Immune System Flashcards
(358 cards)
1
Q
What is the immune system?
A
A versatile defence system that protects us from diseases caused by pathogenic microbes
2
Q
How many lines of defence do we have?
A
3
3
Q
Which lines of defence protect us from anything (non-specific) foreign coming into our bodies?
A
First and second line
4
Q
Describe the first line of defence.
A
A physical barrier against foreign bodies and microbes, created by the skin and mucous membranes
5
Q
What does innate mean?
A
Inborn / natural
6
Q
Describe the third line of defence.
A
The advanced part of our immune system, which targets SPECIFIC foreign bodies
7
Q
Describe the second line of defence.
A
A non-specific immune response, which includes some immune cells, proteins, fever and inflammation.
8
Q
Which line of defence targets specific foreign bodies?
A
The third line
9
Q
Which lines of defence target non-specific foreign bodies?
A
First and second line
10
Q
Which lines of defence make up our innate immunity?
A
First and second line
11
Q
A fever is part of which line of defence?
A
The second
12
Q
What is the purpose of a fever?
A
To create an unfavourable environment for most pathogens (too hot).
13
Q
What is the purpose of inflammation?
A
To create an unfavourable environment for most pathogens.
14
Q
List 3 signs/symptoms of inflammation
A
Redness, pain, swelling
15
Q
List 2 things that can cause inflammation.
A
- Localised physical trauma
2. An infectious pathogen, trying to cause disease/damage.
16
Q
Why is inflammation part of the second line of defence?
A
Because it is non-specific, and targets anything that is foreign.
17
Q
Which line of defence is known as specific / adaptive immunity?
A
The 3rd line of defence
18
Q
In which line of defence are memory cells created, in order to protect us from specific pathogens?
A
The 3rd line of defence
19
Q
Why can we often get infected with a particular virus more than once?
A
Because viruses mutate (i.e, the flu).
20
Q
Name 1 virus that frequently mutates
A
Influenza (flu)
21
Q
What is a pathogen?
A
An infectious organism that can cause disease in a host
22
Q
List 4 ways in which infectious organisms / pathogens can get into the body
A
- Through breaks in the skin (i.e, a cut)
- Via inhalation
- Via swallowing
- Via the eyes
23
Q
How does the digestive system provide first line defence against pathogens?
A
- Saliva contains antibodies
- Stomach acid provides a very unfavourable environment to most pathogens (but not if stomach acid is low)
24
Q
Name 1 thing that can cause reduced stomach acid and reduced salivary antibodies, in turn causing reduced immunity.
A
Stress
25
What is an antigen?
A cell marker (usually protein) that can be recognised by leukocytes.
26
How many types of antigen are there?
2
27
Name the 2 types of antigen
1. Foreign antigens
| 2. Self antigens
28
Where would you find self-antigens?
On cell membranes (self antigens are cell membrane proteins)
29
Where would you find foreign antigens?
On microbes, bacteria, viruses, food, or drugs
30
What are antibodies?
Proteins produced in response to a specific antigen
31
Self antigens are produced through protein synthesis (transcription, translation and then embedding into cell membrane). True or false?
True
32
Which process are 'transcription' and 'translation' a part of?
Protein synthesis
33
What are foreign antigens?
Antigens not made by the body (i.e a bacteria or virus)
34
An immune response is created when ______ and ______ join together.
Antigens and antibodies
35
The ______ and _______ ________ are the first line of defence against pathogens.
Skin and mucous membranes
36
The skin acts as a physical barrier with its layers of tightly packed ________ cells.
Epithelial
37
How does the shedding of the epidermis layer of the skin contribute to our immune function?
When the epidermis sheds it also sheds any microbes that are on it.
38
How often is the epidermis of the skin entirely replaced?
Every 40 days
39
List 2 ways in which sweat contributes to immune function?
1. It removes microbes from the surface of the skin
| 2. It contains IgA antibodies
40
Where would you find IgA antibodies?
Sweat, saliva, tears, breast milk
| IgA = first letter of alphabet, first line of defence
41
What does Ig stand for?
Immunoglobulin
42
Immunoglobulins are antibodies. True or false?
True
43
What type of antibodies are found in sweat, saliva, tears, mucous secretions and breast milk?
IgA
44
How does sebum contribute to immune function?
It contains fatty acids which inhibit microbial growth (stop bacteria from undergoing mitosis).
45
List 3 places we find mucous membranes.
1. The digestive tract
2. The respiratory tract
3. The urogenital tract
46
Saliva, tears and mucous secretions wash away microbes, and also contain anti- ________ substances.
Anti microbial
47
Name 2 body fluids that contain IgA and lysozymes
Tears and saliva
48
What are lysozymes?
Enzymes that break down bacterial cell walls
49
Where would you find the mucocilliary escalator?
In the respiratory tract
50
Tears are really important to provide an immune function on the surface of the eye. True or false?
True
51
Name 2 mucous secretions (substances secreted by mucous membranes).
Tears and saliva
52
What does the Ig in IgA / IgE / IgB, etc stand for?
Immunoglobulin
53
What is secretory IgA and how can it be measured?
Secretory IgA is the IgA present in the stool.
| It can be measured via very comprehensive stool testing.
