Immunology Flashcards

1
Q

Variolation definition?

A

Exposure of an individual to the contents of dried small pox pustules from an infected patient

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

Causes for the emergence of new infectious diseases?

A

Global Village-increased mobility
Population growth- proximity, sanitation
Changes in human behaviour
Changes in dynamics of other infections- increased TB prevalance has lead to more TB cases
Loss of natural habitat- from rainforests
Interactions of pathogens with humans- resistance

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

3 barriers to infection?

A

Skin
Mucous
Commensal bacteria

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

How is skin a barrier to infection?

A

Physical barrier
Physiological factors (low pH)
Sebaceous glands secrete hydrophobic oils
Lysozomes

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

How is mucous a barrier to infection?

A

Secretory IgA
Enzymes
Cilia trap pathogens and remove mucous

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

How is commensal bacteria a barrier to infection?

A

Compete with pathogens for scarce resources

  • Produce anti-microbial short chain fatty acids
  • Compete for essential nutrients
  • Reduction in pH of bowel
  • Synthesis of vits K
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Briefly describe the innate immune response in its response time and type of response?

A
Rapid response (0-4 hours)
General response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What cells does the innate response involve?

A

Mast cells
NK cells
Phagocytes
Complement

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

What are the cells in the immune response responsible for?

A

Acute inflammation

Killing of pathogens

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

What molecules does the innate immune system rely on?

A

PAMPs:PRRs

PRRs detect PAMPs

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

What is a PAMP?

A

Pathogen associated molecular pattern

Detected by PRRs

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

What is a PRR?

A

Pattern recognition receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which immune response are PAMPs:PRRs involved in?

A

Innate

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

Briefly describe the adaptive immune system in its response time and type of response?

A
Slow response (4-96 hours)
Unique response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which two molecules are involved mainly in the adaptive immune response?

A

Antigens are received by antigen receptors

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

Cells of the adaptive immune system?

A

Phagocytes
Lymphocytes
Eosinophils, mast cells & basophils

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

Which types of phagocytes are involved in the adaptive immune system?

A

Neutrophils
Monocytes
Macrophages
Dendritic cells

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

What is the role of phagocytes?

A

Ingest and kill bacteria

Important source of cytokines

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

Types of lymphocytes in the adaptive immune response?

A

T cells
B cells
NK cells

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

What is the role of eosinophils, basophils and mast cells in adaptive immune response? What type of cells are they?

A

Release chemicals for acute inflammation

Granular cells

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

Soluble/humoral factors of the adaptive immune system?

A

Antibodies

Complement proteins

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

Antibodies in the blood are also referred to as?

A

Immunoglobins

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

When are antibodies produced in the adaptive immune response?

A

In response to an antigen

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

What is the role of complement proteins?

A

Critical role in inflammation and defence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Components of the adaptive immune system?

A

Cells + Soluble factors
Cells= phagocytes, lymphocytes, eosinophils/basophils/mast cells
Soluble factors= AB’s & Complement proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Where are mast cells found and what is their role?

A

Reside in tissues

Protect mucosal surfaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What happens when mast cells degranulate?

A

Release histamine and tryptase

Then gene expression causes production of new pro-inflammatory substances eg chemokines, TNF, leukotrienes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Role of baso/eosinophils?

A

Circulate in blood and are recruited to sites of infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Where are neutrophils in the body?

A

Circulate in blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Role of neutrophils?

A

Short-lived professional killer cells
Rapidly recruited to inflamed and infected tissues
PAMP recognition and activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

3 mechanisms how neutrophils attack pathogens?

A
  • Phagocytosis
  • Release of antimicrobial peptides and degradative proteases
  • Generate extracellular traps
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What do active neutrophils produce?

A

TNF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What makes up pus?

A

Dead/dying neutrophils
Tissue cells
Microbial debris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are monocytes?

A

Precursors of macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What do monocytes do?

A

Limit inflammation

Involved in tissue repair and wound healing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Where do macrophages reside?

A

In tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What do macrophages do?

A
Ingest and kill EXTRAcellular pathogens 
Clear debris from dead tissue cells 
Tissue repair and wound healing 
Antigen presentation 
Inflammation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are dendritic cells?

A

Immature cells in peripheral tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

When do dendritic cells mature?

A

When in contact with a pathogen, they mature to secondary lymphoid tissues and stimulate adaptive response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What are NK cells?

A

Natural killer cells

Large granular lymphocytes

41
Q

What do NK cells do?

A

Specifically kill tumour and virally infected cells

-Can also kill antibody bound cells

42
Q

Role of B cells?

A

Produce antibodies

43
Q

Role of T cells?

A

Defence against pathogens

44
Q

What are helper T cells?

A

Regulators of the immune system

Activate other immune cells

45
Q

Role of cytoxic T cells?

A

Kill virally infected body cells

46
Q

What are T helper cells otherwise known as?

A

CD4+ cells

47
Q

What are cytoxic T cells otherwise known as?

A

CD8+

48
Q

What do T cells and B cells become?

A

effector cells or memory cells

49
Q

Where is the site of luekocyte development?

A

Primary lymphoid tissue

Red bone marrow & thymus

50
Q

What occurs at secondary lymphoid tissue?

A

Site where adaptive immune response is initiated

eg tonsils, lymph nodes, spleen

51
Q

What is the mechanism of direct contact in the immune system?

