Immune System Flashcards
1
Q
What are non cellular immune barriers?
A
Eyes (tears) Skin Respiratory tract Genitourinary tract (flushing of urine) Digestive tract (acid in stomach) Skin
2
Q
what is passive immunity?
what is an example
A
immunity passed from one host to another. not long lived.
example: mother to baby
IgG across the placenta IgA secreted during nursing
3
Q
what is the complement system composed of
A
plasma proteins that lyse foreign cells, especially bacteria
4
Q
what is a MAC
A
membrane attack complex
5
Q
where does a MAC occur
A
surface of the invading bacteria
6
Q
how does a MAC work
A
ruptures the bacterial membrane causing the lysis of the bacteria and death of the organism
7
Q
what is chemotaxis
A
calling of white blood cells to the area of injury
8
Q
what are the functions of the complement system
A
- direct destruction of invading microbes by membrane attack complex
- vasodilation and increased permeability of capillaries and venues to proteins
- chemotaxis
- enhancement of phagocytosis
9
Q
what are the primary lymphoid organs
A
thymus and bone marrow: where immune system is generated and developed
10
Q
what are the secondary lymphoid organs and tissue
A
sites of fully grown immune cells. Specialized organs in body that have mature immune cells: waldeyer ring (lymph nodes, tonsils, adenoids) broncos-associated lymphoid tissue Peter patches urogenital lymphoid tissue lymph nodes bone marrow spleen mesenteric lymph nodes lamina propria
11
Q
what is active immunity
A
immunity produced by an individual either after natural exposure to an antigen or after immunization
12
Q
what type of cells are involved in innate immunity response?
A
mast cell dendritic cell macrophage natural killer (NK) cell complement protein neutrophil basophil eosinophil neutrophil granulocyte
natural killer T cell
T cell
13
Q
what cells are involved in adaptive immunity
A
B cell (antibodies) T cells (CD4 t cell, CD8 T cell)
T cell
natural killer t cell
14
Q
where are lymphocyte maturation sites
A
Thymus: T cells
Bone marrow: B cells
15
Q
what is innate immunity
A
Non specific, does not care what the infection is. happens very fast
16
Q
what is adaptive immunity
A
highly specific and coordinated response. slower response due to specificity
17
Q
what are receptors involved in the innate immunity response
A
toll like receptors
N-formyl methionyl receptor,
mannose receptor
scavenger receptor
18
Q
what do toll like receptors do
A
involved in innate immunity.
recognize broad categories of pathogenic associated molecular patterns.
tell cell how to get rid of pathogen.
receptors on the outside recognize organisms outside of cell (bacteria)
receptors inside the cell recognize things inside (virus)
19
Q
what does N-formyl methionyl receptor do
A
involved in innate immunity: mediates antimicrobial response
20
Q
what does mannose receptor do
A
involved in innate immunity. initiates phagocytosis of microbes
21
Q
what does scavenger receptor do?
A
involved in innate immunity.
phagocytosis of cellular debris
22
Q
what is PRR & what does it do
A
pattern recognition receptor. recognize PAMP
23
Q
what is PAMP
A
pathogen associated molecular patterns
24
Q
what is the sequence of events in a localized innate inflammatory response?
