Immunology Flashcards
1
Q
Acute phase protein levels change in response to what?
A
Tissue injury
2
Q
“The personal identifier molecule”
A
MHC
3
Q
A dead vaccine is safer that a live vaccine, why?
A
It has less residual virulence than a live vaccine
4
Q
ADCC
A
Antibody-dependent cell mediated cytotoxicity
5
Q
As well as acting as an activator of the MAC what other function does C3b serve?
A
Combines with IgG to cause strong opsonisation of the pathogen
6
Q
Attachment of IgE to parasites wall causes activation of the IgE Fc receptor leading to which consequences?
A
- Mast cell degranulation
- Worm expulsion
- Increased gut motility - smooth muscle
- increase mucus production
- Cuticle breakdown
- Eosinophil release of NO, MBP and other oxidants toxic to the parasite
- Platelet and macrophage release
7
Q
Avidity
A
The number of bonds made by an antibody determines its strength
8
Q
B cells are most useful in which type of infection?
A
Extracellular
9
Q
By which methods can the alternative pathway be activated?
A
Direct activation of C3
Non-pathogenic - AgAb complexes, carbohydrates etc
Pathogenic - pathogen cell walls, selected viruses and parasites
10
Q
C-reactive proteins cause what process to make bacterial cells more “tasty”?
A
Opsonisation
11
Q
Chemotaxis
A
Increased cell motility in response to chemical release
12
Q
C3a and C5a have no effect on the MAC complex when they are formed. What is their end action?
A
Activation of mast cellsChemokines
13
Q
Describe a site of action of IgE.
A
IgE molecules bind to their specific receptors on mast cells
14
Q
Dead vaccines need less doses to confer immunity to the host than live vaccines.True or False.
A
False
15
Q
Describe the mechanical aspects of innate immunity.
A
Body surfaces - skin and furRespiratory tract cilia Air movement in the respiratory tractMucus secretionLiquid secretion flushes
16
Q
Describe an instance in which MHC 1 May not be present on the surface of a cell. What is the consequence of this?
A
Some tumours and infections cause down regulation of MHC1, this means that they are unable to be targeted by cytotoxic T cells.This causes activation of NK cells which apoptose the affected cell
17
Q
Draw the structure of a lymphnode. How do pig lymphnodes differ to those of other mammals?
A
Pig structure is “backwards”
18
Q
Draw a single unit of the spleens white pulp, label the whereabouts of the two types of lymphocyte found in it.
A
Corona = b PALS= t
19
Q
Draw a C1 complex molecule.
A
C1q - six binding sitesC1rC1s
20
Q
Epitome
A
The part of the pathogen which is recognized by the immune system
21
Q
Exogenous Ag processing causes activation of cytotoxic T cells and endogenous Ag process causes activation of helper T cells.True or false + correct if necessary
A
FalseVisa versa
22
Q
How are immunoglobulins absorbed in the neonate gut?
A
The stomach has low enzyme concentration at this point therefore FcRn receptors on the wall of the small intestine absorb the Ig.
23
Q
Extra components of the complement process can cause which immune processes?
A
Chemotaxis - C5b
Opsonisation
Activation of mast cells
24
Q
How are useful T cells selected for in the thymus?
A
Their affinity for MHC molecules - useful T cells have only a low affinity for MHC 1 and 2
25
How do a capsule and a slime layer differ in the bacterial cell?
Capsule is well defined compared with a slime layer.
26
How do APCs process antigen?
Endogenous - express full processed Ag on cell surface via MHC1Exogenous - Macrophage breaks down Ag and expresses parts of it on its surface or allows other APCs to pick up and express it via MHC2
27
How do antibodies act in a viral infection?
Prevent viral adhesionViral agglutinationMacrophage engulfmentAntibody dependent cell cytotoxicityComplement mediated lysisPrevents viral absorption
28
How do bacteria evade the immune system?
Avoid adaptive immunity
* Mimic host Ag
* Biofilms
* IgA proteases
Survive phagocytosis
Avoid phagocytosis
* A proteins
* M proteins
* Capsular molecules
Manipulate cytokine secretion
29
How do commensal bacteria act as part of the innate immune system?
They provide a barrier to the gut mucosa for other pathogenic bacteria.
30
How do protozoa parasites evade the host immune system?
Hide - coat themselves with host protein
Block dendritic cells
31
How does colostrum become rich in immunoglobulin in the udder?
