Unit 2 - Innate Immunology Flashcards
(159 cards)
1
Q
What organ represents the largest organ of the human immune system?
A
Skin
2
Q
What does the lymphatic system drain into?
A
Vena cava
- circulatory system
3
Q
True or False:
Lymphatic system and circulatory systems use the same vessels
A
False
- they are separate systems that run in parallel
4
Q
Describe the relationship between the heart, the capillaries, and the lymphatic system
A
- Heart pumps blood to capillaries
- Fluid leaks into the tissues
- Fluid is drained into lymph capillaries and returned to the heart
5
Q
What are the two types of lymphatic tissue?
A
- Primary lymphoid tissue
2. Secondary lymphoid tissue
6
Q
What are two examples of primary lymphoid tissue?
A
- Bone marrow
- Thymus
7
Q
What are 2 examples of secondary lymphoid tissues?
A
- Spleen
- Lymph nodes
8
Q
What is the FUNCTION of the primary lymphoid tissue?
A
MAKES the immune cells
- made in the bone marrow
- matures in the thymus
9
Q
What is the FUNCTION of the secondary lymphoid tissue?
A
STORES the immune cells
10
Q
What does bone marrow contain (the cells that differentiate into immune cells)?
A
Hematopoietic stem cells
11
Q
What is the role of the thymus in the immune system?
A
Involved in the maturation of T-cells
12
Q
What is the role of the lymph nodes (3)?
A
- Stores leukocytes
- Filters body fluids
- Detects evidence of infection (antigens, pathogens)
13
Q
What is the role of the spleen in the immune system?
A
Filters blood to remove old red blood cells or pathogens in blood
14
Q
What is the primary component of the cell wall of gram (+) bacteria?
A
Peptidoglycan
- absorbs gram stain and makes them show positive
15
Q
Define innate immunity
A
Defense mechanisms present at BIRTH
16
Q
Define adaptive/acquired immunity
A
Defense mechanisms acquired by exposure to pathogens
17
Q
Which type of immunity tends to be specific? Non-specific?
A
Specific = acquired/adaptive Non-specific = innate
18
Q
What is the first line of defense?
A
INNATE: Surface protection
- anatomical and physiological
- genetic barriers
- non-specific chemical barriers
19
Q
What is the second line of defense?
A
INNATE: cellular and more specific chemical barriers
- mostly non-specific
- no immunological memory
20
Q
What is the third line of defense?
A
ADAPTIVE/ACQUIRED: Specific immune response developed against individual pathogens
- memory for immunity
21
Q
What are 2 examples of first line defenses?
A
- Skin
- Coughing
- Sneezing
- low pH
- Lysozyme
22
Q
What are 2 examples of second line defenses?
A
- Phagocytosis
- Inflammation
- Fever
- Interferon
23
Q
What are 2 examples of third line defenses?
A
- T-lymphocytes
- B lymphocytes
- Antibodies
24
Q
What are some example of chemical barriers in the first line defense?
A
- Oil
- Salt
- Saliva
- Lysozyme
- Defensins
- Urine
25
What do lysozymes break down?
Break down CELL WALLS on bacteria (gram +)
| - they target peptidoglycan
26
How is mucus is physical barrier in the first line defenses?
Epithelial cells secrete mucus
| - traps pathogens to be flushed from the body
27
What is the mucociliary escalator?
The epithelial cells of the respiratory tract that have short hair-like cilia to brush mucus up and out of the tract
28
True or False:
| Lungs should be germ-free
True
29
True or False:
| Pathogens become highly specialized to a specific host, and genetic changes can bring about immunity
True
- this can be done by mutation
- for example: some ppl have 32 base pairs were deleted to create a partial resistance against HIV
30
True or False:
| In order to be successful, pathogens have to overcome physical barriers
False
| - must overcome physical, chemical and genetic barriers
31
Explain the methods used by Helicobacter pylori to overcome the physical, chemical and genetic barriers in humans
```
Physical = flagellum burrows into mucosal layer of the stomach
Chemical = ammonia (from urea) neutralize stomach acid
Genetic = well-adapted to survive in the human stomach
```
32
Explain what a microbiome does for the body
"Good" or resident microbes line our body and block other "harmful" pathogens from adhering
33
Why can antibiotics be bad for you?
