Introduction to Immune System Part I Flashcards
1
Q
3 Circulating effector cells of innate immunity
A
Neutrophils, macrophages and NK cells
2
Q
3 Circulating effector proteins of innate immunity
A
Complement
Mannose-binding lectin
C-reactive protein
3
Q
TNF, IL-1, chemokines
A
Inflammation
4
Q
IFN-a, IFN-B
A
Resistance to viral infection
5
Q
IFN-y
A
Macrophage activation
6
Q
IL-12
A
IFN-y production by NK cells and T cells
7
Q
IL-15
A
Proliferation of NK cells
8
Q
IL-10, TGF-B
A
Control of inflammation
9
Q
Opsonization
A
Process by which a pathogen is marked for elimination
10
Q
PMN
A
Polymorphonuclear
11
Q
Neutrophils
A
Majority of WBCs (60-70%) PMN granulocytes phagocytosis and digestion of microbes Short lived (2-3 days) Produce inflammatory mediators
12
Q
Eosinophils
A
PMN granulocytes
Allergic rxns, defense against helminths
2-5% of WBC
granules for extracellular digestion
13
Q
Basophils
A
Circulate in the blood
PMN granulocytes
Allergic rxns, contribute to elimination of parasites
Key role in anaphylactic reactions
14
Q
Mast cells
A
Tissue fixed
PMN granulocytes
Allergic rxns
15
Q
Monocytes
A
Mononuclear
Circulating macrophage precursor
3-8% of the blood
Important phagocytes
16
Q
Macrophages
A
Tissue fixed
Mononuclear
Phagocytosis and digestion of microbes, antigen presentation
17
Q
What comprises majority of WBCs?
A
Neutrophils
18
Q
Main function of neutrophil?
A
Phagocytosis
19
Q
Neutrophils and basophils produce these inflammatory mediators
A
Cytokines, prostaglandins and leukotrienes
20
Q
Neutrophils have cytoplasmic granules that contain
A
Peroxidase
Lysozyme
Degradative enzymes
Defensins
21
Q
Eosinophilic granules contain
A
Basic proteins
peroxidases
antimicrobial substances
22
Q
Eosinophils secrete granules for
A
extracellular digestion of infectious pathogens
23
Q
Which cell plays key pathogenic role in anaphylactic reactions
A
Basophils
24
Q
Basophil granules contain
A
Histamine
Serotonin
Heparin
Cytokines and chemokines
25
Monocytes are
Blood precursor cells of tissue macrophages
26
Dr. Shnyra thinks this cell type is the beast to end all beasts
Macrophage
27
Macrophages in connective tissue called
Histocytes
28
Macrophages in liver called
Kupffer cells
29
Macrophages in lungs called
Alveolar macrophages
30
Macrophages in the CNS called
Microglial
31
Functions of macrophages in innate immunity
Phagocytosis and degradation
Produce and release enzymes
Produce and release inflammatory mediators
32
Macrophages produce and release these enzymes
Lipases, galactosidase
33
Macrophages produce and release these inflammatory mediators
```
Cytokines and chemokines
Reactive oxygen intermediated (ROI)
Nitric oxide (NO)
```
34
NK Cells
Recognize and destroy a variety of target cell types without prior stimulation or immunization
35
NK cells targets
Virus cells
Cancer cells
Transplant cells
36
NK cells cytotoxic mechanism
secretion of perforin
37
Which part of the immune system do NK cells belong?
