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Biomedicine (Semester II) > 15. Immune System > Flashcards

15. Immune System Flashcards

1
Q

What is the immune system?

A

A versatile defence system that protects us from pathogenic microbes

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2
Q

What are the layers of the defence strategy?

A
  1. First line - innate immunity
  2. Second line - innate immunity
  3. Third line - specific/adaptive immunity
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3
Q

What is the first line of defence - innate immunity?

A

Physical barrier created by the skin and mucous membranes

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4
Q

What is the second line of defence - innate immunity?

A

Non-specific immune response that includes some immune cells, proteins, fever and inflammation

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5
Q

What is the third line of defence - specific/adaptive immunity?

A

Activated by the innate immune system, producing a response towards a specific pathogen

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6
Q

What is a pathogen?

A

An infectious agent that can cause disease in a host

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7
Q

How can pathogens enter the body?

A 
Breaks in the skin
Respiratory system
Digestive system
Reproductive system (male and female)
Eyes
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8
Q

What is an antigen?

A

A substance that can be recognised by leukocytes

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9
Q

What are the two types of antigen?

A
  1. Foreign antigens

2. Self-antigens

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10
Q

What are foreign antigens?

A

Microbes
Food
Drugs

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11
Q

What are self-antigens?

A

Found on cell membranes

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12
Q

What do antigens usually consist of?

A

Proteins (specific 3D shape)

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13
Q

What are antibodies?

A

Proteins produced in response to a specific antigen

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14
Q

What do antibodies and the specific antigens do?

A

Combine

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15
Q

What makes the skin a first line of defence against pathogens?

A

Made up of layers of tightly packed epithelial cells

Outer epidermis - consists of dead epithelial cells which sheds every 40 days to remove microbes

Dermis - contains accessory structures such as sebaceous glands and sweat glands

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16
Q

How does sweat perform an immune function?

A

Removes microbes from skin

Contains IgA

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17
Q

How does sebum perform an immune function?

A

Contains fatty acids which inhibit microbial growth

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18
Q

Where can mucous membranes be found?

A

Digestive tract
Respiratory tract
Urogenital tract
Conjunctiva

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19
Q

What is the function of mucous membranes?

A

Prevent entry into the membrane

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20
Q

How do the mucous membranes perform an immune function?

A

Mucous traps microbes and foreign particles
Saliva, tears and mucous secretions wash away the trapped microbes
They also contain anti-microbial substances

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21
Q

How does the immune function work in the respiratory tract?

A

Mucocillary escalator

Cilia propel any foreign substances towards the pharynx where they are swallowed or coughed up

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22
Q

How do tears and saliva perform an immune function?

A

Contain IgA and lyzozymes

Lyzozymes are enzymes that break down bacterial cell walls

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23
Q

How does the nose perform an immune function?

A

Hairs in the nose filter air

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24
Q

How does the vagina perform an immune function?

A

In menstruating women, vagina is acidic making it unfavourable for microbes

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25
Q

How does gastric acid perform an immune function?

A

Acidity destroys many bacteria

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26
Q

How do microflora perform an immune function?

A

Outcompete pathogens for attachment sites on epithelial cell surfaces (e.g. GALT)

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27
Q

How does the excretion of urine and faeces perform an immune function?

A

Both expel microbes

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28
Q

How does vomiting and diarrhoea perform an immune function?

A

Both rapid means of expelling pathogens

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29
Q

When does the second line of defence get activated?

A

When pathogens penetrate the physical and chemical barriers of the skin and mucous membranes

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30
Q

What does the second line of defence consist of?

A 
Transferrins
Complement system
Phagocytes
Natural killer cells
Inflammation
Cytokines
Fever
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31
Q

What are transferrins?

A

Iron-binding proteins in blood

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32
Q

How do transferrins work?

A

Inhibit the growth of certain bacteria by reducing the amount of available iron

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33
Q

Why are transferrins necessary?

A

Without transferrins, bacteria would use the iron available for their growth

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34
Q

What is the complement system?

A

Secondary defence system made up of over 30 proteins produced by the liver

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35
Q

How are complement proteins identified?

A

By a letter (mostly C) and a number e.g. C3

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36
Q

How does a complement protein start out?

A

Inactive

Only become active when split by enzymes into active fragments e.g. C3 = C3a and C3b

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37
Q

What happens when a complement protein is activated

A

Acts in a cascade

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38
Q

What is the most common mechanism through which complement proteins are activated?

A

Classical pathway

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39
Q

What is the ‘classical pathway’?

A

Where antigens and antibodies join together

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40
Q

What is the role of complement proteins?

A
  1. Promoting phagocytosis
  2. Contributing to inflammation
  3. Causing cytolysis
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41
Q

How do complement proteins promote phagocytosis?

A

The fragment C3b coats a microbe in a process called opsonisation
This promotes the attachment of a phagocyte to a microbe

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42
Q

How do complement proteins contribute to inflammation?

A

C3a and C5a bind to mast cells and cause them to release histamine

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43
Q

How do complement proteins cause cytolysis?

A

The final complement proteins join together and create a hole in the foreign cell
The hole fills with tissue fluid and makes the cell swell and rupture

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44
Q

What are cytokines?

A

Small protein hormones that stimulate or inhibit normal cell functions
Mediate the connection between the innate immune system and the adaptive immune system

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45
Q

What are cytokines secreted by?

A

Leukocytes

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46
Q

What are the types of cytokines?

A

Interleukins
Interferons
Tumour necrosis factor

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47
Q

What are interleukins?

A

Mostly produced by T-helper cells

Mediators between leukocytes

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48
Q

What are interferons?

A

Anti-viral proteins produced by cells that are infected by a virus

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49
Q

What is tumour necrosis factor?

A

Promotes the accumulation of neutrophils and macrophages to an area
Causes cell death

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50
Q

How do interferons work?

A

They diffuse to uninfected neighbouring cells and induce synthesis of anti-viral proteins that interfere with viral replication

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51
Q

Do interferons stop a virus attaching to it?

A

No but they prevent the virus from replicating

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52
Q

What do phagocytes do?

A

They perform phagocytosis - cell digestion - of anything they don’t recognise

Non-selective

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53
Q

How do phagocytes work?

A

They attach to sites of inflammation by chemotaxis

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54
Q

What is chemotaxis?

A

Directed migration of a cell in response to a chemical stimulus

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55
Q

What are the two major types of phagocyte?

A

Neutrophils

Macrophages

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56
Q

What do neutrophils do?

A

First to migrate to a scene of inflammation
Like neighbourhood watch
Try to mop up the day to day problems

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57
Q

What do macrophages do?

A

They follow the neutrophils and eat up the remnants of whatever needs to be broken down and digested

They engulf and digest the pathogen, excrete some of the waste and display the rest on the cell membrane to present to T-lymphocytes

Like the police coming to the scene of a crime

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58
Q

Where can macrophages be found?

A

In tissue

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59
Q

Where can monocytes be found?

A

In blood

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60
Q

What do monocytes do?

A

Migrate to the site of infection and enlarge to form wandering macrophages

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61
Q

What do fixed macrophages do?

A

Stand guard in specific tissues

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62
Q

In which tissues can fixed macrophages be found?

A

Histiocytes (connective tissue macrophages)
Kupffer cells - liver
Microglia - nervous tissue
Alveolar - lungs
Langerhans cells - skin
Tissue macrophages - spleen, bone marrow, lymph nodes

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63
Q

What are the stages of phagocytosis?

A
  1. Chemotaxis - release of chemicals by leukocytes, damaged tissue and activated complement that attract phagocytes
  2. Adherence - attachment of phagocyte to target - aided by complement
  3. Ingestion - cell membrane extends to engulf the microbe
  4. Digestion - ingested structure merges with lysozymes to be digested
  5. Excretion - ingested material is excreted
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64
Q

What are natural killer cells?