54
Why can IgA levels be used as an indicator of stress in a patient?
Because higher stress = lower IgA.
| The more stressed a person is, the lower their IgA levels (and therefore general immune function) will be.
55
Vomiting and diarrhoea are rapid means of expelling _______.
Pathogens
56
Microflora generally outcompete pathogens for attachment sites on epithelial cell surfaces (the car parking spaces analogy), but where in the body / on which epithelial cell surfaces are they generally found?
In the large intestine
| small intestine also, if SIBO is present
57
What is GALT?
Gut Associated Lymphoid Tissue
58
70% of our immune system is in the ______, in the form of _____
In the gut.
| In the form of GALT (Gut Associated Lymphoid Tissue)
59
Which line of defence includes:
| Complement System, Transferrins, Phagocytes, Natural Killer Cells, Inflammation, Cytokines and Fever?
2nd line of defence
60
List 4 mediators / factors in the second line of defence.
1. Complement system
2. Transferrins
3. Phagocytes
4. Natural Killer Cells
5. Inflammation
6. Cytokines
7. Fever
61
What is the Complement System?
A series of proteins
62
List 2 outcomes produced by the complement system.
1. Inflammation
| 2. Phagocytosis
63
What are transferrins?
Iron-binding proteins
64
Where are transferrins found?
In haemoglobin (Hb), in the blood. They are part of the Hb structure.
65
What do transferrins do?
They latch on to iron molecules and lock it away, stopping bacteria/pathogens stealing the iron for their own energy.
66
What are phagocytes?
White blood cells that specialise in engulfing / eating.
67
What are Natural Killer Cells?
Immune cells that release a protein called Perforin, which spears foreign cells, causing damage to the membrane and allowing water in, which in turn causes the foreign cell to rupture.
68
What is perforin?
A protein released by Natural Killer Cells
69
What do Natural Killer Cells do to foreign cells / pathogens?
They go around stabbing them and causing them to rupture! (Using the protein 'perforin')
70
Why is inflammation important?
Because it helps to attract white blood cells to the area (it's a warning sign - a bit like pushing a fire alarm)
71
What are cytokines?
Messenger proteins that are released by cells
| think of them as text messages to other cells
72
Which supplement can feed bacterial growth if not carefully controlled/monitored?
Iron
73
In adults, each Hb molecule contains ___ polypeptide chains; 2 x alpha and ___ x _____
4
| 2 x alpha, 2 x beta
74
How many polypeptide chains does 1 haemoglobin molecule have?
4
75
How many iron molecules can each haemoglobin carry?
4 (1 per polypeptide chain)
76
What is the complement system?
A defence system (involving cascade of events) made of over 30 proteins produced by the liver.
77
Where are the complement system proteins manufactured?
In the liver
78
Complement proteins are inactive and only become active when split into active fragments by ______
Enzymes
79
The main complement protein is known as ____.
C3
80
Whenever you see a letter after a complement protein (i.e, C3a and C3b), it means that protein is fragmented and active. True or false?
True
81
The most common way in which the complement cascade is activated is through the classical ________.
Pathway
82
What does the 'classical pathway' of the complement cascade involve?
An antigen and an antibody joining together
| antigen-antibody complex
83
Give an example of a pathology that involves the classical pathway of the complement system.
Glomerulonephritis
(antigen-antibody complexes deposit on the kidney nephrons, causing inflammation and local damage, and subsequently loss of proteins into urine)
84
What is opsonisation?
The coating of a microbe with an identification protein
85
Collectively, complement proteins destroy microbes by:
1. Promoting __________
2. Contributing to ________
3. Causing _______
1. Phagocytosis
2. Inflammation
3. Cytolysis
86
How do complement proteins promote phagocytosis?
C3b fragments coat microbes in a protein ('opsonisation'), which allows them to be identified as foreign by phagocytes and then engulfed.
87
In the complement system (second line of defence), complement protein fragments contribute to inflammation by binding to _____ cells and cause them to release ______
Mast Cells
| Histamine
88
What is cytolysis?
Destroying (bursting) microbes
89
Which small protein hormones act as chemical messengers between different types of cells?
Cytokines
90
Cytokines are secreted by _________.
Leukocytes
91
What is the name given to the group of non-antibody proteins secreted by leukocytes?
Cytokines
92
Cytokines act on cells involved in _____
Immunity
93
Name 3 types of cytokines.
1. Interleukins
2. Interferons
3. Tumour Necrosis Factor (TNF)
94
Interleukins are a type of _______
Cytokine
95
Interferons are a type of _____
Cytokine (Anti-viral proteins)
96
Which type of cytokine acts as a mediator between leukocytes?
Interleukins
97
Interleukins (cytokines) are mostly produced by ___-_____ cells.
T-Helper cells
98
Interleukin 1 (cytokine) is released by _______
Macrophages
99
Interleukin 1 (cytokine) is a protein hormone that tells your brain to ______ body temperature.
Increase
100
Interferons (cytokines) are involved in anti-_____ responses.
Anti-viral
101
Cells that are infected by a virus produce this type of cytokine.
Interferons
102
Which type of cytokine tells all surrounding cells to stop dividing, in an effort to stop viral spread/infection?
