immunity 1

Question 1

innate immune cells (8)

Answer 1

macrophage, natural killer, dendritic, neutrophil, eosinophil, basophil, t, natural killer t

Question 2

adaptive immune cells (5)

Answer 2

B, T, CD4+ t, CD8+ t, Natural killer t

Question 3

other components of innate immunity (5)

Answer 3

interferons, complement, chemokines, defensins, lysozymes

Question 4

other components of adaptive immunity (3)

Answer 4

interferons, interleukins, chemokines

Question 5

what does innate immunity respond to

Answer 5

chronic inflammation as a result of bacteria or virus

Question 6

what do interferons do

Answer 6

block virus replication

Question 7

what do defensins and lysozymes do

Answer 7

break down bacterial cell walls

Question 8

what does compliment do

Answer 8

actively lyses bacteria

Question 9

how long does the innate immune response take

Answer 9

6-12 hrs

Question 10

how long does adaptive immunity take

Answer 10

10-14 days in primary response

Question 11

pros of adaptive

Answer 11

very effective as it develops memory

Question 12

soluble factors of adaptive

Answer 12

antibodies and interferons

Question 13

soluble factors of innate

Answer 13

lysozyme, complement, acute phase proteins

Question 14

con of innate immune system

Answer 14

no memory

Question 15

complement summary

Answer 15

its a cascade of proteins which results in the activation of another complement component

Question 16

complement and opsonisation

Answer 16

some complement proteins bind covalently to bacteria to opsonise them for them to be engulfed by phagocytes with complement receptors

Question 17

complement proteins as chemoattractants

Answer 17

small fragments of complement proteins act as chemoattractants to recruit phagocytes so complement can be activated

Question 18

what do terminal complement components do

Answer 18

damage some bacteria by creating pores in the bacterial cell membrane - membrane attack complex (MAC)

Question 19

how does the complement cascade work

Answer 19

each component cleaves the next e.g. C1 cleaves C2

Question 20

3 ways that complement is activated

Answer 20

classical pathway, mannan binding lectin (MBL), Alternative pathway

Question 21

what happens when complement is activated

Answer 21

proteolytic cascade (C1-C5) is triggered which leads to the formation of the MAC (C6-C9) on the surface of the closest cell. this pore destabilises the membrane causing lysis of the cell

Question 22

what does the MAC do (membrane attack complex)

Answer 22

punches holes in the cell causing osmotic shock, swelling, lysis and death

Question 23

NK cells

Answer 23

large granular lymphocyte like cells, dont have antigen specific, programmed to kill all the time - when going around the body they are told not to kill by receptors by normal cells.

Question 24

what receptors do NK cells recognise

Answer 24

major histocompatibility complex (MHC)

Question 25

what do viruses do to MHC

Answer 25

down regulate it or switch it off, making NK cells target them as there are no more inhibitory receptors

Question 26

how are NK cells regulated

Answer 26

balance between activating and inhibitory receptors stops them becoming activated.

Question 27

what is known as the 'self' molecule

Answer 27

MHC

Question 28

tumour cells and MHC regulation

Answer 28

they evolve to down regulate MHC and so they are not recognised by immune cells but they maintain just enough MHC to turn NK cells off

Question 29

what are macrophages and what do they do

Answer 29

phagocytic cells that recognise common patterns on many pathogens (PAMPS) which are recognised by receptors on innate cells and stimulate a response like cytokine production and killing

Question 30

what are PAMPS

Answer 30

pathogen associated molecular patterns

Question 31

4 postulates of the clonal selection theory

Answer 31

1. each lymphocyte has a specific receptor 2. lymphocytes are activated when their receptor binds to a foreign molecule with high affinity 3. differentiated cells from the lymphocytes will have the same receptors as their parents 4. lymphocytes are negatively selected for things that do not recognise us

Question 32

2 types of lymphocytes

Answer 32

B cell and T cell

Question 33

similarities of B and T cells

Answer 33

both have antigen receptors

Question 34

differences of B and T cells

Answer 34

B cells have surface immunoglobulins and 2 identical antigen recognition sites, T cells have 1 recognition site and no surface immunoglobulins

Question 35

what do surface immunoglobulins do

Answer 35

recognise antigens

Question 36

what are the 2 components of t cell receptors

Answer 36

alpha and beta chains

Question 37

what do some variants of B cell receptors have that allow it to bind to plasma membranes

Answer 37

transmembrane domains

Question 38

what does T cell activation result in

Answer 38

production of cytokines and cell division for amplified response

Question 39

where are B cells produced

Answer 39

bone marrow

Question 40

where are T cells produced

Answer 40

Thymus

Question 41

where do circulating lymphocytes encounter antigens

Answer 41

peripheral lymphoid tissue

Question 42

what is an epitope

Answer 42

the specific region of an antigen that the receptor binds to

Question 43

what are naïve lymphocytes

Answer 43

when they have not encountered an antigen

Question 44

where is the only place where a naïve lymphocyte is activated

Answer 44

lymph nodes, NOT at site of infection

Question 45

what two signals are required for B cell activation

Answer 45

Signal 1 - antigen receptor binding and Signal 2 - activation of B cell by T cell

Question 46

what cells provide signal 2 for T cells

Answer 46

macrophages and dendritic cells

Question 47

what do B cells make

Answer 47

antibodies, different B cells make different antibodies

Question 48

antibody structure

Answer 48

2 chains - heavy and light, each made of a variable region and constant regions

Question 49

antibodies: light chain structure

Answer 49

one variable region and one constant region

Question 50

antibodies: heavy chain structure

Answer 50

1 variable region and 3 constant regions (hinge between Ch1 and Ch2)

Question 51

what are antibody isotypes

Answer 51

different types of antibodies that are produced - they have different properties

Question 52

When does a B cell change the class of the isotype of the antibody

Answer 52

when it encounters the antigen again

Question 53

What are the different isotypes of antibodies

Answer 53

IgA, IgM, IgG, IgD, IgE

Question 54

which isotypes of antibody are multimeric

Answer 54

IgA and IgM

Question 55

what is the J chain

Answer 55

in IgA, it links 2 constant regions together, it has a receptor that assists delivery to mucosal surfaces

Question 56

what does neutralisation do

Answer 56

prevent infection

Question 57

what does opsonisation do

Answer 57

clears the antigen

Question 58

what does complement activation do

Answer 58

kills directly