A
- injury to tissues cause release of chemicals to imitate the following events
- chemical mediators cause vasodilation (increased blood flow)
- increase in permeability of capillaries and venues in the area. (allows diffusion of protein and filtration of fluid into the interstitial fluid)
- chemotaxis ( movement of leukocytes from venues into the interstitial fluid of the infected area)
- destruction of bacteria in the tissue by neutrophils and phagocytosis or other mechanisms
- capillaries return to normal as neutrophils continue to clear infection
- tissue repair
25
what are the inflammatory mediators
```
kinin
complement
products of blood clotting
histamine
eiocosanoids
platelet activity factor
cytokines (including chemokine)
lysosomal enzymes, nitric oxide, and other oxygen derived substances
```
26
what is the source of kinin (inflammatory mediator)
generated from enzymatic action on plasma proteins
27
what is the source of complement (inflammatory mediator)
generated from enzymatic action on plasma proteins
28
what is the source of products of blood clotting (inflammatory mediator)
generated from enzymatic action on plasma proteins
29
which inflammatory mediators are generated from enzymatic action on plasma proteins
kinins, complement, products of blood clotting
30
what is the source of histamine (inflammatory mediator)
secreted by mast cells and injured cells
31
what is the source of eicosanoids (inflammatory mediator)
secreted by myeloid cells (and others)
32
what is the source of platelet activating factor (inflammatory mediator)
secreted by myeloid cells, endothelial cells, platelets, damaged tissue cells (and others)
33
what is the source of cytokines, including chemokine (inflammatory mediator)
secreted by activated immune cells, monocytes, macrophages, neutrophils, lymphocytes and other nonimmune cells (endothelial cells and fibroblasts)
34
what is the source of lysosomal enzymes, nitric oxide, and other oxygen derived substances (inflammatory mediator)
secreted by injured cells, neutrophils, and macrophages
35
what do natural killer cells do?
primary job is to kill virally infected and tumor cells
produce cytokines (IFN-y) for macrophages early in infection.
lymphocytes (not MCH restricted)
36
what do eosinophils do?
type of granulocyte
play prominent role in response to parasitic infection
involved in allergic reactions and asthma
37
are natural killer cells part of innate or adaptive immunity
innate
38
what do eosinophils release during degranulation
eosinophil cationic protein
major basic protein
eosinophil peroxidase
reactive oxygen and reactive nitrogen intermediate
39
what do neutrophils do
control 95% of circulating granulocytes
| attracted to sites of infection by multiple signals including bacterial products
40
what do lysosomes contain
acid-hydrolyses, myeloperoxidase, muramidase
41
what do lysosomes do
contain ingested bacteria within vacuoles (phagosomes)
42
what are the 2 major functions of monocytes and macrophages
1. phagocytes that engulf particulate antigen and degrade microbes
2. antigen-presenting cells (APC) to take up, process and present antigenic peptides to T cells (professional antigen presenting cell)
43
what is the difference between monocytes and macrophages
all cells leave as monocytes and become macrophage once in tissue
44
which cytokine activates phagocytes
interferon gamma
45
steps in phagocytosis
1. microbe binds to mannose receptor
2. outside of cell membrane starts to zip around
3. microbe is encircled (phagosome)
4. phagosome is cellular organelle created by pinching off outside of cellular membrane around the microbe and pulling microbe in (also takes in external microenvironment)
5. fusion of phagosome with lysosome (phagolysosome
6. activation of phagocyte (by interferon gamma)
7. once phagocytosed able to kill that one microorganism through all lysosomal enzymes and phagolysosomes
46
what is a phagosome
microbe that has been encircled by cell.
47
what is a phagolysosome
when phagocyte and lysosome fuse
48
what are the 3 roles of phagocytosis
1. recognize there is a microbe
2. take up microbe
3. direct other immune response (either presenting antigen or secreting cytokines/ other factors)
49
what are the 2 actions of phagocytes after contact with microbe
1. phagocytosis
| 2. secretion of chemicals ( cytokines and chemokine)
50
what are the roles of phagocytosis
intracellular killing of microbes
51
what are the roles of the chemical secreted by phagocytes
1. regulation of inflammatory process
2. extracellular killing of microbes
3. activation of clotting and anti-clotting pathways
4. hormonal regulation of overall bodily responses to infection
52
what is oponization
tagging a bacteria for death
53
how does oponization work?
opsonin binds the bacteria and makes for a better/bigger target for phagocyte.
enhances phagocytosis by putting more spots to be recognized.
opsonin binds bacteria. phagocyte has opsonin receptors. easier for phagocyte to find/bind
54
what is C3B
type of opsonin
55
what is the main job of a dendritic cell?
