B4 Innate vs. Adaptive Immunity Flashcards Preview

Phase I Medicine > B4 Innate vs. Adaptive Immunity > Flashcards

Flashcards in B4 Innate vs. Adaptive Immunity Deck (103):
1

What is the difference between antigens and immunogens?

Antigens - anything that can bind to an antibody.
Immunogens- anything that can illicit an immune response after binding to an antibody.

2

What is the difference between different epitope structures in antibodies?

Variable regions

3

What is 'Fab' on antibody molecular models?

Combination of light chains

4

What is 'Fc' on antibody molecular models?

Combination of heavy chains

5

What is affinity of antibodies?

How good the binding site is for binding antigens

6

What is avidity of antibodies?

How much more effectively you bind things with more receptors

7

Why is there a hinge in the structure of antibodies?

To change and give extreme flexibility of the structure

8

What are the four ways that allow for an infinite number of different antibodies?

Germ line diversity of genes
Combinatorial Diversity
Junctional Diversity
Somatic Hypermutation

9

What are the components of somatic recombination?

Combinatorial diversity
Junctional diversity

10

When does somatic hypermutation occur?

During an ongoing immune response

11

What is somatic recombination?

Joining together lots of different portions of genes that we already have in different orders

12

What is the term for changing the function of antibody when it gets to the site of infection and realises it has to do something else?

Class switching

13

What allows for class switching?

Somatic hypermutation
Cytokines

14

Why does clonal selection exist?

We can't afford to have one gene for each antibody

15

True or false? Cytokines can induce class switching?

True

16

What is positive selection?

If you pass each checkpoint, you survive and divide.

17

What is negative selection?

If you fail a check point you get killed off.

18

How many T cells die in the thymus via negative selection?

98%

19

True or false? B cells and T cells recognise the same part of the antigen?

False
B cells use Ab
T cells use TCR

20

How do B cells recognise antigens?

Ab to recognise their complementary conformational epitopes

21

How do T cells recognise antigens?

TCR to recognise linear epitopes or enzymatically digested bits from B cell antigen processing

22

What is central tolerance?

How newly developing T cells and B cells are rendered non-reactive to self

23

What is the purpose of MHC molecules?

To identify small fragments of antigens and shuttle them out to the surface

24

What is co-stimulation?

Adding another checkpoint for B lymphocytes

25

Why is co-stimulation necessary?

This ensures that when a B cell phagocytoses something, it doesn't immediately get to make antibodies for it.

26

What signals do highly immunosuppressive drugs block?

BCR and TCR

27

What triggers co-stimulation?

Innate system fine discrimination

28

What are the four steps of the infection pathway?

1. Infection has to establish in face of innate response
2. Induction of adaptive response
3. Reduce/sterilise infection
4. Immunological memory

29

What type of cell is the effector cell of the dermis?

Phagocytic

30

What protein is responsible for opsinization?

C3b

31

What is the role of C3b?

Opsonisation
MAC
Recruitment of inflammatory cells

32

What is MAC?

Membrane Attack Complex

33

How does MAC work?

Forms perforations in cell membrane resulting in cell lysis

34

What is degradation?

Breaking down the whole pathogen/antigen into genetic fragments

35

What is diapedeis?

Movement of while blood cells through intact capillary walls into surrounding tissue.

36

What is another term for diapedesis?

Leukocyte extravasatio
Migration

37

What are dendritic cells?

Very specialised phagocytes that can return to lymph nodes with information about infections

38

What are Langerhan cells?

APCs/ Dendritic cells of skin and mucosa

39

What do Langerhan cells contain?

Birbeck granules

40

Where are Langerhan cells most abundant in the skin?

Stratum spinosum

41

What is the role of dendritic cells?

Turn on T cell responses
Sense the environment
Make a range of cytokines to influence T cell differentiation

42

What class of MHC molecules do dendritic cells have?

MHC II

43

What are high endothelial venues?

Specialised blood vessels for lymphocyte migration

44

How are high endothelial venules generally used by lymphocytes?

Bloodstream -> Lymph nodes

45

What kind of signalling do immune cells use?

Similar to synaptic

46

What happens to T lymphocytes in the process of trapping?

Moved from lymph to bloodstream

47

What is the difference between TH1 and TH2 CD4 T cells?

TH1 bind to macrophages to make more macrophages
TH2 bind to B cells turned APCs to check them/allow them to make antibodies

48

What are the cardinal signs of inflammation?

Heat, Redness, Pain, Swelling

49

Why do the cardinal signs of inflammation come about?

Acute vasodilation of capillaries

50

What are examples of chronic infections?

Autoimmunity and transplant rejection

51

What is a major source of mediators for the immune response?

Liver

52

Why are lipids rapidly synthesised?

They're not dependent on protein synthesis

53

True or false? Cytokines aren't usually dependent on protein synthesis?

False

54

What is the specific mechanism of action for dendritic cells?

