ICS Immunology Flashcards
1
Q
What are the two types of immune responses in humans?
A
Innate and Acquired
2
Q
What type of immunity is the first line of defense?
A
Innate
3
Q
Which WBCs are most abundant in humans?
A
Neutrophil
4
Q
Which antigen presenting cell is considered a professional at activating lymphocytes?
A
Dendritic cell
5
Q
Which of the following is not a component of innate immune system
a) Skin
b) Antimicrobial peptides
c) Antibodies
d) Mucosa
A
Correct answer= C
6
Q
Antigen presenting cells process and present antigens for recognition by
A) Neutrophils
B) Red blood cells
C )Eosinophils
D) T cells
A
Correct answer= D
7
Q
Which of the following are features of the adaptive immune response
A) Does not require prior contact with the pathogen
B) It works with B and T lymphocytes
C) Lacks specificity
D) Distinguishes “self” from “non-self”
E) Enhanced by complement
A
Correct answer= B
8
Q
Which of the following is not part of the Elimination phase of complement activation? A) Opsonisation B) Production of interferons C) Target cell lysis D) Chemoattraction of leukocytes E) Phagocytosis
A
Correct answer= B
9
Q
Which of the following vaccines are administered as live attenuated vaccine in the UK- Hepatitis A, Tetanus, MMR, Flu, BCG?
A
Correct answer= MMR and BCG
10
Q
Which of the following vaccines are delivered as polysaccharide vaccines- Pneumococcal disease, Influenza type B, rabies, Salmonella typhi, meningococcal disease?
A
Correct answer=
Pneumococcal disease
Salmonella typhi
Meningococcal disease
11
Q
Influenza vaccine is targeted towards 'at risk' groups in the UK. Which of the following aren't classified as 'at risk'? A) Asthmatics B) Diabetics C) The obese of any age D) 6 months of age
A
Correct answer= D
12
Q
Which of the following is not an organ-specific auto-immune disease? A) Type 1 diabetes B) Graves disease C) Ulcerative colitis D) Hashimoto's thyroiditis E) Sjorgren's syndrome
A
Correct answer= C
13
Q
Which of the following is not a classical PAMPs?
A) Flagellin, a protein found in bacterial flagella
B) Lipopolysaccharide (LPS) from the outer membrane of gram-negative bacteria
C) Peptidoglycan, found in bacterial cell walls
D) Lipoarabinomannan of mycobacteria
E) Interleukin 12
A
Correct answer= E
14
Q
Is innate or adaptive immunity more specific?
A
Adaptive is more specific
15
Q
Is memory present in innate or adaptive immunity?
A
Adaptive immunity has memory
16
Q
What cells are present in innate immunity?
A
Neutrophils, NK cells, Macrophages
17
Q
What cells are present in adaptive immunity?
A
T cells and B cells
18
Q
Name some soluble factors in immunity
A
Complement proteins
Antibodies
Cytokines and chemokines
19
Q
What are the layers that form when centrifuging a blood sample?
A
- Upper fluid= 55% = plasma
- Middle layer= Buffy coat
- Lower layer= 45%= haemocrit
20
Q
What is plasma composed of?
A
90% Water, some electrolytes, proteins, lipids, sugars
21
Q
What is a buffy coat?
A
The middle layer that forms when centrifuging a blood sample. It is formed of leukocytes
22
Q
What is haemocrit?
A
The cell component of a blood sample- including erythrocytes, platelets etc
23
Q
What is serum?
A
Plasma without fibrinogen and clotting factors
24
Q
Where are leukocytes made and by what process?
A
Made in the bone marrow by haematopoiesis
25
Name 3 polymorphonuclear leukocytes?
- Neutrophils
- Eosinophils
- Basophils
26
Name 3 mononuclear leukocytes?
- Monocytes
- T cells
- B cells
27
Name the different types of T cells
T-regs
T-helper (CD4, Th1 and Th2)
Cytotoxic T cells (CD8)
28
What are complement proteins?
Group of 20 serum proteins secreted by the liver that are activated as part of the immune system and cause a cascade.
29
What are the modes of action of complement proteins?
- Direct lysis
- Attraction of leukocytes to the site of infection
- Coat invading organism
30
Name the classes of antibody
IgG, IgA, IgM, IgD, IgE
31
What is an epitope?
The part of the antigen that binds to the antibody/ receptor binding site
32
What is the role of interferons?
Induce a state of antiviral resistance in uninfected cells
33
What is the role of colony stimulating factors?
Involved in directing the division and differentiation of bone marrow stem cells (Precursors to leukocytes)
34
What is the role of tumour necrosis factor?
Mediates inflammation and cytotoxic reactions
35
What is the role of chemokines?
