Intro to immunology Flashcards

1
Q

Normal immune system is made up of these 3 things….

A

Physical barriers
Innate immunity
Adaptive immunity

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

Physical barriers

A
Saliva 
- lysozyme
- IgA
- IgG
- lactoferrin 
Mucociliary escalator 
Gastric acid 
Normal flora
Physical flushing - urinary tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Examples of consequences of breached defences

A

Xerostomia
C diff infection
Cystic fibrosis
Burns

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

Features of innate immunity

A

Rapid
Already present at birth
No memory - same response with re-exposure
Some specificity

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

What does innate immunity detect?

A

Alteration from homeostasis

  • damage recognition - host
  • pathogen recognition - pathogen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where is the innate immunity found?

A

Within tissues

Within blood

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

Cells of the innate immunity

A
NK cells
basophils
Neutrophils
eosinophils
Monocytes
Platelets
Macrophages
Dendritic cells
Mast cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Mechanisms of innate immunity

A
Inflammation 
Recruitment of immune cells
Activation of complement 
Opsonisation 
Phagocytosis
NK cytotoxicity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What do cytokines do?

A

Regulate the nature, duration and intensity of the immune response
Form a method of communication between components of the immune system
Bind to specific receptors on target cells

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

What predominately produces cytokines?

A

Macrophages

T helper cells

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

Two types of cytokines

A
Pro-inflammatory 
- TNF-a
- IL-1
- IL-6
- Chemokines 
Anti-inflammatory 
- IL-10 
- TGF-B
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Pro-inflammatory cytokines cause…..

A

Fever
Recruit and activate other immune cells
vasodilation

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

What does IFN-y activate?

A

Macrophages

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

What does IL-3, IL-4, IL-5 and IL-13 activate?

A

Eosinophils

Mast cells

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

What does IL-4, IL-5, IL-6 and IL-21 activate?

A

B cells

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

What does IL-2, IL4, IL-12 and IFN-y activate?

A

T cells

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

What causes inflammation of the innate immune system?

A

Detection of ‘foreign’ / breach in defences by pattern recognition receptors (PRRs)

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

Features of inflammation and what causes each

A
Vasodilation 
- NO 
- Bradykinin 
- prostaglandins 
- TNF-a, IL-1
Increased vascular permeability 
- histamine
- nitric oxide 
- leukotrienes
Increased cell adhesion molecules 
- TNF-a, IL-1
Chemotaxis 
- CXCL-8
- neutrophil recruitment into the area
Increased sensitivity to pain 
- bradykinin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Activation of complement

A

Activation of C3
- activated by
- alternative (pathogens)
- classical (combination of own antibodies bound to foreign antigens)
- lectin (free floating proteins in body attaching to pathogens)
Splits into C3a and C3b
- C3b splints into C5a and C5b
- C3a and C5a - anti-inflammatory toxins or protein which will affect mast cells to degranulate

C3a = inflammation 
C5a = chemotaxis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is C5b?

A

Membrane attack complex

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

Activity of complement

A
  1. Chemotaxis of phagocytes to sites of inflammation
    - C3a, C5a
  2. Opsonisation
    - C3b, C4b
    - preparation for eating (reduces repellent negative cell charge and increases no of binding sites for phagocytes)
  3. Lysis of micro organisms
    - C5b-9 complex
  4. Maintain solubility of Ag / Ab complexes
    - C3b, C4b, C2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Main opsonins

A

Complement C3b, C4b
Antibodies
Plasma proteins - mannose binding lectin

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

Phagocytosis is done against what?

A

Extracellular pathogens

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

Two receptors on NK cytotoxicity

A

Activation
- if foreign pathogen / damaged cell
Inhibitory
- if normal cell

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

Features of the adaptive immune system

A
Specific 
Delayed 
Immunological memory 
- faster responses to known antigen 
Humoral 
- antibody mediated 
- B lymphocytes 
Cell mediated
- T lymphocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Two types of cells in the adaptive immune system

A
B cells (can lead to plasma cell) 
T cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Where do B cells mature?

A

Bone marrow

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

Where do T cells mature?

A

Thymus

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

Where do B and T cells migrate to once matured?

A

Secondary lymphoid organs where they encounter antigens

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

What is an antigen?

A

A molecule capable of producing an immune response

31
Q

Specificity of B cells - B cell receptor

A

Antibody attached to B lymphocyte

32
Q

Specificity of T tells - t cell receptor

A

Within the T cells

33
Q

T cell recognition of an antigen

A

Require presentation of antigen via MHC

  • CD4+ given by MHCII (antigen presenting cell e.g. macrophages)
  • CD8+ given by MCHI (all nucleated cells and platelets)
34
Q

B cell recognition of an antigen

A

Recognise antigens directly via BCR (B cell receptor)

35
Q

What is CD4+ given by and where is this found?

A

MCHII

antigen presenting cell e.g. macrophages

36
Q

What is CD8+ given by and where is this found?