Macropinocytosis

55

Where are mast cells usually located?

Next to the vasculature

56

How are prostaglandins made?

Conversion of arachadonic acid to cyclic endoperoxides which get converted into prostaglandins

57

How are leukotrienes made?

Conversion of arachadonic acid into 5-lipoxygenase

58

What are the mediators that resolve inflammation known as?

Lipoxins

59

How are lipoxins made?

Conversion of arachidonate into 15-lipoxygenase

60

What are leukotrienes?

Biologically active compounds made by leukocytes

61

What are the 3 As of NSAIDs?

Anti-inflammatory
Analgesic
Antipyretic

62

Why isn't paracetamol an NSAID?

It isn't an anti-inflammatory

63

What does aspirin do to COX?

Inactivates both isoforms

64

What part of aspirin's actions is responsible for its 3As?

Acetylates catalytic serine residue on position 529

65

On what levels does aspirin affect COX 2 expression?

Transcriptional and post-transcriptional

66

How does aspirin end up producing lipoxins?

COX 2 acetylation modifies the enzyme so that instead of completing its reaction to make prostaglandins it stops at lipoxins.

67

Which mediators are preformed in secretory granules?

Histamine
Serotonin
Lysosomal enzymes

68

What are the mediators of acute inflammations that are newly synthesised?

Prostaglandins
Leukotrienes
Platelet-activating factors
Activated oxygen species
Nitric oxide
Cytokines

69

What are the side effects associated with chronic use of aspirin?

Swelling of eyes, face, lips, tongue or throat
Tinnitus
Loss of hearing
Wheezing
Difficulty breathing
Hoarseness
Fast breathing
Tachycardia
Hives
Cold clammy skin
Melaena
GI complaints

70

True or false? Swelling of the eyes can occur with chronic aspirin use?

True

71

Is dry cough a side effect of chronic aspirin use?

No

72

What are coxibs?

Selective COX 2 Inhibitors

73

What are coxibs used for?

Rheumatoid arthritis

74

What is a famous example of a coxib?

Vioxx

75

What are NO-NSAIDs?

Nitric oxide -donating NSAID

76

What are SAIDs?

Glucocorticoids

77

What does chronic use of corticosteroids cause?

Toxicity

78

How do mast cells release histamine?

Exocytosis

79

What is the Lewis Triple Response (LTR)?

Reddening, Weal and Flare

80

Why does the Lewis Triple Response occur?

Histamine

81

What is the reddening in LTR caused by?

Vasodilation of small arterioles and pre-capillary vessels

82

What is wheal in LTR caused by?

Increased permeability of post-capillary venules

83

What is wheal in the Lewis Triple Response?

Swelling/ Localised oedma

84

What is flare in the Lewis Triple Response?

Redness extending beyond where you put the foreign object

85

What is flare in LTR caused by?

Release of vasodilators caused by antidromic stimulation of local nerves

86

What is the effect of mast-cell activation and granule release on the GI tract?

Increased fluid secretion and peristalsis -> Expulsion of GI tract contents

87

What is the effect of mast-cell secretion on the eyes, nasal passages and airways?

Decreased diameter and increased mucus secretion -> Congestion and coughing

88

What is the effect of mast-cell secretion on blood vessels?

Increased blood flow and permeability (potentially -> via anaphylaxis)

89

What is immediately released by mast-cells on exposure to infection?

Granules containing histamine
TNF alpha
Proteases

90

What can immediate secretions from mast cells cause?

Anaphylaxis
Acute vomiting
Airway constriction

91

What can the secretions released by mast cells (after a few minutes of infection) cause?

Recruitment of lymphocytes like neutrophils

92

What can the secretions released by mast cells (after a few hours of infection) cause?

Class switching from IgG to IgE

93

What is released by mast-cells after a few minutes of infection exposure?

Prostaglandins
Leukotrienes

94

What is released by mast-cells after a few hours of infection exposure?

IL-4
IL-13

95

What are the effects of histamine after being released from mast cells?

-Bronchoconstriction
-Increasing vascular permeability

96

What are the effects of leukotrienes after being released from mast cells?

-Bronchoconstriction
-Increasing vascular permeability
-Mucus secretion
-Chemotaxis

97

What are the effects of prostaglandins after being released from mast cells?

-Bronchoconstriction
-Increasing vascular permeability
-Mucus secretion

98

What are the effects of TNF alpha after being released from mast cells?

Tissue injury
Cell recruitment

99

What are the effects of proteases after being released from mast cells?

Tissue injury
Mucus production

100

What is the only mast cell secretion responsible for mucus production?

Proteases

101

What is the only mast cell secretion responsible for cell recruitment?

TNF alpha

102

What is the only mast cell secretion responsible for chemotaxis?

Leukotrienes

103

How does epinephrine deal with anaphylaxis?

Triggers vasoconstriction, increasing blood pressure