Immune System Flashcards
1
Q
What are 3 types of granulocytes
A
Neutrophils
Eosinophils
Basophils
2
Q
What is the major circulating white blood cell
A
Neutrophils
3
Q
What is the major mechanism of granulocytes
A
Phagocytosis
4
Q
What is the name of the enzymes which produce bleach
A
Myoperoxidases
5
Q
What is a method used by Neutrophils to kill pathogens
A
conversion of oxygen into toxic oxygen free radicals
6
Q
What is special about necleophiles when seen under a microscope
A
Polynucleated, with 1 nucleus in multiple lobes
7
Q
Where are the granules kept in the granulacytes
A
Cytoplasm
8
Q
What is the capsule in which the phagocyte engulfed into called
A
Phagosome
9
Q
Which type of pathogen do Granulocytes focus on
A
bacteria
10
Q
How do Nucleophiles move from the blood vessel into the non-immunological organs
A
Walls become sticky to slow down the cells
Cells squeeze through the epithelium cells towards the infection (extravasation)
11
Q
What happens to the nucleophiles in the blood if there is no infection after 24hrs
A
The Cells die
12
Q
What is the function of macrophages
A
Remove Debris from damaged tissues
13
Q
How do macrophages perform their function
A
Phagocytosis
14
Q
What is the name of Liver Specific Macrophages
A
Kuppfer Cells
15
Q
What si the name of the precursor of the macrophage, and where is it found
A
Monocyte, found in blood
16
Q
When are the macrophages used in the immunological defence against pathogens
A
2nd Wave, when the granulocytes fail. Have stringer killing mechanisms than granulocytes
17
Q
What is the major cell of the adaptive immune response
A
Lymphocytes
18
Q
What are the names of the 2 sub-populations of lymphocytes
A
T and B cells
19
Q
Where do T Cells develop
A
Thymus
20
Q
Where do B Cells develop
A
In the Bone Marrow
21
Q
Which 2 locations do the lymphocytes circulate through
A
the Tissues and Blood
22
Q
What is a typical feature of the Lymphocyte when seen under a microscope, unactivated
A
Almost No Cytoplasm
23
Q
How long does it take for the T Cell to become highly activated
A
24hrs
24
Q
What does a Plasma Cell Differentiate from
A
B Cells
25
What is typical for Plasma Cells
Packed with Endoplasmic Reticulum
26
How Long Lymphocytes live for
20-30 years
27
Where do Lymphocytes re-circulate through
Blood Vessels and lymphatics
28
Where do Effector T Cells leave to go to the tissues to control infection
Blood Stream
29
What do Naive and Memor cells leave the bloodstream to enter lymphoid tissue to search for
Antigens
30
Where does the primary immune response start
Lymph Nodes
31
What is the role of dendritic cells (2)
Sampling Antigens from the environment
| Carrying samples to the lymph nodes
32
What are 3 types of dendritic Cell
Langerhan's Cell
Veiled Cell
Interdigitating Dendritic Cell
33
Which Type of dendritic cell can be found in the skin
Langerhan's Cells
34
Which 3 types of cell are in the innate immune system
Granulocyte
Macrophage
Dendritic Cells
35
Which 2 types of cells are in the Adaptive Immune System
T cells
| B cells
36
What is the type of interaction in immune recognition
Receptor-Ligand Interaction
37
What is the name of the receptors of innate immunity
Patter Recognition Receptors
38
What is the name given to the ligands which are molecular components of the microbe
Pathogen Associated Molecular Patterns (PAMPs)
39
What does Toll-like Receptor 3 bind to
RNA
40
What does Toll-Like Receptor 4 bind to
Gram-negative Bacterial Lipopolysaccharide
41
What does Toll-Like Receptor 2 Bind to
Lipoteichoic Acid
42
Where are Pattern Recognition Receptors (PRR) Found (4)
Blood
Cell Surface
Within Cellular Organelles
Cytoplasm
43
What are 3 Innate Effector Mechanisms
Phagocytosis and intracellular Killing
Extracellular Killing
Interferons and Restriction Factors
44
