Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Immunology > Exam 3: Hypersensitivity Type I > Flashcards

Exam 3: Hypersensitivity Type I Flashcards

1
Q

what type of immune response is hypersensitivity type I

A

antibody mediated immune response

humoral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what kind of antigens trigger type I hypersensitivity

A

allergies

parasite worms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

characteristics of type I hypersensitivity (4)

A

exaggerated Th2 response

excessive amounts of IgE = atopy

genes + environmental factors = allergies

intestinal microflora

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what does early contact with allergens lead to

A

less susceptible to get allergies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are some non microbial antigens that can cause allergies

A

food

insects

pollen

fur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the normal concentration of IgE in serum

A

low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what happens to IgE concentration in type I hypersensitivity

A

IgE overproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what happens to IL-4 in type I hypersensitivity

A

IL-4 overproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what does IL-4 overproduction cause

A

increased Th2 activation and B cell stimulation

when B cells differentiate –> IL-4 increases production of IgE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are the receptors of IgE and what type of binding to the antibody do they have

A

irreversible binding to antibody

FcεR
FcεRI
FcεRII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

FcεR
FcεRI
FcεRII

A

FcεR - has high affinity and irreversible binding

FcεRI - present in mast cells, basophils, neutrophils, eosinophils, macrophages, dendritic cells

FcεRII - present in B cells, NK cells, macrophages, dendritic cells, eosinophils, platelets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

mechanism of type I hypersensitivity reactions

A

numerous biologically active molecules are released by mast cells and basophils when antigen cross-links two IgE molecules on the mast cell surface

some are produced immediately, others may be synthesized within minutes or hours

  1. antigen + mast cell with IgE
  2. Degranulation - cytokines, enzymes, chemotactic molecules, vasoactive molecules
  3. acute inflammation and systemic effects
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

the role of IL-4 in induction if IgE response - normal humoral response

A

IL-4 is produced by Th2 cells

Once released, IL-4 promotes development of more Th2 cells

Th2 cells are major sources of this cytokine and promote IgE responses

Degranulation of mast cells also releases IL-4 to further promote this reaction

NK cells may serve as an initial source of IL-4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what inhibits response of IL-4

A

Response to IL-4 inhibited by IFN-y and IL-12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

the allergy loop

A

dendritic cells express trimeric FcεRI as can bind antigen-IgE complexes

this antigen, once processed, stimulates Th2 responses

these Th2 cells in turn secrete cytokines, which further promote the IgE response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

mast cell resposne

A

the combination of Fcε receptors with their ligands stimulates many different responses in mast cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is CR2

A

CR2 is a complement receptor located in B cells, T cells, and dendritic cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

mast cell response FcεRI

A

antigen –> IgE –> FcεRI (high affinity) –> mast cell degranulation, eosinophil ADCC, dendritic cells, macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

mast cell response FcεRII

A

antigen –> IgE –> FcεRII (low affinity) –> B cell down regulation, Macrophage phagocytosis, NK cells, Dendritic cells, Eosinophils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

mast cell response FcεRIII

A

CR2 –> FcεRIII –> B cell stimulation and survival

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

mast cell - characteristics

A

located in intestine, skin, airways, around nerves

close to blood vessels

release proinflammatory mediators

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what do mast cells release in connective tissue/skin and what is their life span

A

histamine
heparin

life span > 6 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what do mast cells release in intestine/lung and what is their life span

A

chondroitin sulfate
few histamine

life span < 40 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

mast cells - molecules released from exocytosed granules within seconds

A 
histamine
serotonin
tryptase
kallikreins
proteases
proteoglycans
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

mast cells - eicosanoid synthesis and secretion within minutes

A

leukotrienes
prostaglandins
platelet activating factor

These all induce inflammation

26
Q

mast cells - cytokine synthesis and secretion over several hours

A 
IL-4
IL-5
IL-6
IL-13
TNF-a
MIP-1a
27
Q 
Biological properties of IL-33
Innate lymphocytes
Macrophages
Neutrophils
B cells
Th2 cells
Eosinophils
Basophils
Mast cells 
Neurons
A

Innate lymphocytes - Th2 cytokines, IFN-y, TNF-a, IL-2

Macrophages - M2 polarization, tissue repair

Neutrophils - phagocytosis

B cells - IgM

Th2 cells - IL-5, IL-13 –> exotoxins

Eosinophils - IL-8, degranulation –> terminal effector cells of the allergic response

Basophils - IL-3, IL-4, IL-6, IL-13, histamine, GM-CSF –> basophil differentiation in bone marrow

Mast cells - IL-6, IL-13 –> degranulation in presence of IgE

Neurons - itch

28
Q

what does IL-33 do

A

stimulates the production of inflammatory cytokines and chemokines from many different cell types

major mediator in type I hypersensitivity

29
Q

what happens when an allergen binds to a IgE that is attached to a mast cell

A

the mast cell releases granules and begin to synthesize several other factors that have effects on GI tract, airways, blood vessels