A

Non-specific lymphocytes

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65
Q

What percentage of lymphocytes do natural killer cells make up?

A

5-10%

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66
Q

Where can natural killer cells be found?

A

Blood
Lymph nodes
Spleen
Bone marrow

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67
Q

How do natural killer cells work?

A

They attack anything that they don’t recognise including abnormal body cells e.g. cancerous cells

They bind to a target cell and release granules containing the protein perforin

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68
Q

What does perforin do?

A

It inserts into the cell membrane and creates a channel for tissue fluid to flow into the cell - cytolysis

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69
Q

What is inflammation?

A

A non-specific defensive response to tissue damage

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70
Q

What can inflammation be caused by?

A 
Pathogens
Abrasions
Chemicals
Cell distortion/disturbance
Extreme temperatures
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71
Q

What response does inflammation create?

A

Non-specific

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72
Q

What are the cardinal signs of inflammation?

A 
Redness
Heat
Pain
Swelling
Loss of function
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73
Q

What are the stages of inflammation?

A
  1. Vasodilation and increased permeability
  2. Emigration of phagocytes
  3. Tissue repair
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74
Q

How does vasodilation help inflammation?

A

Allows additional blood, oxygen, nutrients, immune cells to get to the area
Toxins and dead cells are removed

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75
Q

How does increased permeability help inflammation?

A

Permits the movement of immune cells, defensive proteins (antibodies) and clotting factors into the tissue

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76
Q

How do vasodilation and increased permeability work together to help inflammation?

A

Together they create redness, swelling and heat

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77
Q

What is the pain of inflammation a result of?

A

Injury to neurons and toxic chemicals released by microbes

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78
Q

What happens when phagocytes migrate to an area?

A
  1. Phagocytes migrate to the scene (via chemotaxis)
  2. Neutrophils stick to the endothelium during vasodilation and squeeze through the vessel wall to reach the damaged area
  3. Monocytes quickly follow and transform into wandering macrophages
  4. Dead phagocytes accumulate pus
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79
Q

What are the types of inflammatory mediators?

A

Histamine
Leukotrienes
Kinins
Prostaglandins

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80
Q

What is histamine and its function?

A

Released by mast cells and basophils

Causes vasodilation and increased permeability

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81
Q

What are leukotrienes and their function?

A

Released by basophils and mast cells

They attract phagocytes and increase permeability

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82
Q

What are kinins and their function?

A

Proteins
Causes vasodilation and increased permeability
Also attract phagocytes and induce pain

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83
Q

What are prostaglandins and their function?

A

Lipids released by damaged cells

Enhance effects of histamine and kinins (intensifying the pain)

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84
Q

What are the benefits of inflammation?

A

Promotes phagocytosis through increased temperature
Promotes immune response via vasodilation/permeability
Dilutes toxins
Fibrin formation - isolates affected area and helps bind wound edges

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85
Q

What are the harmful effects of inflammation?

A

Swelling - dangerous if in cranium
Pain - can become chronic
Adhesions and scar tissue
Atherosclerosis

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86
Q

What are the outcomes of inflammation?

A

Resolution
Chronic inflammation
Granuloma
Fibrosis

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87
Q

What is chronic inflammation?

A

If the injury-causing agent persists
Can cause chronic pain
Prevalence of macrophages, plasma cells and lymphocytes

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88
Q

What is granuloma?

A

Cellular attempt to contain a foreign body through aggregation of macrophages surrounded by lymphocytes

89
Q

What is fibrosis?

A

Formation of scar tissue
Formed by the secretion of collagen by fibroblasts
Occurs as a result of chronic inflammation

90
Q

What is a fever?

A

An abnormally high body temperature

91
Q

Why does a fever occur?

A

Because the hypothalamus thermostat resets

92
Q

When is a fever most likely to occur?

