Lecture 11 - B cell encounter with antigen for activation

Question 1

h

Question 2

h

Question 3

Germinal centre

Answer 3

Non-specific antibody - IgM

Question 4

B cells: how do they survive in the germinal centre?

Answer 4

Germinal centre B cells are prone to dying, they require antigen from follicular dendritic cells and T cell interactions (Tfh cells)

Question 5

g

Question 6

g

Question 7

IL-4: what antibodies are induced and which are inhibited by its presence?

Question 8

IL-5: what antibodies are induced and which are inhibited by its presence?

Question 9

IL-21: what antibodies are induced and which are inhibited by its presence?

Question 10

TGF-beta: what antibodies are induced and which are inhibited by its presence?

Question 11

INF-gamma: what antibodies are induced and which are inhibited by its presence?

Question 12

Class switching: what is it, how does it occur,

Answer 12

Rearranged V region of the heavy chain being placed in front of a different C region

Question 13

Antibody distribution: what is the standard method of transportation and what are some exceptions?

Answer 13

Diffusion

IgA - mucosal surfaces, IgA secreted as a dimer, binds to polymeric immunoglobulin receptor on overlying epithelial cells, transcytosis occurs

Question 14

IgM: when is it formed, what is its affinity (?), where is it mostly found, and what reaction is it best at causing?

Answer 14

First Ab formed

low affinity but higher overall avidity - good at binding multivalent antigens

Usually found in blood stream (large size pentamer)

Complement

Question 15

IgG: when is it formed, what is its affinity (?), where is it mostly found, and what reaction is it best at causing?

Answer 15

First Ab formed

low affinity but higher overall avidity - good at binding multivalent antigens

Usually found in blood stream (large size pentamer)

Complement

Question 16

IgA: when is it formed, what is its affinity (?), where is it mostly found, and what reaction is it best at causing?

Answer 16

First Ab formed

low affinity but higher overall avidity - good at binding multivalent antigens

Usually found in blood stream (large size pentamer)

Poor opsonin - weak activator of complement, neutralisation best

Question 17

IgE: when is it formed, what is its affinity (?), where is it mostly found, and what reaction is it best at causing?

Answer 17

First Ab formed

low affinity but higher overall avidity - good at binding multivalent antigens

Usually found in blood stream (large size pentamer)

Complement

Question 18

g

Question 19

g

Question 20

g

Question 21

g

Question 22

g

Question 23

Antivenins

Answer 23

Antivenin is antibodies made from another animal (usually a horse or sheep) that are injected into a dog after he is bitten by a venomous snake

Question 24

Neutralisation of antibodies: is it enough?

Answer 24

No, need to link to other effector mechanisms -