyers, appendix)
3
Q
What is the purpose of primary lymph organs
A
supply immature, ANTIGEN INDEPENDENT T and B cell precursors to peripheral tissues
4
Q
What is the purpose of secondary lymph organs
A
provide committed, ANTIGEN DEPENDENT T and B cells that respond to specific antigens
5
Q
Where is antigen exposed to lymphocytes
A
secondary lymph organs
6
Q
What lymphatic duct drains most of the body
A
left duct
7
Q
Terminal lymphatic vessels lack
A
smooth muscle walls
8
Q
Collecting lymphatic vessels have both
A
valves and smooth muscle walls
9
Q
Myeloid progenitor cells differentiate into
A
the granulocytes— neutrophils, eosinophils, basophils, mast cells, monocytes, dendritic cells, and macrophages
10
Q
Lymphoid progenitor cells differentiate into
A
B cells, T cells, NK cells
11
Q
What cells act as APCs
A
macrophages, dendritic cells, and B cells
12
Q
What are macrophages derived from
A
monocytes
13
Q
What type of immune cells are osteoclasts and microglial cells
A
macrophages
14
Q
What are the 3 fxns of macrophages
A
phagocytes, APCs, and cytokine producers
15
Q
Large, irregularly shaped cell with large nucleus, many lysosomes and well developed RER and Golgi
A
activated macrophage
16
Q
What are dendritic cells derived from
A
monocytes
17
Q
What type of APCs are highly phagocytic
A
dendritic cells
18
Q
What is the mechanism of DCs
A
phagocytize pathogens—> convert Ags into MHC-peptide complexes—> presents on surface with MHC-II receptors to T cells—> becomes activated
19
Q
Once a DC becomes activated it
A
moves into lymph node to activate T cells
20
Q
What are the differences between DCs and macrophages
A
- DCs can leave the tissue
- DCs ONLY process Ags and present them
21
Q
Where are DCs found
A
- skin (Langerhans, dermal DCs)
- mucosa (nose, lungs, stomach, intestines)
- immaturely in the blood
22
Q
Langerhan cells express
A
- MHC-II receptors
- Cd1a surface antigen
- langerin
23
Q
What layer of the epidermis are Langerhans most prominent
A
spinosum and granulosum
24
Q
Beside the epidermis, where else are Langerhans found
A
- papillary dermis around BVs
- mucosa SSE of mouth, vagina, ectocervix, rectum, foreskin
25
Cells with lobulated nucleus, rod shaped inclusions that have a zipper like appearance with a bulb shape end that look like tennis rackets
Langerhans
26
What type of cells have Birbeck granules
Langerhans (the bulb part of the tennis racket)
27
Where do B cells mature
bone marrow
28
What is the first Ab produced and activates compliment
IgM
29
What is the mechanism of B cell activation
free Ag binds to IgM or IgD on B cell---> B cell engulfs, processes, and presents Ag to activated Th cells---> Th cells release IL4 to provide second stimulation of B cell---> activated B cell differentiates into memory B cells and antibody-producing plasma cells
30
Once Ag is present in a lymphatic nodule, what forms
mantle zone of nonproliferating B cells with a germinal center of FDCs and proliferating lymphoblasts
31
What cells have a comet-like cytoplasm, clock-face nucleus, and ghost-like region
plasma cells
32
Where do T cells originate from
bone marrow
33
What type of connective tissue is found in lymphoid organs EXCEPT the thymus
reticular
34
Reticular fibers in lymphoid tissue is
type III collagen
35
Where do abnormal plasma cells build up in multiple myeloma
bone marrow causing bone tumors
36
What are the blood proteins of innate immunity
complement
37
What are the cells of adaptive immunity
B & T cells
38
What are the 2 principal types of reactions of the innate immune system
inflammation and antiviral defense
39
Innate immune cells recognize
PAMPs & DAMPs
40
Innate immune receptors are encoded in
the germline--- identical in all cells
41
What are the types of receptors produced by the innate immune cells
TLRs, NLRs, RLRs, lectin receptors, mannose receptors, N-formyl methionyl receptors, and complement receptors
42
Where are receptors of the innate immune system located
cell surface, in endosomes, and in cytosol
43
What is the function of cytokines
mount an inflammatory response
44
What are the primary communicators between immune cells
cytokines
45
Children who develop HSE have a deficiency in
TLR3
46
What happens if the initial inflammatory response fails to clear the inflammation
chronic inflammation
47
What are the 5 Rs of a typical inflammatory response
```
Recognition of the injurious agent
Recruitment of leukocytes
Removal of the agent
Regulation of the response
Resolution and repair
```
48
What are the cardinal signs of inflammation
```
Heat
Redness
Swelling
Pain