Attracts leukocytes
36
Name some cytokines
Interferons, Interleukins, Colony stimulating factors, tumour necrosis factors, chemokines
37
Name some exterior defenses used by the innate immune system
- Skin
- Mucous and cilia in bronchi
- Flushing of the urinary tract
- Low pH and commensals of vagina
- Lysozyme in tears
38
What are the hallmarks of inflammation?
- Increased blood supply
- Increased vascular permeability
- Increased leukocyte transendothelial migration (extravasation)
39
What are the steps of phagocytosis?
1. Binding
2. Engulfment
3. Phagosome formation
4. Phagolysosome
5. Membrane disruption
6. Secretion
7. Antigen presentation
40
What are PAMPs?
Pathogen associated molecular patterns= Common features of pathogens that can be detected by the innate immune system.
41
Name some PAMPs
CpG motifs, Double stranded RNA etc.
42
What are PRRs?
Pattern recognition receptors= A family of proteins which recognises and binds to a variety of pathogen ligands
Includes TLR, NLR
43
Give some examples of Cell-associated PRRs?
TLRs, NLRs, Mannose Receptors
44
What are toll-like receptors?
Receptors found on macrophages, dendritic cells and neutrophils. They recognise and bind to PAMPs. This causes second messengers to cause secretion of inflammatory mediators and stimulate immune cells.
45
What does TLR4 recognise?
Lipopolysaccharies on gram -ve bacteria
| Drives signalling
46
What do pattern recognition receptors recognise?
PAMPS (pathogen associated molecular patterns)
| DAMPS (Damage associated molecular patterns)
47
What does NOD2 recognise?
Muramyl dipeptide, a breakdown product of peptidoglycan, and this activates inflammatory signalling pathways
48
What does mannose receptor recognise?
Fungi
49
What is MHC?
Major histocompatibility complex. Has a major role in initiating T cell responses, and acts as a safety mechanism to prevent the immune system being activated too easily= proteins that mark a cell as self
50
Describe MHC I
Intracellular, and found on the surface of most cells of the body (Except erythrocytes). Cytotoxic T cells require an antigen to be associated with MHC I proteins before they kill the cell containing the pathogen
51
Describe MHC II
Extracellular and found mainly on the surface of B cells, macrophages and Dendritic cells. T Helper cells require MCH II proteins before they can help B cells.
52
Briefly describe neutrophils
Polymorphonuclear leukocyte with 6-12 hr lifespan. Most abundant WBC in blood, and first line cells in acute infection= release chemotaxins and cytokines. Granular.
53
Briefly describe macrophages
Express CD16- Involved in phagocytosis, with months lifespan. Functions to remove anything foreign or dead. Have lysosomes.
Link between adaptive and innate immunity
54
Briefly describe eosinophils
Make up 5% of blood, and lifespan of 8-12 days. Granules. Associated with parasitic infection. Neutralises histamine.
55
Briefly describe Basophils
Make up 2% of blood, with lifespan of 2 days. Known as circulating mast cells. Role in immunity and allergic response= releases histamine
56
List the cells/ complexes involved in adaptive immunity
1. Antigen presenting cells
2. Major histocompatibility complex
3. T helper cells
4. Cytotoxic T cells
5. B cells
6. Antibodies
57
What are IgM antibodies role?
1st response to antigen
| Can't cross the placenta
58
What are IgD antibodies roles?
B cell activation
| Can't cross placenta
59
What are IgG antibodies roles?
```
Most common form
Crosses placenta (Passive immunity to fetus)
```
60
What are IgA antibodies roles?
Secreted from mucous membranes
| In colostrum
61
What are IgE antibodies roles?
Histamine reactions and allergies
62
What is an antigen?
A molecule that reacts with preformed antibody and specific receptors on T and B cells
63
What is affinity?
A measure of binding strength between an epitope and an antibody binding site- the higher the affinity the better
64
What are the functions of the complement pathway?
Lyse microbes directly
Increase chemotaxis
Opsonisation
65
Briefly describe the mechanism of the complement pathway
Pore-like channels in membrane so water, ions and small molecules enter microbe which disrupts intracellular environment and kills the microbe
66
What are the three mechanisms of C3 cleavage in the complement?
Classical pathway
Alternative pathway
Lectin pathway
67
What starts the classical pathway?
Antibody-antigen immune complexes
68
What starts the alternative pathway?
Foreign surfaces= antigens
69
What starts the lectin pathway?
Lectin binding to mannose on pathogens surfaces
70
What cells can act as antigen presenting cells?
Dendritic cells
| Also B cells and macrophages
71
What is major histocompatibility complex formed of?
Proteins that mark a cell as self
72
Where are T cells formed?
Produced in the bone marrow and mature in the thymus
73
What is the major role of T cells?