Interferons
103
Can viruses undergo mitosis themselves?
No. They can only replicate once they get inside one of our host cells.
104
Which type of pathogen can only replicate using host somatic cells?
Viruses
105
Tumour necrosis factor is a cytokine protein that promotes the accumulation of which 2 types of white blood cell?
Neutrophils and macrophages
106
In which line of defence would you find interferons and interleukins?
The second line of defence (these are both cytokines - protein chemical messengers)
107
Anti-viral proteins (cytokines) are called _____.
Interferons
108
Which WBC's carry out phagocytosis?
Phagocytes
109
What is the name of the process whereby we engulf and digest cells / microbes?
Phagocytosis
110
Name 2 types of phagocytes.
Neutrophils
| Macrophages
111
Which type of phagocytic cell is always first on the scene?
Neutrophils
112
Macrophages are found in ________, whereas monocytes are found in ________ (they are the same thing, other than location).
```
Macrophages = tissue
Monocytes = blood
```
113
Monocytes travel in the blood, and when they arrive at a tissue they transform into _______
Macrophages
114
Phagocytes are non-selective in their targets. What does this mean?
They attack and engulf anything with a foreign antigen.
115
What do phagocytes use to break down foreign cells?
Lysozomes (balls of digestive enzymes)
116
Macrophages are antigen presenting cells. True or false?
True
117
Macrophages present parts of foreign cells they've digested to __ - ________.
T-lymphocytes
118
Name 2 types of antigen presenting white blood cells.
1. Macrophages
| 2. B-lymphocytes
119
Which WBC's do macrophages and B-lymphocytes present antigens from broken down foreign cells to?
T-lymphocytes
120
Macrophages are known as either _______ macrophages, or ______ macrophages.
Wandering or fixed
121
What is the difference between wandering and fixed macrophages?
Wandering macrophages are monocytes that have migrated in the blood to a site of infection and enlarged in the tissue.
Fixed macrophages stand guard in specific tissues and do not migrate.
122
Give 3 examples of where you would find fixed macrophages.
1. Kupffer cells in the liver
2. Alveolar macrophages in the lungs
3. Microglia in the central nervous system
123
Explain the process of phagocytosis in 5 steps.
> Chemotaxis (attracts phagocytes to the area).
> Adherence of phagocyte to target
> Ingestion of the microbe
> Digestion of the microbe, via lysosomes
> Excretion of indigestible material
124
Phagocytosis occurs in ___ stages.
5 stages
125
What is chemotaxis?
Chemical attraction.
| The release of chemicals by microbes, leukocytes, damaged tissue and activated complement proteins.
126
Name a bacteria that is resistant to the adherence part of phagocytosis, and therefore cannot be digested as normal.
Tuberculosis
127
A macrophage is an ______ presenting cell.
Antigen
128
Which non-specific lymphocytes account for just 5 - 10% of lymphocytes?
Natural killer cells
129
List 4 places that natural killer cells are found.
1. Blood (predominantly)
2. Lymph nodes
3. Spleen
4. Bone Marrow
130
Natural Killer Cells (NKC) attack anything they do not recognise. Name one type of abnormal body cell (not foreign cell) that they may attack.
Cancerous cells
131
Cancerous body cells will display abnormal surface antigens. True or false?
True
132
Natural Killer (NK) cells bind to a target cell and release _______ containing the protein '______'.
Granules, containing perforin
133
How does perforin cause cytolysis in a foreign or abnormal body cell?
Perforin inserts into the cell membrane and creates a channel for tissue fluid to flow into the cell. This causes the cell to rupture.
134
List the 5 cardinal (typical) signs of inflammation.
```
1. Redness
2, Heat
3. Pain
4. Swelling
5. Loss of function
```
135
Mast cells release _______ and _______
Histamine and heparin
136
_______ is the key chemical in inflammation and is created by the de-granulation of Mast cells.
Histamine
137
Describe the 3 basic stages of inflammation.
1. - VASODILATION (increased blood flow)
- Increased vascular permeability (allows arrival of immune cells, antibodies and clotting factors)
- Redness, swelling and heat
2. EMIGRATION OF PHAGOCYTES (via chemotaxis) - neutrophils and monocytes
3. TISSUE REPAIR
138
How many clotting factors are there?
13
139
Which cells release histamine?
Mast cells and basophils
140
Which chemical mediator, involved in inflammation, causes vasodilation and increased permeability?
Histamine
141
List 4 inflammatory mediators
1. Histamine
2. Leukotrienes
3. Kinins
4. Prostaglandins
142
Leukotrienes (inflammatory mediator) are produced by ________ and ____ _____
Basophils and Mast cells
143
What do leukotrienes do?
Attract phagocytes and increase blood vessel permeability, as part of the inflammatory response.
144
What are kinins?
Proteins that induce vasodilation, increase vessel permeability and attract phagocytes, as part of the inflammatory response.
145
Which type of chemical mediator involved in the inflammatory response induces pain (and therefore create a pain response)?
Kinins
146
_________ are lipids released by damaged cells. They enhance the effects of histamines and kinins, and intensify pain.
Prostaglandins
147
Which chemical mediator involved in the inflammatory response intensifies pain?