How does complement act
In a proteolytic amplification cascade system
45
What is the central step of the complement pathway
C3 cleaved into C3b and C3a
46
What are the 3 major functions of complement
Opsonisation
Lysis
Inflammation
47
What is the opsonisation pathway of complement
C3b binds onto C3b receptors on phagocytes leading to Phagocytosis
48
What is the Cell Lysis pathway of complement (3)
C3b cleaves C5 in C5b and C5a
C5b, C9, C6, C7 and C8 form membrane attack complex
Attack Complex causes cell lysis
49
What does C9 Form
Pores in the bacterial cell membrane
50
What is the Inflammation pathway of complement (5)
C3a and C5a cause mast cell degranulation
Degranulation leads to increased vascular permeability
Neutrophils chemotaxis
Granulocytes attracted to the area of infection
Inflammation
51
What are the 3 ways o activate complement
Bacterial Surfaces (Directly activate complement)
Acute Phase proteins
Antibody
52
What are the 3 pathways which lead to the central step in complement
Alternative Pathway
Classical Pathway
Lectin Pathway
53
What do all the complement activation pathways lead to
Cleaving of C3 into C3a and C3b
54
What is the main defence against viruses
Interferons
55
What cells can produce type 1 interferons
All Nucleated Cells
56
What do Interferons induce
A potent anti-viral state
57
How do interferons act
Via the up-regulation of many restriction factors
58
What does the resistant state mean for a cell infected by a virus
Unable to perform regular functions as all energy put into viral defence
59
What is the virus protected from when inside the cell (2)
Complement and Phagocytes
60
What is inflammation
Pathologicalequivalent of a normal immune response
61
What are the cardinal signs of inflammation, aka the symptoms (5)
```
Heat
Redness
Swelling
Pain
Loss of Function
```
62
What is inflammation caused by (2)
Cellular recruitment
| Activation of neutrophils followed by macrophages
63
How is redness caused during inflammation (2)
Lots of Cells were recruited, resulting in more blood
| More blood results in vasodilation and redness
64
What Causes the swelling in inflammation (2)
Lots of Cells are recruited, which increases the leakiness of the vessels
This causes vasopermeability, which results in swelling
65
What Causes Loss of function
Hypoxia
66
What does Interleukin 6 act on
Acts on tissues around the body to activate proteins found in the blood, such as complement compounds
67
What is the role of Interleukin 8
Main Attractor of Neutrophils
68
What is the function of Tumour Necrosis Factor
INcreases the stickiness of the vessel walls to attract neutrophils
69
Which proteins are up-regulated in the blood during the acute phase response (4)
Inflammatory cytokines, especially IL6
Soluble PRRs
Complement compounds
Coagulation factors
70
What can the proteins present during the acute response phase be a useful indicator of
Marker of Inflammation
71
Which common diseases are affected by chronic inflammation (5)
```
Arthritis
Atherosclerosis
Diabetes
Dementia
Cancer
```
72
Which immune cell ism mostly responsible for Chronic Inflammation
Macrophages
73
What are the sections of the antibody (Chains and Regions)
Heavy and Light Chains
| Variable and Constant Regions
74
What are the complementary determining regions called (3)
CDR2
CDR3
CDR1
75
What are the types of bonds involved in antibodies (1+4)
Non-Covalent Interactions
Electrostatic
Van der Waals
Hydrophobic
Hydrogen Bonds
76
What is the name of the region of the antibody which recognises and binds to the antigen
Paratrope
77
What is the name of the antigen which binds to the antibody
Epitope
78
Where, and during which cells development, is diversity generated in antibodies
During B Cell Development in the Bone Marrow
79