30
Q

effects of mast cell degranulation on GI tract

A

fluid secretion, peristalsis

emptying of GI tract (diarrhea, vomiting)

31
Q

effects of mast cell degranulation on respiratory tract

A

mucous secretion, bronchoconstriction

difficulty breathing

32
Q

effects of mast cell degranulation on blood vessels

A

increased vascular permeability

movement of fluids, proteins, and cells out of blood vessels and into inflamed tissues

33
Q

what inhibits mast cell degranulation

A

blocking a adrenoreceptors

stimulating B adrenoreceptors: isoproterenol, epinephrine, salbutamol

34
Q

what enhances mast dell degranulation

A

stimulation of a adrenoreceptors: norepinephrine, phenylephrine

blocking B adrenoreceptors: propranolol

35
Q

what happens when mast cell degranulation enhanced

A

immediate inflammation 10-20 minutes

late phase reaction 6-12 hours

36
Q

what happens when a receptor stimulated and B receptor blocked

A

Mast cells - enhanced degranulation

Smooth muscle - contracts

Blood vessels - constricts

37
Q

what happens when B receptor stimulated and a receptor blocked

A

Mast cells - suppressed degranulation

Smooth muscle - relaxes

Blood vessels - dilates

38
Q

what happens when basophils bind IgE

A
  1. Bind IgE
  2. Basophil degranulation
  3. increasing vascular permeability
39
Q

characteristics of basophils

A

long term allergic states (chronic allergic dermatitis)

initiate helminth immune response as APC (Th2)

protective role in helminth, tick, bacterial infections, degrade toxins in venom, contribute to tumor rejection

40
Q

Eosinophils respond to

A

parasites
pathogens
PAMPs and DAMPs

41
Q

eosinophils produce

A

oxidants and enzymes

lipid mediators

cationic granule proteins

cytokines

chemokines

42
Q

eosinophils - oxidants and enzymes effects

A

tissue damage and inflammation

43
Q

eosinophils - lipid mediators effects

A

pain

smooth muscle contraction

mucus production

44
Q

eosinophils - cationic granule proteins effects

A

tissue damage and inflammation

45
Q

eosinophils - cytokines effects

A

macrophage activation

dendritic cell activation

neutrophil activation

endothelial cell activation

46
Q

eosinophils - chemokines effects

A

T cell chemotaxis and activation

47
Q

clinical type I hypersensitivity

A

allergic anaphylaxis

milk allergy

food allergy

allergy to vaccines and drugs (penicillin)

allergies to parasites, midges, black flies, stable flies, fleas

allergic inhalant dermatitis

atopic dermatitis (house dust mites, molds, trees, weeds, grass pollen)

hygiene hypothesis

48
Q

which breeds are more susceptible to atopic dermatitis

A 
retrievers
terriers
beagles
boxers
bulldogs
shar-pei
49
Q

what is most affected in dogs with allergic anaphylaxis

A

liver - hepatic veins

50
Q

what is affected in most species with allergic anaphylaxis

A

respiratory tract and intestines

51
Q

what is used in severe allergic anaphylaxis reactions

A

epinephrine – epi-pen

52
Q

is allergic anaphylaxis a severe, life threatening systemic hypersensitivity reaction

A

yes

can be fatal

53
Q

immune response in atopic dermatitis

A 
allergens --> 
trauma --> 
keratinocytes -->
cytokines --> 
TSLP --> sensory neurons (with  input from IL-31) --> 
itch
54
Q

which IL is most important in atopic dermatitis and what does it do

A

IL-31

Gives itching sensation

55
Q

diagnosis of type I hypersensitivity

A

intradermal skin testing

passive cutaneous anaphylaxis (PCA)

measuring IgE

56
Q

treatment of type I hypersensitivity

A

avoid exposure to allergen

corticosteroids

antihistamines

B stimulants - epinephrine, isoprenaline, salbutamol

a antagonists - methoxamine, phenyleprine

allergen specific immunotherapy

57
Q

intradermal allergy test

A

bunch of injections into skin to see which allergens you react to

58
Q

immunotherapy

A

injections or oral drops

injections or oral drops contain small amounts of the allergen –> vaccines

objective of these vaccines is tolerance and increased IgG production (class switching from IgE)

59
Q

why do we want increased IgG production in immunotherapy

A

higher amounts of IgG will compete with IgE to bind allergen and allergen will be eliminated/destroyed

60
Q

canine atopic dermatitis

A

caninized anti-cIL-31 monoclonal antibody (mAb)

mAb specifically targets and neutralizes canine IL-31 which is involved in sending itch signal to brain

interrupts cycle of itch and inflammation

how apoquel works

61
Q

best treatment for type I hypersensitivity in humans

A

have a chihuahua dog
because they help with asthma apparently
but no scientific explanation (or evidence really)

Immunology (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions