Immunology Flashcards
1
Q
Why is immunology important to vet med
A
Recovery from infection
Vaccination to prevent infection
Allergy and autoimmunity
Inflammation
2
Q
What happens when we are infected with a microorganism
A
Detect the microorganism
Capture/ phagocytose the microorganism
Destroy the microorganism
3
Q
Innate immunity has what factors
A
Physical barriers
Secretions
Enzymes
Complement
Phagocytose cells
Nk cells
Interferons
4
Q
Intrinsic immunity has what factors
A
Restriction factors- TRIM5, APOBECs, Tetherin, SAMHD1
5
Q
Adaptive immunity has what factors
A
Antibody
Helper T cells
Cytotoxic T cells
6
Q
What does adaptive immunity develop
A
Develops in response to antigens on the invading organism
7
Q
What are the two key attributes to the immune response
A
- Specificity
- Memory
8
Q
What can macrophages detect
A
Lipids
Sugars
Other molecules unique to invading organisms
9
Q
What can invading organisms be destroyed by
A
Engulfing by phagocytosis
10
Q
What can be trapped in nets
A
Neutrophils
11
Q
Phagocytosis cells kill microbes by
A
Oxygen dependent mechanisms
Oxygen independent mechanisms
12
Q
What is oxygen dependent killing
A
Oxygen is needed to kill pathogens
Protective mechanism in macrophage through hydrogen peroxide to water using catalase
13
Q
What is oxygen independent killing
A
Low molecular weight defending
Cathepsin G
Cationic proteins
Bacterial permeability increasing protein
14
Q
Lysozyme function
A
Destruction of bacterial cell wall
15
Q
Lactoferrin function
A
Chelation of iron
16
Q
Proteolytic enzymes and hydrologic enzymes function
A
Digestion of ingested organisms
17
Q
Microbicidal activity involves
A
Oxygen dependent killing
Oxygen independent killing
18
Q
Inflammation and fever involves
A
IL-6, TNFa, IL1
Prostaglandins
Complement
Clotting factors
19
Q
Lymphocyte activation involves
A
Antigen processing
Antigen presentation
IL1 production
20
Q
Tissue reorganisation involves
A
Elastase, collagenase, hyaluronidisc
Fibroblast stimulating factors
Angiogenesis factors
21
Q
Modulation of the immune response involves
A
IL12
Th1
Il10
TH2
22
Q
What does complement do
A
Targets the immune response to the invading organism
23
Q
What does triggering complement contributes to
A
The rejection of xenotransplantation organs
24
Q
What is the pathway of complement activation pathway
A
Microbe enters the body
Complement C3b binds to microbial surface and is stabilised
C3bBb complex forms and splits more C3 into C3a and C3b
Cleavage products C3a and C5a promote local inflammation
C3a and C5a attract leukocytes to the site of infection
C3b coated microbe is phagocytosed
Assembly of the membrane attack complex on the microbial surface triggers lysis
25
Structure of an antibody
Fc receptor binding site
Complement fixation
Antigen binding at either end
26
When do the hormones peak at Primary response to antigen
IgM peaks at 7 days
IgG peaks at 14 days
27
Hormones involved in response to an antigen
IgM
IgG
28
Secondary response involves
A sharp increase of IgG
Steady increase of IgM
29
What happens with hormones in antigen response
IgM is released first followed by IgG
30
Secondary response features
Takes less time to respond
Larger response to the recovery threshold
31
Allotypic variation is
Variation in the amino acid sequence between light and heavy chains
32
Isotypic variation is
The heavy chain a certain way or light chain a certain way
33
Idiotypic variation is
Variation in the antigen binding domain
34
Immunoglobulin structure
Light chain and heavy chain is where an antigen binds
Then there is a hinge region which is flexible and can rotate
They are symmetrical
CL shows allotypic variation
Variable domain at VDJ
35
What is hinge region
Flexible and can rotate
36
Passive transfer is through what
The colostrum and properties are species specific
37
What is an epitope
Binding site on antibody that antigen binds to
38
Epitopes can either be
Linear
Conformational
39
In humans what amount of polymeric IgA is translocated to the gut daily
40mg per kg
40
What is estimated daily production of IgG
30mg per kg
41
IgG in response to antigen
Secondary response
42
IgG with receptor binding what
Fc
43
What does IgG do
Neutralises antigen
Fixes complement
44
Is IgG high affinity
Yes due to affinity maturation
45
What structure is IgM
Pentameric
46
What response is IgM
Primary response
47
Is IgM a low affinity
Yes
48
What does IgM do
Neutralises antigen
Fixes complement
49
How many binding sites does IgM have
10
50
In IgA what is special about the hinge region
Heavy glycosylation
51
In IgA what component is present which isn’t in other immunoglobulins
J chain
52
What type of structure is IgA
Dimeric or tetrameric
53
Features of IgA
Secreted immunoglobulin, resistant to proteolytic degradation
Secretory component mediates transport across epithelial surfaces
54
IgD is expressed on the surface on what type of cell
B cell during developmental phase
55
What is IgD use
Facilitator of immunity to respiratory bacteria
56
What are antibodies produced by
B cells
57
Where are B cells produced
Bone marrow
Foetal liver
Bursa of fibricus- birds
58
IgE triggers the release of what
Histamine
59
What does histamine release
Mast cell degranulation
60
Is IgE is expressed on what cells
Mast cells
Basophils
Monocytes
61
B cells derive from where
Hematopoietic stem cells
62
What are virgin B cells
Newly formed B cells
63
Features of virgin B cells
Short lived
75 percent leaves the BM
64
What antibodies are present on B cells
IgM
IgD
65
Where do gene rearrangements occur in BM
Variable region rearrange to generate VDJ and VJ
66
Where do gene rearrangments occur in lymphoid tissue
Isotype- class switching- occurs following stimulation of virgin B cell with antigen
67
What are the lymphoid organs
Lymph node
Spleen
Bone marrow
Thymus
GALT
68
Vaccination mimics what
Re exposure to a pathogen
69
Where do B cells encounter antigens
B cells and T cells traffic to lymphoid organs
70
Where are B cells made
Bone marrow
71
Where are T cells made
Thymus
72
How are antigens carried to lymphoid tissues
Lymphatic systems
73
B cell trafficking pathway
Bone marrow then B cells leave BM and enter blood vessel to the medulla
74
What parts are involved in the lymph node
Afferent lymphatic
High endothelial venue
Germinal centres
Efferent lymphatic
Medullary chords
B cell area
T cell area
75
What causes travel of lymphatic fluid
Simple act of motion
76
What direction is the movement of lymphatic fluid
Unidirectional
77
What does vaccine need to come into contact with in draining lymph fluid
B and T cells
78
Where can u vaccinate in the body
Everywhere
79
Lymphatic circulation pathway
Interstitial fluid
Lymph capillaries
Collecting lymph vessels
Lymph node
Lymph duct
Lymph trunks
Venous system
80
What vessels have a beaded appearance
All vessels except lymph capillaries
81
What do semilunar valves do
Ensure flow in one direction
82
Germinal centre consists of what
Helper T cell- producing cytokines
Dendritic cells
Some of these cells will make memory cells
83
Pathways of germinal centres
B cell to encounter with antigen to secondary lymphoid follicle to germinal centres
84
Pathway of centroblast
Centroblast
Centrocyte
Lymphoblasts
Memory B cells or plasma cells
85
What are B cells competing for
Antigen
86
What happens when antigen levels decrease
Affinity increases
87
If affinity increases what happens
More likely to survive the cells
88
Times of vaccination selects for what
Best affinity
89
How is the thymus formed
Gene is switched on and then cells congregate and the thymus forms
90
What happens to your thymus as you get older
Decreases in size and you become more immune deficient
91
Cells within the thymus are called
Thymocytes
92
What do the cells go into the thymus as and leave as
Go in as precursors and leave as T cells
93
Thymus structure and components
Cortex- cortical epithelial cell, trabeculae, thymocyte