What is the name of the random selection of Variable, Diversity and Joining regions which cause diversity in antibody generation
VDJ Recombination
80
What are the 2 types of Light Chains fromed during recombination
Lambda
| Kappa
81
What is somatic hypermutation
Introduction of addition mutations after antigen recognition
82
What is the equivalent antibody on the T Cells Called
T-Cell Receptor (TCR)
83
What is one way in which TCR is different to antibody
TCR not secreted, only acts as a receptor
84
During the generation of TCR Diversity, which process is notably absent but present in Antibody Diversity generation
Somatic Hypermutation
85
What are the 3 independent sets of antigen receptors
Antibody
TCRab (alpha-beta)
TCRyd (gamma delta)
86
What is the name of the enzymes involved in the rearrangement of the VDJ Regions
Recombinase Enzymes (RAG)
87
What is the benefit of the large diversity of antibodies
Almost any pathogen, including those which can mutate, can be recogised
88
What is the difference between Transmembrane antibody and secreted antibody
Secreted antibody does not have the part which anchors the antibody to the cells
89
What are the differences between the primary (PIR) and secondary Immune Response (SIR)
More antibodies in SIR (More specific B Cells)
SIR Faster than PIR
the Antibody in SIR have a stronger affinity than those produced in PIR
90
What are the Different Antibody Isotypes and there Heavy Chain specific gene
```
IgG - y (Gamma)
IgA - a (alpha)
IgM - u (mu)
IgD - d (delta)
IgE - e (epsilon)
```
91
What is the most common Antibody Isotype
IgG
92
Which Antibody is found on mucosal surfaces
IgA
93
Which is the main antibody produced during PIR
IgM
94
What is the antibody expressed during the start of life in B Cells
IgM
95
Which is the Antibody isotype expressed in Naive B Cells
IgD
96
What is the main Antibody Isotype expressed in allergy
IgE
97
What type of polymer is produced by IgA
Dimer (Dimeric Secretory IgA)
98
What type of polymer is produced by IgM
Pentamer (Pentameric Circulating IgM)
99
What si the name of the chain which holds together the monomers in the IgA and IgM Polymers
J Chain
100
Antibody-antigen reactions are ... and as a result are able to reach ... (2)
1. Reversible
| 2. Equilibrium
101
What is Avidity
the overall binding strength of the antibody to the antigen
102
During an immune response, which antibody is released at the start of the infection and why
IgM, due to its high avidity
103
During an immune response, which antibody is released second and in larger amounts
IgG
104
Why is IgM production turned off during an immune response after the release of IgG (2)
High Affinity better than Avidity
| High Avidity can form large complexes, which could block blood vessels
105
What is the Effector Function of IgM
Complement
106
What are the effector functions of IgG (3)
Neutralisation (toxins and viruses)
Direct opsonisation
Phagocytosis
107
How is antibody involved in the neutralisation of toxins
The Binding of antibodies prevents the toxin from being able to bind to the receptor and create pathology
108
What are 2 examples where toxin neutralisation is required
Tetanus
| Diptheria
109
How is antibody involved during virus neutralisation
Viral Particles bind to the antibody, which prevents it from binding to the receptor and entering the cell, causing disease
110
What is the name of the receptors which allow phagocytes to bind to antibody
Fragment C Receptors (Fc Receptors)
111
How is antibody involved during opsonisation and phagocytosis (3)
Encapsulated Bacteria (usually resistant to phagocytosis) are coated with antibody (IgG)
IgG has Fragment C (Fc) Receptor, which binds to the Fcy (gamma) on phagocytic neutrophils
Bacteria able to be destroyed by the neutrophils
112
Which complement pathway is activated by antibody
