Lecture 6B - Specific Immunity - The Humoral Response (Antigens & Antibodies)

Question 1

What must be done to properly defend the body against attack by a major pathogen?

Answer 1

lymphocytes must be recruited and a specific immune response generates

Question 2

What is the specific immune system important for?

Answer 2

to defend us against pathogens that are not of the same chemical signatures of the tissues in our body

Question 3

What happens in autoimmune disease?

Answer 3

the immune system targets out own body tissues

Question 4

Is specific more internal or external?

Answer 4

internal

Question 5

What do we want our immune system to do?

Answer 5

specifically recognise the proteins and sugars which uniquely belong to pathogens like bacteria and parasites, while leaving our own vital proteins alone

Question 6

What did Von Behring find?

Answer 6

exposure of a guinea pig to a sublethal dose of diptheria toxin rendered them immune to subsequent dose that would normally be lethal

Question 7

What is transferring immunity?

Answer 7

serum from a previously exposed animal could also protect an unexposed animal from the fatal effects of the diptheria toxin

Question 8

How is the immunity specific?

Answer 8

it only protected against diptheria toxin but not against others

Question 9

What did Von Behring call the transferrable chemical agents which provided immunity?

Answer 9

antibodies

Question 10

How can specific immunity act externally?

Answer 10

eyes, gut, mouth, lungs, saliva, bladder, sex organs, maternal milk

Question 11

How can specific immunity act internally?

Answer 11

blood stream, kidney, liver, brain, heart and other body tissues

Question 12

What is specific immunity?

Answer 12

a specific response to particular antigens

Question 13

What are antigens?

Answer 13

substances recognised by the immune system as being ‘non-self’ and which provoke an immune response

Question 14

What are most antigenic?

Answer 14

irregular, proturburant domains of protein molecules

Question 15

What might a large polypeptide have?

Answer 15

several antigenic determinant sites - each of which can provoke an immune response

Question 16

Polysaccharides antigenic?

Answer 16

have a simpler structure than proteins and are less antigenic

Question 17

What do many successful parasitic organisms have?

Answer 17

surface proteins which are highly glycosylated

this helps to screen antigenic determinants on their surface proteins from the immune system

Question 18

Antigenicity of regular polymers and metal lattice structures?

Answer 18

very low antigenicity and are useful materials for implants

smoothness does not alert the immune system of their presence

Question 19

What often does not produce an immune response?

Answer 19

smooth domains

Question 20

What do parasites do to evade the immune system?

Answer 20

change the sugars on their cells

Question 21

MW of antigens?

Answer 21

usually large MW substances - proteins

Question 22

What is an epitope?

Answer 22

each separate antigenic determinant site on a molecule

Question 23

How can small molecules become antigenic?

Answer 23

after binding to large molecules (proteins)

such small molecules are called haptens

Question 24

What happens if a drug molecule binds to a white blood cell?

Answer 24

it makes a molecular shape the immune system has not seen before and an immune reaction will lead to lysis of the white blood cell

Question 25

What is anaphylactic shock?

Answer 25

a severe allergic reaction that occurs in susceptible individuals

Question 26

What are haptens a problem with?

Answer 26

drug treatment

Question 27

What does the specific immune response begin with?

Answer 27

the entry of an antigen into the body

Question 28

What happens when the immune system detects the antigen?

Answer 28

it recognises it as a species that is not part of the body this enables activation of the immune system

Question 29

What does activation of the immune system do?

Answer 29

amplifies the number of immune cells and antibodies specifically targeted against the antigen and eliminates it

Question 30

Humoral mediators of specific immunity?

Answer 30

antibody mediated immunity antibodies are DIRECTLY responsible for eliminated the antigen

Question 31

What do antibodies belong to?

Answer 31

the gamma globulin class of proteins called immunoglobulins -

Question 32

What are immunoglobulins?

Answer 32

the class of proteins which cause immunity of the animal to the toxin

Question 33

What is cell mediated immunity?

Answer 33

cells are ultimately responsible for eliminating the antigen, requires cell to cell contact to cause cell death

Question 34

What does humoral immunity involve?

Answer 34

antibodies circulating in the blood and lymph which can recognise foreign molecules

Question 35

How do antibodies work?

Answer 35

they do not kill cells directly, but can neutralise viruses and toxins or mark cells and parasites for destruction by phagocytic cells

Question 36

How can immunoglobulins target cells?

Answer 36

from some distance to be destroyed

Question 37

Classes of antibodies?

Answer 37

``` IgA IgD IgG IgE IgM ``` MADGE

Question 38

IgG?

Answer 38

most abundant antibody class in the blood and is also transferred across the placenta to give additional protection to unborn child binds toxins

Question 39

IgA?

Answer 39

secreted in saliva and mother breast milk to give protection when immune system is weak

Question 40

IgE?

Answer 40

can bind to trigger mast cells and basophils

Question 41

IgM?

Answer 41

associated with compliment activation and forms almost a snowflake structure with 5 of the Y shapes antibodies connecting to form a weak ring