A

In infection and inflammation

93
Q

What happens pathophysiologically during a fever?

A

Bacterial toxins elevate body temperature which triggers release of fever-causing cytokines e.g. interleukin-1

94
Q

What is the key function of interleukin-1?

A

To induce fever

95
Q

What does an elevated body temperature do?

A

Makes interferons more effective
Inhibits growth of some microbes
Speeds up the reactions that aid repair

96
Q

What can be granular or agranular?

A

Leukocytes

97
Q

Which leukocytes are classed as granular?

A

Basophils
Eosinophils
Neutrophils

98
Q

Where can you find basophils?

A

In blood

99
Q

Where can you find mast cells?

A

In tissue

100
Q

What do basophils and mast cells do?

A

Release histamine and heparin
Release leukotrienes
Express receptors for IgE

101
Q

What does histamine do?

A

Causes vasodilation

Increases vessel permeability

102
Q

What does heparin do?

A

Anti-coagulant

103
Q

What do eosinophils do?

A

Destroy parasitic worms via phagocytosis

Play a role in inflammation (central in asthma)

104
Q

What do neutrophils do?

A

Phagocytic cell

Granules release lysozymes that digest debris

105
Q

Which is the most abundant leukocyte?

A

Neutrophils (60%)

106
Q

Which leukocytes are classed as agranular?

A

Monocytes/macrophages
Natural killer cells
B and T lymphocytes

107
Q

Where can you find monocytes?

A

In blood

108
Q

Where can you find macrophages?

A

In tissue

109
Q

What do monocytes/macrophages do?

A

Phagocytic

Secrete cytokines e.g. IL-1 and TNF

110
Q

What do natural killer cells do?

A

Target foreign cells

Secrete perforin to induce cytosis

111
Q

What are B and T lymphocytes?

A

Effector cells of the adaptive (specific) immunity

112
Q

Which leukocytes are phagocytic?

A

Neutrophils

Monocytes/macrophages

113
Q

Name the different types of T-lymphocytes

A

Cytotoxic T-cells
Helper T-cells
Memory T-cells
Regulatory T-cells

114
Q

What do helper T-cells do?

A

Co-ordinate the immune response (head office of FBI)

115
Q

What do cytotoxic T-cells do?

A

Immune cells out in the field

116
Q

What do memory T-cells do?

A

Create a memory of a pathogen after they’ve been exposed to it

117
Q

What do regulatory T-cells do?

A

Turn off the immune response when it’s finished to avoid excessive reactions

118
Q

Where are T-cells produced/mature?

A

Produced in bone marrow

Mature in the thymus

119
Q

Name the different types of B-lymphocytes

A

Plasma cells

Memory B-cells

120
Q

Where are B-cells produced/mature?

A

In red bone marrow

121
Q

Where do T-cells and B-cells function?

A

In the 3rd line of defence

Adaptive (specific) immunity

122
Q

How do T-cells and B-cells know how to respond to foreign antigens?

A

Through learning

They usually can tell the difference between self and non-self antigens

123
Q

Which sort of pathogens do T-cells and B-cells go after?

A

Specific ones

124
Q

How do T-cells and B-cells know which antigens they’ve met before?

A

Through immune memory

125
Q

What does immune memory allow T-cells and B-cells to do?

A

Produce a quicker and more effective attack next time they encounter the pathogen

126
Q

When is the 3rd line of defence activated?

A

When the 1st and 2nd lines fail to destroy the pathogen

Otherwise they are resting

127
Q

What are major histocompatibility complexes?

A

Group of proteins on cell surface that are used by the immune system to recognise cells that are self cells vs non-self

128
Q

What are MHCs formed from?

A

4 polypeptide chains

129
Q

How do MHCs work?

A

They display a protein (a self-antigen) produced by the cell on its binding groove

130
Q

How do MHCs help T-cells?

