Immune System Flashcards
1
Q
What substances cause neutrophil recruitment?
A
PAF and TH17
2
Q
Which kind of fungus impairs neutrophils?
A
Deep filamentous mould
3
Q
Which kind of fungus spreads through epithelia into arteries if neutrophil numbers are reduced?
A
Aspergillus
4
Q
Which T cell response stimulates eosinophils?
A
TH2
5
Q
Which co-stimulatory receptors do dendritic cells express?
A
B7.1 and B7.2
6
Q
Which cytokines can macrophages secrete?
A
IL1, TNF, IL8
7
Q
Which negative regulatory molecules do macrophages express?
A
TGFbeta
8
Q
Which T cell response activates macrophages?
A
TH1
9
Q
Which IFN does macrophages secrete?
A
IFN-gamma
10
Q
Which receptor is macrophage tropic?
A
CCR5
11
Q
Which kinds of fungi impair macrophages?
A
Yeasts and dimorphic fungi
12
Q
What do fungi secrete once inside a macrophage?
A
Calcium binding protein
13
Q
Which kind of T cell response stimulates mast cells?
A
TH2
14
Q
Which mast cell receptor causes mast cell degranulation in hypersensitivity?
A
FCgammaRIII
15
Q
Which cytokines can NK cells secrete?
A
IFNgamma and TNFalpha
16
Q
Which NK cell receptor detects MHC class I?
A
KIR
17
Q
Which NK cell receptor detects LLT-1?
A
NKR-P1
18
Q
Which NK cell receptor detects MIC-A (stress marker)?
A
NKG2D
19
Q
Which cytokine activates NK cells?
A
IFNgamma
20
Q
Which T cells activate NK cells?
A
TH1
21
Q
Which NK cell receptor triggers ADCC?
A
FCgammaRIII
22
Q
Which cytokine activates a mature naive T cell?
A
IL2
23
Q
Which T cells are CD25+?
A
Tregs
24
Q
Which kind of T cells trigger type IV hypersensitivity?
A
TH1
25
Which type of cells mediate abacavir sensitivity?
T cells
26
Which receptor is T cells tropic?
CXCR4
27
Which kind of fungal infections impair T cells?
Yeasts and dimorphic fungi
28
Which constant region does IgD have?
Delta
29
Which constant region does IgM have?
Micro
30
Which cytokines stimulate soluble antibody production?
IL 4,5,6
31
What do some viruses encode to promote growth of infected B cells?
vIL-10
32
What produce IL-1beta?
Inflammasome
33
What does IL-1 and TNFalpha activate when it binds to its receptors?
NFkB and AP1
34
What is IL-1 a cofactor for?
IL-3 and IL-6
35
What is IL-1 cleaved by?
Caspase 1
36
Synthesis of what does IL-2 promote?
IL-1
37
Which cells does IL-2 activate?
B cells and NK cells
38
What is the IL-2 receptor?
CD25
39
Which kind of T cell does IL-4 stimulate production of?
TH2
40
Which isotype switch does IL-4 promote?
IgE
41
Which receptors does IL-6 bind?
IL-6Ralpha and IL-6ST
42
What kind of a receptor is the CXCL8 receptor?
GPCR
43
Which cells does IL-12 stimulate?
T and NK
44
Which cytokine production does IL-12 increase?
IFNgamma and TNFalpha
45
Which kind of T cell does IL-12 stimulate differentiation into?
TH1
46
Which cells secrete TNFalpha?
NK and sentinel macrophages
47
What kind of a response does type 1 IFN produce?
Antiviral
48
Which kind of T cell response does IFNgamma downregulate?
TH2
49
What stimulates IFNbeta production?
IRF3 and NFkB
50
Which MHC class do type 1 IFNs upregulate?
I
51
Which T cell response does type 2 IFN promote?
TH1
52
Which kind of cells are type 3 IFN important in?
Epithelial
53
What does ISGF3 act on in the JAK-STAT pathway?
ISRE
54
Which are the ISG antiviral genes?
OAS, PKR, Mx
55
What does PKR activate?
eIF2-alpha
56
What does FAS binding to receptor FAS induce?
