Humoral (II)

Question 1

Explain how antibodies are produced from the lymph nodes

Answer 1

Antigen comes into contact w BCR and activates B cells (complementary via clonal selection)

B cell differentiates and proliferates into memory B cells complementary/clones and also plasma cells which then secrete Bcr forming antibodies

Question 2

What are the disulfide bonds between

Answer 2

H-H and H-L chains

Question 3

How many variable VH and VL are there (antigen binding site)

Answer 3

2 of each (VL VH. VH VL)

Question 4

Which chains can be glycosylated

Answer 4

Heavy chains

Question 5

How many Constant light CL domains are there always

Answer 5

1

Question 6

Do domain number of CH differ between antigens

Answer 6

Yes, can be 3 or 4 CH domains

Question 7

What are domains

Answer 7

Folded globular units of proteins which can have functional units eg binding sites VL and VC

Question 8

How many amino acids make up globular unit domains on ig

Answer 8

110

Question 9

Which bond is present in domains

Answer 9

Disulfide bonds

Question 10

What makes up the VL and CL (Vl 1 Cl 1)

Answer 10

2 beta sheets (globular domains) joined together and intrachain joined via disulfide bonds

Question 11

Why are VL and VH antigen bs called HYPERVARIABLE sites

Answer 11

They have variable (HV) regions

Question 12

How many hyper variable regions are there at VH and VL which determine specificity for antigen

Answer 12

3 for VH and 3 for VL = 6 in antibodies all together

Question 13

Where are ig domains also found (not just in antibodies)

Answer 13

T cell receptors ( alpha and beta domains)

Mhc molecules

Cell adhesion molecules

Question 14

What are the 5 antibody isotypes

Answer 14

M A D G E

Mu, alpha , delta , gamma, epsilon

Question 15

What is an antibody isotype differentiation

Answer 15

The CH region only. The rest is same

Question 16

What are the 2 types of light chain called

Answer 16

Kappa and lamda

Question 17

What is antibody valency

Answer 17

Number of antibody valency / binding sites eg igm has 10 (it has 5 ig) most have 2

Question 18

What holds 5 ig together to form Igm

Answer 18

J chain

Question 19

Why isn’t Igm a problem for donation of blood

Answer 19

Can’t cross placenta

Question 20

Which ig is produced FIRST IN PRIMARY RESPONSE ALWAYS

Answer 20

Igm ( then branches off to others)

Question 21

How many domains does the mu / heavy chain on Igm have

Answer 21

5- 1 x VH

4 x CH

Question 22

Which antibody has high avidity

Answer 22

Igm

Question 23

How is Igm low affinity improved

Answer 23

Pre affinity maturation

Question 24

What is missing on an Igm

Answer 24

Hinge region between fab and fc

Question 25

What is Igm main function

Answer 25

C1q activation and opsonisation

Question 26

How many domains does igG have on its gamma Heavy chain

Answer 26

4- 1 x VH 3 x CH

Question 27

Which antibody is most prevalent in serum

Answer 27

IgG

Question 28

Which antibody is most likely in the secondary response (first is Igm)

Answer 28

IgG

Question 29

How many subtypes of IgG is there and why

Answer 29

4 They are produced at diff times, structure different and hinge is different

Question 30

How many IgG are needed for c1q activation

Answer 30

2

Question 31

How does IgG allow passive immunity

Answer 31

Can cross the placenta from mother

Question 32

How does iga travel different in serum than mucosa

Answer 32

Monomer in serum Joined by J chain to form a dimer in mucosal surfaces

Question 33

Which cells give iga a secretory component to get to mucosal sites

Answer 33

Epithelial cells

Question 34

How many domains does a chain have on iga

Answer 34

4 1 VH 3 CH

Question 35

Which subtype of iga is in serum and which in mucosa as a dimer

Answer 35

Iga 1 is serum Iga 2 dimer in mucosa

Question 36

How does iga dimer form protection on mucosal surfaces

Answer 36

Stops pathogen adhesion Neutralises toxins By binding and macrophages Stops commensals entering blood

Question 37

Where is iga predominant

Answer 37

In secretions such as milk

Question 38

Which 2 antibodies are lowest in serum

Answer 38

D and E (e lowest)

Question 39

Which 2 ig can be co expressed on Bcells as bcr together

Answer 39

Igm and igd

Question 40

What do igd stimulate basophils and mast cells to release

Answer 40

AMPs eg defensins

Question 41

How many domains does delta have

Answer 41

4 1 VH 3 CH

Question 42

How many domains does Ige have

Answer 42

5 | 4 CH like Igm does

Question 43

What is the most important job of ige

Answer 43

Bind to fc receptors on basophils and mast cells and cause histamine degranulation

Question 44

Why do antibodies ige cause anaphylaxis

Answer 44

Release of histamine causes circulatory shock

Question 45

Which area is there no Ig

Answer 45

Brain

Question 46

Which 2 are present in serum most (ecf)

Answer 46

IgG and igA monomer

Question 47

How can antibody switching occur from Igm to others

Answer 47

Dna cleavage of the constant heavy chain

Question 48

Are the different isotypes for constant heavy on different genes

Answer 48

Yes but same chromosome