Loss of function
```
49
What are the 2 components of acute inflammation
vascular and cellular
50
What causes pain in an inflammatory response
prostaglandins, neuropeptides, and cytokines
51
What causes tissue damage in inflammation
toxic metabolites
52
What are the causes of inflammation
infections (microbes)
foreign bodies (exogenous and endogenous)
tissue necrosis (ischemia, trauma, physical and chemical injury)
immune reactions (autoimmune and allergies)
53
What immune cells mediate asthma
eosinophils (IgE antibodies)
54
What is seen pathologically in ARDS lung tissue
DAD- diffuse alveolar damage
55
What are the 3 morphologic patterns of acute inflammation
serous, fibrinous, and purulent
56
Exudation of fluid into spaces created by injury that typically has no infectious agents or leukocytes present
serous inflammation
57
What is effusion in serous inflammation
the derivation of fluid from either the plasma or secretions of mesothelial cells
58
Fibrous inflammation occurs when
the vascular leaks are large or there is a local procoagulant stimulus
59
What type of inflammation is commonly seen in the meninges, pericardium, and pleura
fibrinous inflammation
60
How is fibrin inflammation mediated
by fibrinolysis and cleared by macrophages
61
What happens if fibrin is not removed during acute inflammation
it can lead to fibrous scarring called "organization"
62
What is the most frequent cause of purulent inflammaiton
pyogenic bacteria
63
What is pus
exudate of neutrophils, liquefied debris of necrotic cells, and edema fluid
64
What type of inflammation is acute appendicitis
purulent inflammation
65
What are the 3 genes involved in H chain recombination
VDJ
66
What is the first step of B cell development
commitment of the common lymphoid progenitor to the B cell lineage
67
What is an antibody composed of
2 identical H chains and 2 identical L chains
68
What is located between the V and C genes in the HSCs germline
D & J segments
69
Only the H has both
D & J segments
70
What are the committed B cells called
pro-B cells (progenitor B cells)
71
What are RAG genes
Recombination Activating Genes
72
When are RAG genes expressed
from the start of the pro-B cell stage until they are immature B cells
73
What markers are associated only with B cells
CD19, CD20, CD21
74
What are the 2 pathways of TLR signaling
1. TLR recognizes PAMP
2. Toll IL 1 receptor (TIR) recruits adaptor proteins NF-kB
3. NF-kB activates transcription
4. Increased cytokines, costimulators, and adhesion molecules lead to
5. Acute inflammation and stimulation of adaptive immunity
OR
1. TLR recognizes PAMP
2. Toll IL 1 receptor (TIR) recruits adaptor proteins IRFs
3. IRFs activate transcription
4. Production of type 1 interferons (IFN alpha & beta) leads to
5. Antiviral state
75
What are the components of an inflammasome
NLR + adaptor + inactive caspase 1
76
What is the function of an inflammasome
convert caspase from inactive form to active form which can then cleave pro-IL1 B into IL1-B
77
NLRP3 defects or deficiency can lead to
autoinflammatory syndromes with gain of function leading to chronic inflammation
78
Secreted IL1-B function
pro-inflammation
fever
promote leukocyte migration
79
What are the type 1 IFNs
IFN alpha and IFN beta
80
What is the fxn of type 1 IFNs
antiviral state
81
What type of innate receptors recognize peptidoglycan on GRAM POSITIVE bacteria
NOD 1 and NOD 2
82
What innate receptors recognize viral RNA
RLRs- RIG 1 and MDA 5
83
What innate immune cell is most predominant in circulation
neutrophil
84
What are the major cytokine producing cells of the innate immune system
macrophages
85
What kind of cells produce extracellular traps
neutrophils-- NETs
86
Type 2 IFNs are
IFN gamma
87
What is the main function of IFN type 2
macrophage activation
88
What does complement do
coats pathogens for phagocytosis
89
If a macrophage receives signals from TLR ligands or IFN gamma what is their response
microbe killing and inflammation
90
If a macrophage receives signals from IL 13 or IL 4 what is their response
anti-inflammatory response and tissue repair
91
M1 vs M2 macrophages
M1--- pro-inflammatory and anti-microbial
vs
M2--- anti-inflammatory and tissue repair
92
Where are mast cells found
skin and mucosa
93
What do mast cells express
CD16 and CD56
94
NK cells share similarities to
CD8+ T cells
95
To kill an infected cell, NK cells release
perforin and granzyme B
96
NK cells will not kill a cell if
it expresses self antigen via MHC I on the surface--- inhibitory receptor
97
What are the 2 types of receptors that NK cells express on the surface