Prostaglandins
148
Prostaglandins are lipids released from cells when those cells are ______.
Damaged
149
Prostaglandins are made from the ______ ______ _____ part of damaged cell membranes.
Fatty acid tails
150
List 4 benefits of inflammation.
1. Promotes phagocytosis
2. Promotes immune response
3. Dilutes toxins
4. Fibrin formation (helps to isolate a wound and stop infection spreading)
151
List 4 harmful effects of inflammation.
1. Pain
2. Swelling (esp. dangerous in the cranium)
3. Adhesions and scar tissue
4. Atherosclerosis
152
How does fibrin formation contribute towards a healthy immune system?
Fibrin helps to clot and isolate a wound, which helps to stop infection spreading further.
153
Atherosclerosis is a harmful effect of ___________
Inflammation
154
What is a granuloma?
A multi-cellular attempt to contain a foreign body/pathogen by encasing i, if it can't be broken down and removed.
155
What is fibrosis?
Scar tissue formation
156
Does scar tissue have any function?
No
157
What is a fever?
An abnormally high body temperature.
158
The release of which chemical mediator from macrophages, causes the hypothalamus to trigger a fever?
Interleukin-1
159
Name a fever-causing cytokine.
Interleukin-1
160
Which cells release the fever-causing cytokine, Interleukin-1?
Macrophages
161
List 3 ways in which a fever enhances immune response.
1. It makes interferons more effective
2. It inhibits the growth of some microbes
3. It speeds up the reactions that aid repair
162
Many ________ toxins elevate body temperature.
Bacterial
163
A fever is a natural, beneficial response to an immune challenge and therefore, shouldn't be suppressed. However, there is a temperature point at which a fever becomes harmful. What is this temperature?
39.5 degrees and beyond
| Becomes harmful to proteins and starts to denature and change the shape of them .
164
State 2 possible outcomes of acute inflammation.
1. Resolution
| 2. Chronic inflammation
165
What is the function of Interleukin-1? Is it a cell or a protein?
Interleukin-1 induces a fever.
| It is a protein (a cytokine)
166
Explain the role of interferons.
Interferons are anti-viral proteins. They stop surrounding cells from replicating the viral DNA. They are released by the virus-infected cell.
167
Virus-infected cells release cytokines called ________ which send a message to all surrounding cells, telling them not to replicate (therefore reducing the chances of the viral DNA replicating).
Interferons
168
What type of cells are either granular or granular?
Leukocytes (WBC's)
169
List 3 granulocytes
1. Basophils/Mast cells
2. Neutrophils
3. Eosinophils
170
Which type of cell is the most abundant WBC in the blood, accounting for up to 60% of leukocytes?
Neutrophils
171
__________ are first on the scene in an immune response and are phagocytic.
Neutrophils
172
What is the difference between basophils and mast cells?
They are the same, except basophils are in the blood and mast cells are in the tissues.
173
Name 2 inflammatory cells / cells that create inflammation.
Basophils and mast cells
174
Name 2 inflammatory cells that release histamine and heparin.
Basophils and mast cells
175
Histamine creates ________ and _______ vessel permeability.
Vasodilation and increased vessel permeability
176
________ is an anticoagulant, released by basophils and mast cells. So in the inflammatory response it ensures an easy flow of fluid / stops stagnation.
Heparin
177
Mast cells have receptors for Ig___
IgE (immunoglobulin E)
178
____ is the antibody protein implicated in allergic responses.
IgE
179
Name a natural anti-histamine.
Quercetin
180
Which type of WBC destroys parasitic worms via phagocytosis and is also the predominant cell found raised in asthmatic reactions?
Eosinophils
181
List 3 agranulocytes.
1. Monocytes & macrophages
2. Natural Killer Cells
3. B & T-lymphocytes
182
What is the difference between monocytes and macrophages?
They are the same, but monocytes are circulating in the blood whilst macrophages (wandering/fixed) are found in tissues.
183
_______ and _______ are phagocytic and secrete cytokines such as interleukin-1 (fever) and tumour necrosis factor (TNF).
Monocytes and macrophages
184
Which type of leukocyte targets foreign cells and secretes perforin to induce cytolysis.
Natural Killer Cells
185
Which 2 leukocytes are involved in the 3rd line of defence?
B and T-lymphocytes
186
Which 2 leukocytes are involved in 'specific immunity'?
B and T-lymphocytes
187
In which line of defence do we create immunological memory?
The 3rd line of defence
188
In which body system do lymphocytes live?
In the lymphatic system
189
Where are lymphocytes developed/formed?
In the red bone marrow
190
Where do B-lymphocytes mature?
In the red bone marrow
191
Where do T-lymphocytes mature?
In the thymus
192
Name the 4 types of T-lymphocytes
1. Cytotoxic T-Cells
2. Helper T-Cells
3. Memory T-Cells
4. Regulatory T-Cells
193
Which type of T-lymphocytes are the most active in terms of going out and destroying particular foreign cells?
Cytotoxic T-cells
194
Which type of T-lymphocyte mediates the immune response?
Helper T-Cells
195
When are memory T-cells created?
When we have an active exposure to a disease
196
Which type of T-cells turn off an immune reaction when the immune response should be finished (stopping excessive immune reactions)?