They kill off bad bacteria AND "good" bacteria, leaving us vulnerable other bacteria (good/bad) taking up residence
34
What are the 7 methods of innate immunity?
1. Physical barriers
2. Chemical barriers
3. Genetic barriers
4. Inflammatory response
5. Interferons
6. Phagocytosis
7. Complement
35
What immune system is active at birth? Which one takes time to develop?
Birth = INNATE
| Takes time = ACQUIRED
36
What is centrifugation?
Components of blood separate when spun at high speed
37
What is blood plasma?
Blood minus cells
| - it looks cloudy
38
What is blood serum?
Plasma minus clotting proteins
| - it looks clear
39
What is the buffy coat?
The layer of WBCs after blood has been subjected to centrifugion
40
Where do RBCs, platelets and leukocytes come from?
The same stem cell
| - Hematopoietic stem cell
41
What are the two lineages of leukocytes?
1. Myeloid
| 2. Lymphoid
42
Which immune cells (leukocytes) are active at birth?
1. All myeloid cells
| 2. One lymphoid cells (NK cells)
43
What is the function of leukocytes?
Recognize non-self cells
| - like cells with cell walls
44
From the lymphoid lineage, what cells are innate and which are acquired?
```
Innate = Natural killer cells
Acquired = everything else
```
45
What are the leukocytes that are part of the innate system that are derived from the myeloid lineage?
1. Neurtrophils
2. Basophils
3. Eosinophils
4. Monocytes
46
What are the 3 leukocytes derived from the lymphoid lineage?
1. T cells (acquired)
2. B cells (acquired)
3. Natural killer cells (innate)
47
What is the name of the leukocyte system that resides in the network of reticular connective tissue?
Mononuclear phagocyte system
- this is between the cells and tissues
(formerly reticuloendothelial system)
48
What cells are made up of aneucleated cell fragments?
Platelet (Thrombocyte)
49
What are platelets produced by?
Megakaryocyte
50
When platelets are activated, what do they release?
Blood clotting agents
51
Define thrombocytopenia
Failure to form blood clots
52
Define thrombocytosis
Too many blood clots
| - can lead to blood vessel blockage
53
What chemotactic agent do platelets release that cause other cells to move toward its source?
Platelet-derived growth factor
54
True or False:
| Platelets help to fight off infections
False
- platelets release platelet-derived growth factor that attract leukocytes to the site - which DO fight off the infection
55
Phagocytes are cells that are part of which immune system (innate or acquired)?
INNATE immune system
56
Which phagocytes have special PRRs that are callled toll-like receptors (2)?
1. Neutrophils
| 2. Macrophages
57
How do phagocytes tell the difference between "self-cells" and "non-self" cells?
Pattern recognition receptors (PRRs)
| - can "feel" abnormal surface on non-self cells
58
What is the name for the abnormal surface of the invading cell, that the phagocyte will recognize with their PRRs?
Pathogen associated molecular patterns (PAMPs)
59
How are neutrophils able to chase down invading bacteria?
Chemotaxis!
60
What is the reason that RBCs don't get eaten by neutrophils?
RBCs lack the pattern (PAMPs)
| - therefore they don't get eaten
61
Neutrophils have receptors on them that act as PRRs (Pattern recognition receptors), what are these receptors made up of?
Proteins
62
What happens to the bacteria after the PRRs bind with the PAMPs?
The phagocyte invaginates and "eats" the bacteria
63
What is the name of the cell compartment that is filled with toxins and enzymes?
Lysosomes
64
What is the name of the resulting somal body from the fusion of a phagosome and a lysosome?
Phagolysosome
65
What is the function of lysosomes?
Digest things!
