immunology Flashcards
(303 cards)
1
Q
what is the innate immune system
A
always present and first line of defence but not specific
2
Q
what is the adaptive immune system
A
specific to the invader but slow to act
3
Q
examples of primary lymphoid organs
A
- thymus
- bone marrow
4
Q
what is primary lymphoid organs
A
where cells originate
5
Q
where do cells and molecules of immune system circulate
A
in the blood
6
Q
where does immune response take place
A
at site of infection
7
Q
where does memory specific cells reside
A
in the spleen and lymph nodes
8
Q
what are the specific cells called
A
lymphocytes
9
Q
what are the specific cells molecular form called
A
antibodies
10
Q
what are other examples of secondary lymphoid organs
A
- adenoids
- tonsils
- Peter’s patch in small intestine
- lymphoid
11
Q
where do all immune cells derived from
A
pluripotent stem cells
12
Q
where are pluripotent stem cells generated
A
in bone marrow
13
Q
where are T cells generated
A
thymus
14
Q
where do both lymphocytes activate
A
in peripheral tissue
15
Q
what can B cells become
A
antibodies
16
Q
what is the lymphoid tissue at mucosa surfaces called
A
mucosa-associated lymphoid tissue
MALT
17
Q
what do neutrophils defend
A
major first line defence against pathogens
18
Q
what role do mast cells, eosinophils and basophils have
A
immunity to parasites
and
allergies
19
Q
what do monocytes and macrophages defend against
A
bacteria, fungi, parasites
20
Q
what do dendritic cells do
A
antigen presenting to T lymphocytes
21
Q
what do B lymphocytes produce
A
antibodies
22
Q
what are CD4
A
helper cells
23
Q
what are CD8
A
cytotoxic
24
Q
what are barriers against pathogens
A
- skin
- mucous
- cough reflex
- urine flow
- gastric pH
- commensal flora
25
what is used to monitor HIV
CD4 count
26
what do cytokines do
change the function of the same or other cells
27
what is paracrine function
modulates adjacent cells
28
what are endocrine effects
modulates cells and organs at remote sites
29
what are the main cytokines
- interferon
| - interleukins
30
what are some types of interferons
- alpha
- beta
- gamma
31
what is the function of chemokine
chemotactic molecules that attract cells along a gradient from low to high
32
what is another feature of chemokine
ability to activate immune cells
33
what are the 2 parts to the immune system
- physical barrier
| - blood-borne system
34
what is the most abundant white cell
neutrophil
35
what are neutrophils involved in
phagocytosis
36
what is the first line of defence
neutrophil
37
what is the least common white blood cell
basophil
38
what do basophils contain
histamine and heparin
39
what does histamine and heparin do
- vasodilatation
| - anticoagulation
40
what are basophils involved in
parasitic defence and allergies
41
what are eosinophil key in
asthma
42
what are monocytes precursors of
macrophages and Kupffer cells
43
where do monocytes differentiate into macrophages
peripheral tissue
44
what are the 3 pathways of complement cascade
- mannose
- classical component
- classical
45
when does innate immune system present
from birth
46
what is the innate immune system mediated by interaction between
PAMPs and PRRs
47
does innate immune system require memory
no
48
when does immune system occur
immediately
49
does the adaptive immune response require memory
yes
50
how long does adaptive immune response take
1-2 weeks on first encounter
3-7 days on second encounter
51
what is the complement system
cascade of >40 proteins
52
what do lysosomes do
cleaves bacterial cell wall
53
what does activation of certain cells in the innate immune system lead to
activation of adaptive immune response
54
what forms a bridge between innate and adaptive system
dendritic cell
55
where are complement proteins produced
liver
56
what form do compliment proteins circulate in
inactive form
57
what are the 3 pathways of the compliment cascade
- alternative
- classical
- mannose-binding
58
what does C3a lead to
inflammation
59
what does C3b do
opsonisation of pathogens
60
what is the flow of cascade of classical pathway
C1 --> C2 --> C4 --> C3
61
what forms the MAC complex
C5b + C6-C9
62
what are the main functions of MAC
- promote inflammation
- recruit cells
- kill target cells
- solubilise antigen complexes and remove them
63
what do neutrophils do
phagocytose and kill microorganisms
64
how do neutrophils kill pathogens
by releasing antimicrobial compounds e.g. defensins
65
where are neutrophils derived
from bone marrow
66
what makes the bacteria more ingestible
opsonisation
67
what is opsonisation
bacteria being coated to make them more ingestible
68
what does elastase do
break down fibrous structure in extracellular matrix, facilitating progress of the neutrophil