Medulla- macrophage, medullary epithelial cell, hassals corpuscle, dendritic cell
94
What mutation do nude mice have
FOX1 gene
95
Do nude mice have a functioning thymus
No- virtually no T cells
96
The impact on nude mice FOX1 gene the impact on this acquired immune response is
Defective antibody formation
No cell mediated response
No delayed type hypersensitivity
No killing of malignant or virus infected cells
No graft rejection
97
Thymic selection pathway
Nurse cell
Blast cell
Thymocytes
Gene rearrangement
To CD4/CD8
TCR expression
Interdigitating cell
Macrophage
Naive T cells
98
What is positive selection
Interaction with MHC class 1 or MHC class 2 on cortical epithelium
99
Do T cells kill parasites
Yes
100
what does CD4 do
Stabilise interactions with receptors
101
Helper T cell uses what CD
CD4
102
Cytotoxic T cell uses what CD
CD8
103
Dendritic cells instruct what
Helper T cells to respond in an appropriate way
104
T cells promote what
Cellular response
105
Once activated what can T helper cells do
Interact with B cells and support their expansion
106
Humoral immunity
B cell proliferation
Class switching
Increase Ig production
107
Th17 promotes
Neutrophil response
108
What do TH2 cells favour
Humoral response
Induce mast cell production
109
What happens when neutrophils kill a cell
Neutrophil
110
Cytotoxic T cells do what
Kill cells as they tigger cell death
111
What are granules
Modified lysosomes that contain effector proteins in an active form
112
What do NK cells recognise
Stress signals
113
natural killer cells have a high number of what on their surface
Fe receptors
114
Pattern recognition receptors
Pathogen associated molecular patterns- PAMPS
Damage associated molecular patterns- DAMPS
115
What does PAMPS and DAMPS do
If something is dangerous and recognising a foreign body
116
What is antigen presentation
Display of processed peptide fragments to T cells for recognition by their T cell receptor
117
What mechanisms have macrophages developed with which they can sense danger
Mannosyl fucosyl receptor
CD14
Fc receptors
Complement receptors
MHC class 2
118
What is the function of mannosyl fucosyl receptors
Bind to sugars on the surface of microorganism
119
CD14 function
Bind to lipopolysaccarhide receptor
120
Fc receptor function
Bind to immunoglobulin and triggers phagocytosis
121
Complement receptors function
Bind to complement factor on surface of microbe
122
MHC class 2 function
Antigen presentation to T cells
123
In histology the red is
Dendritic cells
124
What is MCH class 1 responsible for
Peptide binding groove- non covalent
125
What is MCH class 2 responsible for
Alpha and beta chains
126
What are peptides recognised by
Human MCH class 1
127
Anchor residue function
Holds the peptide
128
Cheetahs affect with the MCH system
Cheetahs are inbred and have less genetic MCH diversity this causes a lessened immune response
129
A killed vaccine doesn’t have what type of cell
Cytotoxic T cells
130
What does live attenuated vaccine route of antigen processing
Make cytotoxic T cell
131
Why do we need the MCH system
If we all had the same MHC molecules then we would have a limited ability to protect ourself against antigens
Allow infinite diversity against different pathogens
Diversity of MCH molecules means more immunity
Small tight population means that there is not enough MCH
132
What happens when we loose MCH expression
CTCV cells down regulate MCH and secrete immunosuppressive cytokines
Deregulates MCH so we cant see it on the surface and means tumour cells can grow and develop
133
What did vaccination start with
Smallpox vaccine
134
Killed vaccines
No longer able to replicate following treatment
Protection is short lived
Booster needed
135
Killed vaccine examples
Rabies
Lepto
136
Live attenuated vaccines
Usually more potent than killed vaccines as limited viral replication
Antigen is produced by exogenous and endogenous pathways- stimulate cytotoxic T cells