Classical Pathway
113
Simply, what are monoclonal Antibodies
Antibodies of a single specificity
114
Monoclonal antibodies are used as drugs to treat which diseases (3)
Inflammatory Disease
Viral Infections
Cancer Treatments
115
What are the 3 subsets of the T Cells
CD4 Helper Cells
CD8 Cytotoxic Cells
CD4 Regulatory Cells
116
Which MHC Class do CD8 Cells Recognise
Class 1
117
Which MHC Class do CD4 Cells Recognise
Class 2
118
What are 2 pathways used by CD8 Cells to kill pathogens
Fas/FasL Pathway
| Granzyme/perforin Pathway
119
How does the Fas/FasL Pathway work
FasL on the CD8 cell binds to the Fas receptor on the pathogen, causing caspase signalling
120
How does the Granzyme/Perforin pathway work (3)
Antibody recognises antigen
Perforin makes small holes in the membrane of the pathogen
Granzymes are released into the pathogen, leading to caspase signalling
121
What does Caspase Siganlling cause
Apoptosis
122
Why are innate lymphoid cell less precise
no TCR (T Cell Receptor)
123
What are the 6 types of cytokines
```
Interleukins
Chemokines
Interferons
Tumour Necrosis Factor
Colony-Stimulating Factors
Growth Factors
```
124
What is meant by Cytokine Pleiotropism
One cytokine acts on several different types of cells, with different outcomes
125
What is meant by Cytokine redundancy
Several cytokines have similar effect on target cells
126
What is meant by Cytokine Synergism
Combined effect on two cytokines is greater than additive effect on each
127
What is meant by Cytokine Antagonism
Effect of one cytokine inhibits/cancels
128
Which receptors are expressed on the Helper T Cells
CD4
129
Which branches are controlled and amplified by the helper T cells (5)
```
Macrophages and Intracellular pathogens
Eosinophils and mast cells in parasite immunity
Neutrophils and extracellular pathogens
B cells, antibodies and humoral immunity
Cytotoxic T Cells and Viral Immunity
```
130
What are the important Th subpopulations (4)
Tfh (follicular cells)
Th1
Th2
Th17
131
What do Tfh (follicular cells) help with
Help B Cells make specific antibody
132
What do Th1 Cells activate (2)
Macrophages
| Cytotoxic T cells
133
What do Th2 Cells activate (3)
Mast Cells
eosinophils
IgE
134
What does Th17 activate (1)
Neutrophils
135
How do T-B Interactions work (linked help) (5)
Costimulatory molecules B7 (B Cell) bind with CD28 (T Cell)
B cell presents peptide of antigen on MHC Class 2
T Cell Receptor recognise peptide
CD40 on the B Cell binds with CD40L on T Cell
Cytokines released by the T Cell, acting on the the B cell
136
What is Linked Help essential for (3)
Class Switching
Somatic Hypermutation
Memory
137
How do Th1 Cells activate macrophages to kill intracellular pathogens (5)
Peptides from intracellular pathogens presented on MHC Class 1 on the macrophages
TCR recognises the peptide
CD40 on macrophage binds to CD40L on T Cell
Th1 Cell releases INFy (Interferon-gamma) to mediate macrophage
Macrophage releases TNFa (alpha) and IL-1
138
How do Th1 Cells help activate CTL
Th1 cell releases interleukin 2, which activates CTL Cells
139
Th2 helps during parasitic infections. Which interleukins does it release
IL3
IL9
IL5
IL13
IL4
140
How do IL3 and IL9 released by Th2 help (1+2)
Drive Mast Cell recruitment
Mast Cells:
Release of granules
Recruits Inflammatory Cells
141
how does IL5 released by Th2 help (1+2)
IL5 recruits and activates eosinophils
Eosinophils:
Release of Granules
Cause Parasite killing
142
How does IL13 release by Th2 help (1+1)
IL13 induces epithelial cell proliferation and stimulates mucus production
Epithelial cells hinder parasite colonisation
143
How does IL4 released by Th2 cells help (1+1)
IL4 favours IgE production
| IgE arms mast cells and eosinophils
144
How do Th17 Cells work in bacterial and fungal infections (2)
