The Innate Immune system

Question 1

Why we need an immune reponse

Answer 1

prevent infection & cancer

remove dead or non-functioning components

Question 2

5 Pathogen classifications

Answer 2

Virus - hijacks host

Bacterium - prokaryote

Fungus - euaryote

Protozoal parasite - multiple hosts

Multicellular parasite - multiple life cycles

Question 3

Pathogen definition

Answer 3

disease causing microorganism

Question 4

What are the bodies physical barriers

Answer 4

Skin, Cilia, hair, mucosal surfaces, urine/tears (flushing), peristalsis

Question 5

How does the skin prevent disease

Answer 5

• Sebaceous glands make oils preventing life

- desquamation (skin sheading)

Question 6

How do mucosal surfaces prevent disease

mouth, lungs, GI tract ect

Answer 6

• Anti microbial proteins

- Protective gut bacteria that outcompete pathogens

Question 7

what immune cells are found in the GI tract

Answer 7

Laminar propria (villi like)

Question 8

Chemical defence examples

Answer 8

• lysozyme (saliva)
• Stomach acid
• urinary tract flushing
• mucus lining
• rapid pH change in body

Question 9

What is Flora?

Answer 9

various microorganisms that live in the body without causing disease

Question 10

what do Flora do

Answer 10

make it harder for other pathogens to reproduce

Question 11

What is the order of defence in the body

Answer 11

1st - skin/mucosal layers
2nd - innate immune system
3rd - adaptive immune system

Question 12

What are cytokines

Answer 12

cell signalling molecules (proteins)

Question 13

what are the 2 groups of cytokines

Answer 13

pro-inflammatory (IS activating)

anti-inflammatory (dampen IS)

Question 14

3 different types of cytokine

Answer 14

Interleukins

Interferons

chemkines

Question 15

what do interleukins do

Answer 15

target leukocytes allowing communication

Question 16

what do interferons do

Answer 16

prompt anti viral response

Question 17

what do chemokines do

Answer 17

mediate cellular chemotaxis

Question 18

can cytokines have different Reponses on different cells?

Answer 18

yes

Question 19

can cytokines work together to increase response

Answer 19

yes

Question 20

what do para, endo, autocrine cytokines do

Answer 20

para - act on other cells (most common)

auto - act on itself

endo - travel in blood to target

Question 21

what does C-reactive protein do?

Answer 21

Help innate immune cells recognise pathogens

activates complement system

Question 22

where is C-reactive protein produced

Answer 22

Liver

Question 23

what are the 3 pathways of the complement system

Answer 23

Lectin

classical

alternative

Question 24

what is the lectin pathway?

Answer 24

manos binding lectin binds to sugars on bacteria

Question 25

what is the classical pathway?

Answer 25

C1 binding to pathogen antibodies

Question 26

what is the alternative pathway?

Answer 26

Complement protein C3B binds to carbohydrate on bacteria

Question 27

what happens after a complement system pathway is activated

Answer 27

protein C3 is cleaved = C3a and C3b

Question 28

what does protein C3a do?

Answer 28

inflammation and mast cell activation Causes C5 to be cleaved

Question 29

what does protein C3b do?

Answer 29

opsonisation Causes C5 to be cleaved

Question 30

What does C5 produced when cleaved

Answer 30

C5a and C5b

Question 31

What is the innate immune system and what does it do

Answer 31

1st cellular line of defence non specific initiates inflammation

Question 32

what is a negative about the innate immune system

Answer 32

its reponse can damage surrounding tissue

Question 33

5 signs of inflammation

Answer 33

``` Heat Redness Swelling Pain Loss of function ```

Question 34

What causes inflammation?

Answer 34

mast cells

Question 35

what do mast cells do when activated

Answer 35

degranulate and kickstart the inflammatory response

Question 36

What happens local due to inflammation

Answer 36

vasodilation = ^ Blood flow endothelial cells activated - junctions broken (more permeable blood vessels - recruits more blood)

Question 37

What are neutrophils and what do they do?

Answer 37

most abundant immune cell, short lived, phagocyte, release antimicrobial products from granules

Question 38

what is phagocytosis (6 stages)

Answer 38

- recognition - engulfing - encasing (phagosome) - lysosomes fuse (phagolysosome) - bacteria is killed (antibacterial compounds) - component's released

Question 39

what is the respiratory burst?

Answer 39

NADPH converts 02 into superoxide Superoxide dismutates to hydrogen peroxide or hypochlorous acid (both acid and will kill pathogens)

Question 40

what is chemotaxis?

Answer 40

directed movement of a cell along a conc grad | migrate to site of infection) where conc is ^

Question 41

how are leukocyte recruited?

Answer 41

they bind to P/E selectin allowing them to detect chemokines they will look for a gap in the blood vessel to get through into tissue

Question 42

Other granulocytes & their targets

Answer 42

Basophils - rare, for allergies Eosinophil - anti parasitic

Question 43

what are nature killer cells and what do they do?

Answer 43

a lymphocytes cause cell death of 'stressed' cells (cancerous/infected) activate macrophages

Question 44

what does NK Perforin & Granzyme do?

Answer 44

Perforin forms a pore on the pathogen Granzyme goes through pore and kills the cell

Question 45

how does pathogen recognition system work?

Answer 45

Pattern recognition receptors - find common pathogen characteristics

Question 46

What PRR's bind to

Answer 46

Pathogen associated molecular patterns on pathogen surfaces

Question 47

what do toll-like receptors (PRR) do?

Answer 47

detect a variety of microorganism-derived molecular structures and active APC's to produce pro-inflammatory cytokines

Question 48

Pathogen associated molecular patterns (PAMPs) examples

Answer 48

``` lipoproteins Flagellin DNA RNA envelope proteins Sugars ```

Question 49

what is an antigen?

Answer 49

any protein not recognised by the immune system (not derived from host)

Question 50

what do antigen presenting cells (APC's) do?

Answer 50

internalise proteins during phagocytosis and process them with major histocompatibility II (MHC II) and then display them on the cell surface

Question 51

what are Macrophages (APC's) and what do they do

Answer 51

Monocyte-derived macrophages kill pathogens with phagocytosis or respiratory burst produce NO (vasodilator)

Question 52

What are dendritic cells?

Answer 52

phagocytes (& APC's) w/ dendrites | little arms

Question 53

what do dendritic cells do after internalising a pathogen

Answer 53

migrate to lymph nodes and activate components of the adaptive immune system

Question 54

what are lymph nodes

Answer 54

sites around the body contain lymphocytes that are waiting for an immune stimulus