Regulatory T-cells
197
What do B-lymphocytes produce?
Plasma cells
198
Which cells produce antibodies?
Plasma cells (produced by B-lymphocytes)
199
Every single type of plasma cell will create one type of antibody. True or false?
True
200
___-lymphocytes attack and regulate the immune response. ____-lymphocytes produce plasma cells, which produce antibodies.
T-lymphocytes attack & regulate
| B-lymphocytes produce antibodies (via plasma cells)
201
Which cells, involved in the 3rd line of defence, function in specific immunity (they learn to respond to specific foreign antigens)
T and B-lymphocytes
202
Which cells produce immune memory for previously encountered antigens?
T and B-lymphocytes
203
_______ present antigens from foreign particles they've digested to ______ _______ cells, who then releases their own cytokines to mediate the body's response.
Macrophages (or B-cells) present antigens to T-Helper cells, who then coordinate the response.
204
T and B-lymphocytes are normally at rest but become activated on encountering a foreign antigen. True or false?
True
205
Which are the effector cells of the 'adaptive' immune system?
T and B-lymphoctes
206
What is the Major Histocompatibility Complex (MHC)?
A group of cell surface proteins that are required for the immune system to recognise cells that are healthy body cells, versus cells that are 'non-self'.
207
What is the name given to the group of cell surface proteins that are required for the immune system to recognise cells that are healthy body cells, versus cells that are 'non-self'?
The Major Histocompatibility Complex (MHC)
208
What are the names of the 2 types of Major Histocompatibility Complex (MHC) proteins?
- Class 1 Major Histocompatibility Complex (MHC-I)
| - Class 2 Major Histocompatibility Complex (MHC-II)
209
How many types of MHC are there?
Two:
- Class 1 Major Histocompatibility Complex (MHC-I)
- Class 2 Major Histocompatibility Complex (MHC-II)
210
Which molecules function to present foreign antigens to T-cells?
MHC's (Class i and II)
211
MHC's are each formed of 4 ________ ______and display a _____ produced by the cell (a self antigen) on its binding ______
4 polypeptide chains
Display a protein
Binding groove
212
Which body cells have MHC-1 (which is effectively your self antigens)?
All body cells except erythrocytes
213
Erythrocytes are the only cells in the body that don't have ________
Class 1 Major Histocompatibility Complex (MHC-I)
214
When might a body cell start to produce abnormal proteins?
When it is cancerous, or invaded by a pathogen.
215
Abnormal proteins produced by a cell are combined with _______ and displayed on the cell membrane, flagging it up as a non-self cell to leukocytes.
MHC-1
216
What allows our leukocytes to determine healthy body cells from abnormal/infected cells?
MHC-1, which combines with abnormal proteins produced by the cell and displays them on the cell membrane for the attention of leukocytes.
217
MHC-1 is essentially a transmembrane protein. True or false?
True
218
Which is the only body cell that doesn't create its own proteins?
Erythrocytes
219
DNA Transcription happens in the _______. Translation happens in the ________ of the cell.
```
Transcription = nucleus
Translation = ribosomes
```
220
Whereabouts on the MHC-I and MHC-II is the cell protein/antigen attached/displayed?
In the binding groove.
221
Which are the only cells to have MHC-II?
The antigen presenting cells (macrophages and B-lymphocytes)
222
Macrophages and B-lymphocytes at the the only cells that have MHC-II. True or false?
True
223
What is the role of MHC-II?
To display whatever that particular cell (macrophage or B-lymphocyte) has broken down.
224
What is displayed on the binding groove of MHC-II?
Parts of digested foreign pathogens (antigen presentation)
225
What displays foreign antigens to T-helper cells, on its binding groove
MHC-II on the cell membranes of macrophages and B-lymphocytes
226
Why are MHC-II's critical in the process of antigen presentation?
Because they are used to display the foreign antigen digested by macrophages/B-lymphocytes to the T-helper cells.
227
Which cells play a central role in cell-mediated immunity?
T-lymphocytes (T-cells)
228
Which cells play a central role in antibody-mediated immunity?
B-lymphocytes (B-cells)
229
__ cells create plasma cells. Plasma cells release _______
B-cells create plasma cells
| Plasma cells release antibodies
230
Which cells are produced in the bone marrow and matured in the thymus?
T-lymphocytes
231
T-cells are divided into T-Helper cells and _______ T-cells
Cytotoxic
232
What is unique about all T-lymphocytes?
They each have a unique T-cell receptor, that only recognises a particular antigen.
233
At what point in life has the thymus atrophied?
By mid-teenage years
234
Why are T-helper cells also known as CD4 cells?
Because they express the CD4 receptor protein on their surface.
235
Which 2 immune cells express the CD4 receptor protein on their surface?
T-helper cells & macrophages
236
What are CD8 cells also known as?
Cytotoxic T-cells
237
Why are Cytotoxic T-cells also known as CD8 cells?
Because they express the CD8 receptor protein on their surface.
238
What 2 traits must T-cells have, in order to function properly?
1. Self recognition - the ability to recognise self antigens
| 2. Self tolerance - the lack of reactivity to self antigens
239
If T-cells lack self tolerance (non-reactivity to self antigens), what medical condition can arise as a result?