Recognise the antigen displayed by APCs, and produce cytokines
74
What is the lifespan of a T cell?
hrs-years
75
What are CD8 cells?
Cytotoxic T cells
Induce apoptosis in infected body cells using perforin. Expresses Fas Ligand which binds to Fas 🡪 apoptosis. Recognise Ag in the context of MHC I.
76
What are CD4 cells?
T helper cells= help immune response for intracellular pathogens and help B cells make antibodies. Include TH1 and TH2
77
What are specific roles of Th1 cells?
Cell-mediated immunity. Regulate monocytes and macrophages.
78
What are the specific roles of Th2 cells?
Humoral immunity. Regulators of eosinophils, basophils, and mast cells. Stimulates B cells.
79
How do Th1 cells cause B cells to produce antibodies?
1. APC presents Ag with MHC II to CD4
2. Stimulation with high levels of IL-12 activates naieve cells to Th1
3. Th1 goes into secretory lymphoid tissue
4. Activated Th1 proliferates
5. Th1 cell recognises Ag on infected cell via T cell receptor
6. This induces B cell to produce antibodies via IL-2 secretion
80
What are the roles of treg cells?
Suppresses autoimmunity (Anti inflammatory), and down regulates other T cell subsets via IL-10. Antagonist to Th17 cells.
81
How are babies protected against diptheria, tetanus, streptococcus, rubella, mumps and polio?
Natural passive immunty by the transfer of maternal antibodies across the placenta in a developing foetus
82
Give some uses of passive artificial immunisation
- Botulism, tetanus and diptheria= given anti toxin
| - Hepatitis, measles and rabies= Given prophylactically after exposure
83
Briefly describe active immunisation
1. Engage innate immune system
2. Elicit danger signals that activate the immune system, triggers PAMPs and engage TLR receptors
3. Activate specialist APCs
4. Engage adaptive immune system= Generate memory T and B cells
84
Which lasts longer- active or passive immunity?
Active immunity
85
Why is influenza vaccine repeated annually?
- It is important to maintain high levels of antibody
| - Influenza mutates frequently so new vaccines must be given
86
Why is influenza dangerous?
It has a rapid onset, and infection can be established before immunological memory can be activated
87
Which vaccines are given via a living whole organism (Attenuated)?
TB (BCG) , Polio sabin, Typhoid, MMR
88
Which vaccines are given as dead organisms?
Anthrax, cholera, hepatitis A, Influenza, Rabies, Polio Salk
89
What vaccines are given as toxoids (inactivated endotoxins)?
Diptheria, neurotoxins
90
What vaccines are given as capsular polysaccharide vaccines?
Pneumococcal disease, salmonella typhi, meningococcal disease
91
Why may attenuated vaccines be used or not used?
+ Full immune response, only single dose required
| - Immunocompromised patients may become infected, vaccine needs to be refrigerated
92
Why may killed, inactivated pathogen vaccines be used or not used?
+No risk of infection, less critical storage
| - Only activates humoral response, booster vaccines
93
Why may toxoid vaccines be used or not used?
+ Safer as no risk of infection, easier to store
| - Less powerful immune response, and booster vaccines needed
94
What are some pros and cons of passive artificial infection?
+ Immediate protection even in immunocompromised patients
| - Short lived, serum sickness
95
What are the three types of subunit vaccines?
Toxoids, polysaccharides and recombinant vector vaccines
96
What is an adjuvant?
Any substance that is added to a vaccine to stimulate the immune system ensuring a powerful immune response
97
Give some examples of adjuvants
Whole killed organisms, taxoids, proteins or chemicals
98
What are notifiable diseases?
Diseases, infections and conditions specifically listed as notifable under the public health regulations of 1988.
99
Why are there notifiable diseases?
To detect changes in disease spread, and allows interventions targetted at vulnerable group
It also allows investigation into who may have been exposed.
100
List some notifiable diseases
```
MMR diseases
Cholera
Food poisoning
Meningitis
Rabies
Leprosy
SARS
TB
```
101
How does meningococcal infection present?
Meningitis or septicaemia
102
What are some complications of meningococcal infection?
Brain abcess, brain damage, seizure disorders, hearing impairment, focal neurological disorders, organ failure, gangrene, death
103
How is meningococcal infection spread?
Inhaling respiratory secretion from the throat or mouth, or by direct contact (kissing)
104
What is the treatment of meningococcal infection?
Antibiotic therapy of cefotaxime and ceftriaxone
105
Who is "at risk" for flu vaccine?
- Those 65 and over
- Certain medical conditions including asthma and diabetes
- Long-star residential care
- Frontline health or social care workers
- Those that are the main carer for someone at risk
106
What vaccines are given to 8 week old babies?
Infanrix hexa- Hep B, Diptheria, tetnus, polio, pertussis, haemophilius influenza B,
Meningococcal B (Bexsero)
Rotavirus
107
What vaccines are given to 12 week old babies?