More potent so selects for high affinity B cells so higher affinity maturation which causes a longer immune response
137
Live attenuated vaccine examples
Kennel cough
138
Subunit vaccines
Protective virus neutralising antibodies tend to be directed against surface proteins of the virus
139
Examples of subunit vaccine
Canine herpes virus
Strangles
140
Vectored vaccine function
Using attenuated virus to deliver gene encoding
141
Examples of vectored vaccine
Feline leukaemia virus
142
Advantages of inactivated vaccine
Safety- no reversion to virulence
Do not induce disease
Induce response against multiple viral proteins
Inexpensive
Antigen consistence
Stable at room temperature
143
Disadvantages of inactivated vaccine
Need to ensure complete inactivation
Response may require adjuvant
Cellular components may cause side effect
Cold chain required for storage and transport
More than one injection is usually required as antigen does not persist
144
Live attenuated advantages
Antigenic epitopes are preserved
Antigen persists, response may be long lived
Inexpensive
Administration across mucosal surfaces
145
Live attenuated vaccine disadvantages
May revert to virulent form
May induce disease in weakened immune system
Cellular components may cause side effects
146
Sub unit advantages
Safe
Focussed immune response
No hazards associated with production
No cellular contaminants
147
Sub units disadvantages
More than one injection may be required as antigen does not persist
Cold chain required for storage and transport
Response may require adjuvant
148
Advantages of vectored vaccines
Single gene
Mostly safe
Focused immune response
No hazards associated with production
No cellular components
Oronasal delivery possible
Endogenous and exogenous antigen presentation
149
Disadvantages of vectored vaccines
May not induce response to tertiary structures
May cause mild pox virus symptoms
Response to vaccine may be weak
Response to vector may affect subsequent doses
150
What is the perfect vaccine
A good safety profile
Highly efficacious
Induce both Humoral and cellular immunity
Minimal requirement for boosting
Goofed breadth of immunity against diverse viral stains
Stability and ease of administration
151
What is an adjuvant function
Enhance immune response
152
How does an adjuvant work
Danger hypothesis takes something non dangerous and switch on antigen presentation by promoting uptake of antigen presenting cells or by switching on macrophages
153
Autoimmune reaction represents what
A breakdown of self tolerance
154
What is tolerance
State of unresponsiveness that is specific for a particular antigen and which is induced by prior exposure to that antigen
155
Dizygotic twin calves in tolerance. What happens
They can exchange haemotopoietic stem cells as a result of placental fusion.
The twins are thus tolerated to each others MHC molecules
156
In peripheral tolerance, the endothelial barrier segregates what
T cells from self antigens
157
In peripheral tolerance, what triggers an immune response
Self antigens that present in insufficient quantities
158
What is clonal deletion
When high levels of self antigen is present which causes destruction of B cells
159
Autoimmunity arises through bypass of the control of
Autoreactivity
160
Autoimmune conditions
Addisons disease- adrenal glands
Rheumatoid arthritis
Myasthenia gravies
Immune mediated haemolytic anaemia
SLE
161
What is the full name of an ELISA
Enzyme linked immunosorbent assay
162
Method of ELISA
Add test sample to well of ELISA plate
Wash well to remove unbound antigens
Add antibody enzyme conjugate
Wash well to remove unbound conjugate
Add chromogenic substrate for enzyme
Read absorbance on microplate reader
163
What does monoclonal antibody grab onto in ELISA plate
Antigen
164
Pathway of ELISA
Monoclonal antibody grabs onto antigen and anchors it on the ELISA plate.
Then remove unbound antigen then add second antibody.