Autoimmunity
240
A loss of T-cell self tolerance leads to ________
Autoimmunity
241
T-cells are 'tested' in the thymus (T-cell school!). Where are B-cells tested?
In the bone marrow
242
What causes autoimmunity?
Lack of self-tolerance in T-cells
243
Define adaptive immunity.
Adaptive immunity is the ability of the body to defend itself against specific agents.
244
How many types of adaptive immunity are there?
2
245
Name the 2 types of adaptive immunity.
1. Cell mediated immunity (T-cells)
| 2. Antibody mediated immunity (B-cells)
246
Adaptive immunity is characterised by which 2 things?
1. Specificity (for particular foreign antigens)
| 2. Production of immune memory
247
Which type of T-cell actively goes out and attacks foreign cells (like Natural Killer Cells)?
Cytotoxic T-cells
248
What is the difference in the action of Natural Killer Cells and Cytotoxic T-cells?
Natural Killer Cells attack anything foreign
| Cytotoxic T-cells attack specific foreign cells
249
Which of the 2 types of adaptive immunity defends mostly against intra-cellular pathogens?
Cell mediated immunity (T-Cells)
250
Which of the 2 types of adaptive immunity defends mostly against extra-cellular pathogens?
Antibody mediated immunity (B-cells)
251
Antigen presentation involves communication between the macrophage / B - lymphocyte and the ___ ______ cells
T-helper
252
When an antigen fragment binds with a T-helper cell, the T-helper cell secretes a cytokine called ________,
Interleukin II
253
Which cytokine, released by T-helper cells:
a) is the prime trigger for T-cell proliferation
b) stimulates clonal selection of B-cells
Interleukin II
254
Which type of T-cell uses perforin and granzymes to attack foreign cells?
Cytotoxic T-cells
255
Which type of T-cell releases cytokines (including Interleukin II) to increase the activity of immune cells such a T, B and Natural Killer cells?
T-Helper cells
256
Which type of T-cell recognises an antigen with any future contact, ready to mount an immune reaction when needed?
Memory T-cells
257
What do Regulatory T-cells do?
Switch off the immune response when it is no longer required.
258
How do Regulatory T-cells switch off an immune response?
By deactivating immune cells (T-helper cells, macrophages and B-cells)
259
What would happen if we didn't have regulatory T-cells?
The body would continue trying to fight off a disease that no longer exists (and would eventually end up fighting its own cells).
260
Which cells regulate and prevent excessive immune reactions/responses?
Regulatory T-cells.
261
When regulatory T-cells fail to work properly, what can often result?
Autoimmune conditions
262
B-lymphocytes form and mature in the _____ ______ and are fixed in ________ tissue where they do not leave.
Bone marrow
| Lymphoid tissue
263
In antibody mediated immunity, __________ cells recognise the antigen on the B-cell membrane and release the cytokine _________, which triggers B-cell clonal selection.
T-helper cells
| Interleukin II
264
Which cytokine triggers B-cell clonal selection in antibody mediated immunity, and which cells is it released by?
Interleukin II. Released by T-helper cells
265
Which 2 types of cell are produced in B-cell clonal selection?
1. Plasma cells
| 2. Memory B cells
266
Which type of cell is short-lived and a few days after antigen exposure, secretes hundreds of millions of antibodies into the blood each day until they die?
Plasma cells
267
Which type of B-cells are long-lived and remember specific antigens for next time?
Memory B-cells.
268
What are antibodies?
Glycoproteins (part sugar/carbohydrate, part protein). Also known as Immunoglobulins
269
What is another name for Immunoglobulins?
Antibodies
270
How many antigen binding sites do antibodies generally have?
2 (Y-shaped)
271
What type of glycoprotein has a Y-appearance and is made up of 4 polypeptide chains?
Antibodies / Immunoglobulins
272
How many polypeptide chains do antibodies contain?
4 (2 x heavy and 2 x light chains)
273
Antibodies bind specifically with the antigen that stimulated their production ("lock and key"). True or false?
True
274
List 5 ways in which antibodies can inactivate antigens.
1. Immobilisation: by latching on to bacterial cilia or flagella
2. Agglutination: using their binding sites to clump foreign bodies together.
3. Neutralising: Binding to bacterial toxins
4. Activating complement: Antigen-antibody complexes activate the compliment cascade.
5. Enhancing phagocytosis: Flagging to phagocytes
275
What is the most abundant antibody in our bodies (c80%) and what does it do?
IgG. Protects us against bacteria and viruses.
276
Where is IgG mostly found?
In the blood. (Also some in the lymph and intestines)
277
Which antibody can cross the placental barrier?
IgG
278
Where is IgA found and what is its function?
IgA is found in sweat, tears, saliva and breast milk. It gives localised protection of mucous membranes.
279
Which antibody is very closely linked to stress levels (i.e, is lowered/depleted when a person is stressed)
IgA
280
Which type of antibody is the first on scene in an immune response, normally then followed by IgG?
IgM
281
Which antibody type accounts for <1% of the antibodies in the blood and is involved in allergic reactions?
IgE
282
Which antibody type causes mast cells to release histamine and heparin?
