Immunology Flashcards
1
Q
Name the 6 molecular systems of innate immunity.
A
Defensins Lysozyme/sweat Myeloperoxidase Acute Phase Proteins Complement Interferons
2
Q
What are the two roles of defensins?
A
Immune signalling
Direct, anti-microbial action
3
Q
In which organ system are defensins important?
A
Skin
4
Q
What is the MOA of lysozymes?
A
Attack peptidoglycan cell wall of bacteria
5
Q
What is to role of acute phase proteins?
A
Opsonisation
6
Q
Where is myeloperoxidase found?
A
Lysosomes in granulocytes/macrophages
7
Q
What is the MOA of myeloperoxidase?
A
Production of hypochlorite and singlet oxygen
8
Q
Which cells produce IFN a and b?
A
Virally infected cells
9
Q
Which cells produce IFNy?
A
Lymphocytes
10
Q
IFNs are key in tackling which two pathologies?
A
Tumours, Viruses
11
Q
What are the 4 cellar innate defences/
A
Macrophages
Polymorphs
Mast Cells
NK cells
12
Q
What is the role of macrophages & polymorphs?
A
Phagocytosis
13
Q
What is the role of mast cells?
A
IgE Ab receptors - inc vascular permeability
14
Q
What is the role of NK cells?
A
Kill tumour cells, virally infected cells, and ab coated cells
15
Q
What are the 3 cardinal features of adaptive immunity?
A
Specificity
Self/Non-self discrimination
Memory
16
Q
Which are the two major secondary lymphoid organs?
A
Spleen
LNs
17
Q
Which are the additional secondary lymphoid organs? (4)
A
Tonsils
Appendix
Peyers Patches
Mucosa-Associated Lymphoid Tissue (MALT)
18
Q
Which histological feature is UNIQUE to the thymic medulla?
A
Hassals Corpuscles
19
Q
Which two cell types are found in the thymic cortex?
A
Maturing Lymphocytes
Macrophages (remove apoptotic thymocytes)
20
Q
Which three cell types are found in the thymic cortex?
A
Adult T Lymphocytes
Macrophages
Dendritic Cells
21
Q
Which process, as part of maturation, occurs in the thymus?
A
Tolerance
22
Q
Where do B cells develop?
A
Bone Marrow
bursa of fabricius in birds
23
Q
What are the 3 main divisions of a LN, and which cells can be found in each section?
A
Cortex: B cells
Paracortex: T Cells
Medulla: T and B cells
24
Q
Which 3 organ systems contain MALT?
A
GIT
Resp
UGT
25
Where are peyers patches located?
Ileal submucosa of SI - M cells
26
Where is complement produced?
Liver
27
What are the 3 antimicrobial MOAs of complement?
Opsonization
Chemoattraction
Membrane Lysis
28
What are the 3 complement pathways?
Classical
Lectin
Alternative
29
Describe the Classical Pathway.
```
IgM/G(6) pathogen.
C1qrs binds.
C2/4 binds & cleaved
C2a/4a splits off
C2b/4b bind nearby
C3 binds to 2b/4b
C3a splits off
C3b cleaves C5
C5b binds nearby
C6/7/8/9 bind to C5b
MAC formed - lysis
```
30
Describe the MBL Pathway.
MBL cleaves C2/4 instead of qrs.
| Otherwise same.
31
Describe the Alternative Pathway.
Bacteria > Fatcor B > C3 convertase > C3a/b
| Then same.
32
How does C3a cause cell death?
Combines with C5a - Inflammatory response: MC degranulation
33
How does C3b cause cell death?
Lysis (MAC) AND
| Opsonisation
34
List the 3 chemotactic agents of the complement system in order of potency.
c5a>c3a>c4a
35
What is recognised on a pathogen surface by the innate immune system?
PAMPs
36
Which part of the innate immune system recognises PAMPS?
PRRs
37
What are the two forms of B cell post-activation?
Memory Cells
| Plasma Cells
38
What are the CD4+ T cells?
T helper cells (enhances CD8+ action & Ab response)
| AND Treg cells (prevent autoimmunity)
39
What are the CD8+ T cells?
Cytotoxic Tc (kills infected host cell & activates mø)
40
What is the Tc antigen receptor called?
TCR
41
What is the role of MHC?
Present Ag to Tc
42
What is the role of MHC I & where is it found?
Most Nucleated Cells
Present Ag to CTc (Cd8+)
43
What is the role of MHC II & where is it found?
APCs
Present Ag to Th cell (CD4+)
44
What is +ve selection in the thymus?
T cells which react with low affinity to self MHC + peptide survive
45
What is -ve selection in the thymus?
T cells which react strongly to self-Ags undergo apoptosis
46
What is the role of APCs?
present Ag to Th Cell
47
What are the 3 main APCs?
Dendritic Cell
Bc
Mø
48
What do Th1 cells do?
(CMI) Tc and macrophage activation in response to INTRACELLULAR infection.
49
What do Th2 cells do?
(humoral) Assist Bc to make Ab in response to EXTRACELLULAR infection
50
Name 4 Th1 Cytokines
IFNy
TNFa
IL2
IL12
51
Name 4 Th2 Cytokines
IL4, IL6, IL10
| TGFB
52
What are NK cells?
Lymphocytes which respond to an ABSENCE of MHC 1
53
How does passive immunity occur?
Maternally derived from colostrum or placenta
54
Why are SQ vaccines so succesful at producing an immune response?
Langerhans cells capture/process Ag in skin.
Precursor to dendritic cells.
Travel to LN.
Effective T cell stimulation.
55
Which bovine pathogens may cause Dz in the foetus, but not the mother?