A

By presenting foreign antigens to T-cells

131
Q

Name the two types of MHC

A

Class I Major Histocompatibility Complex (MHC-I)

Class II Major Histocompatibility Complex (MHC-II)

132
Q

Where can you find MHC-I?

A

On all body cells except erythrocytes

133
Q

How do MHC-I work?

A

When body cell is cancerous or invaded by pathogen, the cell starts to produce abnormal proteins

These proteins are combined with MHC-I and displayed on the cell membrane

Flags up to (mostly) cytotoxic T-cells as a non-self antigen

134
Q

Where can you find MHC-II?

A

Only on the cell membrane of ‘antigen presenting cells’ - macrophages and B-lymphocytes

135
Q

How do MHC-II work?

A

The MHC-II displays the foreign antigen on its binding groove, having ingested the foreign cell

136
Q

What are MHC-II specifically used for?

A

Communication between themselves and T-helper cells

They present the antigen to the T-helper cells as part of antigen presentation

137
Q

How does an antigen become associated with MHC-i or II

A

By the route it’s trafficked through the cell

138
Q

Which type of immunity do T-cells play a central part in?

A

Cell-mediated immunity

139
Q

What is unique about T-cells?

A

Each has a unique T-cell receptor (TCR) that only recognises a specific antigen

140
Q

What are T-helper cells also known as?

A

CD4 cells

because they express the CD4 protein on their surface

141
Q

What are cytotoxic T-cells also known as?

A

CD8 cells

142
Q

To function properly, which traits should T-cells have?

A

Self-recognition - to recognise self antigens

Self-tolerance - must lack reactivity to fragments of self antigens

143
Q

What does a lack of self-tolerance lead to?

A

Autoimmunity

144
Q

How are T-cells tested?

A

Against epithelial cells in thymus

Should be able to recognise self antigens

145
Q

What happens to T-cells if they don’t recognise self antigens?

A

They undergo apoptosis

146
Q

What percentage of T-cells make it through the maturing process?

A

1-5%

147
Q

What is adaptive immunity?

A

Ability of the body to defend itself against specific foreign cells

148
Q

What is adaptive immunity characterised by?

A

Specificity for particular foreign antigens

Production of immune memory

149
Q

What are the two types of adaptive immunity?

A

Cell-mediated

Antibody-mediated

150
Q

What is cell-mediated immunity?

A

Driven by T-cells
Cytotoxic T-cells directly attack specific invading antigens
Mostly against intracellular pathogens

151
Q

What is antibody-mediated immunity?

A

Driven by B-cells
B-cells transform into plasma cells, which synthesise and secrete specific antibodies (Igs)
Mostly against extracellular pathogens

152
Q

Which cells are antigen-presenting cells?

A

Macrophages

B-cells

153
Q

What happens during antigen presentation?

A
  1. Antigen presenting cells break down the antigen into fragments (using lysozymes)
  2. Some fragments are combined with MHC-II molecules on their cell membrane
  3. They migrate into lymphatic tissue where they present the antigen to T-helper cells
  4. Antigen fragment binds with the T-helper cell
  5. T-helper cell secretes a cytokine called interleukin-2
  6. Interleukin-2 causes the T-helper cell to undergo clonal selection
154
Q

What happens during clonal selection of T-cells?

A

Division and proliferation of activated T-cells

155
Q

What does the process of T-cell clonal selection produce?

A
  1. Cytotoxic T-cells that bind to target cell and destroy it using granzymes and perforin
  2. Memory T-cells - these are inactive but will recognise the antigen in the future if it appears again
  3. Helper T-cells that release cytokines which increase the activity of immune cells such as T, B and NK cells
156
Q

What do granzymes do during T-cell clonal selection?

A

Break down the foreign cell

157
Q

What does perforin do during T-cell clonal selection?

A

Burst the foreign cell

158
Q

Why are regulatory T-cells important?