69
what is another name for antibody receptor
Fc receptor
70
what is granule release initiated by
products of bacterial cell wall, complement proteins, leukotrienes and chemokiens
71
what cytokine can cause granule release
tumour necrosis factor-alpha
72
what do eosinophils release
pro-inflammatory mediators
73
what do pro-inflammatory mediators provide
immunity against parasites
74
where are most eosinophils
in tissues
particularly at epithelial surfaces where they survive for several weeks
75
what is the main role of eosinophils
protection against multicellular parasites such as worms
76
how is protection achieved by eosinophils
release of pro-inflammatory mediators, which are toxic
77
what receptors promote development of eosinophil
IL-3
| IL-5
78
what do mast cells release
pro-inflammatory and vasoactive mediators
79
what do mast cells have a role in
allergy
80
what do mast cells and basophils contain
- histamine
81
what do mast cells and basophils have a high affinity for
immunoglobulin E
| IgE
82
where are mast cells found
tissues (skin and mucosal)
83
where are basophils found
blood
84
what do both mast cells and basophils release
pro-inflammatory mediators
85
what are the effects of histamine
- vasodilator
- increase vascular permeability
- smooth contraction in airways
86
what do proteases do
digest basement membrane causing increased vascular permeability
87
what do proteoglycans do
anticoagulant activity
88
what does platelet-activating factor do
vasodilator
89
what do prosaglandins do
- increase vascular permeability
- bronchoconstriction
- vasodilatation
90
what is histamine
low-molecular weight amine
91
how long does histamine last in blood
less than 5 minutes
92
what does histamine cause
reddening (erythema)
| swelling
93
what do C3a, C4a and C5a activate
basophils and mast cells
94
where are monocytes
in the blood
95
where are macrophages
in the tissues
96
what are the roles of macrophages
- ingest and kill bacteria
- release pro-inflammatory molecules
- present antigens to T lymphocytes
- immunity to intracellular pathogens
97
what is CD14 a receptor for
lipopolysaccharide
98
what is CD16 a receptor for
IgG antibodies
99
when in vitro what can monocytes differentiate into
myeloid dendritic cells
100
what is a key role of tissue macrophages
maintenance of tissue homeostasis
101
how do macrophages recognise pathogens
PAMPs
102
what is the major function of dendritic cells
activation of naive T lymphocytes to initiate adaptive immune responses
103
what are dendritic cells a bridge between
innate and adaptive immune system
104
what are the major types of dendritic cell
- myeloid
| - plasmacytoid
105
what binds lipopolysaccharide
toll-like receptor 4
106
where are lipopolysaccharide found
gram negative
107
what PAMP does the PRR TLR2 bind to
peptidoglycan (PAMP)
108
what PAMP does the PRR TLR7 bind to
single stranded RNA
109
what can a mature dendritic cell cease
pinocytosis
110
what does mature dendritic cell activate
T cell
111
what cytokines does dendritic cells cause the release of
IL-12
112
how do T lymphocytes remove a pathogen
- direct kill it
| - recruit B lymphocytes to make specific antibodies
113
how do lymphocytes orchestrate immune responses
via cell to cell interactions and cytokine release
114
what is the receptor on T cells
T cell receptor (TCR)
115
what is the receptor on B cells
B cell receptor (BCR)
116
what is another name for BCR
immunoglobulin
117
what is another name for immunoglobulin
antibodies
118
what are the 4 chains of immunoglobulin
- 2 heavy chain
| - 2 light chain
119
what does each chain contain
highly variable and constant regions
120
what does the variable region do
binds antigens
121
what does the constant region of the heavy chain dictate
the function of the antibody
122
examples of antibodies
```
IgM
IgG
IgA
IgD
IgE
```
123
what's the most dominant immunoglobulin
IgG
124
what immunoglobulin is first produce in immune response
IgM
125
what immunoglobulin is found in mucous membrane secretions
IgA
126
what immunoglobulin is present in allergies
IgE
127
what immunoglobulin is found on B lymphocyte surface membranes
IgD
128
what immunoglobulin has the longest half life
IgG
129
what immunoglobulin binds to mast cells
IgE
130
what immunoglobulin crosses the placenta
IgG
131
what immunoglobulin is helpful for diagnosis of infection
IgM
132
what immunoglobulin dominates in second exposure to antigen
IgG
133
what is IgA present in
secretions - tears, saliva, GI tract
134
what immunoglobulin helps protect a new born baby
IgA as present in breast milk
135
what does the T lymphocyte exist as
heterodimer
136
how many types of T cell receptor are there