Fc receptors in the mammary tissue pull Ig from the serum into the gland as it passes through, this is secreted in the milk.
32
How does the secretory piece of an IgA molecule function?
It protects the IgA molecule from the harsh environment of mucosal surfaces where IgA has its action. Prevents break down by proteinases.
33
How is the body protected from complement mediated damage?
Complement proteins breakdown easily - LabileCells have specific complement receptorsFactors I and H cleave C3 - reduce reactionRBC's have c3b receptors which mop up excess complement proteins
34
How many litres of colostrum should the neonate receive in the first six hours?
1L
35
How would low immunoglobulin levels in the neonate be treated in cases which are over and under 15 hours old?
Over 15 hrs = IV Ig Under 15 hrs = Oral colostrum
36
Humoral immunity is mediated by which type of lymphocyte?
B cells
37
Interleukin 10, which causes inhibition of TH1 interferon gamma release, is released by what cell?
TH2
38
Lymphocytes are produced in the _____ \_\_\_\_\_\_\_, a _______ lymphoid organ . Once produced T cells are moved to the ________ for maturation.
Bone marrow - primaryThymus
39
Label this bacterial cell.
40
MHC
Major histocompatibility complex
41
Name and state the producing cells of the different types of interferon.
IFNa/b - fibroblasts IFNgamma - T cells and NK cells
42
Name the four major components of the T cell receptor molecule.
Alpha subunit Beta subunitCD3 complexEither CD4 or CD8 molecule
43
Name two types of mucosa associated lymphatic tissue.
Peyers patches Tonsils
44
Name two types of animal which are know to suffer with complement deficiency disorders.
Finnish landrace lambsBrittany spaniels
45
NO is produced by which phagocytotic cell to cause oxidative damaged in bacterial cells?
Macrophages
46
Outline and briefly explain the potential outcomes of a viral infection.
Cell division - viral tumoursCell lysis - destruction of host cellPersistent infection - slow release of viral particlesLatent infection - delay between infection and symptoms
47
Outline the characteristics of the ideal vaccination.
Provides strong immunityLong-termConferred to foetusMinimal side effectsCheap/stableDIVA testable
48
Outline the formation of the membrane attack complex in the classical pathway.
C1q/r/s complex binds to Ab/Ag complex \> C1 cleaves C4 and C2 into a and b molecules \> C4&2b attach to nearest bacterial protein \> c3 binds and is cleaved to a and b \> b cleaves c5 to a and b \> b causes binding of c6/7/8/9 this forms the MAC
49
Outline the process of complement activation via the lecithin pathway.
Mannan-building lecithin binds to pathogen surface via PAMPs C4 and C2 bind to MBL and dissociate to a and b molecules causing activation of the C3 molecule
50
Outline the process of phagocytosis.
Attachment of microbe to phagocyte receptorPseudopodia engulf the microbe and form the phagosomeThe phagosome fuses with the lysosome Lysosome digests microbeMicrobial proteins are expelled from the phagocyte
51
Outline the role of the high endothelial venules in the lymphnodes.
They grab lymphocytes using integrins from the blood and pull them into the lymphnode.
52
PAMP
Pathogen associated molecular patterns
53
PRR
Pattern recognition receptors
54
T cells are useful in which type of infection?
Intracellular - they destroy infected cells
55
The C1 complex is vital in the activation of which complement pathway?
Classical
56
The membrane attack complex is made up of which 5 complement proteins?
C5bC6C7C8C9
57
The PALS of the white pulp of the spleen surround what and contain which type of lymphocyte?
Central arteryT cells
58
The primary response to a pathogen is ____ than the secondary reponse.
Smaller
59
The variable region of antibodies can also be known as what?
The antigen binding site The functional site
60
These types of cytokines regulate immunity by acting on lymphocytes.
Interleukins
61
This interleukin inhibits the release of interferon gamma therefore causing the upregulation of B cell production.
Interleukin 10
62
This PRR can be found on monocytes, macrophages, mast cells and Bcells and has a non-specific manner of detecting PAMPs.
Toll-like receptors
63
This type of Bovine Viral Diarrhoea causes abortion and malformation of the foetus.
Cytopathic.
64
This type of interferon causes secretion of NO and therefore prevents viral growth in cells and also activates macrophages.From which cells does it originate?
Type 2 - IFNgammaT cells and NK cells
65
This type of interferon increases MHC1 expression of antigen, what effect does this have?