Infanrix hexa booster
Rotavirus booster
Pneumococcal
108
What vaccines are given at 17 weeks?
Infanrix hexa booster
| Bexsero Booster
109
What vaccines are given at one year?
Haemophilius influenza B and Men C
Pneumococcal booster
MMR
Meningococcal B booster
110
What vaccines are given at 3 years 4 months?
Diptheria, tetanus, pertussis, and polio boosters
| MMR booster
111
What vaccine is given to boys and girls aged 12-13?
Human papillomavirus
112
What vaccines are given at 14 years old?
Tetanus, diptheria and polio boosters
| Meningococcal groups A, C, W and Y
113
What vaccine is given at 70 years old?
Shingles
114
Where are B cells produced?
Produce and mature in the bone marrow
115
What can B cells differentiate into?
Plasma cells and memory cells
116
What is clonal expansion?
When a specific B cell divides, producing new B cells that recognise the same antigen (occurs at lymph nodes)
117
What is the major purpose of the complement pathway?
To remove or destroy antigens, either by direct lysis or opsonisation
118
What is opsonisation?
A process by which an antigen becomes coated with substances that make it more easily engulfed by phagocytic cells
119
What is the major component of complement activation?
C3
120
What is C3b?
The major fragment of activated C3
| Mediates a number of vital biological activities particularly opsonisation and lysis of pathogens
121
What is activated during complement activation?
C3 component
122
What is C3a?
The minor fragment of activated C3. It acts to enhance inflammation
123
What complement proteins are involved in the classical pathway?
C1, C4 and C2
124
Briefly explain the classical pathway
Antigen:antibody complexes are formed, which activates C1, C4 and C2. This can then activate C3 convertase.
125
What are the primary lymphoid organs?
Bone marrow and thymus
126
What are the secondary lymphoid organs?
Lymph nodes, spleen, sites of DC and T cell interactions
127
What is a tertiary lymphoid organ?
Any accumulations of lymphocytes and stromal cells in an organised structure outside of a secondary lymphoid organ
128
What is within the white pulp of the spleen?
Lymphatic tissue, mainly made up of white blood cells
129
What is within the red pulp of the spleen?
Blood filled cavities and splenic cords. These contain different types of red and white blood cells
130
What complement elements are involved in formation of MAC?
C3b
| C5b-C9
131
What complement elements increase chemotaxis?
C3a
| C5a
132
What complement elements aid in opsonisation?
C3b
133
What does C5-9 formation cause?
MAC formation= Cell lysis
134
What does C3b formation cause?
Opsonisation
| Removal of immune complexes
135
What does C5a, C4a and C3a formation cause?
Inflammation and cell recruitment
136
What is haematopoeisis?
The production of all cellular components of the blood and blood plasma
137
What are the two main intracellular granules in neutrophils?
Primary lysozymes= Myeloperoxidases
| Secondary granules= Specific molecules like lactoferrin and respiratory burst component
138
What is the function of lactoferrin?
Binding and transport of iron ions, antibacterial, antiviral
139
Where is lactoferrin found?
Within the secondary granules of neutrophils
140
What chromosome codes for MHC?
Chromosome 6
141
Give an example of a type 1 hypersensitivity reaction
Anaphylaxis, asthma, Hay fever
142
Give an example of a type 2 hypersensitivity reaction
Goodpasture’s syndrome
| Haemolytic anaemia
143
Give an example of a type 3 hypersensivity reaction
SLE
Serum Sickness
Granulatoma
Farmers lung
144
Give an example of a type 4 hypersensitivity reaction
TB
Contact dermatitis
Rheumatoid arthritis
IBD
145
What is the mechanism of type 1 hypersensitivity?
Production of IgE antibodies
146
What is the mechinism of type 2 hypersensitivity?
Antibody binds to an antigen on the target cell, leading to phagocytosis
147
What is the mechanism of type 3 hypersensitivity?
Deposition of antigen-antibody complexes
148
What is the mechanism of type 4 hypersensitivity?
Activate T lymphocytes
149
What are the clinical features of anaphylaxis?
CVS – vasodilation, increased vascular permeability, lowered BP
Respiratory – dyspnoea, mucus production
Skin – rash, swelling
GI – pain, vomiting
150
What happens in reoxposure to an irritant in anaphylaxis?
1. Allergen bind to IgE
2. Causes receptor cross linking, triggering a signal transduction cascade
3. Mast cell degranulation and release of pharmacologically active substances= Histamine, Slow Reacting Substance-A (SRS-A), prostaglandins – induces inflammation,
151
Which is more potent; Histamine or SRS-A?
SRS-A
152
Which type of antibody crosses the placenta?