A

MCH1

all nucleated cells and platelets

37
Q

Processing of MHC1

A

Intracellular pathogens

Presented to MHC1 and highlights this to the immune system

38
Q

Processing of MHC2

A

extracellular pathogens

39
Q

What is an antibody?

A

A glycoprotein produced by B lymphocytes that binds antigens with a high degree of specificity and affinity

40
Q

Two types of immune tolerance

A

Central tolerance

Peripheral tolerance

41
Q

Central tolerance T cells types - thymus

A
Positive selection 
- can T cells recognise MHC?
- if cant = destroyed 
Negative selection 
- does T cell interact too strongly with self antigens via MHC?
- if cant = destroyed
42
Q

Central tolerance B cells types - bone marrow

A

Self reacting BCR?

- if yes = destroyed

43
Q

Features of peripheral tolerance

A

Monitoring of lymphocytes within secondary lymphoid organs and circulation
Regulatory T cells

44
Q

What do regulatory T cells do?

A

Recognise and destroy self reaction lymphocytes

45
Q

Cytotoxic CD8+ cells release what?

A

IFN-y and TNF-a
Cytotoxic granules
ALSO
- apoptosis via FasL-Fas interactions

46
Q

Perforin + granzyme = what/

A

Apoptosis of target cell

47
Q

What happens in perforin induced apoptosis?

A

Release of perforin and granzyme
Perforin creates a hole/pore in cell membrane allowing granzyme to enter cell
triggers apoptosis

48
Q

What do helper T cells do? (CD4+)

A
Release cytokines to 'help' the activity of other immune cells
Promote B cell antibody class switching e.g. IgM to IgG
49
Q

Types of helper T cells (CD4+)

A

Th1
Th2
Th17

50
Q

Th1 features

A

Intracellular pathogens

  • maximise macrophage and CD8+ activity
  • release IFN-y
  • inhibit TH2 response
51
Q

Th2 features

A

Extracellular pathogens

  • release IL-4, IL-5, IL-13
  • activate mast cells, basophils, eosinophils
  • class switching to IgE
  • inhibit Th1 response
52
Q

Th17 features

A

Extracellular pathogens

  • PRO INFLAMMATORY
  • recruit neutrophils and macrophages via CXCL-8
53
Q

What do regulatory T cells do?

A

Suppress CD4+ and CD8+ T cells
Control the response to self antigens
Secrete IL-10 and TGF-B

54
Q

What do IL-10 and TGF-B do?

A

Anti-inflammatory

Suppress the immune response

55
Q

B cells have humoral immunity via what?

A

Antibodies

  • FAB region - binds to antigen
  • FC region - communicates with immune cells
56
Q

Immunoglobulin isotypes of B cells

A
Different heavy chains = different function 
IgM 
IgG
IgA
IgE
IgD
57
Q

What is IgM best at?

A

Activating complement

58
Q

What can IgG do?

A

Cross the placenta

59
Q

What happens to IgA?

A

It is contained in secretions

60
Q

Features of IgE

A

Parasitic infections

Allergy

61
Q

What are antibodies produced by?

A

B lymphocytes - plasma cells

62
Q

Antibody mediated immunity phases

A
  1. Lag phase
    - take a while for the specific immunity to kick in
  2. If re-exposed
    - Very quick and very high risk in IgG
63
Q

What is B activation done by?

A

T helper cells

64
Q

Functions of antibodies

A

Immune complex formation
Opsonisation
Activating the cascade complement
Antibody dependent cellular cytotoxicity (ADCC)

65
Q

What does antibody dependent cellular cytotoxicity do?

A

Binds to target cells and initiates a non-phagocytic cell mediated destruction

66
Q

Normal variation in immune function is seen in….

A

Pregnancy
Neonates
Elderly

67
Q

Differences in an elderly persons immune function

A
Thymic involution 
Fewer naïve T cells 
Reduced ability for T cell expansion 
Reduced B cell development and diversity 
- diminished response to vaccination 
More dependent on innate immunity
68
Q

Causes of secondary immune deficiency

A
Malnutrition 
- protein calorie malnutrition 
- zinc
- iron 
Trauma
Burns
HIV
DM
renal failure
asplenia 
malignancy 
Splenectomy
Drugs 
- immunosuppressive, antirheumatic, antiepileptic, glucocorticoids, ciclosporin
69
Q

Molecules of the innate immune system

A

Complement
Interferon
Cytokines
Acute phase reactant

70
Q

Receptors of the innate immune system

A

Pattern recognition receptors

  • toll like receptors
  • mannan-binding lectin
71
Q

Molecules of the adaptive immune system

A

Immunoglobulins

Cytokines

72
Q

Receptors of the adaptive immune system

A

TCR
BCR
MHC/HLA

73
Q

What does TCR stand for?

A

T cell receptor

74
Q

What does BCR stand for?

A

B cell receptor