Type 1 - IFNa/b Causes activation of cytotoxic Tcells
66
This type of T cell prevents auto-immunity by "turning off" CMI.
Treg cell
67
This type of vaccination contains an attenuated pathogen created by modification of the pathogen by heat, chemical etc or gene knockout or deletion.
Live
68
This vital organ is an example of secondary lymphoid tissue. Explain what is meant by this.
SpleenAn area of proliferation and differentiation of lymphocytes
69
Valence
The number of bonds made
70
What action do interferons have on the body?
Protect cells and their neighboring by binding and blocking viral receptors.
71
What action of an immature B cell causes its apoptosis in the bone marrow?
If it produces self recognizing antibodies
72
What are defensins an example of, how do they work?
Molecular innate immunityThey insert into microorganism membranes and cause cell lysisThey are found in epithelial cells and phagocytes
73
What are Langerhanns cells? How do they aid subcut vaccination effectiveness?
Precursors of dendritic cells. They transmit Ag from the subcut to circulating t cells.
74
What are the critical properties of vaccines?
Stimulate b and t cellsActivate APC's Stimulates several epitomesPersistent vaccine antigen
75
What are the effects of TH2 driven immunity to helminths?
* IL5 mediated activation of Eosinophils
* Macrophage supression
* Mast cell degranulation
* IL4 release
* IgE coat the parasite
76
What are the sites of action of IgG and IgM molecules?
Lymphoid organsIn circulationIn tissue
77
What are the types of outcome of complement mediated protection?
Cell lysis - MAC Chemoattraction of phagocytesOpsonisation
78
What cytokines released by T cells stimulate NK cell action in later stages of viral infection?
TNF, IL12, IL2
79
Pyrexia and pH changes within the body are examples of what type of immunity?
Physiological innate immunity
80
What does the Zinc Turbidity test measure?
It estimates IgG in serum based on its precipitation when added to a zinc-containing solution. Precipitation generally occurs when levels are over 400–500 mg/dL
81
What functions does the bone marrow have in production of B cells?
Ag receptor constructionDevelops specificityKills self reactive B cellsSends useful cells to the periphery Production of antibodies?
82
What innate cytokines stimulate NK cell action in early viral infection?
IFNa/b and IL12
83
Th2 cells produce which cytokine to cause the proliferation of B cells?
IL4
84
What is a basic unit of immunoglobulin made from? Draw one & label it.
Two light and heavy chains joined together by disulfide bonds
85
What is a cytokine?
A cellular hormone
86
What is an adjuvant?
An agent which modifies the effect of another agent. They enhance the ability of a vaccine to stimulate the hosts immune system.
87
What is meant by immune tolerence?
Failure to mount an immune response to an antigen.
88
What is meant by polyclonal?
Has many epitomes, stimulates many different B cells
89
What is the common molecular goal of the three complement pathways?
C3
90
What is the difference between serum and plasma?
Serum is the fluid extracted from contracting blood clots whereas plasma is the fluid spun off anticoagulated blood
91
What is the function of an APC? Name three types of APC.
APCs present antigen to T cells to cause their activationDendritic cells MacrophagesB cells
92
What is the method of action of NK cells?
They recognize cells with low MHC1 and destroy them.
93
What is the quaternary structure of IgM like? How does IgM function biologically in the body?
A circular pentamer.IgM is the main antibody found in the primary response to a pathogen, it is the most efficient antibody
94
What is the T to B cell ratio?
80 T: 20 B
95
What percentage of T cells remain once selection within the thymus is complete?
5%
96
What causes blue eye during an adenovirus infection?
Antigen antibody complexes forming and collecting in the eye.
97
What products of myeloperoxidases are used to kill pathogens?
Hypochlorite and single oxygen free radicals
98
What type of relationship exists between Th1 and Th2 cells? Explain.
AntagonisticLike a see-saw, each releases cytokines which inhibits the other cell type
99
Where in the body are the complement proteins produced?
Liver
100
Where in the body is mannan-building lecithin produced?
Liver
101
Which antibodies are most effective in a viral infection?
IgG, IgM, IgA
102
Which antibodies cause activation of the complement system?
IgG IgA
103
Which antibodies cause opsonisation of pathogens? What is the effect of this?
IgG attracts phagocytes
104
Which antibodies neutralize pathogens by recognizing and binding to them?
IgG IgMIgA
105
Which antibody causes cytotoxicity of pathogens by activation of NK cells?