Apoptosis
57
What kind of DNA is a bacterial PAMP?
unmethylated CpG-rich DNA
58
Which kind of DNA/RNA are PAMPs in viruses?
dsRNA, uncapped RNA, cytoplasmic DNA
59
What kind of dimers do TLRs signal as?
Homo or hetero
60
Where is TLR4 found?
Cell surface
61
Where is TLR3 found?
Endosomes
62
What does TLR4 ligation result in?
NFkB
63
What does TLR3 result in?
IRFs
64
Where are NLRs found?
Cytoplasm
65
What do NLRs recognise?
Peptidoglycan degradation products
66
What does NLR ligation result in?
NFkB
67
What does NLR signal by to activate the inflammasome?
NALP3
68
Where are RLRs found?
Cytoplasm
69
What do RLRs recognise?
RNA
70
What does RLR ligation result in?
IRF3 and IRF7 for antiviral IFN1 response (type 1)
71
Which factor produces bradykinin?
XII
72
How does histamine affect tight junctions in endothelial cells?
Releases them
73
What is IL-1a/b cleaved by?
Caspase 1
74
What does TNF and IL-1a/b activate?
NFkB and AP1
75
What do ferritin, hepcidin, ceruloplasmin and haptoglobin do?
Limit iron available for pathogen
76
What do sentinel macrophages secrete?
IL1, TNF and IL8
77
What does L-selectin on neutrophil, monocyte or T cell bind to on the endothelium?
PSGL
78
What does LFA-1 on neutrophil bind to on the endothelium?
ICAM-1
79
What does PSGL on the neutrophil bind to on the endothelium?
P selectin first, then E selectin
80
What does VLA-4 on the monocyte bind to on the endothelium?
VCAM-1
81
When is L-selectin expressed on most leukocytes?
Constitutively
82
Which secretory bodies have P-selectin?
Weibel-Palade
83
What do all selectins bind?
sialyl Lewis x
84
What are the selectins?
Ca dependent lectins
85
Under what conditions does PSGL bind the selectins?
Flow
86
With which selectin does PSGL mediate rolling?
E
87
Where is the anaphylatoxin on C3a?
At end of alpha chain
88
Which things can perform nucleophilic attack on thioester bond of C3b?
Water or OH or NH2 on bacterial surface
89
What is C3b further cleaved into?
Inactive C3c and C3d
90
What are factor P deficient people susceptible to?
Neisseria
91
Which kind of bacteria are factor I deficient people susceptible to?
Encapsulated
92
Where is factor H found?
Plasma
93
What does factor H bind on vertebrate cells?
Sialic acid
94
What is the structure of a "tulip protein"?
Head group on long protein chain, ends with a collagen-like sequence
95
Which part of the C1q binds the CRP?
Phosphocholine
96
When can Clq bind antibdy Fc regions?
When they are bound to their target antigen
97
Is C2a or C2b smaller?
C2b
98
How does C9 polymerise?
Self polymerises
99
What can C5-9 deficient people suffer from?
Neisseria
100
What is iC3?
C3(H2O)
101
What protects host cells from MAC and C9?
CD59
102
What happens in paroxysmal nocturnal haemoglobinuria?
RBCs lacking CD59 are lysed by complements
103
What is a linear epitope?
AA sequence
104
What is a conformaional epitope?
3D protein structure
105
Why don't neuronal cells have MHC?
If killed they don't recover
106
What are the costimulatory molecules from the macrophage after the PRRs are ligated?
B7 and CD40
107
What is affinity maturation?
Cells with highest affinity are induced to proliferate
108
How do FDCs trap antigen?
Antigen/antibody/C3b complex
109
Which Igs have three constant domains?
G, A, D
110
Which Igs have four constant domains?
M and E
111
Which Ig is always made?
IgM
112
Which CDR is most variable?
CDR3
113
Why are IgMs always made?
Closest to VDJ segment
114
Where does somatic hypermutation happen?
In lymph node
115
What enzymes deaminates cytosine to uracil?
Activation Induced Cytosine Deaminase
116
Which enzymes drives isotype switching?
AID
117
Which Ig is secreted into the gut to protect mucous membranes?
IgA
118
What is the structure of IgM?