IgE
283
A true food allergy involves ____ antibodies, whilst a food intolerance will typically involve an _____ antibody response.
Food allergy = IgE
| Food intolerance - IgG
284
How long can memory cells last?
Decades
285
Why is a second exposure to a particular antigen/bacteria/virus much more effective when it comes to antibody production?
Because the first exposure = a slow rise in IgM then IgG (takes a few days for the body to get on it).
Subsequent exposure is a much faster response because the immune system has already developed thousands of memory cells from the last attack. Often the secondary response is so effective that it kills off the microbe before you exhibit any signs or symptoms.
286
What is the basis for vaccination against certain diseases?
Immunological memory
287
Why do vaccines contains lots of ingredients in addition to the partially live/dead foreign microbe?
- To keep the microbe in tact/alive until injected.
- To make sure the microbe doesn't get broken down
- To create an immune response against the pathogen
288
Why are toxic heavy metals often added to vaccines?
To ensure the creation of an immune response when the vaccine is injected.
289
List 4 harmful ingredients often found in vaccines.
1. Aluminium (to create immune response)
2. Formaldehyde (vaccine preservative)
3. Polysorbate 80 (to allow heavy metals through the blood-brain barrier)
4. Mercury (to create immune response)
290
List 3 ways in which we can acquire immunity.
1. Natural exposure to a disease
2. Transfer of IgG antibodies across the placenta
3. Transfer of IgA antibodies in breast milk
4. Vaccination
5. Injection with immunoglobulins (ie, anti-snake venom)
291
Give an example of naturally acquired active immunity.
Natural expose to a disease
292
Give an example of naturally acquired passive immunity.
- Transfer of IgG antibodies across the placenta
| - Transfer of IgA antibodies in breast milk
293
Give an example of artificially acquired active immunity.
Vaccination
294
Give an example of artificially acquired passive immunity.
Injection with immunoglobulins (i.e, anti snake venom)
295
What is the difference between active and passive immunity?
Active immunity - your body works to produce an immune response & antibodies
Passive immunity - the immune response / antibodies are delivered into the body, so it doesn't need to do anything itself to create them.
296
How many main types of antibody are there?
4 - IgM, IgG, IgA, IgE
297
Which types of immune cells are found in GALT (Gut Associated Lymphoid Tissue)?
Macrophages, B & T-lymphocytes
298
Which layer of tissue within the wall of the gut contains GALT?
The lamina propria (2nd layer)
299
Why is the gut microbiome important in immune health?
Because leukocytes learn from the microflora in the gut.
300
Define hypersensitivity.
An excessive immune response produced by the immune system.
301
Hypersensitivity is divided into ____ types.
4
302
Which hypersensitivity types are antibody mediated?
Types I, II and III
303
Which type of hypersensitivity is cell mediated?
Type 4
304
Which type of T-cells are involved in hypersensitivity Type 4?
Cytotoxic T-cells
305
What is another name for a Type I Hypersensitivity?
An allergy
306
Which type of hypersensitivity is immediate/rapid in its response and mediated by IgE antibodies?
Type I hypersensitivity (allergy)
307
What is anaphylaxis?
A big immune response (Type I hypersensitivity)
308
List 3 pathologies associated with localised Type I hypersensitivity (antibody mediated) reactions
1. Hayfever
2. Eczema
3. Some contact dermatitis
309
What type of (antibody mediated) hypersensitivity reactions are involved when we get blood transfusion reactions?
Type II hypersensitivity
310
Give an example of a Type II hypersensitivity (antibody mediated) pathology
Haemolytic Disease of the Newborn
| rhesus negative mother, rhesus positive baby
311
Which type of antibody is involved in all Type II hypersensitivity responses?
IgG
312
List 3 pathologies associated with Type III hypersensitivity immune reactions
1. Glomerulonephritis
2. SLE (lupus)
3. Rheumatoid arthritis
313
Antibody-antigen complexes activate the ________ system.
Complement system
314
Type ____ hypersensitivity is IgA, IgG and IgM mediated.
Type III hypersensitivity
315
Why is the deposition of antibody-antigen complexes common in the glomerulus?
Because the blood pressure in the glomeruli is so high (4x higher than the systemic circulation)
316
Which type of hypersensitivity is associated with an over-reaction of cytotoxic T-cells to an antigen?
Type IV (4) hypersensitivity
317
Name 2 pathologies associated with Type IV hypersensitivity.
- Multiple Sclerosis
| - Skin graft rejection
318
What is an allergen?
An antigen that generates allergy (a type I hypersensitivity reaction)
319
Give 4 examples of common allergens
1. Dust mites
2. Animal dander
3. Dust
4. Latex
5. Pollen
6. Certain foods
320
IgE cross-links _____ cells with an antigen, causing degranulation.
Mast cells
IgE antibodies grab the allergen on one of their Y arms and a mast cell with the other Y arm, linking them and causing the mast cell response.
321
Give an example of a common food intolerance and explain the cause.
Lactose intolerance.
| Caused by a lack of the enzyme lactase, which is needed to properly digest lactose.
322
What is anaphylactic shock?
A very sudden, severe, systemic allergic response, within 5-10 minutes of antigen exposure.
323
Why is anaphylactic shock so dangerous?