phagocyting microbes to be able to present peptide antigens to lymphocytes (naïve T cell) to activate t cell response
link innate immune response to the adaptive immune response
is a phagocytic cell but does not primarily participate in phagocytosis
56
what are cytokines
proteins produce by many different cell types that mediate inflammatory and immune reactions
principal mediators of communication between cells of the immune response
57
what are the major cytokines
1. Interleukin 1, tumor necrosis factor alpha, and interleukin 6
2. interleukin 2
3. interferon type 1
4. interferon type 2
5. chemokine
6 cologne stimulating factors
58
what is the major function of interleukin 1, tumor necrosis factor- alpha, and interleukin 6
stimulate interleukin 2 receptor expression, induce fever, stimulate systemic responses to inflammation infection and injury
59
what is the major function of interleukin 2
stimulate proliferation of helper T cells, NK cell, B cells
promote conversion to plasma cells
60
what is the major function of interferon type 1
stimulate cells to produce antiviral proteins (innate response)
61
what is the major function of interferon type 2
activation of NK cells and macrophages and elimination of infection
62
what is the major function of chemokine
facilitate accumulation of leukocytes at sites of injury and inflammation.
Influence chemotaxis
tell cells when to leave and when to stay during homeostasis
63
what is the major function of colony stimulating factors
stimulate proliferation of neutrophils and monocytes in the bone marrow
64
what is type 1 interferon do
attaches to unaffected (by virus) cells and test them to make an anti viral protein to protect themselves
65
what does binding of interferon 1 to unaffected cell do?
creates antiviral protein in cell.
prevents infection of the cell
if cell becomes infected will not allow virus to replicate
66
what components of the innate immune response are common to all pathogens
1. phagocytosis and killing of microbes
2. antigen presentation
3. cytokine production to induce inflammation and reactive endothelium
67
what is apart of the innate immune system
epithelial barriers, phagocytes, complement, NK cells
68
what is apart of the adaptive immune system
antigen (Ag) specific cells
| T cells, B cells
69
what does a B cell receptor (Ig) do in the adaptive immune system
recognize soluble intact macromolecules (proteins, lipids, polysaccharides) and small chemicals
70
what does a t cell receptor (TCR) do in the adaptive immune system
only recognize processed antigen fragments presented by MHC on the surface of antigen presenting cells
71
what are the 3 stages of the immune response in specific immune defense
1. encounter and recognition of antigen by lymphocytes
2. lymphocyte activation
3. attack by lymphocytes and their secretions
72
what are the parts of a lymphocyte receptor (antibody)
constant end
| variable end
73
what is the constant region on an antibody
same within a class of antibodies. tail end of Y
74
what is the variable region on an antibody
prong end of Y. varies for different antigens, gives specificity to antigen binding
75
how many chains on an antibody receptor? what types?
4: 2 heavy, 2 light
76
what is the Fc stem
tail end of antibody receptor. can bind immune cell. how antibodies communicate
77
what are the antibody function in humoral immunity
the antibody functions to bind the specific antigen
| leads to inactivation and destruction of the foreign antigen
78
what are the 5 classes of antibodies
IgG, IgM, IgE, IgD, IgA
79
what is IgG
majority of antibodies in circulation. can cross placenta. happens after time when you have the antigen to protect in future. only after you have been exposed and have memory
80
what is IgM
expressed on surface of B cells (naÏve). secreted first for new/current infection. most common receptor on B cell
81
what is IgE
important for allergic reactions and parasitic infection
82
what is IgD
expressed on surface of b cells (nïve) less common than IgM
83
what is IgA
found in mucosal areas such as gut, respirator tract, urogenital track, mucosal secretions. can get passed through breast milk
84
what are special about plasma cells
were b cells that become activated and can secrete any antibody
85