IgG
106
Which aspect of arthropod mediated disease causes an immune response in the host?
Parasite saliva
* TH1 activation - infiltration of basophils
* TH2 activation - IgE and inflammatory response
107
Which aspects of innate immunity are vital in parasite immunity?
Host factors
* Age
* Sex
* Health status
Parasite specificity
* Species of parasite are specific to host
108
Which cells of the body are considered parts of the innate immune system?
MacrophagesPolymorphic granulocytesMast cellsNK cells
109
Which class of MHC molecule is found on the surface of APC's, macrophages, B cells and activated T cells?
MHC 2
110
Which interleukin is released by macrophages and causes activation of TH1 cells?
IL12
111
Which of the complement a molecules is considered the strongest Chemokines?
C5a \> C3a \> C4a
112
Which of the immune system structures develops first in the neonate?
Thymus
113
Which oxidative species are produced by neutrophils to destroy bacteria?
H2O2
114
Which part of the C1 complement protein binds to the antigen-antibody complex in the classical pathway?
C1q
115
Which physiological changes in the host also decrease likelihood of parasitic infection?
Increased goblet cell number
Mucin secretion
Water influx into intestinal lumen
Increased intestinal motility
116
Which structural molecule to lysozymes act upon?
Peptide glycine of the bacterial cell wall.
117
Which enzyme which is part of the innate immune system is mainly found within cellular lysosomes in macrophages?
Myeloperoxidase
118
Which type of B cell makes antibodies?
Plasma cells
119
Which type of T cell expresses CD4 on its T cell receptor?
Helper T cells
120
Which type of T cell recognizes MHC1 molecules?
Cd8 cells - cytotoxic T cells
121
Which type of T cell recognizes MHC2 molecules?
Cd4 cells - helper T cells
122
Which types of bodily secretions can lysozymes be found in?
1. Saliva
2. Tears
3. Mucus
123
Which types of equipment do we use to assess colostrum quality?
1. Colostrometer
2. Refractometer
124
Which types of test do we use to assess Ig levels in the neonate?
1. Radial immunodiffusion
2. Zinc turbidity test
125
This virus uses antigen variation though genetic drift to evade the hosts immune system.
Influenza
126
Outline the methods by which viruses evade the immune system.
1. Immunosuppression - destroy APC's, induce tolerence, alter the helper T cell balence
2. Antigen variation - genetic drift
3. Spread too quickly for immune system to act
4. IFN interference
5. Inhibit antigen processing
6. Non-neutralising antibody production
7. Latent infection
127
How does Herpesvirus interfere with interferons of the body?
Produce a IL-10 analogue which inhibits IFNgamma
128
This virus type inhibits viral antigen processing through MHC1.
Bovine Herpes Virus
129
1. What are the cellular factors which can cause tumours to occur?
2. Which molecules are they presented on in the cell?
1. Causes - products are expressed on MHC1
1. Tumour supressor gene malfuction
2. Viral
3. Oncogenes
4. Mutated normal genes
5. Overproduction of normal proteins
6. Foetal proteins
7. Mutated glycolipids
8.
2. MHC1
130
How do benign and malignant tumours differ?
1. Benign are at a single site
2. Malignant metastisise and form secondary tumours elsewhere
131
How does ADCC act in tumour immunology?
1. NK, monocytes, pmn's and eosinophils bind to FcR on Ab leading to cell death
2. Antibodies from abnormal cells become antigens
3. Tumour antigens - proteins acting abnormally
132
How do cytotoxic T cells recognise and destroy tumour cells?
They recognise viral Ag bound to and MHC1 molecule and produce granulozymes, perforins and FAS(L) molecules which cause cell lysis or self apoptosis of the cell. They also release IL2 which stimulates the action of NK cells.
133
Describe the origination of NK cells.
They make up 15% of lymphocytes. They are a type of T cell which has become part of the innate immune system.
134
1. Interferon gamma is released during tumour immunity by which cells?
2. What does it release cause?
1. Tumour cells themselves and due to NK and Tc cell activation
2. Causes further activation of NK cells and stimulates phagocytosis of tumour cells by macrophages.
135
Which cytokines produced by macrophages cause increased activity of Th cells and NK cells?
TNF and IL1
136
How can tumour cells evade the bodies immune systems?