IgG
153
Which type of antibody is in the colostrum?
IgA
154
```
Which of the following is not a component of the innate immune system?
A) Complement system
B) Toll-like receptors
C) Macrophages
D) T helper cells
E) C-reactive protein
```
Correct answer= D
155
```
Which of the following is a type 3 hypersensitivity reaction-
A) Tuberculosis
B) Goodpasture’s Disease
C) Systemic Lupus Erythematosus
D) Contact Dermatitis
E) Anaphylaxis
```
Correct answer= C
156
```
Which of the following antibodies is implicated in asthma?
IgG
IgA
IgM
IgE
IgD
```
Correct answer= D
157
```
Which of the following antibodies is implicated in the secondary response to infection?
IgG
IgA
IgM
IgE
IgD
```
Correct answer= A
158
What drugs can be used to treat anaphylaxis?
```
IM Adrenaline
IV hydrocortisone
IV Chlorphenamine
IV Fluids
Oxygen
```
159
What is the process of the alternative pathway?
1. C3 undergoes spontaneous and continuous cleavage into C3a and C3b
2. C3b is then able to combine with factor D and B to form the active enzyme C3bBb also known as C3 convertase
3. C3bBb can go on to break down more C3 producing more C3a and C3b
160
What is the process of the lecthin pathway?
Mannose binding lectin binds mannose on pathogen surfaces, activating C3 convertase
161
What would a complement deficiency cause?
Recurrent infections
162
What is systemic lupus erythrematous?
An autoimmune disease, resulting in impaired clearance of apoptotic cells and immune complexes
163
What is atopy?
Inherited tendency for overproduction of IgE antibodies to common environmental antigens
164
Briefly define haemolytic disease of the newborn
The mother is RhD negative but the baby is RhD positive. When the mothers blood is exposed to baby’s blood, mothers immune system recognises the foreign blood and begins making antibodies against baby’s blood. The first baby is unaffected, but the mother is sensitised to rhesus postive blood. If mother’s second baby also has RhD positive blood, then antibodies are produced immediately, and begin destroying babies' erythrocytes, resulting in haemolysis of the foetus and newborn.
165
Which type of hypersensitivity reaction is independent of antibodies?
Type 4 reaction
166
What is an allergy?
Abnormal response to a harmless foreign material
167
What cell type releases histamine?
Mast cells
| Basophils
168
What types of chains are in antibodies?
2 identical heavy chains and two identical light chains
169
How may different types of heavy chains are there?
5
170
How many different types of light chains are there?
2
171
Which region of the antibody binds to the antigen?
Variable regions
172
What is an interleukin?
A cytokine that acts between cell of the immune system
173
What is a chemokine?
A group of proteins that direct the movement of leukocytes from the blood stream into the tissues or lymph nodes by binding to specific receptors
174
What cells release CXCL?
Neutrophils
175
What cells release CCL?
Monocytes, lymphocytes, eosinophils, and basophils
176
What is VDJ recombination?
The diversity of T cell receptors and antibody/ Immunoglobulins on B cells
177
Describe hyperacute transplant rejection
Occurs minutes to hours following transplantation, due to performed circulating cytotoxic antibody which reacts with MHC class I antigens in the donor organ.
178
Describe acute transplant rejection
Occurs a few days or weeks following transplantation in up to 20% of all transplants. Associated with increased expression of MHC class I and class II antigens in inflamed grafts, and with early infiltration of CD8+ T lymphocytes.
179
What are the two phases of transplant rejection?
Afferent and efferent
180
What drugs can be used to prevent graft rejection?
Ciclosporin, azathioprine, corticosteroids and specific monoclonal antibodies.
181
What is immunodeficiency?
Deficiency in the immune response, can either acquired or inherited
182
What cell type is implicated in HIV?
CD4+ T cells
183
What is Hypogammaglobulinemia?
Low immunoglobulins
184
List some organ specific autoimmune diseases
Type 1 diabetes mellitus
Hashimoto’s thyroiditis
Pernicious anaemia
Multiple sclerosis
185
Describe how you would identify a bacteria as Salmonella using Microbiology tests including differentiating it from Shigella
Salmonella is a gram-negative bacilli. Gram Stain= Pink.
- Bacilli Appearance= Rod shaped.
- MacConkey Agar tests for fermentation of lactose, Salmonella does not therefore plate remains clear (fermenters go pink).
- Do serotyping (API strip) to confirm Salmonella vs Shigella.
186
HIV can be diagnosed by measuring the level of a specific white blood cell. Which type of cell is measured? What level indicates AIDS?
CD4+ count
| <200
187
HIV is a global condition. Name 3 at risk groups for HIV and the age group for which 50% of all new infections worldwide occur
At risk Groups= Men who have sex with men, IVDU, Commercial sex workers.