what are antibody functions
1. neutralization
2. agglutination
3. opsonization
4. complement activation
5. enhanced natural killer cell activity
86
what is the summary of events in antibody mediated immunity against bacteria
1. bacterial antigen binds to receptor on b cell plasma membrane
2. antigen presenting cell (most likely dendritic)
2a. presents to helper t cell through MCH class 2 on the antigen presenting cell
2b. secretes IL1, TNF-alpha, and other cytokines which act on the helper t cells
3. helper t secretes IL2 to stimulate helper T themselves to proliferate and secrete IL2 and other cytokines
4. activate antigen bound b cells to proliferate and differentiate into plasma cells
5. plasma cells secrete antibodies specific for the antigen that initiated the response and the antibodies circulate
6. antibodies combine with antigen on the surface of the bacteria
7. presence of antibody bound to antigen facilitates phagocytosis of the bacteria by neutrophils and macrophages
8. activates the complement system
9. further enhances phagocytosis and can directly kill the bacteria by MAC
10. may induce antibody depended cellular cytotoxicity mediated by NK cells that bind to the antibodies FC portion
87
what are the 3 professional antigen presenting cells
dendritic, macrophages, b cell
88
what kind of antigens do B cells process
antigens specific to for themselves (need help from t cell)
89
what are the steps in antigen presentation to T cells
1. antigen is taken up (phagocytosis in macrophage endocytosis in b cell)
2. antigen is broken down into parts
3. bound to MHC class 2
4. recognized from t cell receptor
90
what is MHC
major histocompatibility complex molecules
91
what is another name for MHC
HLA (human leukocyte antigen)
92
what are 2 classes of MHC molecules and how are they different
Class 1: expressed on the surface of all nucleated cells.
important for viral infections
Class 2: on the surface of macrophages, activated b and T cells and thymus cells.
important to create helper T cells
93
what do MHC molecules do?
Self recognition.
unique to each individual.
mark cells as “self” or beacon that cells are foreign
94
what is important for activation of helper T cell
```
CD4 important for MHC with interactions with antigen presenting cells
CD4 recognizes class 2 MHC allowing for helper t cells to make cytokines to help other cells
```
95
what is the main function of CD4
```
help macrophage, b cell be better at their job.
recognize class 2 MHC allowing for helper T cells to make cytokines to help other cells
```
96
what are important functions of cytotoxic T cells
```
CD8 main function to kill off virally affected cell or tumor cell
recognize class 1 MHC
```
97
what is the main function of CD8
kill off virally affected cell or tumor cell and recognize class 1 MHC
98
what are NK cells
natural killer cells:
class of lymphocytes (similar to cytotoxic t cell)
major target virus infected cell and cancer cells
not antigen specific
influenced by antibodies and helper T cells
99
what does C3B do
enhance phagocytosis
100
what does C1 do in the complement activation process
activates classical complement pathways. which activate MAC and C3b
101
how does memory in immune response work
primary and secondary immune response
102
how does the primary immune response work
1st exposure.
takes 10-17 days.
symptoms of illness occurs
antigen-selected B and T cells proliferate and differentiate into effector cells
103
how does secondary immune response work
all other exposures after 1st.
takes less time (2-7 days)
greater response
occurs due to memory cells
104
how does defense against virus/infected cells/ cytotoxicity work
1. infected cell recognizes viral antigen (MCH class 1)
2. needs help from other t cell
3. macrophage recognized. present antigen to helper T via MHC class 2
4. t cell makes cytokine IL2, interferon gamma
4a. allows cytotoxic t cell to proliferate/activate/make more of itself
5. cytotoxic t cell (NK and t cells do the same/ function same way) travel to site of infection
6. find infected cell secrete perforin to “poke holes”
7. secrete granzymes that is able to get into infected cell due to perforin
8. apoptosis/ virus can not replicate
105
what is the role of perforin
released by activated cytotoxic t cell.