2
137
what T receptor has alpha and beta
CD4 and most CD8
138
what HLA molecules does CD4 require presentation from
HLA class II
139
what HLA molecule does CD8 require presentation from
HLA class I
140
what marker is the helper T lymphocyte
CD4
141
what marker is the cytotoxic T lymphocyte
CD8
142
what is most abundant CD4 or CD8
CD4
143
what molecules can stop inflammatory response
programme death ligand 1 and its protein
PD-L1
144
what cancers are monoclonal antibodies presenting
- melanoma
| - renal cell carcinoma
145
where are most naive T lymphocytes resident
lymph nodes or spleen
146
where are naive T lymphocytes activated
lymph nodes
147
how are T lymphocytes activated
by antigens presented to their TCR as short peptides bound to major histocompatibility complex (MHC) molecules on the surface of DCs
148
what is nuclear factor kappa B
pivotal transcription factor in chronic inflammatory disease and malignancy
149
what cytokines stimulate Th1
IL-12
150
what cytokines does Th1 produce
- IFN-gamma
- IL-2
- TNF-alpha
151
what is the function of Th1
pro-inflammatory
152
role of Th1 response
- organise killing
- activate macrophages to kill
- instruct CD8 cells
153
what cytokines cause production of Th2
IL-4
154
what cytokines are produced by Th2
- IL-4
- IL-5
- IL-13
155
what is the function of Th2
pro-inflammatory
156
what does Th2 have a role in
- kill parasites
- recruits eosinophils
- promotes IgE
157
what cytokines cause production of Th17
- IL-6
- IL-23
- TGF-beta
158
what does Th17 cause production of
IL-17
159
what is major marker of Th1
CD4
160
what is a major marker of Th2
CD4
161
what is the main role of Th2
- protect from extracellular pathogens
| - role in allergic reactions
162
what is major marker of TH7
CD4
163
what is role of Th17
- protect from fungi
| - role in autoimmune inflammatory disease
164
what is major marker of cytotoxic T lymphocyte
CD8
165
what is role of CD8
- kill target cells via HLA class I
| - protect from viruses
166
how does CD4 influence the immune system
- release of cytokines
| - direct cell-cell interaction
167
what are the major function of CD4
- licensing of DCs
- licensing of B lymphocytes (initiate and mature antibody responses)
- secretion of cytokines (growth and differentiate of range of cells)
- regulation of immune reactions
168
what is the main subtype of CD4 T lymphocytes
Th1
169
what does Th1 drive
activation of monocytes/macrophages and CTLs
170
what do Th1 have important pathology with
protection against intracellular pathogens e.g. viruses and mycobacteria
171
how are Th1 cells recognised
by their secretion of pro-inflammatory cytokines IFN-gamma and TNF-alpha
172
what do TH2 cells drive
antibody response, especially IgE
promote eosinophil granulocyte function
173
what do Th2 cells have important role in
protection from extracellular parasites
| - immune response for allergic reactions
174
how are Th2 cells recognised
secretion of IL-4, IL-5 and IL-13
175
what do Th17 cells drive
inflammatory responses through recruitment of neutrophil granulocytes
176
what are Th17 cells important in
protection from fungal infections
177
how are Th17 cells recognised
by secretion of IL-17
178
what interleukin stops inflammation
IL-10
179
what are CD8 involved in
defence against viruses
180
when do CD8 kill viral cells
HLA class I present
181
where must CTL be activated
in lymph nodes by DCs
182
how do CD8 kill
- cytotoxic granule proteins
- toxic cytokines
- death inducing surface molecules
183
where are natural killer cells made
in bone marrow
184
where are natural killer cells present
blood and lymph nodes
185
what is the main surface molecule for natural killer cells
CD16
186
what is the role of natural killer cells
kill abnormal host cells
187
what do natural killer cells secrete
- IFN-gamma
| - TNF-alpha
188
what does migration into inflamed tissue require
- an affected organ or tissue
| - responding immune cells bind and adhere
189
what does ICAM-1 help migration
expression on tissue endothelium is sensitive to numerous pro-inflammatory molecules
allow immune cells to be guided form the blood into tissues
190
where are MHC molecules located
chromosome 6
191
what is another name for MHC
HLA
192
what does MHC play a role in
immune function
193
how many classes of MHC are there
3
194
what does HLA class I have a role in
presenting short antigenic peptides to T cell receptors
195
where is class I HLA expressed
on all nucleated cells
196
where are HLA II expressed
antigen presenting cells
197
examples of antigen presenting cells
- dendritic cell
- monocyte / mactopahges
- B lymphocytes
198
what is the endogenous route of antigen presenting
all nucleated cells
