Adaptive immunity

Question 1

Where are low levels of complement system proteins normally found

Answer 1

plasma
extracellular fluids

Question 2

Where can complement system proteins be activated

Answer 2

once in tissues

Question 3

What occurs once the complement system is activated

Answer 3

cascade of chemical reactions

Question 4

What can occur as result of the chemical of cascade reactions once the complement system is activated

Answer 4

Opsonisation of pathogens
direct pathogen killing
acute inflammation
leukocyte recruitment

Question 5

What leukocyte is commonly recruited in response to acute inflammation

Answer 5

neutrophil

Question 6

What is the inactive precursor of the complement system

Answer 6

C3

Question 7

What are the 3 methods of cleaving c3

Answer 7

classical pathway
MBL pathway
alternative pathway

Question 8

what is formed as result of cleaving c3

Answer 8

C3b and C3a

Question 9

Why is the MBL pathway at targeting bacterium

Answer 9

MBL binds to mannose which is not a self molecule, can only be found on bacteria

Question 10

What happens when MBL binds to mannose

Answer 10

produces another C3 converting enzyme which can result in activation of the alternative pathway

Question 11

What ensures that the amplification loop can only begin when pathogens are around

Answer 11

C3b is produced which is unstable
tissue cells have inhibitors and so loop can only be activated when pathogens around

Question 12

What happens when c3b binds to a pathogens surface

Answer 12

C5 is cleaved into C5b and C5a

Question 13

What is the function of C5b

Answer 13

Builds membrane attack complex (MAC) which punctures pathogen cells

Question 14

What is the function of C5a

Answer 14

promote inflammation

Question 15

What is the function of C3a

Answer 15

promote inflammation via mast cells of histamine

Question 16

What is responsible for activating the complement system

Answer 16

acute phase response in the liver

Question 17

Which adaptive immune cell is responsible for humoral immune responses

Answer 17

B cells

Question 18

Which adaptive immune cell is responsible for cellular immune responses

Answer 18

T cells

Question 19

Which adaptive immune cell is responsible for killing extracellular pathogens

Answer 19

B cells

Question 20

Which adaptive immune cell is responsible for defence against intracellular pathogens

Answer 20

T cells

Question 21

What are the 2 main types of T cell

Answer 21

CD4+
CD8+

Question 22

What is the main function of CD4+T cells

Answer 22

Key regulators of the immune system via cytokines

Question 23

what is the main function of CD8+T cells

Answer 23

kill virally infected body cells (the “muscle” of T cells)

Question 24

How do adaptive immune cells detect invading pathogens

Answer 24

recognise antigens via antigen receptors (specific)

Question 25

What are B cell receptors

Answer 25

antibodies

Question 26

What is the structure of a B cell receptor (BCR)

Answer 26

polypeptide chains 2 heavy chains 2 light chains unique variable region

Question 27

What are the 2 forms of antibody

Answer 27

membrane bound soluble

Question 28

What is the humoral immune response needed for

Answer 28

production of soluble antibodies

Question 29

What do B cell antibodies bind to

Answer 29

soluble antigens

Question 30

What do T cell receptors bind to

Answer 30

peptide antigens

Question 31

What does the T cell antigen receptor consist of

Answer 31

alpha chain beta chain

Question 32

What is needed for T cell receptors to bind to antigens

Answer 32

MHC molecules must present the antigen to the receptor

Question 33

What are the examples of soluble antigens B cell receptors can respond to

Answer 33

lipid antigen protein antigen carbohydrate antigens

Question 34

Which class of MHC presents antigens to CD8

Answer 34

MHC 1

Question 35

Which class of MHC present antigens to CD4

Answer 35

MHC 2

Question 36

Where is MHC 1 expressed

Answer 36

on all nucleated cells

Question 37

Where is MHC 2 expressed

Answer 37

only on professional antigen presenting cells (APCs) dendritic cells macrophages

Question 38

Where does the adaptive immune response occur

Answer 38

secondary lymphoid tissues

Question 39

How do T and B cells enter lymph nodes

Answer 39

high endothelial venue

Question 40

How do B cells encounter antigens

Answer 40

soluble antigens are released by phagocytes which drain through lymphatic vessels

Question 41

How do T cells encounter antigens

Answer 41

dendritic cells display peptides derived from pathogens on their surface

Question 42

Do dendritic cells express MHC 1 and MHC 2

Answer 42

yes

Question 43

When do T cells replicate

Answer 43

once antigen is bound