BHV1, BVD, Bluetongue
56
Why does interuterine infection with BVD cause the calf to succumb to the disease?
Builds tolerance as no maternal reaction --> no immunity when re-challenged
57
In dogs and cats, state what proportion of passive immunity is gained from the maternal placenta, and the maternal colostrum.
5% placental
| 95% colostrum
58
In cows/pigs/horses, state what proportion of passive immunity is gained from the maternal placenta, and the maternal colostrum.
100% colostrum - NONE from placenta
59
What are the two features of the neonatal GIT which aid absorption of MDAs? How long do they last? (ruminant)
Oesophageal Groove. 20d.
Specialised Fc receptor on intestinal epithelia. 6h decline, 24h gone.
60
Describe the colostrum requirements for a neonatal calf/foal.
1L within 6h of birth.
61
How can you assess colostrum quaity?
Hydrometer: measures SG which correlated with Protein and IgG content.
Refractometer.
62
What are IgG and IgA protective against in the newborn animal?
IgG: septicaemia
| IgAL enteric Dz
63
What are the 3 causes for FPT?
Failure of Production, Ingestion or Absorption.
64
What is a quick, on-farm test used to measure foal IgG?
Zinc Turbidity Test
65
How can we quantify FPT in foals?
Radial Immunodiffusion:
FPT: IgG <2mg/ml
Partial: IgG 204mg/ml
Adequate: >4mg/ml
66
How do you treat a foal with FPT <15h old?
NGT/Bottle Colostrum
67
How do you treat a foal with FPT >15h old?
Commercial IV plasma
68
At what age do MDAs reach sufficient decline to allow adaptive immunity development?
10-12w
69
What are TLRs?
Subtype of PRR.
| Induce Cytokines and inflammation.
70
What are the 3 mechanisms bacteria use to avoid phagocytosis?
```
Capsules.
Protein A (inactivates C3.
M protein (blocks complement & opsonisation)
```
71
What is the major ctyokine driving the Th2 response?
IL-4
72
What is the major ctyokine driving the Th1 response?
IL-12
73
Name the common endotoxin associated wiht GRam -ve bacteria.
LPS
74
What is the cause of toxic shock syndrome?
SuperAg on bacteria hypersitmulate T cells.
| Causes shock & possibly death.
75
What is the most effective form of anti-fungal immunity?
T cell immunity
76
What are the 4 way in which protozoa evade the innate immune system?
Resist Complement
Survive inside phagocytes
Manipulate dendritic cells
Poor PAMP expression
77
What is the main immune response to helminth infections?
Th2 - Humoral IgE, Mast Cells & Eosinophilia
78
Which stage of the helminth life cycle invokes a cTc immune response?
Larvae
79
What are T1 IFNs and where are they produced?
IFN a & b
Infected Tissue Cells (fibroblasts)
80
What are T2 IFNs and where are they produced?
IFN y
Ag stimulated T cells and NK cells
81
What do T1 IFNs stimulate?
NK Cell activity
IFNy secretion
MHC I expression
82
What do T2 IFNs stimulate?
NO secretion
IFNy secretion
Mø activation
83
What are the 3 major cell types involved with anti-tumour immunity?
CD8+ Tc
Macrophage
NK cell
84
Describe the roles of Tumour-Assocaites Macrophages
M1 - anti-tumour
M2 - pro-tumour
85
What is a common Tumour Escape Mechanism of lymphoid tumours?
Tumour-induced Immunosuppression
86
Which type of lymphoma responds best to chemotherapy?
B cell Lymphoma
87
How is peripheral tolerance maintained?
Apoptosis
Anergy (unresponsive)
Tregs and Bregs
88
What is the pathogenesis of Rheumatoid Arthritis?
Auto-immune dz.
| Anti-collagen Abs > imm. complex in joint
89
What is the pathogenesis of Systemic Lupus Erythematosus?
Multi AutoAbs
IC's circulate.
Complement Deficiency.
Glomerulonephritis.
90
What is the pathogenesis of Myasthenia Gravis?
AutoAbs against AchR
| Muscle doesn't respond to Ach
91
What is type I hypersensitivity??
IgE production in response to Ag.
Atopy.
92
What is a common clinical sign of Type I hypersensitivity?
Urticaria
Anaphylaxis
Allergy
93
What is type II hypersensitivity??
Ab mediated damage to host by complement & NK.
94
Which 2 conditions are caused by Type II hypersensitivity?
Haemolytic Dz of the newborn foal
IMHA
95
What is type III hypersensitivity? What may it lead to?
Immune complex formation/deposition.
Glomerulonephritis
96
Name 2 conditions are caused by Type III hypersensitivity?
Canine Anterior Uveitis (adenovirus)
COPD in horses
97
What is Type IV hypersensitivity?
Chonic Ag load > Tc > cytokine > Mø
98
Name a use for Type IV hypersensitivity reactions.
TB skin test.
99
What is the cause of transplantation rejection?
MHC I/II differences
100
Which Dz of Irish Setters and Holsteins, presents with leucocytosis and recurrent bacterial infections? Px?
Leucocyte Adhesion Deficiency.
FATAL - test genetics.
101
Which disease of TB horses causes overwhelming infection and death at 4-6m?
SCID - no functional T or B cells once MDAs left
102
Which disease of FELL PONIES causes overwhelming infection and death at 4-6m?
Foal Immunodeficiency Syndrome
103
Which 2 canine diseases, preventable by vaccine, can cause immunodeficiency?
Distemper - leucopenia
Parvovirus - lymphopaenia
104
What is the difference between serum and plasma?
Serum = plasma - fibrinogen
105
What do direct and indirect immunofluorescence tests measure?
Direct: Ag in sera
Indirect: Ab in sera