| - comes from within
199
what is the exogenous route of antigen presenting
- property of antigen presenting cells
| - antigens are internalised
200
what is cross presentation
ability of some antigen presenting cells to internalise exogenous antigens and process them through endogenous route
201
what is the essential component in the activation of CD8 cells
cross presentation
202
what is the early and rapid host response to tissue injury
acute inflammation
203
what does increase pathogen numbers lead to
activation of complement in the tissues
204
what do inflammatory mediators change
the blood flow and attract and activate granulocytes
205
what are some symptoms of acute inflammation
- fever
- heat
- pain
- swelling
- redness
206
what mediates the production of CRP in the liver
IL-6
207
what does lysis lead to formation of
fluid in the tissue space containing dead and dying bacteria
208
what is there usually at site of pathogen entry
tissue hypoxia
209
how can the inflammation become walled off
through local fibrin deposition to protect the host
210
how to antigens from the pathogen travel
via the lymphatics
211
how are dendritic cells activated
via the PRR-PAMP system
212
what does the adaptive immune response lead to
activation of pathogen specific T lymphocytes
213
what does adaptive immune response cause release of
IgM
214
what is resolution aided by
scavenging activity of tissue macrophages
215
what is chronic inflammation
inflammation arising in response to insults that cannot be resolved in days/weeks
216
examples of chronic inflammation
- viruses (Hep A, B and C)
- bacteria
- environmental toxins (asbestosis, silicon)
217
what does mycobacterium leprae cause
leprosy
218
what does tuberculosis immune response cause
nerve damage and numb patches of skin
219
how leprosy resolved
antibiotics
220
what are tests for tuberculosis
- Mantoux test
| - interferon gamma release blood test
221
when tuberculosis becomes chronic what persists
macrophages in the lesions fuse to form giants cells and epithelioid cells
222
what genes are involved in inflammation for crohns disease
- NOD2
223
what results would indicate an inflammatory response or infectious disease
high CRP level
224
what result would indicate a state of immune deficiency
low concentration of IgG
225
what result would indicate a state of immune pathology
presence of autoantibodies or allergen-specific IgE
226
what does raised CRP levels indicate
infection or inflammation
227
what does low levels of immunoglobulins indicate
antibody deficiency
| e.g. primary immunodeficiency
228
what does raised IgE suggest
allergy
229
what does raised neutrophils suggest
bacterial infection
230
what does low neutrophils suggest
secondary immune deficiency
231
what does high eosinophils suggest
allergic or parasitic disease
232
what does low levels CD4 suggest
HIV
233
what does double stranded DNA autoantibodies suggest
rheumatoid arthritis
234
what is ANCA for
vasculitis
235
what is mitochondrial autoantibodies for
primary biliary cholangitis
236
when does primary immunodeficiency arise
birth
237
what diseases can T lymphocyte deficiency cause
- DiGeorge syndrome
- AIDS / HIV
- T cell activation defects
- X-linked hyper-IgM syndrome
238
what disease can B lymphocyte deficiency cause
- X-linked agammaglobulinaemia
- common variable immunodeficiency
- IgA deficiency
239
what disease does combined T and B cell defects cause
- severe combined immunodeficiency (SCID)
240
what diseases does neutrophil defects cause
- chronic granulomatous disease (CGD)
| - leucocyte adhesion deficiency
241
what are features of infections associated with immunodeficiency
- chronic, severe or recurrent
- resolve only partly
- caused by unusual organisms
242
do opportunistic pathogens have low or high virulence
low
243
examples of opportunistic organisms
- atypical mycobacteria
- pneumocystis jiroveci
- staphylococcus epidermidis
244
what do phagocyte defects cause
- deep skin infections
- abscesses
- osteomyelitis
245
what does T lymphocyte deficiency cause
- infection with fungi
- Protozoa infection
- intracellular organism
246
when do congenital deficiencies present
several months after birth due to 28 day half life of maternal IgG
247
what inheritance if only males of the family are affected
X-linked
248
what is Di-George syndrome due to
T lymphocyte deficiency
249
what is Di-George syndrome
when the third and fourth pharyngeal arches fail to develop
so no parathyroid gland, aortic arch or thymus
250
how does Di-George syndrome present
- at birth
- dysmorphic facies
- hypoparathyroidism
- cardiac defects
- infections
251
what chromosome is Di-George syndrome affected by
chromosome 22
252
