Immunology!

Question 1

What is danger in terms of immunology?

Answer 1

Anything that could cause damage to the organism

Question 2

What part of the physical defences would a wound or insect bite target?

Answer 2

The external epithelia

Question 3

Where in the body are the mucosal surfaces found?

Answer 3

The airway, the gastrointestinal tract and the reproductive tracts

Question 4

What do cells have embedded in their membranes that recognise types of pathogens?

Answer 4

Pattern recognition receptors - extremely diverse

Question 5

What is a function of the lymph nodes?

Answer 5

A point in a network at which pathways intersect.

Question 6

Describe red blood cells: How many are in the blood roughly? How many are made roughly per second? How long do they live for? What do they transport?

Answer 6

Roughly 5-6 x10^6 red blood cells in the blood, with 2x106 being made per second. They live for 110 days and transport CO2 and O2

Question 7

What is a complement in terms of the immune response?

Answer 7

A cascade of proteins activated by antibodies which amplifies the inflammatory response. This has the ability to directly kill pathogens or attract immune cells.

Question 8

Describe Neutrophils: Relative abundance, effect on pathogens, how they are recruited and lifespan.

Answer 8

They are the most abundant type of white blood cell. They are active phagocytic cells which can consume and kill pathogens. They are recruited by inflammation and live for a short time.

Question 9

describe Macrophages: Where do they develop, effect on pathogens, activated by, and lifespan.

Answer 9

They develop in tissues from precursors. They are active phagocytic cells which can consume and kill pathogens. They are recruited by inflammation and are long lived.

Question 10

Describe dendritic cells: Where do they develop, effect on pathogens, migration patterns, part played in the lymphatic system.

Answer 10

They develop in tissues from precursors. They are active phagocytic cells. They migrate out of peripheral tissues and carry proteins to the lymph nodes. This activates the adaptive immune response

Question 11

What is the antigen/epitope?

Answer 11

The broken-down part of peptide chains - helps with specificity of the pathogen

Question 12

What is a special function of B and T cells? What is the specific name for these?

Answer 12

They can specifically recognise antigens via specialised surface receptors. They are called B and T cell receptors.

Question 13

How do T cells collectively recognise different forms of antigens?

Answer 13

They recognise processed antigen presented on MHC molecules on the surface of antigen presenting cells

Question 14

What do CD4 T cells respond to?

Answer 14

Longer peptides in MHC class 2 molecules

Question 15

What do CD8 T cells recognise?

Answer 15

short peptides in MHC class 1 molecules

Question 16

Where are adaptive immune cells generated?

Answer 16

Thymus and Bone marrow

Question 17

Where are the adaptive immune cells activated from?

Answer 17

Lymph nodes and spleen

Question 18

What are the three stages of the adaptive immune response?

Answer 18

T cell activation –> T cell differentiation –> T cell effector stage

Question 19

True or false: There is an information transfer from the pathogens to the adaptive immune cells to the innate cells?

Answer 19

False - the information is transferred to the adaptive cells by the innate cells, not the other way around.

Question 20

Describe IgM in terms of avidity and affinity

Answer 20

Low affinity and a high avidity

Question 21

Define avidity

Answer 21

The cumulative binding strength of an antibody

Question 22

Describe IgG in terms of abundance

Answer 22

IgG is the most abundant type of B cell in the serum

Question 23

What is IgE involved in?

Answer 23

The allergy and anti worm responses

Question 24

Where is IgA found?

Answer 24

They are found at mucosal sites

Question 25

How can antibodies protect the host?

Answer 25

Neutralise the pathogen, activate the complement to enhance the immune system, enhance phagocytosis by binding to receptors on phagocytes.

Question 26

What types of cells express MHCII molecules?

Answer 26

Professional antigen presenting cells i.e. B cells.

Question 27

What cells express MHCI molecules?

Answer 27

All nucleated cells

Question 28

What does it mean if a cell is said to be cytotoxic?

Answer 28

It kills the cells at the site of infection, normally by triggering apoptosis

Question 29

What does immunological memory enable?

Answer 29

The rapid control of pathogens met previously

Question 30

What is variolation?

Answer 30

The deliberate exposure to controlled amount of infectious agent to induce infection and subsequent immunity

Question 31

The eradication of which disease is described as “the single greatest health intervention in history”?

Answer 31

Smallpox

Question 32

In relation to vaccines, what is attenuation?

Answer 32

The methods to prepare weakened versions of infectious agents as vaccines

Question 33

What are some problems when developing vaccines against intracellular pathogens?

Answer 33

1. You need to grow large amounts of the pathogen 2. You must figure out how to attenuate the pathogen 3. Figure out how to test the vaccine’s efficacy

Question 34

How can you create a “killed” vaccine?

Answer 34

Use chemicals to heat or kill the organism. The antigens from the dead organism can still induce immunity

Question 35

How can you create a “subunit” vaccine?

Answer 35

Isolate antigens from the virus and then the antibodies to those antigens can protect against infection

Question 36

Name one example of a memory cell vs a naive lymphocyte

Answer 36

Memory = B cells Naive = CD4 & CD8 T cells

Question 37

What are two defining features of CD4 & CD8 T cells in terms of immune response?

Answer 37

They have lower activation thresholds and better effector functions

Question 38

What are three defining features of B cells in terms of immune response?

Answer 38

They produce more Ab, produce higher affinity Ab, and work better with IgG and IgA molecules in terms of effector functions.