Because it causes bronchoconstriction and vasodilation, which results in blocked airways.
324
How is anaphylactic shock treated?
By epi-pen (adrenaline)
325
What are autoimmune disorders?
Conditions associated with an immune response against the body's own tissues.
326
Define autoimmunity.
A breakdown of mechanisms responsible for self tolerance.
327
There are significant links between autoimmunity and _____ gut.
Leaky gut
328
What can zonulin be used for?
A biomarker for increased intestinal permeability (leaky gut).
329
Which chronic, multi system autoimmune disease follows a relapsing-remitting course and involves antibodies that directly focus on targeting the nucleus and components of the offending cell's DNA?
Systemic Lupus Erythematosus (SLE)
330
What is unique about the action of IgG antibodies in Lupus (SLE?)
They directly target components of cell nuclei (DNA, nucleic acids, etc)
331
Which autoimmune pathology would you be looking to diagnose if you test for Anti-nuclear antibodies in the blood?
Systemic Lupus Erythematosus (SLE)
332
Lupus is a multi-factorial disease, involving genetics, hormones and environmental factors. True or false?
True
333
List 5 potential causes of Systemic Lupus Erythematosus (SLE).
1. Oestrogen dominance
2. Low vitamin D levels
3. Chronic bacterial infections
4. EBV
5. Smoking & silica dust
334
Patients with SLE usually suffer from significant sensitivity to sunlight, so are often told to apply factor 50 suncream. Why is this a bad thing?
Because it means that they are most likely vitamin D deficient and D3 deficiency is a cause / risk factor for SLE.
335
List 3 things that can cause flare-ups in patients with SLE.
1. Contraceptive pill use
2. HRT
3. UV light
4. Stress
5. Pesticides
336
List 5 signs/symptoms of lupus (SLE).
1. General fatigue and malaise
2. Butterfly rash on the face
3. Photosensitivity
4. Joint pain
5. Vasculitis (pain in fingertips)
6. Raynaud's Syndrome
7. Pleurisy
8. Nephrotic syndrome
9. Pericarditis
10. Anaemia
337
What is the allopathic treatment for lupus (SLE)?
- Immunosuppressants
- Corticosteroids
- High factor sun cream
- NSAIDs
338
Which chronic, systemic autoimmune disease primarily attacks the synovium (potentially all organs except the brain)?
Rheumatoid Arthritis
339
Which genes are implicated in Rheumatoid Arthritis?
HLA-DR4 and DR1
340
Which auto-antibody is present in around 80% of RA sufferers?
Rheumatoid Factor (RF)
341
________ _________ is an antibody that attacks other antibodies (IgG) in the blood, causing immune complexes that deposit in synovial joints and other tissues.
Rheumatoid Factor
342
List 5 signs/symptoms of RA.
1. Symmetrical/bilateral arthritis of small joints (mostly hands and feet)
2. Progressive morning stiffness, lasting >1hr
3. Deformity of joints (swan neck, ulnar deviation)
4. General fatigue and malaise
5. Subcutaneous nodules
343
Which systemic autoimmune disease is associated with chronic inflammation of the spine and sacroiliac joints?
Ankylosing Spondylitis (AS)
344
Ankylosing Spondylitis more commonly effects _____ between the age of 15 - ____ years of age.
Males
| Between 15 - 30yrs
345
Which gene is present in 95% of patients with Ankylosing Spondylitis (AS)?
HLA-B27
346
Which autoimmune disease has been linked to inflammatory bowel diseases (and leaky gut), as well as urogenital or intestinal infections such as Salmonella & Shigella?
Ankylosing Spondylitis (AS)
347
List 4 signs/symptoms of AS.
1. Pain & stiffness in the lower back, ascending.
2. Kyphotic posture
3. Worsening morning stiffness
4. Fatigue and malaise
5. 20% suffer acute iritis
348
In which autoimmune disease would you find raised CRP/ESR, the HLA-B27 gene and potentially a 'bamboo spine' on X-ray/MRI?
Ankylosing Spondylitis (AS)
349
Which autoimmune disease occurs when antibodies start reacting with thyroglobulin proteins and/or thyroid cells?
Hashimotos Thyroiditis
350
In which autoimmune disease might you see an absence of knee reflexes?
Hashimotos Thyroiditis
351
In which autoimmune disease might you see goitre and exophthalmos?
Graves Disease
352
In which autoimmune condition do we see IgG antibodies binding to TSH receptors, stimulating production of thyroid hormones?
Graves Disease
353
What is the allopathic treatment for Graves Disease?
Carbimazole (drug)
| Radioactive iodine
354
Explain the role of Interleukin-II
Interleukin-II is a cytokine that causes clonal selection (the creation of T-helper cells, cytotoxic T-cells, memory T-cells, plasma cells and Memory B-cells)
355
Briefly describe the structure of an antibody.
A Y-shaped structure that has 4 polypeptide chains, a constant and variable region and 2 binding sites.
356
What is the most abundant antibody found in the blood?
IgG
357
Give an example of naturally acquired passive immunity.
Transfer of IgA antibodies through breast milk.
| Transfer of IgG antibodies through the placenta
358
Where does self-recognition and self-tolerance of T-cells develop?
In the thymus (where they mature)