A

Without them the body would continue to fight off a disease that no longer exists and could end up fighting its own cells

159
Q

What happens during antibody mediated immunity?

A
  1. Antigen binds to specific B-cell receptors
  2. It’s taken into the cell and broken down into fragments
  3. Fragments are expressed on the MHC-II
  4. Helper T-cells recognise the antigen complex on the B-cell membrane and stimulate it by releasing IL-2 which triggers B-cell clonal selection
160
Q

What types of cell does B-cell clonal selection produce?

A

Plasma cells - secrete antibodies into blood, short lived

Memory B-cells - remain inactive until next immune reaction, long lived

161
Q

Which group of glycoproteins do antibodies belong to?

A

Globulins/immunoglobulins

162
Q

How are antibodies structured?

A

4 polypeptide chains - 2 heavy, 2 light
Variable region for each type of antibody
2 antigen binding sites

163
Q

What do antibodies combine with?

A

The antigen that triggered their production

164
Q

What does the combining of an antibody with an antigen produce?

A

Antibody-antigen immune complex

165
Q

How to antibodies inactivate antigens?

A
  1. Neutralising
  2. Immobilising
  3. Agglutinating and precipitating
  4. Activating complement
  5. Enhancing phagocytosis
166
Q

What happens when antibodies neutralise an antigen?

A

Neutralises bacterial toxins or prevent viral attachment to cells

167
Q

What happens when antibodies immobilise an antigen?

A

Binds to it on bacterial cilia or flagellae

168
Q

What happens when antibodies agglutinate and precipitate an antigen?

A

Antibodies use both of their binding sites to cause a dumping of cells

169
Q

What happens when antibodies activate a complement?

A

Antigen-antibody complexes activate the complement cascade

170
Q

What happens when antibodies enhance phagocytosis?

A

Antibody acts as a flag to attract phagocytes and aids phagocytosis via agglutination and complement

171
Q

What are the 4 different types of antibodies?

A

IgG
IgA
IgM
IgE

172
Q

IgG - location, how common, function?

A 
Blood, lymph, intestines
Most abundant (80%)
Protects against bacteria
173
Q

IgA - location, how common, function?

A

Sweat, tears, saliva, breast milk
10%
Localised protection of mucous membranes
Decreases with stress

174
Q

IgM - location, how common, function?

A

Blood, lymph
10%
Early immune response

175
Q

IgE - location, how common, function?

A

Blood
0.1%
Allergic reactions
Binds to mast cells

176
Q

What happens during the primary response of immunological memory?

A

Slow response
Antibodies start to appear after several days
Slow rise in IgM, followed by IgE

177
Q

What happens during the secondary response of immunological memory?

A

Faster response as a full immune response has been developed in the memory cells
Usually so quick, the pathogen is killed off before any signs and symptoms present

178
Q

How do vaccinations help the immune system?

A

With immunological memory against the disease the vaccination covered

179
Q

What do vaccinations contain?

A

Weakened, whole or partially-killed portions of microbes

180
Q

What happens after a vaccination is given?

A

B and T-cells are activated in a primary response

Can take several days

181
Q

In what 4 ways can you acquire immunity?

A
  1. Naturally acquired active immunity
  2. Naturally acquired passive immunity
  3. Artificially acquired active immunity
  4. Artificially acquired passive immunity
182
Q

What is naturally acquired active immunity?

A

Natural exposure to a disease

183
Q

What is naturally acquired passive immunity?

A

Transfer of IgG antibodies across the placenta from mother to child
Transfer of IgA antibodies from mother to child via breast milk

184
Q

What is artificially acquired active immunity?

A

Vaccination

185
Q

What is artificially acquired passive immunity?

A

Injection with immunoglobulins e.g. snake anti-venom

186
Q

What cells can be found in GALT?

A

Macrophages

B and T-cells

187
Q

Where can GALT be found?

A

Tonsils
Oesophagus
Small intestine
Large intestine

188
Q

What is a hypersensitivity reaction?