This will recognise a different epitopes in order to detect that second antibody, the antibody is coupled with an enzyme
165
What is the amount of antigen in an ELISA well directly proportional to
Amount of conjugated enzyme
166
Amount of antigen is directly proportional to
The amount of colour change
167
In immunoassay Less colour has
More progesterone
168
Immunoassay using labelled competitor method
Add test sample- 10ml to well of elisa plate
Progesterone in the sample bins to coating antibody
Add progesterone enzyme conjugate 200ml
Wash well to remove unbound progesterone enzyme complex
Add chromogenic substrate for enzyme
169
Immunoblotting also stands for
Western blotting
170
In electrophoresis proteins are separated firstly by
Size
171
Western blotting methods
Incubate blot with primary antibody
Wash
Incubate blot with enzyme conjugated secondary antibody
Wash
Incubate blot with substrate
172
Western blotting is washed.WHY
So there is no antibody’s left on the slide
No contamination occurs
173
Chromatin will go what colour
Completely blue
174
Enzyme catalyses colour change of what
No colour to colour
175
Immunodiffusion precipitates test size of ring is what to amount of antigen present
Directly proportional
176
Coombs test can be used for what
Haemolytic anaemia
177
Allergy is what
An overreaction of the immune system to a harmless antigen
178
What type of immune response does an allergy trigger
Inappropriate immune response
179
Hypersensitivity can be classed into four different sections
Class 1
Class 2
Class 3
Class 4
180
Class 1 hypersensivity
Binding of antigen to surface IgE
181
What hypersensitivity class is primarily on mast cells
Class 1
182
In class 1 what happens
Mast cell degranulation then an inflammatory response occurs
183
Class 2 hypersensitivity
Small molecules binding to cell surface components modify the antigency and render it immunogenic
184
In class 2 hypersensitivity b cells response to antigen does what to the cell
Destroys the cell
185
class 3 hypersensitivity
Soluble protein antigens bind to immunoglobulin forming immune complexes. Complexes are deposited in blood vessel walls and phagocytic cells pick them up and destroy them
186
Where are complexes in class 3 deposited
In blood vessel walls and phagocytic cells pick them up and destroy them
187
Class 4 hypersensitivity
Antigen specific T cells
188
Reactions to class 3
Arthrus reaction eg. Tetanus vaccine
Serum sickness eg. Drugs
Farmers lung
Hypersensitive penumonitis
189
Hypersensitivity type 1 features
Antigen- soluble antigen
Effector mechanism- mast call degradation
Reaction- asthma, allergic rhinitis
Granule contents- histamine, hepatin, proteases, enzymes, cytokines
190
What wont work with with an antihistamine present
Steroids
191
Antihistamines block binding of
Histamine so vasodilation doesn’t occur
192
What is harder to treat a chronic allergy or a acute allergy
Chronic allergy
193
Diseases hypersensivity class 1 symptoms
Asthma
Flares on skin
Coughing
Diarrhea
Atopic dermatitis- house mites and fleas
Food allergies
In horses- sweet itch- insect bites
Heaves- allergy to mould
194
Sweet itch symptoms
Alopecia
Atopical dermatitis
Thickening and ridgening of skin
Due to saliva of insect bites- manifests on horses coat
195
Hypersensitivity class 2 function
Can create an epitope
Only binds to rbc when drugs are present
196
Hypersensivity class 2 features
Antigen and altered cell surface components
Effector mechanisms- IgE binds to novel antigen, complement cascade triggered.
FcR targeting leukocytes. IgE binds to cell surface receptor- autoimmunity
Reaction- haemolytic anaemia
Drug modification of a protein antigen
Transfusion reaction- neonatal isoerythrolysis
197
Immunodeficiencies
Results of a defect in an immune response
198
Hypersensitivity class 3
Antigen- soluble antigen
Effector mechanisms- immune complexes, complement, phagocytes
199
How can neonatal isoerythrolysis be detected
Erythrocyte agglutination test
200
Hypersensitivity class 4
Soluble antigen
Effector mechanisms- macrophages, eosinophils
Reaction- asthma, contact dermatitis
When cells from immune system move into site of allergen exposure.
Delayed hypersensitivity of 1-3 days
201
IgA inherited deficiency
Secreted immunoglobulin
Resistant to proteolytic degradation
Secretory component mediates transport across epithelial surfaces
High affinity receptor on monocytes and neutrophils
202
Immunodeficiency is in response to
Viral infection
203
Viruses and infections to do with immunodeficiency
Lentiviruses
FeLV- thymic atrophy
Distemper
Parvovirus infection
Parasite infection- generalised immunosuppression
204
Atopic dermatitis is in what class of hypersensitivity
Type 1
205
