Lecture 6 - B cell activation

Question 1

how many signals are there for B cell activation?

Answer 1

2

Question 2

signal 1 increases if there is lots of what present? (hint: complement)

Answer 2

C3b

Question 3

BCR associated peptides have …… motifs?

Answer 3

ITAMS

Question 4

the crosslinking of which receptors activates kinases?

Answer 4

BCRs

Question 5

which 3 molecules form the BCR co-complex?

Answer 5

CR2, CD19, CD81

Question 6

thymus independent antigens produce which Ig only?

Answer 6

IgM

Question 7

thymus independent antigens deliver signal 2 to B cells in one of 2 ways.

what are these 2 ways?

Answer 7

signal delivered from antigen itself

signal delivered from BCR cross linking

Question 8

do thymus dependent or thymus independent antigens give a better antibody response?

Answer 8

thymus dependent

Question 9

with thymus dependent antigens, what cell type is required for signal 2 to reach B cells?

Answer 9

CD4+ T cells

Question 10

thymus dependent antigens involve the …… ………. of antibodies?

Answer 10

class switching

Question 11

in B cell activation with thymus dependent antigens, B cells initially divide to become what?

Answer 11

centroblasts

Question 12

centroblasts (divided B cells) undergo what, leading to class switching of antibody isotypes?

Answer 12

somatic hypermutation

Question 13

somatic hypermutation involves which enzyme?

Answer 13

AID

Question 14

if a BCR does not bind to an antigen, and it has not become a non dividing centrocyte, what happens to it?

Answer 14

dies in lymphoid tissue

Question 15

in germinal centres, B cells have which 3 options?

Answer 15

differentiate into plasma cells

differentiate into memory cells

die

Question 16

which molecule, derived from T cells, helps to protect centrocytes?

Answer 16

CD40

Question 17

what happens in an individual who has a CD40 deficiency? which syndrome do they have?

Answer 17

hyper IgM syndrome = no class switching

Question 18

in the influenza B conjugate vaccine, a polysaccaride is coupled to a tetanus toxin which converts the antigens from what to what?

Answer 18

from thymus independent to thymus dependent

Question 19

could a polysaccaride act as a TI antigen?

Answer 19

yes

Question 20

could a polysaccaride act as a TD antigen?

Answer 20

no, it could act as a TI antigen

Question 21

which type of molecule can act as a TD antigen?

Answer 21

peptide/protein

Question 22

What is a centroblast and where is it found

What is a centrocyte and where is it found

Answer 22

centroblast - rapidly/actively dividing B cell, going through SHM and class switching, found in DARK GC zone. large

centrocyte - smaller, has finished dividing and is now undergoing neg or pos selection, found in GC LIGHT zone