- they are acidic
- they have digestive enzymes inside of them
66
What are the two mechanisms that phagocytes use to achieve intracellular killing?
1. Oxygen dependent mechanisms
| 2. Oxygen independent mechanisms
67
Describe reactive oxygen species (respiratory burst)
1. Oxygen is converted to superoxide (if we remove an electron
2. Superoxide + water = H2O2 (hydrogen peroxide)
3. If we break H2O2 in half ... we get OH radicals (which are more toxic than H2O2)
4. O2+ (superoxide), H2O2, OH and bleach are all found inside lysosomes
68
What is hypochlorite made up of?
Chlorine (Cl-) + Hydrogen peroxide (H2O2)
69
What are the 3 electrically charged proteins that are involved in oxygen independent mechanisms in phagocytes?
1. Lysozyme
2. Lactoferrin
3. Protease
70
How do lysozymes damage membranes?
Lysozymes target the cell wall in gram (+) bacteria
71
What does lactoferrin do to bacteria?
It's a protein that binds to iron
- bacteria are starved for iron
- this pulls the iron away from the bacteria
72
What does protease do to bacteria?
Breaks down proteins and peptides
73
What is the other name for neutrophils?
Polymorphonuclear cells (PMN cells)
74
What is the most abundant leukocyte in blood?
Neutrophils
75
Where are neutrophils mainly found in the body?
Circulating in the system (blood, to tissues, to lymph vessels)
76
What are two characteristics of neutrophils?
1. Granulocyte
| 2. Phagocyte
77
What is the role of monocytes?
They circulate in the blood and enter tissues during infection
- they regulate the inflammatory response
78
What can monocytes differentiate into (2)?
Macrophages or Dendritic cells
79
What do macrophages promote (3)?
1. Localized inflammation
2. Immune response
3. Custodial role (cleaning up debris)
80
What leukocyte is the bridge between the innate and adaptive immune systems?
Dendritic cells
81
Where are monocytes typically found (3)?
Lungs
Liver
Spleen
82
How are eosinophils and basophils different from neutrophils (in regards to the method killing foreign objects)?
Eosinophils and basophils RELEASE the contents of their granules to the EXTRACELLULAR SPACE
- neutrophils deal with the foreign object INSIDE (phagolysosome)
83
What are mast cells functionally equivalent to?
Basophils
84
True or False:
| Mast cells are not granulocytes but have granules
True
- mast cells are not typically found in the blood, even though they have the same function
- this is how they were missed in the classification of granulocytes
85
True or False:
| Mast cells are avid phagocytes
True
86
True or False:
| Monocytes are granulocytes
False
| - The cells that are granulocytes are neutrophils, basophils, eosinophils and mast cells
87
What do eosinophils target?
Multicellular parasite - that are too big to phagocytose
| - therefore, release their toxins to EXTRACELLULAR space
88
What is frustrated phagocytosis?
```
The cell (eosinophil) DEGRANULATES to release toxins in the vicinity of the pathogen
- histamine may also be released
```
89
What happens to the surrounding tissues if frustrated phagocytosis occurs?
Toxins will affect healthy "self" cells as well
| - causing stress and maybe necrosis
90
What are some parasites coated in, that make eosinophils especially attracted to them?
IgE antibody
| - results in antibody-dependent cell-mediated cytotoxicity (antibodies that are calling the WBCs to them)
91
Mast cells and basophils are quite different cells but perform the same function. What is that function?
Induce inflammation
92
Where are mast cells found? Where are basophils found?
Mast cells = connective tissue
| Basophils = circulate in blood
93
What do mast cells and basophils release (2)?
1. Histamine
| 2. Prostaglandins
94
If Basophils and mast cells are able to release histamine and prostaglandins, how do they store it in the cells?
```
Histamines = stored in the granules
Prostaglandins = produced as needed
```
95
What are inflammatory cytokines?
Chemicals that coordinate the immune response
96
What are the two inflammatory cytokines (of basophils and mast cells)?