KAR--- activating receptor
| KIR--- inhibitory receptor
98
What complements induce inflammation
C3a and C5a
99
What is opsonization
when complement proteins or Ab coat a pathogen for phagocytosis
100
Which complement induces opsonization and phagocytosis
C3b
101
What complements induce lysis of the microbe
C6, C7, C8, C9
102
C6-C9 complements induce lysis of the microbe by
forming a MAC
103
Rolling of a leukocyte happens because
selectin on the tissue binds with the selectin ligand expressed by the leukocyte--- this weak binding slows down the leukocyte so that it can migrate into tissues
104
What enzymes are important for oxygen-dependent phagocytosis of innate cells
NADPH oxidase, myeloperoxidase, nitric oxide synthase
105
What area of the brain is responsive to pyrogens which results in fever
hypothalamus
106
Which cells are mainly responsible for producing IFN B during antiviral response
fibroblasts
107
How do pneumococci resist phagocytosis
capsular polysaccharide
108
How do staphylococci evade innate immune response
resistant to ROS during phagocytosis due to production of catalase
109
What are the 3 major mechanisms of the anatomical barriers
1. directly prevent entry
2. can produce local antibiotics
3. intraepithelial T cells
110
What are the 3 major sentinel cells
mast cells, DCs, and macrophages
111
What are the inflammatory mediators produced upon recognition of a pathogen by sentinel cells
1. histamines
2. prostaglandins
3. leukotrienes
112
What are the 3 types of CD4+ T cells
Th1, Th2, Th17
113
What are the 2 signals of T cell activation
1. TCR signal after recognition of MHC on APC
| 2. CD28 on T cells binding B7 (CD 80 and CD86) on APCs
114
What does a T cell produced after it receives both of its activation signals
IL-2 AND the IL-2R (receptor)
115
What type of Th cells are best for intracellular pathogens
Th1
116
What type of Th cells are best for extracellular bacteria and parasites
Th2
117
What type of Th cells are best for extracellular bacteria and fungi
Th17
118
What cytokines drive differentiation of T cells in to Th1
IL-12 produced DCs & macrophages
| IFN-gamma produced by NKs
119
What main cytokine does Th1 cells produce
IFN gamma
120
Other than IFN gamma, how else do Th1s activate macrophages
CD40L on Th1 binding CD40 on macrophage
121
Once fully activated by Th1s, what do MPs produce to kill pathogens
ROS and NO
122
How do M1 MPs amplify T cell response
higher expression of MHC II and increased B7 costimulatory molecules
123
Other than Th1 cells producing IFN gamma, how else can M1 macrophages become activated
CTLs produce IFN gamma also
124
IFN gamma activates M1 macrophages but what effect does IFN gamma have on B cells
can lead B cells to class switch to IgG which acts as an opsonin to enhance phagocytosis and complement activation
125
What stimulates differentiation of T cells in Th2 cells
IL-4 produced by mast cells
126
What do Th2 cells produce
IL-4, IL-5, and IL-13
127
How do Th2 cells induce B cells to class switch to IgE
IL-4
128
What action does IL-4 and IL-13 have on intestines during a parasitic infection
increases mucus production and stimulates peristalsis
129
What is the function of M2 macrophages
tissue repair and fibrosis
130
What promotes differentiation of macrophages into M2 macrophages
IFN gamma, IL-4 and IL-13
131
What type of T cells play a primary role in allergies
Th2s
132
What cytokines induce differentiation of T cells into Th17s
IL-1, IL-6, and IL-23
133
What are the major cytokines produced by Th17 cells
IL-17 and IL-22
134
What is the major function of Th17s
recruitment of neutrophils and monocytes
135
What does IL-22 produced by Th17s do
promote repair of damaged epithelium
136
What would you expect to find in a patient who has defects in their Th17 cells
mucocutaneous candidiasis, bacterial skin abscesses, psoriasis, RA, and IBD
137
What is cross presentation
when a DC presents extracellular Ag on MHC I to CD8+ cells
138
What 3 binding processes take place during activation of a CTL
MHC I, TCR, and CD8 coreceptor
139
What holds CTLs and infected cells together
LFA-1 (an integrin)
140
What do CTLs release upon binding and activation by an infected cell
perforins and granzymes
141
What does granzyme B released by CTLs do to the infected cell
activates caspases which leads to apoptosis
142
CTLs express FasL which binds to Fas (CD95). What is the purpose of Fas
promotes cell death
143
How does murine CMV evade NK cells
expresses decoy MHC I like molecules
144
How does EBV evade CTLs and NKs
inhibits proteasomal activity
