Immunology

Question 1

What are key mediators and give an example?

Answer 1

Cells
Molecules
Eg. Histamine

Question 2

Define innate immune system

Answer 2

First line of defence

Question 3

Define adaptive immune system

Answer 3

Adapt as pathogens adapt

Question 4

What does the adaptive immune system involve?

Answer 4

Cellular cytotoxic cells
Humoral - antibody production

Question 5

What are examples of exterior defences?

Answer 5

Skin, mucous membranes, cilia secretions and tissue fluid

Question 6

What do phagocytes do ?

Answer 6

Engulf, internalise and destroy

Question 7

Where are phagocytes found?

Answer 7

In circulation and in tissue

Question 8

Give 4 examples of phagocytes

Answer 8

Monocytes
Neutrophils
Basophils
NK cells

Question 9

What do auxiliary cells do and give an example?

Answer 9

Attract leukocytes
Release mediators of inflammation

Platelets

Question 10

What do lymphocytes do?

Answer 10

Initiate the adaptive response

Question 11

Give 3 examples of lymphocytes

Answer 11

B cells
T cells
NK cells

Question 12

What are some roles of lymphocytes

Answer 12

Produce antibodies
Recognise foreign molecules
Kill infected cells

Question 13

What does PAMP stand for?

Answer 13

Pathogen associated molecular patterns

Question 14

What do cells recognise microbes through?

Answer 14

PAMP and opsonisation

Question 15

What is a PAMP

Answer 15

Sugar or lipid on the microbial surface vital to the bacterial wall

Question 16

What is opsonisation?

Answer 16

Process where pathogens are coated with opsonins making them recognisable to be engulfed

Question 17

What receptors recognise PAMP?

Answer 17

Scavenger receptor
Carbohydrates receptor
Toll like receptor

Question 18

Where are toll like receptors found?

Answer 18

On all phagocytic cells

Question 19

Explain the mechanism of phagocytosis

Answer 19

Microbes bind to phagocyte receptors

Phagocyte membrane zips up around microbe

Microbe ingested into phagosome

Phagosome lyses with lysosome

Degradative enzymes and reactive oxygen species in the lysosome break down the microbe

Question 20

What is a neutrophil

Answer 20

A phagocyte

Question 21

What do neutrophils do?

Answer 21

Engulf and destroy invading bacteria and then die.

Their dead bodies are the bulk of pus

Question 22

What do monocytes do?

Answer 22

Develop into macrophages

Phagocytose bacteria

Question 24

What is a cytokine?

Answer 24

Immunomodulating agent

Question 25

What does a cytokine do?

Answer 25

Signals molecules in cellular communication

Question 26

What does TNF do?

Answer 26

Attaches to receptors up regulating molecules on the surface of leukocytes Which makes the leukocytes sticky

Question 27

What is a complement?

Answer 27

Immune system defence central to the development of inflammatory reactions

Question 28

What does a complement do?

Answer 28

Amplifies inflammatory response Clearance of immune complexes Cellular activation Microbial killing Developing antibody responses

Question 29

What is the acute inflammatory response?

Answer 29

The complete removal of a pathogen Resolution of the damage Disappearance of leukocytes Full resolution of tissue function

Question 30

Name 2 pro inflammatory cytokines

Answer 30

TNF and IL-1

Question 31

What does TNF and IL1 do?

Answer 31

Increase production of complement Activate NK cells releasing IFN Which then activates macrophages

Question 32

What causes dendritic cells to mature?

Answer 32

Contact with bacteria which also increases the antigen presenting capability

Question 33

What do cytotoxic T cells do?

Answer 33

Eradicate virus or infected and tumour transformed cells

Question 34

What do helper T cells do?

Answer 34

Produce antibodies

Question 35

What do B cells do?

Answer 35

Differentiate into antibody producing plasma cells with correct stimulus from helper T cells

Question 36

What is MHC?

Answer 36

A complex that allows the body to differentiate between self and non self

Question 37

Which cells express MHC1

Answer 37

All nucleated cells

Question 38

What does MHC stand for?

Answer 38

Major histocompatability complex

Question 39

Which cells recognise antigens?

Answer 39

Lymphocytes B cells T cells Antibodies

Question 40

What does T cell activation cause?

Answer 40

Cytotoxicity Humoral response

Question 41

What is the Humoral response?

Answer 41

Antibody production from plasma cells which were derived from B cells

Question 42

What is cytotoxicity?

Answer 42

Cells that have the ability to kill specific cells

Question 43

What activates T cells?

Answer 43

MHC + antigen

Question 44

What cells have MHCII isoform?

Answer 44

Cells that phagocytose and digest

Question 45

What part of an antibody recognises antigens?

Answer 45

TCR and Fab fragments

Question 46

What happens when an antigen is recognised in the lymph?

Answer 46

T cells and B cells are activated

Question 47

What is an antigen?

Answer 47

Peptide sequence

Question 48

What do T helper cells and cytotoxic T killer cells have in common?

Answer 48

Have TCR Releases cytokines

Question 49

Name 3 characteristics of T helper cells

Answer 49

Have CD4 molecule Recognises MHCII Helps B cells and Tc cells

Question 50

Name 3 characteristics of cytotoxic T cells?

Answer 50

Have CD8 molecule Recognises MHCI Kills cells via enzyme action and apoptosis

Question 51

What happens when an antigen + MHCII is presented in the lymph?

Answer 51

T cell receptors and CD4 molecule bind to it The T helper cell becomes activated

Question 52

How does a B cell become primed?

Answer 52

By phagocytosing a pathogen through surface immunoglobulin receptors

Question 53

What does a T helper cell look for?

Answer 53

A B cell expressing the same antigen + MHCII complex

Question 54

What is the result of the interaction between T helper cells and B cells?

Answer 54

B cells differentiate into plasma cells that are capable of secreting antibodies of the same specificity as the immunoglobulin receptor

Question 55

How is a cytotoxic T cell primed?

Answer 55

By binding to a antigen presenting cell

Question 56

How does the T helper cell help the primed cytotoxic T cell?

Answer 56

The T helper cell releases cytokines IL6 and IFN which activate the cytotoxic cells

Question 57

Which cell are antibodies produced by?

Answer 57

B cells

Question 58

What are immunoglobulins?

Answer 58

Glycoproteins Membrane bound receptors on the surface of B cells Soluble molecules secreted by plasma cells

Question 59

What are the 2 functions of immunoglobulin?

Answer 59

Recognise the antigen Promote killing of the pathogen

Question 60

Name 5 antibodies

Answer 60

IgG IgA IgM IgD IgE

Question 61

What does Fc fragment bind to?

Answer 61

Leukocytes

Question 62

What does Fab fragment bind to?

Answer 62

Pathogen

Question 63

Outline the structure of IgG

Answer 63

4 chains 2 light chains bound to 2 heavy chains by disulphide bridges

Question 64

What does Fab stand for?

Answer 64

Fragment antigen binding

Question 65

What does Fc stand for?

Answer 65

Constant fragment

Question 66

Which antibody exists in the highest concentration?

Answer 66

IgG

Question 67

Which antibody exists in the lowest concentration?

Answer 67

IgD and IgE