1. Histamine
| 2. Prostaglandins
97
Which inflammatory cytokine has an immediate effect and which has a prolonged effect?
```
Histamine = immediate
Prostaglandins = prolonged
```
98
True or False:
| Phagocytes can end up being the host for a virus or endocytic parasite
True
| - such as TB!
99
True or False:
| Natural Killer Cells are lymphocytes that phagocytose their targets
False
| - NK cells either lyse the target cell or induce apoptosis
100
How do natural killer cells (NK) kill their target cells (2)?
1. Lyse the target cell (inject toxins into the cells)
| 2. Induce apoptosis (cause cells to kill themselves)
101
What is a cell that will NOT become a host for tuberculosis?
Natural killer cells
- because they do not phagocytose their target cells
- TB wants to be eaten to take over the host cell and hide in it
102
What is the name of the molecule that cells have on them that identify them as "self"?
MHC-1
| - its a protein
103
What action will natural killer cells take if a cell does not have MHC-1 protein on it?
NK cells will KILL it!
104
What happens if a cell has the wrong MHC-1 protein on it's cell surface?
NK cells will KILL it!
105
What kind of response will eosinphils produce?
A systemic response
| - to a parasite or an allergy
106
What kind of response will basophils and mast cells produce?
A systemic response
| - inflammation or an allergy
107
Which cells in the body perform phagocytosis (5)?
1. Neutrophils
2. Monocytes
3. Macrophages
4. Dendritic cells
5. Mast cells
108
What lineage of WBCs do natural killers cells come from?
Lymphoid!
| - not myeloid (that's basically everything else)
109
Which WBCs will fight off a bacteria infection (4)?
1. Neutrophil
2. Monocyte
3. Macrophage
4. Dendritic cells
110
What are 4 characteristics of inflammation?
1. Rubur (redness)
2. Calor (warmth)
3. Tumor (swelling)
4. Dolor (pain)
111
What are the 5 stages of inflammation?
1. Vasoconstriction (until clots forms)
2. Chemokines (chemotaxis) - attract WBCs
3. Cytokines (stimulate inflammation)
4. Vasodilation (increase blood flow)
5. Edema/swelling (accumulation of WBCs to fight infection
112
Why is it important that vasoconstriction is the first stage of inflammation?
Reduce the amount of blood lost
113
If the skin is punctured, what leukocytes will be there first? Second?
1. Macrophages (residents of tissue)
| 2. Neutrophils (arrive from circulation)
114
What effects do cytokines have (3)?
1. Vasoactive (ex: histamine)
2. Chemotactic (ex: PDGF)
3. Both!
115
What is the name of the cytokine released from platelets that cause leukocytes to come and help assist?
Platelet-derived growth factor
116
What are examples of cytokines that have vasoactive effects (4)?
1. Histamine
2. Serotonin
3. Bradykinin
4. Prostaglandins
117
What are examples of substances that have chemotactic effects (5)?
1. Endotoxins
2. Platelet activating factor
3. Leukotrienes
4. Mast cell chemotactic factors
5. Bacterial peptides, PAMPs
118
What are 4 examples of chemical mediators that have both vasoactive and chemotactic effects?
1. Complement components
2. Cytokines (such as interferon and interleukin)
3. Some products of arachidonic acid metabolism
4. Platelet activators
119
Where is histamine primarily formed? Where is it stored? How quickly does it act?
- Formed by basophils and mast cells
- Stored in granules
- Acts rapidly
120
Where is prostaglanin formed? Where is it stored? How quickly does it act?
- Formed by basophils and mast cells
- Not stored - made as needed!
- Slow to act
121
What is serotonin primarily involved in?
Intestinal movements
| - happy feelings after feeding
122
What is serotonin secreted by?
Platelets to induce blood clotting
123
What does bradykinin do?
Increases the sensation of pain and vasodilation
124
What is the relationship between vasodilation and leukocytes?
Dilation of the blood vessels increases the permeability for leukocytes
1. SLOWED at the site
2. BIND to the endothelial wall of the vessel
3. ENTER the tissues
125
What two leukocytes are the primary WBCs that slow down, bind and enter tissues when there is vasodilation?