“pokes holes in virally infected cells”
facilitates entry for granzymes
106
what is the role of granzymes
release by activated cytotoxic t cell. enter virally infected cell and cause apoptosis
107
what is the role of IL 2
proliferation of B cell to create plasma cell to allow cells to proliferate.
made by helper t.
turn on cellular immune response
108
what is the role of interferon gamma
activate macrophage and NK cell.
made by helper t
turn on cellular immune response
109
innate response main cells involved
anatomical barriers, inflammation, interferon type 1
| body surface linings, tissue macrophages, most cell types after viruses enter
110
what are the actions of innate response
provide physical barrier, antiviral chemicals. provide phagocytosis of extracellular virus. type 1 interferon nonspecifically prevents viral replication inside host cell
111
adaptive response antibody mediated main cell involved and action.
plasma cells (derived from b cells) that secrete antibodies
antibodies neutralize virus and prevent viral entry into cell.
antibodies activate complement which leads to enhanced phagocytosis of extracellular virus
antibodies recruit NK cells via antibody mediated cellular cytotoxicity
112
adaptive response helper cells involved and action
helper T
secrete interleukins. keep NK cells, macrophages, cytotoxic t cells and helper T cells active.
help convert b cells to plasma cells
113
adaptive response direct cell killing. cells involved and action
cytotoxic t cell, NK cells, activated macrophages .
destroy host cell via secreted chemicals and thus induce release of virus into extracellular fluid where it can be phagocytksed.
activity stimulated by IL 2 and interferon gamma
114
examples of antigenic over stimulation/ over reaction of immune response
allergies (hay fever, sinusitis, contact dermatitis), autoimmunity (arthritis, lupus), graft and transfusion rejection
115
examples of antigenic under stimulations/ under creation of immune response
cancer, immunodeficiency
116
what is the process of systemic manifestations of infection
1. microbes microbial products, tissue injury
2. monocytes and macrophages secrete IL 1, TNF, IL 6
3. increase plasma IL, TNF, IL
4. affect brain, liver, bone marrow, adipose tissue, muscle, hypothalamus anterior pituitary
117
how is the brain affected in systemic manifestations of infection
fever, decreased appetite, decreased food intake, fatigue, sleepiness
118
how is the liver affected in systemic manifestations of infection
retains iron, zinc
secretes acute phase proteins
leads to decreased plasma iron and zinc
increased plasma acute phase proteins
119
how is the bone marrow affected in systemic manifestations of infection
increased production and release of leukocytes.
leads to increased leukocytes in the blood
120
how is the adipose tissue affected in systemic manifestations of infection
increased lipolysis
leads to increased plasma free fatty acids
121
how is the muscle affected in systemic manifestations of infection
increased protein breakdown.
increased amino acid release
leads to increased plasma amino acids
122
how is the hypothalamus/anterior pituitary affected in systemic manifestations of infection
increase in plasma ACTH
leads to adrenal cortex increase cortisol secretion
leads to increased plasma cortisol
123
what are the major types of hypersensitivity
1. delayed hypersensitive
2. immune complex hypersensitivity
3. cytotoxic hypersensitivity
4. immediate hyper sensitivity
124
important about delayed hypersensitivity
only type independent of antibodies.
mediated by helper t cells and macrophages.
example TB test
125
important about immune complex hypersensitivity
mediated by antigen-antibody complexes deposited in tissue
example lupus
126
important about cytotoxic hypersensitivity
mediated by antibodies that lead to damage or destruction of cells
example: hemolytic disease of the newborn
127
important about immediate hypersensitivity
mediated by IgE antibodies, mast cells, eosinophils
example: allergy (inhale or ingest)
128
what are factors that can alter the body’s resistance to infection
```
nutrition
pre existing disease
stress
physical exercise (heighten immune response)
sleep deprivation
genetic deficiency
```
129
what are some harmful immune responses
```
graft rejection
transfusion reaction
allergy (hypersensitivity)
autoimmune disease
excessive inflammatory response
```
130
what is active immunity
immune response to vaccine or pathogen. gives immunity due to memory cells
131
how does vaccine work
introduction of a microorganism or its antigen in a form not expected to cause disease.
induces immune response including production of memory cells
132
what is passive immunity
comes from administration of synthetically produced antibodies.
no memory cell production
no long term memory or immunity
can come from mother to child in placenta (IgG) or breast milk (IgA)