Age group: 19-24yo
188
Name the different types of polymorphonuclear leukocytes and which is the most abundant.
Polymorphonuclear Leukocytes: Neutrophil, Basophil, Eosinophil.
Most abundant = Neutrophil.
189
List some allergic diseases
Anaphylaxis, allergic asthma, allergic rhinitis, eczema, allergic conjunctivitis, oral allergy syndrome, angioedema
190
What immunglobulin is used in allergy?
IgE
191
What are the major cells involved in allergy which express high affinity IgE receptors?
Mast cells, eosinophils, basophils
192
List some mediators of allergic responses
Cytokines, Chemokines, lipids, small molecules
193
What is the high affinity receptor for IgE?
Fc(epsilon)RI
194
What effects does histamine have?
Vasodilation, increased vascular permeability, bronchoconstriction= allowing for neutrophil extravasation
195
What is the low affinity receptor for IgE?
Fc(Epsilon)RII
| Also known as CD23
196
What is the function of low affinity receptor IgE ?
Regulation of IgE synthesis
197
What cell is the main effector cell in IgE mediated immunit?
Mast cells
198
What is c-kit protein?
The protein that is required for mass cell development
199
What compounds to mast cells carry?
Histamine, chemotactic factors, proteases, proteoglycans
Leukotrienes. Prostaglandin D2, Platelet activating factor
Cytokines
200
What is the serum marker of allergy?
Tryptase
201
What is the function of prostaglandin D2?
It is a potent inducer of smooth muscle contraction
202
What do mast cell cytokines do?
Promote a Th2 response and lead to B cell class switching, leading to IgE production
203
What do mast cell chemotactic factors do?
Lead to eosinophil attraction and activation
204
List some allergens
Latex, venoms, foods, drugs, pollens, dust mite faeces
205
Why is prior sensitization required for allergy?
To have production of IgE (without prior sentisiation, there won't be an immune response)= APC activated T helper cell, which uses IL4 to cause a class switch of antibodies on B cells to IgE, and uses IL21 to activate these B cells to become IgE plasma cells. IgD is class switched to IgE and IgE mast cells form
206
What happens on second exposure to an allergen?
The allergen cross links IgE on mast cells using the Fc(epsilon) receptor, which degranulate and release histamine
207
What is the effect of prostaglandin release from mast cells?
Bronchospasm
208
What is the role of IL4 in type 1 reactions?
It is responsible for class switching of antibodies into IgE immunoglobulins
209
```
Which type of cytokine causes B cells to produce IgE?
A) IL-1
B) IL-3
C) IL-4
D) IL-5
E) IL-13
```
Correct answer= C
210
What is cross linking?
One allergen binding to two seperate antibodies
211
```
What type of T cell plays an important role in type 1 hypersensitivity reactions?
A) Th-1
B) Th-2
C) Th-17
D) TC
E) Treg
```
Correct answer= B
212
Which IL's are anti-inflammatory?
IL-4 and IL-10
213
What does TLRR2 detect?
Lipoteichoic acid on gram +ve bacteria
214
What is the main pattern recognition receptor responsible for detecting gram +Ve bacteria?
TLR2
215
What is the main pattern recognition receptor responsible for detecting gram -Ve bacteria?
TLR4
216
In general, where would you find a TLR that detects genetic material?
Endosomes within cells
217
In general, where would you find a TLR that does not detect genetic material?
Cell membranes
218
In general, where would you find a NLR?
Cytosol
219
How are macrophages formed?
They are derived from circulating monocytes and activated by INF gamma
220
Is TNF-Alpha pro or anti-inflammatory?
Major pro-inflammatory (causes fever and neutrophil chemotaxis)
221
What cells produce TNF-alpha?
Macrophages
222
How do neutrophils kill pathogens?
Neutrophils are attracted to the site via IL-8. They kill by internalising bacteria and degranulating their contents into a phagolysosome. Major components include alpha-defensins and lactoferrin.
They can also kill via respiratory burst
223
What enzymes do NK cells contain?
Granules contain perforin and granzymes that induce apoptosis and cell lysis
224
How does a NK cell recognise self from non-self?
Recognise self and non-self by the presence of MHC-I on cell surfaces
225
What receptor do NK cells have which aid in killing?
CD16
226
What 3 things must occur for a response to happen when immune cells come together?
1. Binding of primary receptors e.g. TCR to MHC II.
2. Binding of co-stimulatory molecules e.g. CD28/CTLA4 to CD80/CD86.
3. A robust release of the appropriate cytokines.
227
What is meant by "naive cell"?
It has not yet encountered an antigen
228
What are the roles of Th17 cells?
Leads to inflammation via IL-17. Active at mucosal membranes. Antagonist to Treg cells.
229
What is CD3 a marker of?