acronym to help remember Di-George syndrome
CATCH 22
- cardiac abnormalities
- abnormal facies
- thymic dysfunction
- cleft deformities
- hypokalaemia
+
chromosome 22
253
what causes the lack of T lymphocytes in Di-George syndrome
no thymus
254
what is treatment for Di-George syndrome
- calcium supplementation
- correction of cardiac abnormalities
- prophylactic antibiotics
- thymic transplantation
255
what is severe combined immunodeficiencies due to
impaired T, NK, B lymphocyte
256
what is most common SCID defect in
IL-2 receptor
257
treatment for SCID
SCT preferably from HLA-identical donors e.g. siblings
258
what is Wiskott-Aldrich syndrome
X-linked defect in a gene involved in signal transduction and cytoskeleton function
259
what is chronic granulomatous disease characterised by
deep-seated infections
260
when is chronic granulomatous disease present
toddler age
261
treatment of chronic granulomatous disease
- prophylactic antibiotics
| - anti fungal therapy
262
what is allergic hypersensitivity
binding of an antigen to specific IgE
263
how many phases do allergic reactions have
2
264
what are the late phase responses mediated by
Th2 cells
| - they recruit eosinophils
265
what does the late phase response give rise to
chronic inflammation
266
what does the late phase response cause in asthma
prolonged wheezing
267
where do Th2 cells accumulate
around small blood vessels
268
how long do Th2 cells persist for
1-2 days
269
what do histamine and serotonin cause
- bronchoconstriction
| - increased vascular permeability
270
what do leukotrienes do
chemoattract
271
what are the Th2 cytokines
- IL-4
| - IL-5
272
what makes some allergens so powerful
they are proteolytic enzymes this allows them to cross skin and mucosal barriers
273
what is atopy
allergic response
274
how is allergic disease made
skin prick testing
275
treatment for allergic reactions
- avoidance = 1
- antihistamine
- corticosteroids
- CYLTs receptors
- omalizumab
-
276
how do corticosteroids help in allergic reaction
inhibit prostaglandin and leukotrienes mediators
cause vasoconstriction which leads to reduced cell and fluid leakage from vasculature
277
what do CYSTL antagonistic do
inhibit leukotrienes by blocking the type 1 receptors
278
what is omalizumab
monoclonal antibody that binds IgE
279
when is omalizumab used
in asthma that cannot be controlled by corticosteroids plus LABA
280
what is anaphylaxis
serious allergic reactions that is rapid in on set and may cause death
281
how does anaphylaxis start
as an acute, generalised IgE-mediated immune reaction involving specific antigen, mast cells and basophils
282
what foods can cause anaphylaxis
- nuts
- shell fish
- dairy products
- egg
- citrus fruits
283
other causes of anaphylaxis
- wasp, bee stings
| - medications (antibiotics)
284
what is central to the cause of anaphylaxis
activation of mast cells and basophils
285
what are initial symptoms of anaphylaxis
- tingling
- warmth
- itchiness
286
what are late symptoms of anaphylaxis
- generalised flush
- angio-oedema
- hypotension
- bronchospasm
- laryngeal oedema
- cardiac arrhythmia
- death may occur within minutes
287
management of anaphylaxis
ABCDE
- lie patient flat on bed with feet raised
- ensure airway is free
- give O2
- monitor blood pressure
- find venous access
- administer IV adrenaline
- administer IV antihistamine
- administer IV hydrocortisone
288
what is best treatment of anaphylaxis
prevention by avoiding triggers
289
what adrenaline is given for anaphylaxis
epinephrine
290
what is autoimmunity
when the immune response turns against itself
291
what does IL-12 stimulate
Th1
292
what do cytokines recruit
effector cells (macrophages)
293
what is IgG4 disease
fibro-inflammatory condition with the formation of swellings in multiple sites
294
what is IgG4 related disease driven by
Th2 T cells
295
what is Addisons disease
rare chronic endocrine system disorder
296
who does autoimmune hepatitis usually affect
women
297
what are risk factors of rheumatoid arthritis
- smoking
- previous viral infections
- human herpes virus
- vitamin D deficiency
298
what is major criteria for autoimmune disease
- evidence of autoreactivity
- clinical response to immune suppression
- passive transfer of the putative immune effectors
299
what is acute organ rejection mediated by
CD4 and CD8 T lymphocytes
300
what do glucocorticoids do
- potent effects on monocyte production
- blockade of T lymphocyte production of IL-2
- reduced activation of a range of innate immune cells
301
what is an example of a purine analogue
azathioprine
302
how does azathioprine work
inhibits DNA synthesis in dividing adaptive immune cells
303
what are cytokines
pleiotropic agents