A pentamer
119
Which cells express FCgammaRIII?
NK, neutrophils, eosinophils, phagocytes
120
What is the affinity of the FCgammaRIII receptor?
Low
121
What does the FcgammaRIII receptor detect?
Antibody/antigen complexes
122
What does IgE bind to on the eosinophil?
FcERI (high affinity)
123
Which Ig receptors do mast cells and basphils have?
FcERI and FcgammaRIII
124
Which Igs protect mucosal surfaces?
IgA and IgM
125
Which Ig can cross the mucosal surface?
IgA
126
Which chain of the IgA does its receptor recognise?
J chain
127
What does IgA in the milk do?
Remains in the infant gut and prevents bacteria/toxins attaching to gut epithelia
128
Which Ig travels across the placenta to pretect against pathogens in the birth environment?
IgG
129
What acts as a negative signal to terminate B cell response?
B cells, immune complexes, BCR and FcgammaRIIB
130
What is the avidity and affinity of IgM antibodies?
Low affinity, high avidity
131
Which chromosome is the MHC locus on?
6
132
How are the class 1 alpha chain and beta2-microglobulin linked?
Non-covalently
133
Which extracellular domain does the Class 1 alpha chain have?
Alpha1,2,3
134
Which alpha extracellular domains form the peptide binding groove in Class 1 MHC?
Alpha 1 and alpha 2
135
How many peptides can the class 1 MHC fit?
8-9
136
What has the base of the class 1 groove got?
B pleated sheet and two alpha helices
137
Which chains has the class 2 MHC got?
Alpha and beta
138
What is the structure of the peptide binding groove in MHC class 2?
Formed by alpha1 and beta1 domains, supported by alpha2 and beta2 domains
139
How many types of MHC class II are there?
6
140
How does class I groove restrict peptide chain length?
Has pockets to interact with carboxy terminus
141
Which loci encode class I?
HLA-A,B and C
142
Which loci encode class II?
HLA-DP,DQ,DR
143
How are class I peptides moved to the ER?
TAP
144
In the endocytic pathway, what small peptide is found in the peptide binding groove?
CLIP
145
What is the compartment called where the CLIP is removed?
MIIC
146
Which enzymes cause recombination in T cells?
RAG1 and RAG2
147
What is the B7 receptor?
CD28
148
Which costimulatory molecules does the APC express?
B7.1 and B7.2
149
Which cells do Th1 cells activate?
Macrophages, NK cells and CTL
150
What do Th17 cells defend against?
Extracellular bacteria and some fungi
151
Which cytokines switches off production of Th2 cells?
IFN gamma
152
Which cytokine dampens macrophage activation?
IL-10
153
Which chain is the surrogate in the T cell?
Surrogate alpha chain
154
Where are double positive T cells found?
Thymus
155
Which complex is required for TCR alpha/beta chain expression?
CD3
156
Which complex transduces the signal in the BCR?
CD79
157
What expresses the peripheral antigens?
AIRE
158
What do AIRE mutations cause?
APECED
159
Which transcription factor do Tregs express?
Fox3p
160
What do people without Fox3p get?
IPEX syndrome
161
Which are the placental immunosuppressive factors?
alpha-fetal protein and IDO
162
What is IDO
A tryptophan catalysing enzymes
163
Which kind of autoimmunity is IgE mediated?
None
164
What kind of autoimmunity is analogous to type II hypersensitivity?
Direct antibody mediated effects
165
What causes direct antibody-mediated autoimmunity?
Autoantibodies in serum
166
What kind of autoimmunity is analogous to type III hypersensitivity?
Immune complex medaited effects
167
In SLE what are the autoantibodies against?
Cytoplasm and nucleus
168
Which complement molecules are depleted in SLE?
C1, 2, 4
169
Which kind of autoimmunity is analogous to type IV hypersensitivity?
T cell mediated
170
What is the autoantigen in Goodpasture's syndrome?
Type IV collagen
171
Which mutation affects diabetes susceptibility?
Position 57 of DQB chain changed to not aspartate
172
What is type I hypersensitivity caused by?
IgE mast cells
173
What is type II hypersensitivity mediated by?
IgM/IgG binding to cells
174
What is type III hypersensitivity mediated by?