T cells
230
What are CD19 and CD20 a marker of?
Mature B cells
231
What is an effector B cell?
Plasma cell
232
What are the stages of B cell activation?
- Clonal expansion
- Somatic hypermutation
- Improved affinity (or disadvantageous mutations)
- Selection
- Class switching
- Differentiation into plasma or memory cells
233
What is the role of the constant region of an antibody?
Constant region determines Antibody type and therefore effector function.
234
What is the role of the fab region of an antibody?
Fab region (antigen-binding fragment) bind epitopes of antigen.
235
What is the role of the Fc region of an antibody?
Fc region (fragment crystallizable region) is the area that binds Fc receptors on immune cell surfaces
236
Which cell type is raised in bacterial infection?
Neutrophils= Neutrophilia especially in pyogenic infections
237
Which cell type is raised in viral infections?
Lymphocytes= Lymphocytosis
238
```
Which of the following antibodies is implicated in the primary response to infection?
IgG
IgA
IgM
IgE
IgD
```
C
239
What is a hypersensitivity reaction?
Undesirable response to antigenic, allergenic, self material. This requires a pre-sensitized state of the host.
240
What is the negative phase of a vaccine?
A period after initial antigen exposure where ones immunity is actually lower than before encountering the antigen
241
What is the role of IL-1?
Acute inflammation, Induces fever
242
What cells produce IL-10 and what is its role?
Produced by Th2 cells
| Inhibits Th1 cytokine production (anti inflammatory)
243
What is HLA-A3 associated with?
Haemochromatosis
244
What is HLA-B27 associated with?
Ankylosing spondylitis
Reiter's syndrome
Acute anterior uveitis
245
What is HLA-DQ2/DQ8 assocaited with?
Coeliac's disease
246
What is HLA-DR3 associated with?
Dermatitis herpetiformis
Sjogren's syndrome
Primary biliary cirrhosis
247
What is HLA-DR4 associated with?
Type 1 diabetes mellitus
| Rheumatoid arthritis
248
```
The immune system is made up of both innate and adaptive aspects and involves a variety of cells. Which is the most abundant white blood cell in humans?
Basophils
CRP
Neutrophils
Mast Cells
Lymphocytes
```
C
249
```
A mother brings her 3-year-old child to the GP saying he has a fever and is generally unwell. The GP suspects the they have a viral infections such as respiratory syncytial virus. What cell would you expect to be raised in this patient?
Mast Cell
Microglia
Neutrophils
Macrophages
Lymphocytes
```
E
250
```
A 34-year-old male comes into the GP complaining of haemoptysis. He notes that he wakes up at night due to waking up in a pool of sweat and mentions he recently returned from a holiday in Pakistan. The GP suspects tuberculosis. Which of the following cytokines is primarily responsible for activating macrophages?
IL-2
IL-4
TNFα
IL-1β
IFN-γ
```
E
251
```
A 5-year-old girl is brought to the GP after repeated episodes of allergic rhinitis and eczema. Which cytokine is involved in atopy and, amongst other things, causes class switching of immunoglobulins to IgE?
IL-4
IL-17
IL-5
IL-1β
IFN-γ
```
A
252
```
A 35-year-old woman presents to her GP complaining of unintentional weight loss, palpitations, and oligomenorrhoea. She is subsequently diagnosed with Graves disease by a specialist. Given their involvement in autoimmunity, where does T cell maturation occur?
Spleen
Bone Marrow
Bursa of Fabricius
Thymus
Liver
```
D
253
```
It’s your first day on placement and you take a history from an elderly gentleman who is currently running a high-grade fever. You later find out he is currently suffering from a Pseudomonas aeruginosa infection. Which pattern recognition receptor is most likely to detect this infection?
TLR2
TLR6
TLR4
NOD-2
RIG1
```
C
254
```
It’s your second day on placement and you take a history from an elderly gentleman who is currently running a high-grade fever. You later find out he is currently suffering from a Streptococcus pneumoniae infection. Which pattern recognition receptor is most likely to detect this infection?
TLR2
TLR6
TLR4
NOD-2
RIG1
```
A
255
```
An intravenous drug user presents to A&E complaining of fever, a hot painful red lump, and general malaise. The F1 who clerked them suspects an MRSA infection. Which white blood cell is most likely to be raised in this patient?
Neutrophil
Mast Cell
Basophil
Lymphocyte
Dendritic cell
```
A
256
```
An infant presents to hospital with a fever, shortness of breath and a cough producing yellow sputum. She has had many previous admissions due to similar infections and has been diagnosed with a deficiency in mannose binding lectin (MBL). Which substance is failing to trigger a complement cascade reaction in this patient?
IgE
IgM
C3 Convertase
Pathogen surface carbohydrates.