1. Neutrophils
| 2. Monocytes
126
What do endothelial cells near the site of infection express, which cause leukocytes to stick to the vessel wall?
ICAMs
| - intercellular adhesion molecules
127
What is the name of the process whereby ICAMs are expressed and leukocytes stick to the vessel wall?
Margination
128
What is the name of the process whereby leukocytes pass through the small holes in the endothelial cells in vessels?
Diapedesis
129
Once leukocytes are inside the tissues (after diapedesis) how do they know where to go?
Chemotaxis!
130
True or False:
| Tumor necrosis factor (TNF) is a cytokine that is a pyrogen
True
131
True or False:
| IL-1 is a cytokine that is a pyrogen
True
132
True or False:
| IL-6 is a cytokine that is a pyrogen
True
133
True or False:
| IL-8 is a cytokine that is a pyrogen
False!
| - non-pyrogenic
134
True or Flase:
| IL-12 is a cytokine that is a pyrogen
False!
| - non-pyrogenic
135
What is the role of interferons?
Chemical (protein) produced by cells that are used to WARN other cells that one is infected by a VIRUS
- gives cells an opportunity to prepare themselves for battle
136
What do interferons cause other cells to produce?
Enzymes that will degrade the viral mess anger RNA
| - preventing viral protein synthesis
137
What are the 3 cytokines that contribute to fever?
1. TNF
2. IL-1
3. IL-6
138
What do pyrogens do to the body?
Raise the natural body temperature
139
What happens during a cytokine storm?
1. Body is infected by an unrecognized pathogen
2. Immune cells respond rapidly - producing cytokines
3. Immune response leads to a positive feedback loop
4. Patient dies due to the IMMUNE response - NOT the infectious disease
140
What can happen if you get a WBC stem cell transplant?
The transplanted WBCs recognize YOU as "non-self" and attack YOU!
= cytokine storm
141
Is the complement system part of the innate or adaptive immune response?
INNATE
142
What does the complement system do to foreign things in the body?
Poke holes in the surface of the foreign cell
143
True or False:
| The complement system is vasoactive
True(ish)
| - it is BOTH vasoactive AND chemotactic!
144
True or False:
| Each protein in the complement pathway is a protease that activates the next protein in the pathway
True
145
True or False:
| Only the classical pathway and MB-lectin pathways converge on C3 convertase
False
| - ALL 3 pathways converge on C3 convertase
146
What does C3 convertase change C3 into?
C3a and C3b
(a = active)
(b = bound)
147
What does C3a do?
| What does C3b do?
```
C3a = released and stimulated inflammation
C3b = embedded in membrane
```
148
What does opsonization do?
Makes things more LIKELY to be phagocytized
| - sugary donut vs. plain donut example
149
What does C3b become?
C5 convertase
150
What does C5a stimulate?
Chemotaxis
| - attraction of neutrophils
151
What does C5b react with and what does it form?
Reacts with: C6, C7, C8 and up to 15 C9 proteins
| Forms = membrane attack complex (MAC)
152
Which complement pathway requires antibodies to be present in order to be activated?
Classical pathway
153
What is the complement is responsible for inflammation?
C3a
154
Which complement is responsible for the attraction of neutrophils?
C5a
155
Which complement is responsible for opsonization?
C3b
156
Which complements are responsible for cell lysis?
C5b, C6, C7, C8, C9
157
What are the 4 steps involved to find out if a person has antibodies against hepatitis B?
1. Serum is heated (antibodies are stable and complement is destroyed)
2. HBV antigen and complement are added in a known amount
3. If patient HAS antibodies for hep b it will sequester the complement
4. Sheep RBC and anti-RBC are added - if the complement was not sequestered, lysis is observed
158
Which comlements are vasoactive (2)?
C3a and C5a
159
What is the name of the test to determine if a patient has certain antibodies?
Complement fixation test