A

An excessive immune response produced by the normal immune system

189
Q

What are the 4 types of hypersensitivity?

A

Type I, II and III - antibody mediated

Type IV - cell mediated

190
Q

What is Type I hypersensitivity?

A

An allergy

191
Q

What is a Type I hypersensitivity mediated by?

A

IgE antibodies that bind to mast cells

Causes degranulation

192
Q

What are the 2 types of type I hypersensitivity reactions?

A

Systemic e.g. anaphylaxis

Localised e.g. hay fever, eczema, irritant contact dermatitis

193
Q

How soon is there a Type I hypersensitivity response?

A

Immediate - within minutes of exposure

194
Q

What is Type II hypersensitivity?

A

Blood transfusion reactions

Haemolytic disease of the newborn

195
Q

What is a Type II hypersensitivity mediated by?

A

IgG antibodies which bind to antigen and activate the complement system

196
Q

How soon is there a Type II hypersensitivity response?

A

Rapid onset

197
Q

What is a Type III hypersensitivity mediated by?

A

IgG
IgA
IgM antibodies

198
Q

How soon is there a Type III hypersensitivity response?

A

Within 4-8 hours

199
Q

In which pathologies does a Type III hypersensitivity reaction occur?

A

RA
Systemic lupus erythematosus (SLE)
Glomerulonephritis

200
Q

What happens in a Type III hypersensitivity reaction?

A

Antibody-antigen complexes form and deposit in capillaries, skin, kidneys, joints etc triggering an immune response
They activate the complement system

201
Q

What is a Type IV hypersensitivity mediated by?

A

Cells

202
Q

What happens in a Type IV hypersensitivity reaction?

A

Overreaction of T-cells to an antigen

Large numbers of cytotoxic T-cells activated and cytokines released that can damage normal tissue

203
Q

How soon is there a Type IV hypersensitivity response?

A

48-72 hours

204
Q

What is an allergy?

A

A powerful immune response to an allergen

205
Q

What is an allergen?

A

An antigen that generates allergy

Usually harmless

206
Q

How does an immune response towards an allergy develop?

A
  1. Initial exposure causes sensitisation
    Slow response as not many cells have learnt how to respond yet to that antigen
  2. Subsequent exposure has a much quicker response
    The full immune response has been developed and antibodies are readily available
207
Q

How does the body prepare for an allergen response?

A

Body produces IgE specially for that antigen (B-cell):

  1. Plasma cells activated
  2. Antibodies produced targeting that specific antigen - one side binds to the antigen, the other side to the mast cell
208
Q

What are the symptoms of an allergy?

A

Runny nose
Streaming eyes
Anaphylaxis

209
Q

What percentage of adults are affected by a food allergy?

A

2%

210
Q

What percentage of children are affected by a food allergy?

A

6%

211
Q

What is a food allergy?

A

An IgE-mediated immune response

212
Q

How is food intolerance different to an allergy?

A

Food intolerance doesn’t have a defined immune response

213
Q

What is a food intolerance?

A

Symptoms triggered by eating a quantity of food and lacking the enzymes/probiotics/bile/HCI and other digestive factors needed to deal with the food

214
Q

What is missing if a person is lactose intolerant?

A

The enzyme lactase

215
Q

What is anaphylactic shock?

A

Severe, systemic, allergic response to an allergen exposure

216
Q

How soon can anaphylactic shock appear?

A

Within 5-10 mins

217
Q

What happens in the body to create anaphylactic shock?

A
  1. Exposure to allergen causes IgE to activate mast cells and basophils
  2. Histamine is released
  3. Causes bronchoconstriction, vasodilation and oedema of tissue
218
Q

Why is anaphylactic shock dangerous?

A

Can cause occlusion of the airways

219
Q

What is the treatment for anaphylactic shock?

A

EpiPen (Epinephrine)

Biomedicine (Semester II) (20 decks)

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