Introduction to Immunology

Question 1

What is the immune system and what does is do?

Answer 1

complex cellular and protein network

protects from pathogenic microbes and involved in tissue repair

Question 2

What is the function of the immune system?

Answer 2

identify and eliminate microorganism + danger signals
distinguish between self and non self
balance between responding to pathogens and collateral damage of host

Question 3

What does the host exert on the pathogen and vice versa?

Answer 3

selection pressure

Question 4

What kind of genes control the immune system? How are they selected for?

Answer 4

polymorphic/variable

exposure of the population to infectious diseases selects genes

Question 5

Name the 2 types of receptor

Answer 5

soluble molecule or on CSM

Question 6

Summarise the 2 basic strategies used my the immune system to recognise danger

Answer 6

Strategy 1

• recognise molecular patterns
• hundreds of receptors
• germ-line encoded
• 1 gene = 1 receptor protein

Strategy 2

• recognise precise structure
• millions of receptors
• generated by random recombination of gene segments in lymphocyte development

Question 7

What are the advantages and disadvantages of germ-line encoded response?

Answer 7

advantages - many cells express the same receptor allowing rapid effective response
disadvantages - limited diversity so some pathogens poorly recognised

Question 8

What are the advantages and disadvantages of random gene recombination response?

Answer 8

advantage - large diversity so all structure potentially recognised
disadvantage - very few cells express specific receptor so have to be expanded to produce response, diversity can cause autoimmunity

Question 9

Name the two triggers for Pattern Recognition Receptors (Strategy 1)

Answer 9

Pathogen-Associated Molecular Patterns

Damage-Associated Molecular Patterns

Question 10

How are DAMPs produced?

Answer 10

released by damaged cells

Question 11

Give some examples of PAMPs

Answer 11

LPS, flagellin, envelope glycoprotein

Question 12

Give some example of DAMPs

Answer 12

EC-ATP, nuclear cell components, hyalauron, aggrecan

Question 13

What does Strategy 2 use?

Answer 13

antigen specific receptors on lymphocytes

Question 14

Give characteristics of innate immunity

Answer 14

Uses germ-line strategy
independent of previous exposure
depends on pre-formed and rapidly synthesised components
rapid
limited specificity

Question 15

What does innate immunity do?

Answer 15

destroy invading nucleic acids in cytoplasm
activates inflammatory pathways
signals for immune cell recruitment to infection site
elicits type 1 interferons
allows adaptive immunity to start
directs appropriate response

Question 16

Give characteristics of adaptive immunity

Answer 16

uses random gene recombination strategy
acquired immunity
depends on clonal selection
slow
highly specific
forms memory 
requires priming

Question 17

What are the 2 effector arms of acquired immunity?

Answer 17

cellular - T/B lymphocytes

humoral - antibodies

Question 18

What are the cells of acquired immunity?

Answer 18

T/B lymphocytes

each subset had distinct CSM

Question 19

What are the cells of innate immunity?

Answer 19

neutrophils, macrophages ad eosinophils

Question 20

What are the soluble factors of acquired immunity?

Answer 20

antibodies and cytokines

Question 21

What are the soluble factors of innate immunity?

Answer 21

acute-phase proteins, complement, cytokines

Question 22

What cells are involved in both acquired and innate immunity?

Answer 22

basophils, dendritic cells, natural killer cells

Question 23

What is a naive lymphocyte?

Answer 23

lymphocyte the hasn’t recognised its antigen

Question 24

What are toll-like receptors?

Answer 24

transmembrane pattern recognition receptors

Question 25

What do toll-like receptors lead to?

Answer 25

production of interferon and cytokines