IL17 activates myeloid (immune) and stromal (non-immune) cells to produce GCSF and IL8
This recruits and activates neutrophils, which release granules that kill
145
What determines the Th type
the microenvironment around the antigen-presenting cells at the time the T cell is activated
146
On Th1 Cells ... (2) causes ... (1) to be presented during activation
1. IFNy (gamma) and IL12
| 2. IFNy (gamma)
147
On Th2 Cells ... (1) causes ... (3) to be presented during activation
1. IL4
| 2. IL4, IL5 and IL13
148
On Th17 Cells ... (3) causes ... (2) to be presented during activation
1. TGFb (beta), IL6 and IL23
| 2. IL17 and IL22
149
On Th21 Cells ... (1) causes ... (1) to be presented during activation
1. IL6
| 2. IL21
150
What is the qualitative regulation of the T Cell
Co-Stimulation via cytokines
151
What is the gatekeeper of the T cell
Antigens/MHC
152
What is the Quantitative regulation of the T Cell
Co-Stimulation via cell-to-cell contact
| Increased co-stimulation = increased response
153
What is Excessive T Cell help associated with
the underlining of many pathologies
154
What holds the peptide onto TCR
Major Histocompatibility complex
155
Where is the peptide held in TCR
the peptide binding groove
156
How is CD3 involved in the T cell antigen receptor
CD3 transducer signal and aids in the decision of what happens to the binded cell
157
What is involved in T cell activation, other than the antigen (5)
Co-stimulation CD28 and CD80/86 (positive signals)
Negative signals CD28/CTLA4; PD1/PDL1
Professional and non-professional presenting cells
Dendritic Cells
The innate adaptive interface
158
What are the names of the 2 pathways peptides are loaded onto MHC, and which class are they specific to
Endogenous - Class 1
| Exogenous - Class 2
159
What is Endogenous Processing (4)
```
Protein (usually viral) is broken into peptides by a proteasome
Peptides enter the endoplasmic reticulum via the TAP gene and transporters
Peptide join MHC class 1 and enter Trans-Golgi vesicle
MHC class 1 and peptide expressed on the cell surface
```
160
What is Exogenous processing
Protein broken into peptides by protease enzyme-containing endoscope
MHC Class 2 and peptide join in MHC Class 2 loading compartment
MHC 2 expressed on the cell surface
161
What is the target for MHC class 2
CD4
162
What are the purposes of specialised lymphoid tissue (3)
Reticular meshwork to trap antigens
Facilitates cellular communication by slowing cells down
Separate T and B Cell areas for specialised differentiation pathways
163
What is the scaffolding built around lymphoid tissue built of
Collagen fibres laid down by fibroblasts
164
What binds naive T and B cells from the blood into the lymphoid tissue
High Endothelial Venules (HEV)
165
Where are B Cells differentiated
Germinal Centre
166
Where is the germinal centre located
Within the outer cortex of the kidney
167
What are the steps in B cell Differentiation (3)
Antigen-Specific B Cell undergoes Clonal amplification
Follicular dendritic cells carry antigen in original conformation
Competition exists between B Cells to produce cells with the highest affinity
168
What happens in the Dark Zone (2)
Proliferation
| Somatic Cell Hypermutation
169
What Happens in the light zone
B Cell Selection
170
What are 2 examples of specialised Mucosa-associated lymphoid tissue (MALT)
Gut-associated lymphoid tissue (GALT)
| Bronchus-associated lymphoid tissue (BALT)
171
What is the receptor which transports secretory IgA across the mucosal barrier
Poly Ig receptor
172
How does IgA work in the mucosal surfaces
IgA prevents the adhesion of microbes to surfaces
| If microbe enters coated in IgA, then it will be rapidly destroyed by granulocytes
173
Which organ is the main producer of the acute phase and complement proteins
Liver
