Innate Immune System Flashcards
(122 cards)
1
Q
what cells are sentinel cells
A
macrophage
dendritic cells
2
Q
what cells have phagocytic functions
A
macrophages
neutrophils
3
Q
what cells are antigen presenting cells
A
macrophages
dendritic cells
4
Q
what are the ways a cell can create signals intercellularly
A
- cell surface receptors
- small soluble molecules
5
Q
when are cell surface receptors expressed
A
mostly when induced
6
Q
what can a cell surface receptor be used for
A
- binding signaling molecules from other cells
- bind microbes and host cells
7
Q
what are types of intercellular signaling used in the innate immune system
A
- cell surface receptors
- small soluble molecules
8
Q
what is the fate of the signals secreted from the cell
A
bind on receptors of other cells
9
Q
how do cells bind to each other
A
using complementary receptors
10
Q
True or False:
Cells integrate/regulate intercellular signals in a regulated manner
A
true
11
Q
what are the functions of the signals sent to other cells
A
- divide/stop dividing
- die
- express receptors
- secrete more signals
12
Q
what is released in the event the cells of the immune system are activated
A
cytokines
13
Q
what are cytokines
A
small, soluble protein molecules
14
Q
what are the main cytokines
A
- interleukines
- lymphokines
- chemokines
- interferons
15
Q
besides communication with other cells and impact on cellular behavior, what are cytokines’ function
A
growth
differentiation
secretion
16
Q
where can cytokines be present
A
local or systemic
17
Q
what is needed for a cell to be able to respond to a cytokine
A
receptors
18
Q
True or False:
One type of cytokine can be made by several different cells
A
true
19
Q
how is the function of a cytokine determined
A
per situation
20
Q
what is the MAIN result of the activation of cytokines
A
initiates inflammation
21
Q
what cytokine acts as growth and differentiation factors for cells of the immune system
A
interleukins
22
Q
which cytokine is secreted by lymphocytes
A
lymphokines
23
Q
which cytokine has pro-inflammatory and chemotactic properties
A
chemokines
24
Q
what cytokine can interfere with viral replication
A
interferons
25
which cytokine kills tumor cells and also can regulate inflammation
tumor necrosis factor
26
what are the primary activators of the innate immune system
sentinel cells
27
what is the job of sentinel cells
recognize invader or tissue damage
28
which sentinel cell is responsible for identifying, capturing, and killing microbes
macrophage
29
True or False:
Macrophages are not APCs
False
Macrophages are APCs because of their presence of cell surface receptors
30
what cell is the primary antigen-presenting cell
dendritic cell
31
how do macrophages and dendritic interact with the acquired immune system
through antigen presentation
32
where can you find sentinel cells
highest concentration at infection site
33
what do sentinel cells and all phagocytic cells express on their surface
Pathogen Recognition Receptors (PRRs)
34
what do PRRs recognize
Pathogen-Associated Molecular Patterns
(PAMPs)
35
what are PAMPs
conserved molecular patterns on microbial surfaces
36
what is the purpose of the Pathogen Recognition Receptors?
They are used to recognize molecular patterns on the surface of microbes
37
why is inflammation the main result of the release of cytokines by sentinel cells
- increased vascular permeability
-increased blood flow
- attraction of neutrophils to the site
38
what is the major mechanism of the innate immune response to a microbe
inflammation
39
what are the signs of inflammation
1. redness
2. swelling
3. heat
4. pain
5. loss of function
40
what phagocytic cell is found in the blood
monocytes
41
what phagocytic cells is found in tissues
macrophages
42
what are the polymorphonuclear cells
-neutrophils
-eosinophils
-basophils
43
what activates phagocytic cells
dead and dying cells
44
how are tissue macrophages named
based on location
45
what is the impact steroids have on macrophages
down-regulated
46
how would steroid use impact the immune system
decreases the ability of macrophages to kill pathogens
47
with what clinical sign should be hesitant/ cautious to use steroids with
inflammation
48
why should we be careful using steroids with cases of inflammation
inflammation could be caused by infection and steroids would decrease macrophage abilities
49
what is the major phagocyte to respond to infection
neutrophils
50
where can you find neutrophils?
-high numbers in circulation (blood)
-bone marrow
51
what do we count in a CBC
amount of neutrophils in the circulating pool
52
what is the presence of above normal concentration in the circulating pool
Neutrophilia
53
what are the two places in circulation the neutrophils can be found?
