Immunology

Question 1

Which cytokines have anti-viral activity?

Answer 1

Interferons

Question 2

Which cytokines control and direct cell migration?

Answer 2

Chemokines

Question 3

Which cells produce antibodies?

Answer 3

Antigen-activated B cells

Question 4

What lymphocytes have a regulatory effect on the immune system?

Answer 4

T helper cells

Question 5

Where are the complement proteins synthesised?

Answer 5

In the liver

Question 6

Where are monocytes found?

Answer 6

Circulating in the blood

Question 7

How do macrophages help to limit inflammation?

Answer 7

They secrete anti-inflammatory cytokines and are involve in tissue repair and wound healing.

Question 8

What is the half life of a neutrophil in the bloodstream?

Answer 8

6 hours

Question 9

Which cells phagocytose antigens and mature and migrate to secondary lymphoid tissues where they play a key role in antigen presentation?

Answer 9

Dendritic cells

Question 10

Name some primary lymphoid tissues.

Answer 10

Bone marrow

Thymus

Question 11

Name some secondary lymphoid tissues.

Answer 11

Spleen
Lymph nodes
Peyer’s patch

Question 12

What branch of the immune system is responsible for acute inflammation?

Answer 12

Innate

Question 13

What molecules are expressed by pathogens that allow macrophages, mast cells, NK cells and dendritic cells to recognise self from non-self?

Answer 13

PAMPs (pathogen associated molecular patterns)

Question 14

What receptors are expressed by innate immune cells, allowing them to bind to PAMPs?

Answer 14

PRR (Pattern recognition receptors)

Question 15

How do macrophages recognise apoptotic cells?

Answer 15

During apoptosis, cells flip certain intracellular membrane lipids to the cell surface.

Question 16

What anti-inflammatory cytokine is secreted by macrophages to limit host damage?

Answer 16

IL-10

Question 17

What cytokine is able to induce superactivation of macrophages?

Answer 17

IF gamma

Question 18

What abilities does a superactivated macrophage have?

Answer 18

Increased production of toxic oxygen and nitrogen species

Increased antigen presentation

Question 19

How do healthy cells inhibit NK cells?

Answer 19

Healthy cells express MHC 1 displaying a self peptide. The NK cell can bind to this ligand and is inhibited.

Question 20

Which cytokines activate NK cells?

Answer 20

IF alpha and IF beta

Question 21

Which pro-inflammatory cytokine is secreted by NK cells?

Answer 21

IF gamma

Question 22

What is the acute phase response?

Answer 22

Systemic response involving changed to the plasma concentrations of specific proteins in response to inflammation. Changes are due to altered protein synthesis in the liver.

Question 23

How many subunits does CRP have?

Answer 23

5

Question 24

Which cytokines stimulate the synthesis of CRP in the liver?

Answer 24

IL-6 and IL-1beta

Question 25

What is the role of CRP in the acute phase response?

Answer 25

Enhances phagocytosis and activates the complement system

Question 26

What inflammatory mediators are released by mast cells?

Answer 26

Histamine TNFalpha Leukotrienes Prostaglandins

Question 27

By what mechanisms can neutrophils eliminate pathogens?

Answer 27

Phagocytosis Degranulation Neutrophil Extracellular Traps (NETs)

Question 28

Why is pus yellow?

Answer 28

Due to the high iron content of neutrophils

Question 29

Describe the downstream events of the complement cascade in pathogen killing.

Answer 29

C3b cleaves C5 to C5a+C5b. C5b binds to pathogens. C6, 7, 8 and 9 assemble with C5b forming the membrane attack complex. It inserts into target cell walls causing osmotic lysis. (C5b, b for binding)

Question 30

What is opsonisation?

Answer 30

The coating of pathogens by humoral factors to facilitate phagocytosis.

Question 31

Which complement protein is an opsonin?

Answer 31

C3b

Question 32

Which complement proteins are known as anaphylatoxins that promote inflammation?

Answer 32

C3a and C5a (a for anaphylaxtoxins)

Question 33

Describe the nature of the response of the adaptive immune system.

Answer 33

Slow and specific to each antigen

Question 34

In which part of the lymph node are opsonised antigens trapped?

Answer 34

Stromal B cell zones

Question 35

Which MHC molecules present to CD8+ T cells?

Answer 35

MHC I

Question 36

Which MHC molecules present to CD4+ T cells?

Answer 36

MHC II

Question 37

Which cells express MHC II?

Answer 37

Professional antigen presenting cells e.g. dendritic cells, macrophages, B cells.

Question 38

Why do plasma cells have lots of ER?

Answer 38

To churn out antibodies

Question 39

Which Ig is the first produced during an immune response and responsible for activating B cells?

Answer 39

IgM

Question 40

Which Ig exists as a pentamer in the plasma and secretory fluids?

Answer 40

IgM

Question 41

Which Ig is most abundant in normal human serum?

Answer 41

IgG

Question 42

Which Ig is transported across the placenta into the foetal blood supply to offer foetal immune protection?

Answer 42

IgG

Question 43

What is the function of membrane bound IgD?

Answer 43

B cell activation

Question 44

Which Ig is transported in breast milk?

Answer 44

IgA

Question 45

What Ig is most important in mucosal immunity?

Answer 45

IgA

Question 46

Which Igs trigger allergic reactions?

Answer 46

IgE

Question 47

Which T cell cause superactivation of macrophages?

Answer 47

TH1

Question 48

Which T cells cause proliferation and differentiation of B cells?

Answer 48

TFH