Immune complexes
175
What is type IV hypersensitivity mediated by?
T cells (delayed type)
176
What is atopy?
A predisposed state to type 1 hypersensitivity, with higher IgE levels
177
In type I hypersensitivity, which mast cell receptor does the IgE bind to?
FcERI
178
What response does a low dose of allergen cause?
IL4 producing Th2 response
179
Which kind of responses are ABO and rhesus?
II
180
What is the core of the ABO molecule?
H antigen
181
What is the modification of the A molecule?
Terminal N-acetylgalactosamine
182
What is the modification of the B molecule?
Terminal galactose
183
Which antibody is produced in HDN?
Anti-RhD IgG
184
How are HDN complexes cleaved?
No complement so maternal Abs coat and are cleared by spleen Fc receptors
185
Which receptor do type III complexes bind to on the mast cell?
FcgammaRIII
186
What is the Arthus reaction?
Bump rather than wheal and flare
187
Which kind of T cells trigger type IV hypersensitivity?
TH1
188
Which mutations cause abacavir sensitivity?
HLA-B*57
189
Which kind of rejection is like type II hypersensitivity?
Hyperacute
190
Which proteins regulate damage to self tissues and don't work across species?
DAF
191
In transplantation, which MHCs are matched and which are removed?
I matched, II removed
192
What causes acute rejection?
T cell recognition
193
What is direct acute rejection?
Donor APCs activate host T cells
194
What is indirect acute rejection?
Donor tissue H antigens are presented to host T cells
195
What is indirect allorecognition?
Indirect recognition of minor H antigens
196
What is is minor/H antigen?
non-MHC protein which differs between host and recipient
197
What kind of rejection is like type III hypersensitivity?
Chronic
198
What is used to mobilise pluripotent stem cells?
GM-CSF
199
Which + stem cells are selected?
CD34
200
What is GM-CSF?
Granulocyte macrophage colony stimulating factor
201
How are HLA matches tested?
Using a microtoxicity test
202
What do macrophages secrete?
Leukotrienes, histamine, prostaglandin
203
Which systems activate the vascular endothelium?
Fibrinolytic, clotting and kinin
204
Deficiency of what causes pyogenic infection?
C3, factor I and H
205
What does IgM do?
Activates complement
206
What does IgG/A do?
Neutralise
207
What does IgG1 do?
Opsonise
208
Which cytokines promote ECM reconstruction?
IL4 and 13
209
What is CD19?
B cell marker
210
What activates TLR4?
LPS from gram -ve
211
What does TLR3 detect?
dsRNA from viruses
212
What does NLR detect?
PG from gram +ve/-ve
213
What is the host protein that chelates iron?
Lactoferrin
214
Which complement does lipid A activate?
Lectin
215
What is the ETEC toxin type?
ADP-ribosylating enzymes
216
What is the Shiga toxin enzyme?
Glycosidase
217
What is the tetatnus toxin enzyme?
neurotoxin
218
What is the clostridial alpha toxin enzyme?
Phospholipase
219
What is the streptolysin O enzyme?
Pore former
220
Are endotoxins or exotoxin more heat stable?
Endotoxin
221
Which T cell response drives isotype switching?
Th2
222
What do chloramphenicol and aminoglycosides inhibit?
Peptide elongation
223
How much lower is malarial risk in HbAS?
10x
224
What do defensins do?
Intercalate into and disrupt membranes
225
When do antibody responses peak?
8-10 days after infection
226
Which Ig does mucosal infections need?
IgM
227
Which Ig binds C1q?
IgM
228
Why does IgM not opsonise?
Pentamer - Fc not available
229
Which diseases is HLA-B27 defect associated with?
Psoriasis, Ankylosing spondylitis, Inflammatory bowel disease, and Reactive arthritis.
230
What do Th17 cells do?
Enhance the neutrophil response - particularly for bacteria colonising the epithelium
231
What are M2 macrophages?
Alternatively activated macrophages
232
What activates AAMs?
Il-4 (as in a Th2 response)
233
How do AAMs cause tissue repair?
secrete growths factors to stimulate healthy cells to divide and replace lost cells, and to stimulate fibroblasts to secrete collagen to rebuild lost connective tissue
234
Is AAM innate or adaptive?