Membrane attack complex
```
D
257
```
A 13-year-old boy has been brought to the GP by his dad after having a sore throat and a cough for the last week. After an examination, the GP concludes that he likely has a viral infection that will resolve without other treatment. Which immune cells are responsible for directly combating this type of infection through apoptosis?
Basophils
Plasma Cells
T helper cells Neutrophils
Cytotoxic T-cells
```
D
258
```
A 10-year-old boy presents with an itchy rash on his elbows. The rash is red and there are excoriation marks. He has a past history of hay fever and has generally dry skin. The GP diagnoses him with eczema and he is prescribed hydrocortisone. Which antibody is responsible for mediating type 1 hypersensitivity?
IgG
IgA
IgM
IgE
IgD
```
D
259
```
An office worker has recently taken time off due to contracting the flu. A few weeks later other members of their office start showing flu symptoms. The worker asked his GP if he is at risk of contracting the flu again. Which antibody is responsible for secondary responses to a previous infection?
IgG
IgA
IgM
IgE
IgD
```
D
260
```
A mother is concerned about infection of her newborn child. She asks her GP about best to protect their child from infections. Which is the most abundant antibody in colostrum?
IgG
IgA
IgM
IgE
IgD
```
B
261
```
A 38-year-old male attends the human immunodeficiency virus (HIV) clinic for routine blood tests for monitoring of his condition. The number of which of the following cells is used to measure the progression of disease in HIV positive patients?
Neutrophils
B Cells
NK cells
CD4 T cells
CD8 T cells
```
D
262
```
A 34-year-old man is referred to the gastroenterologist due to persistent epigastric pain and nausea. He returned travelling from south-east Asia ten weeks ago. Blood tests reveal iron deficiency anaemia, and faecal microscopy reveals the presence of hookworm eggs. Which immune cell is responsible for the defense against helminths (parasitic worms)?
Basophils
Eosinophils
Neutrophils
Macrophages
Dendritic Cells
```
B
263
```
A 14-year-old boy complains of a 3-day history of fatigue, aches and pains, and fever. Upon examination his temperature is 38ºC and his tonsils are inflamed. He is suspected to have a bacterial infection which will be fought by his adaptive immune system. Which of the following cell-surface proteins are found on cytotoxic T-cells?
CD4
CRP
MHC I
CD 8
MHC II
```
D
264
```
A 65-year-old man is admitted to hospital following a fall. He subsequently developed hospital-acquired pneumonia. Given the most likely causative microorganism, which molecule is responsible for presenting its antigenic material to immune cells?
CD4
MHC III
MHC I
TCR
MHC II
```
E
265
```
A father brings their 6-year-old boy to the GP complaining of an incredibly lengthy chest infection and recurrent gastritis. He is referred to an immunologist. His bloods extremely low levels of IgA and IgG. He is diagnosed with common variable immunodeficiency (CVID). Which adaptive cell type is essential in aiding class switching of B cells?
Natural Killer T cells.
Th17 cells
Th2 cells
Th1 cells
Dendritic Cells
```
D
266
A 24-year-old lady collapses after being stung by a wasp. You run to her aid and find marked facial oedema and a loud wheeze. You suspect anaphylaxis. Which type of immunoglobulin (Ig) is associated with this kind of reaction?
```
IgG
IgA
IgM
IgE
IgD
```
D
267
What is Anti-CCP associated with?
Rheumatoid arthritis
268
What is Anti-IgG (RF) associated with?
Rheumatoid arthritis
269
What is Anti-dsDNA assocaited with?
SLE
270
What is Anti-Nuclear antibodies associated with?
SLE
271
What is anti-histone assocaited with?
Drug induced lupus
272
What is anti Ro and Anti lo associated with?
Sjorgrens syndrome, SLE
273
What is anti-phospholipid associated with?
Antiphospholipid syndrome
274
What is anti-mitochondrial antibody associated with?
Primary biliary cirrhosis
275
What is anti-thyroid peroxidase assocaited with?
Hashimoto thyroiditis
276
What is anti-thyroglobulin associated with?
Hashimoto thyroiditis
277
What is anti-Ho associated with?
Dermatomyositis and polymyositis
278
What is anti-basement membrane associated with?
Goodpasture syndrome
279
What is anti-gliadin IgA associated with?
Coeliacs
280
What is anti-endomysial IgA associated with?
Coeliacs
281
What is anti-transglutanase IgA associated with?
Coeliacs
282
What is p-ANCA associated with?
Microscopic polyangitis
| Churg-strauss syndrome
283
What is C-ANCA assocaited with?
Wegener granulomatosis
284
What is anti-glutamic acid decarboxylase associated with?
Diabetes type 1
285
What TLR is associated with flagellin?
TLR5
286
What TLR is double stranded DNA associated with?
TLR3
