lecture 36

Question 1

what are the 5 classes of antibodies we need to know about

Answer 1

IgM, IgG, IgE, IgA and IgD

Question 2

what form is IgG in

Answer 2

monomeric

Question 3

please order the antibody classes in order of prevalence

Answer 3

IgG, IgA, IgM, IgE, IgD

Question 4

whats IgGs prevalence

Answer 4

most common antibody in the blood.

Question 5

whats the function of IgG

Answer 5

opsonisation and neutralisation. targets virus and bacteria

Question 6

what does passive immunity mean

Answer 6

Passing the antibodies onto the fetus is called passive immunity as the fetus doesn’t develop its own immune cells, it is instead passed on from the mother to their developing child.

Question 7

IgG is the only antibody to do

Answer 7

This is the only antibody that may cross the placenta as the fetus develops.

Question 8

how long does passive IgG stay in the body

Answer 8

It can stay presnt in the bloodstream for a long time after being given to us by mothers in placenta. The IgG from mother will stay in blood until the baby can develop its own immune system.

Question 9

what form is IgA present in in the blood and tissue

Answer 9

monomeric in the blood and dimeric in the mucosal tissue

Question 10

what are the monomers of IgA and IgM linked by

Answer 10

a J chain

Question 11

what are examples of mucosal tissue dimeric IgA is present in

Answer 11

Present in secretions such as tears, saliva, mucus, and breast milk

Question 12

function of IgA

Answer 12

Its most important function is the protection of our mucosal membranes.
This is also an example of passive immunity as the antibodies are passed onto the breastfeeding child through the breastfeeding of their mother.
targets bacteria and virus

Question 13

what antibodies do passive immunity

Answer 13

IgG and IgA

Question 14

what form is IgM present in

Answer 14

pentameric form

Question 15

whats cells are IgM presented on mainly

Answer 15

naive B cells

Question 16

what’s the first antibody produced after initial exposure to an antigen

Answer 16

IgM

Question 17

what is IgM good at

Answer 17

This is a good activator of the complement alternative pathway.
These are secreted at the start of the immune response so they are good activators of complement and thus good communicators between the stages of the innate and adaptive immune response.

Question 18

when on the cell surface IgM is in what form, when secreted they go to what form

Answer 18

IgM on their cell surface as monomer. When secreted it forms to be pentameric. In pentameric form its best antibody for activating complement, so early immune response.

Question 19

what form is IgE present in

Answer 19

monomer

Question 20

distribution of IgE

Answer 20

Present in blood
at low concentrations

Question 21

function of the IgE

Answer 21

These help to activate the mast cells
IgE evolved to protect us from multicellular parasites like worms
These are responsible for allergies. These activate mast cells which trigger parasite immunity. As the mast cells release the histamine. This histamine is whats also a part of an immune response.

Question 22

what form is IgD in

Answer 22

monomer

Question 23

what is IgD distribution

Answer 23

expressed on naive B cells

Question 24

function of IgD

Answer 24

Suspect that it works in coordination with IgM as an antigen receptor. but we dont know exactly.

Question 25

what type of cell is a B cell and where do they develop

Answer 25

lymphocytes being made in the bone marrow

Question 26

whats a plasma B cell and a memory B cell

Answer 26

Plasma cells are activated B cells that secrete antibody, Express antibody as BCR, but do not secrete antibody. instead responding rapidly on second antigen exposure

Question 27

what is native antigen and what does this mean for the antibodies

Answer 27

an antigen that is not yet processed by an APC to smaller parts. so B cell receptors can respond to any part of this whole unprocessed antigen.

Question 28

where do the B cells mature and be made

Answer 28

they are made and matured in the bone marrow, making sure they arent self reactive

Question 29

antibody is what as it has 2?

Answer 29

Antibody chain is bivalent as it has 2 Arms.

Question 30

describe structure of the antibody

Answer 30

There are two identical light chains and two identical heavy chains.

Question 31

clonal selection of the B cell occurs where

Answer 31

in the lymph nodes

Question 32

what links the antibody to the plasma membrane

Answer 32

transmembrane domains

Question 33

whats a naive b cell

Answer 33

A naive B cell is a B cell that has not been exposed to an antigen

Question 34

what changes in class switching and why

Answer 34

the constant region of the antibody changes as the variable BCR is kept the same so that the antigen responds to the same antigen but it functions different

Question 35

the B cell receptors on the B cell are

Answer 35

all identical in the antigen they detect

Question 36

what are the three main functions of an antibody

Answer 36

1:neutralisation 2:opsonisation 3: complement activation

Question 37

whats neutralisation and whats an example

Answer 37

For example, a toxin or virus that would bind to our cells can be blocked "neutralised" by antibodies. Neutralisation can also come in the example of antigen binding to the covid-19 coat protein and preventing it from binding to our cells.

Question 38

whats the constant region of the antibody

Answer 38

this is the part which is bound to the membrane and it does not come into contact with the antigen.

Question 39

whats the order of prevalence for antibodies

Answer 39

GAMED

Question 40

how are plasma B cells and memory b cells different

Answer 40

An activated B cell secretes antibodies and divides into plasma and memory cells. These are different to the plasma cells as they don’t secrete antibody, but they do still present BCR on the plasma membrane. So when these memory B-cells encounter antigen they will become plasma cells, which then do secrete antibodies which then aids in the immune response.

Question 41

how does a vaccine work

Answer 41

Vaccinating creates memory b cells in the body for next time it sees the pathogen. These memory B-cells can stay in the lymphatic tissue and blood for years. so next time the antigen is present the immune response is fast

Question 42

what antibody classes are secreted in primary and secondary immune responses

Answer 42

secondary: which in this time is mainly IgG. With some class switch to IgA and IgE primary: In this time there is a relatively low amount of antibody produced and it is mainly IgM.

Question 43

what are stimulation requirements for the B cells

Answer 43

cytokine secretion from CD4 and direct by the native antigen on the BCR

Question 44

heavy chain is linked to light chain by?

Answer 44

disulfide bridges