Innate
235
Which cells release IL-4?
Mast cells and activated B cells
236
How do parasites activate AAM?
IgE activates mast cells to make IL-4 which activates AAMs
237
Which lineage is NK cells?
Lymphoid
238
Which deficiencies predispose to Neisseria infections?
C5,6,7,8, properdin, factor D
239
Which deficiencies cause pyogenic infections?
C3, factor I and H
240
Which cells generate defensins?
Epithelial
241
What does NALP3 recognise?
Cholesterol crystals, uric acid, DNA, ATP, toxins, dsRNA, paramyxovirus
242
How does factor H affect the alternative pathway?
Inhibits
243
Which kind of tolerance allows the existence of autoreactive B cells?
Split tolerance
244
What do lymphocytes enter lymph node through?
High endothelial venules
245
Which thymus region does negative selection occur in?
Medullary
246
WHich cell dirves isotype switching?
Tfh
247
What stimulates dendritic cell migration?
TNF-a
248
Which enzyme generates point mutations during somatic hypermutation?
Activation induced cytidine deaminase
249
Are HLAs alleles?
No, isotypes
250
Why don't inflammasome cause apoptosis?
Different caspases
251
WHich b doesn't have a thioester bond?
C5b
252
Which complement pathway does factor XII activate?
Classical
253
Which complement things does thrombin cleave?
C3 and C5
254
What happens if second signal is absent?
Anergy
255
What is pleiotropism?
One cytokine can have multiple effects
256
What is the structure of FAS?
Trimer
257
What is the structure of perforin?
Monomer
258
Which complement component is Perforin similar to?
C9
259
How many TLRs are there is humans?
10
260
Which PRRs have LRR domains?
TLRs
261
Which domains do TLRs signal through?
TIR
262
How many NLRs are there in humans?
22
263
WHich adaptor do DNA receptors in the cytoplasm work through?
STING
264
What does AIM2 interact with the make the inflammasome?
ASC and caspase 1
265
Which enzyme produces the leukotrienes?
5-lipoxygenase
266
Where is properdin made and stored?
neutrophils
267
Which protease does CR1 recruit?
Serine protease factor I
268
How many variable gene segments does the human heavy chain locus encode?
38-46
269
What accounts for CDR1/2 variation?
V gene segments
270
What account for CD3 variation?
DJ and junctional segments
271
How many heavy chains do B cells have?
1
272
How many diversity segments do light chains have?
None
273
Which light chain is rearranged first?
K
274
Which sequences do recombinases recognise?
COnserved heptamer and nonomer
275
Which enzymes do junctional diversity?
Terminal deoxynucleotide transferase
276
Which enzyme changes C to U during somatic hypermutation?
AID
277
How are soluble or membrane bound Igs produced?
Different polyA sites
278
What do low affinity FcRs bind?
Multivalent antigen/antibody complexes (not monovalent)
279
Which are the low affinity FcRs?
FcgammaRII and III
280
Which is the high affinity FcR?
FcgammaRI
281
Which cells express FcgammaRs?
Macrophages and neutrophils
282
Which cells express FcgammaRIII?
NK, neutrophils, eosinophils, phagocytes
283
Which animals get IgG post-natally using an IgG-receptor in the gut?
Ruminants and rodents
284
What is MHC alpha chain non-covalently linked to?
Beta-2 microglobulin
285
How many peptides can the MHC class II accommodate?
13-25
286
How many peptide-MHC molecules per cell?
Mean 100
287
What do MHC class II molecules associate with to prevent binding peptides in the ER?
Invariant chain
288
Do T cells or B cells have somatic hypermutation?
B cells only
289
Which cells mediate positive selection?
Cortical epithelial cells
290
Defining feature of pAPC?
Co-stim molecules
291
What are fungal spores coated with the avoid the immune system?
Hydrophobin
292
Which cancer is associated with immunosuppression?
Kaposi's sarcoma in HIV
293
What is contact hypersensitivity?
Cutaneous response to hapten (Th1 cells activate macrophages)
294
What is a hapten?
Forms stable complex with host protein