A

Receptor- ligand interactions

52
Q

Indirect communication in the immune system?

A

Production and secretion of cytokines

53
Q

When are cytokines produced in response to?

A

Infection, inflammation and tissue damage

54
Q

What to cytokines do?

A

Coordinate the immune system by modulating cell behaviour

55
Q

Examples of cytokines?

A

Interferons = anti-viral function
TNF= Pro-inflammatory
Chemokines = Control and direct cell migration
Interleukins- various functions dependant on which IL it is

56
Q

Function of IL2?

A

T cell proliferation

57
Q

Function of IL10?

A

Anti-inflammatory

58
Q

What does TNF stand for?

A

Tumour necrosis factor

59
Q

Local effects of acute inflammation?

A
Redness 
Heat 
Swelling 
Pain 
Loss of function 
Fever (systemic)
60
Q

Phases of the innate immune response?

A

Recognition phase- PRRs & PAMPs
Activation phase
Effector phase

61
Q

What does the liver produce in response to pro-inflammatory cytokines? Give examples of the cytokines. What is this response called?

A

Acute phase proteins
IL1, IL6, TNF
Acute phase response

62
Q

What is the acute phase response for?

A

Infection
Trauma
Chronic inflammation

63
Q

Examples of acute phase proteins?

A

CRP
Complement proteins - C3, C4, mannose-binding lectin
Serum amyloid A

64
Q

Cells associated with cell-mediated immunity?

A

ABs
B cells
T cells
Dendritic cells

65
Q

Examples of secondary lymphoid tissues?

A

Spleen
Tonsils
Lymph nodes

66
Q

Cells associated with the innate immune system?

A
Macrophages 
Mast cells 
Basophils 
Eosinophils 
Neutrophils 
Dendritic cells
Complement system 
NK cells
67
Q

Cells associated with adaptive immune system?

A

T cells
B cells
Dendritic cells
ABs

68
Q

Primary lymphoid tissues?

A

Bone marrow

Thymus

69
Q

Associated with humoral (body fluids) mediated immunity?

A

Complement system

ABs

70
Q

What is the complement system?

A

Family of proteins produced in the liver that circulate in the blood
They enter infected and inflammed tissues

71
Q

3 pathways in the complement system?

A

Classical pathway
Lectin pathway
Alternative pathway

72
Q

What is C3 cleaved into?

A

C3a & C3b

73
Q

Functions of the complement system?

A
Membrane attack complex 
Opsonisation 
Chemotaxis
Clearance of immune complexes
Inflammation
74
Q

What is opsonisation?

A

Coating of microorganisms by immune proteins (opsonins)

This enhances phagocytosis

75
Q

Examples of opsonins?

A

C3b, CRP, ABs

76
Q

Explain complement mediated lysis?

A

C5b binds to pathogen surface

C6, C7, C8, C9 +C5b= membrane attack complex

77
Q

What consists of a membrane attack complex?

A

C6, C7, C8, C9 +C5b

78
Q

Explain complement mediated inflammation and chemotaxis?

A

C3a and C5a bind to receptors on mast cells/basophils and release granules which produce histamine and chemokines

79
Q

What do antigens do?

A

Cause adaptive immune response by activatin B/T cells

80
Q

How do B and T cells recognize a pathogen?

A

T cell antigen receptor

B cell antigen receptor

81
Q

Describe a B cell antigen receptor?

A

Membrane bound antibody (IgM or IgD)

It has light and heavy chain and disulphide bridges

82
Q

Describe a T cell antigen receptor?

A

Membrane bound heterodimer

Has alpha and beta chain

83
Q

How do T/B cells find pathogens?

A

By secondary lymphoid tissues

84
Q

Process of activating B/T cells?

A

MHC/HLA proteins display peptide antigens to T cells
Class 1= Expressed on all nucleated cells- present peptide antigens to cytoxic T cells

Class 2 = Expressed only on dendritic cells. macrophages and B cells- present peptide antigens to helper T cells

85
Q

What do B cells produce in response to an antigen?

A

Immunoglobins

86
Q

What are the variable regions in immunoglobins for?

A

Antigen binding sites

87
Q

5 Types of Immunoglobins?

A
IgG
IgM
IgA
IgE
IgD
88
Q

IgG?

A

Most abundant

Actively transported across the placenta

89
Q

IgM?

A

Surface bound monomer

1st Ig type produced during an immune response

90
Q

IgD?

A

Extremely low levels in blood, surface bound

91
Q

IgE?

A

Extremely low levels normally, produced in allergic reactions

92
Q

IgA?

A

2nd most abundant type, monomeric form in blood, dimeric form in breast milk, saliva, tears, mucosal secretions

93
Q

What is the most abundant Immunoglobin?

A

IgG

94
Q

1st Ig produced in an immune response?

A

IgM

95
Q

What Igs do mothers give to babies?

A

Dimeric IgA and IgG

96
Q

Function of IGs?

A

Recognition function: binding to antigen mediated by variable region sites

Effector functions: Clearance mechanisms mediated interaction of constant region with effector molecules

97
Q

What is agglutination?

A

Immune complex formation

98
Q

What happens in B cell activation/differentiaion?

A

Either become plasma cells which produce ABs or memory B cells

99
Q

What is germinal centre reaction?

A

B cell proliferation
AB heavy chain switching
Generation of high affinity ABs
Differentiation into plasma cells & Memory B cells