1. Activate Treg cells
2. Cause lymphocyte apoptosis
137
Immunotherapy
Stimulate the immune system to attack tumours
138
How can immunotherapy be used to combat tumours?
1. Passively - using interferons
2. Active - attempts to stimulate the host's intrinsic immune response
1. Specific - focus on specific cancer generated antigens to stimulate CMI and Ab
2. Non-specific - general immune response using cytokines
3. "Educated dendritic cells" - which target tumour proteins
4. Activated Tc or NK cells which are returned to the host
139
How are tolerent B and T cells disposed of in the body?
B cells:
1. Clonal abortion - immature
2. Functional deletion - apoptosis, Treg, no TH cells
3. Clonal exhastion - no further proliferation of plasma cells
T cells:
1. Thymic deletion
2. Post-thymic - suppression, abortion and deletion of self reactive cells
140
This type of hypersensitivity is caused by the production of IgE as a secondary response to a pathogen rather than IgA/ IgG.
What is the response to this?
Type I hypersensitivity
Causes mast cell degranulation leading to inflammation.
141
What clinical conditions are caused by type I hypersensitivity?
* Food allergies
* Parasite allergies
142
Sytemic Anaphalaxis is characterised by what symptoms?
* Respiratory stress
* Diarrhoea
* Collapse
* Increased blood pressure
143
What is type II hypersensitivity?
Name some clinical conditions which are caused by this.
Antibodies produced by the body attach to the host cells causing **a****ntibody dependent cell cytotoxicity**
* IMHA
* Foal haemolytic disease
144
Blue eye is an example of which type of hypersensitivity?
Define this hypersensitivity.
Type III hypersensitivity.
Immune complexes form/ deposite in tissues causing complement reactions, frustrated phagocytosis, cytokine release.
145
Frustrated Phagocytosis
Release of phagocytitic enzyme into the tissue environment due to the inability of a phagocyte to phagocytose a cell (too big etc)
146
# Define type IV hypersensitivity.
Delayed hypersensitivity - sensitised Tc cells react to a specific antigen and release cytokines which induce inflammator reactions and attract and trap macrophages leading to granuloma formation.
eg TB and TB testing
147
Differenciate between primary and secondary immunodeficiencies.
Primary immunodeficiencies are inherited defects whereas secondary have extrinsic causes
148
Immunodeficiency
Increased susceptibility to opportunistic infections and increased risk of tumours.
149
Define Chediak-Higashi syndrome.
* Enlarged cytoplasmic granules burst
* Increased bleeding
* increased susceptibility to infection
150
How do Leucocyte Adhesion Deficiencies work?
Failure of granulocytes to leave the blood and enter infections.
Absence of CD11B/18 receptor on leucocyte membranes.
151
BLAD and CLAD disorders are caused by mutation of what amino acids?
1. BLAD - Asp - Gly
2. CLAD - Cys - Ser
152
Pelger Huet abnormality
Is it fatal?
Neutrophil nucleus fails to segment
No.
153
Canine cyclic haematopoiesis
Cyclic neutropenia and other cell deficiencies (11-12day cycles)
Seen in grey collies
154
Name the aquired immunity defects.
1. Lymphocyes defects
2. Severe combined immunodeficiency
3. Foal immunodeficiency syndrome - low B cells - Dales and Fells
4. Nude cats - T cell deficiency
5. IgM deficiency - Low IgM
6. Ehler - Dalos syndrome - skin defect
155
Describe the different types of SCID in equines and canines.
1. Equines - Arabians - DNA repair failure - T and B cells are present but don't work
2. Canine
1. Bassett hound - No response to IL-2 - No IgG/A, low T cells, lack of TH cells
2. JRT - No Ig's and non-functional T and B cells
156
Name secondary aquired defects and the viruses they are caused by.
Describe each of them briefly.
1. Parvo
2. Distemper - CMI and AB depressed, cytokine interuption and lymphocyte lysis.
3. Lentiviruses - FIV, HIV, SIV
4. FeLV - lymphopenia, kidneys and tumours
157
DID
**Double immunodiffusion** - Measures the simmilarity between know and unknown complexes.
158
RID
**Radial Immunodiffusion **- Quantify Ag or Ab response
159
Immunoelectrophoresis
Normal vs patient comparisons
160
How does serology allow us to measure Ab response?
Relies upon Ag/Ab binding complexes. Lattice formation causes visible complexes.
161
How do DIVA tests work?
Vaccines contain markers which are detected by the DIVA test .