1. circulation pool
2. marginating pool
54
where is the marginating pool of neutrophils found
adhering to endothelium
55
in what species can there be 3x more the amount of neutrophils in the MP than CP
cats
56
what can stress in cats cause to be shown on a CBC
neutrophilia
57
what is the importance of bone marrow when it comes to neutrophils
1. proliferation pool
2. maturation pool
3. storage pool
58
what leads to the death of neutrophils
phagocytosis
59
what is attracted to dying neutrophils
macrophages
60
which neutrophils do no undergo proliferation
circulating & mature
61
when do neutrophils become active
immediately after release from bone marrow
62
True or False:
Neutrophils are used for long-term killing
FALSE
incapable of sustained killing
63
what receptors are present in neutrophils
1. surface receptors for complement proteins
2. receptors for Fc part of antibody
64
do macrophages or neutrophils have a greater speed of response for phagocytosis
neutrophils
65
which phagocytic cell is involved in tissue repair and APCs
macrophage
66
what is the 1/2 life of blood monocytes
1 day
67
what is the life span of tissue macrophages
several months or years
68
which phagocytic cell has greater antimicrobial abilities
macrophages
69
what are the main defense factors of phagocytes
-enzymes
-defensins
-interferons
-complement proteins
70
what is used by phagocytes to cause oxidative damage to membranes
enzymes
71
what is a defensin
anti-bacterial peptide
72
what can be produced by phagocytic cells to interfere with viral replication
interferons
73
what is produced by macrophages and hepatocytes
complement proteins
74
what coats microbes and enhances phagocytosis
opsonins
75
what is the function of the receptors on the phagocytic cells
recognize molecules on pathogens
76
what is a cell surface molecule that promotes adherence of a cell to various things
integrens
77
True or False:
phagocytic cells have receptors for complement proteins
true
78
what is the purpose of a complement protein
coat microbes for ID
79
what are complement proteins similar to (slightly mimic)
opsonins
80
what is the purpose of having receptors for complement proteins and Fc part of the antibody receptors
cells can now see and bind to the microbe because of the coating
81
how are phagocytic cells able to coat microbes in order to reveal them
complement proteins
82
what is the name of the mechanism used by phagocytes to facilitate adherence to microbes through complement proteins
opsonization
83
what are the 4 steps to phagocytosis
1. Chemotaxis
2. Adherence
3. Ingestion
4. Destruction
84
what is directed migration according to the chemical gradient
chemotaxis
85
what happens after a phagocyte arrives to the site of inflammation
adherence to epithelium via integrins
86
in a clinical case of pyoderma, what diagnostic test would be used to confirm the case
impression smear of skin
87
in what clinical case would you see an impression smear of skin filled with many phagocytes
pyoderma
88
after the phagocytes arrive at the site of infection, what cells come in to kill the organism in the innate immune system
neutrophils
89
what do phagocytic cells use to recognize microbes
adherence
90
what is used to promote adherence in macrophages and neutrophils
- receptors of Fc part of Ab
- Opsonins
-receptor for complement protein
- PRR
91
True or False:
all macrophages and neutrophils cant express identical receptors
FALSE
they can express identical receptors for recognizing microbes (PRRs)
92
what are often molecules essential for the survival of the microbe
Pathogen-Associated Membrane Patterns
PAMPs
93
what is unique about PAMPs that makes them the ideal protection for survival
do not mutate or change expression
94
what is the most important group of PRRs
Toll-like receptors (TLRs)
95
where are Toll-like Receptors present
-cell surface
-intracellular
96
what is the purpose of cell surface TLRs
recognize extracellular invaders
97
What is the purpose of intracellular TLRs
detect intracellular viruses
98
True or False:
A TLR is a PRR
true
99
what do TLRs interact with
PAMPs
100
what is the result of a TLR signal to the host cell
- killing of microbe
- production of cytokine resulting in inflammation
101
what are two destruction mechanisms used in the innate immune system by phagocytic cells
oxygen-depending & oxygen-independent killing
102
which phagocytic destruction mechanism is essential to survive
oxygen-depending killing
103
which destruction mechanism can we expect to take place in a low pH environment
oxygen-independent
104
in what cell type can Mycobacterium bovis and Rhodococcus equi survive
macrophages
105
True or False:
some pathogens can become resistant to lysosomal contents or inhibit phagolysosomal fusion
true
106
what clinical cases can be seen to inhibit phagolysosomal fusion
1. Mycobacterium bovis
2. Rhodococcous equi
3. Brucella abortus
4. Listeria monocytogenes
5. Salmonella typhimurium
107
what cell will not only kill the microbe but also the host cell
natural killer cells
108
True or False:
NK cells and CTLs have the same recognition mechanism for host cells
False
CTLs need antigen to be presented
109
True or False:
NK cells kill microbes directly as well as infected host cells
FALSE
NK cells are only responsible for killing the infected host cell
110
what makes NK cells dangerous if left unregulated
they do not need an antigen present for activation. They will kill any host cell they deem infected
111
what can NK cells express to antibodies
FcR
112
how can an NK cell identify an infected host cell
a host cell will have antibody attached to the surface and the FcR on the NK cells will attach to it
113
how can NK cells recognize antibodies made for foreign material
B-lymphocytes make the antibodies for the NK cell to recognize
114
what is Antibody-dependent cell-mediated cytotoxicity (ADCC)
Interaction between FcR and antibody on the cell triggering the NK cell to release cytolytic granules
115
what is the purpose of cytolytic granules
initiates apoptosis of the host cell
116
how would ADCC be useful in drug development
antibody specific for tumor antigens can lead NK cells to kill the tumor cell faster and more effectively
117
what mechanisms do NK cells use to target cells
1. ADCC
2. Receptors for complement proteins
3. lack of MHC-1 expression
118
how are NK cells effected by the presence of MCH-1 molecules
inhibited by the host cell
119
what does MHC-1 molecules signal for
normalcy / healthy cells
120
True or False
All normal, nucleated cell can express MHC-1
true
121
what occurs is the host cell does not express any MHC-1 molecules
the NK cell will try to kill it because "it is not normal"
122
what are NK cells regulated by
cytokines