Innate
| -broad, non-specific cytotoxic activity
38
Basic mechanism of self non-self discrimination
PAMPs - pathogen associated molecular patterns
39
PAMPs
Basic mechanism of recognizing self/non-self
| No structural similarity with self Ags
40
Cell receptors recognizing PAMPs are termed
Pattern recognition receptors (PRRs)
41
Mannose-tailed glycans are
Essential surface molecules of bacteria and viruses
42
PRRs Receptors
Encoded in germline (in gamete producing cells)
| Limited diversity
43
PRR distribution of receptors
nonclonal; identical receptors on all cells of the same lineage
44
PRR discrimination of self and nonself
Yes; host cells are not recognized or they may express molecules that prevent innate immune reactions
45
Toll-like Receptors (TLRs)
Some are present on cell surface where they recognize products of extracellular microbes
Others are located in endosomes into which microbes are ingested
46
TLRs present on cell surface
```
TLR1
TLR2
TLR4
TLR5
TLR6
```
47
TLRs located in endosome
```
ONLY respond to nucleic acids
TLR3
TLR7
TLR8
TLR9
```
48
TLR1
Bacterial lipopeptides
49
TLR2
Bacterial lipopeptides
| Bacterial peptidoglycan
50
TLR4
LPS
51
TLR5
Flagellin
52
TLR6
Bacterial lipopeptides
53
TLR3
dsRNA
54
TLR7
ssRNA
55
TLR8
ssRNA
56
TLR9
CpG rich DNA
57
TLR that recognizes Gram + bacteria PGN
TLR2
58
TLR that recognizes Gram - bacteria LPS
TLR4
59
TLRs Trigger
Activation of immune cells
| NF-kB
60
Role of PRRs in Phagocytosis
Microbes bind to phagocyte receptors
Phagocyte membrane zips up around microbe
Microbe ingested in phagosome
Fusion of phagosome with lysosome
Killin of microbes by lysosomal enzymes in phagolysosomes or killing of phagocytksed microbes by ROS and NO
61
Complement System
Set of serum proteins which normally exist as soluble inactive precursors
Upon activation, cleaved into two fragments
62
Complement large fragments
have enzymatic properties and activate the downstream components resulting in formation of Membrane Attack Complexes (MAC)
63
Complement small fragments serve as
Opsonins
Chemotactic factors
Anaphylatoxins
64
Opsonins
Deposited on microbes and enhance their uptake by phagocytes bearing complement receptors
65
Chemotactic factors
attract immune cells
66
Anaphylatoxins
cause degranulation of mast cells/basophiles and release vasoactive substances
67
Activation of complement can be triggered 3 ways
Classical pathway
Alternative pathway
Lectin pathway
68
Classical pathway
activated by Ag-Ab complexes
69
Alternative pathway
activated by microbial-cell walls
70
Lectin pathway
activated by interaction of microbial carbohydrates with mannose-binding protein in the plasma
71
2 Phases of Complement activation
Activation of C3 component
| Activation of C5 component
72
Acute Phase Proteins
Blood circulating proteins involved in defense against infections
These plasma proteins are induced rapidly by cytokines after infection
Ex. Mannose-binding lectin
C-reactive protein
73
Mannose-binding lectin
acute-phase protein
| protein that recognizes microbial carbohydrates and activates the complement cascade through the lectin pathway
74
C-reactive protein
Binds to phosphorylcholine on membranes and coats the membranes for phagocytosis by macrophages
75
Cytokines
Small proteins secreted by many cell types
Mediate inflammation, immunity and hematopoiesis
Can be endocrine, paracrine or autocrine
Pro or anti-inflammatory
76
Chemokines
Small protein chemoattractants important for trafficking of immune cells
77
Cell source TNF
M, T cells
78
Cell source IL-1
M, endothelial cells, some epithelial cells
79
Cell source Chemokines
M, endothelial, T lymphocytes, fibroblasts, platelets
80
Cell source IL-12
M, DCs
81
Cell source IFN-y
NK cells, T lymphocytes
82
ONLY cytokine that doesn't come from M
IFN-y
83
Cell source IL-12
M, T cells - mainly Th2
84
Cell source IL-6
M, endothelial cells, T cells
85
Cell source IL-15
M, others
86
Cell source IL-18
M
87
TNF
```
Endothelial cells - activation
Neutrophils - activation
Hypothalamus - fever
Liver - synthesis of acute phase proteins
Muscle, fat - catabolism
Many cell types - apoptosis
```
88
IL-1
Endothelial cells - activation (inflammation, coagulation)
Hypothalamus - fever
Liver - synthesis of acute phase proteins
89
Chemokines
Leukocytes - chemotaxis, activation
90
IL-12
NK cells and T cells - IFN-y synthesis, increased cytolytic activity
T cells - Th1 differentiation
91
IFN-y
Activation of macrophages
| Stimulation of some antibody responses
92
Type I IFNs (IFN-a, IFN-B)
```
All cells - antiviral state, increased class I MHC expression
NK cells - activation
```
93
IL-10
Macrophages - inhibition of IL-12 production, reduced expression of costimulators and class II MHC molecules
94
IL-6
Liver - synthesis of acute phase proteins
| B cells - proliferation of antibody-producing cells
95
IL-15
NK cells - proliferation
| T cells - proliferation
96
IL-18
NK cells and T cells - INF-y synthesis
