B cells and Antibodies

Question 1

What are the 2 types of antigen epitope

Answer 1

linear and conformational

Question 2

what are conformational epitopes

Answer 2

epitopes formed by amino acid residues not in linear sequence but spatially juxtaposed

Question 3

what are the secondary antibodies

Answer 3

IgG IgA IgE

Question 4

what is effective immunity

Answer 4

may get infected and transmit virus but no symptoms

Question 5

what is sterilising immunity

Answer 5

will not get infected or transmit virus

Question 6

how is antibody diversity generated

Answer 6

clonal selection
memory b cells
subclass switching
somatic mutations
allelic exclusion

Question 7

what is the clonal selection theory

Answer 7

antigens select appropriate antibody from existing pool

Question 8

how many potential antigen binding sites does IgM have

Answer 8

10

5 effective

Question 9

what is the first antibody made in response to infection

Answer 9

IgM

Question 10

what is IgM involved in

Answer 10

complement activation and bacteria/virus neutralisation

Question 11

what antibody can cross the placenta

Answer 11

IgG EXCEPT IgG2

Question 12

what type of IgA is mainly found in secretions

Answer 12

IgA2

Question 13

what is IgE involved in

Answer 13

worm infections and hypersensitivity

Question 14

how many aas are in the light chain of antibodies

Answer 14

212

Question 15

how many aas are in the heavy chain of antibodies

Answer 15

240

Question 16

what are the 6 mechanisms for the generation of antibody diversity

Answer 16

1. germ line V genes
2. V-J V-J-D recombination
3. n nucleotide addition
4. recombinational inaccuracies
5. somatic hypermutation
6. assorted heavy and light chains

Question 17

how does VJD junctional diversity occur

Answer 17

nucleotides are randomly deleted and inserted

- interrupts codons

Question 18

what is allelic exclusion

Answer 18

co expression of both maternal and paternal alleles are prevented

Question 19

when does antibody class switching occur?

Answer 19

around 28 days

Question 20

what region of the antibody changes in class switching

Answer 20

Fc

Question 21

what cytokines play a role in class switching

Answer 21

IL4 - IgG4 and IgE

IFNy - IgG2

Question 22

what is the mode of action of antibodies

Answer 22

direct neutralization
opsonisation of pathogen promotes ADCC
activation of complement - lysis

Question 23

what does ADCC stand for?

Answer 23

antibody dependent cellular cytotoxicity

Question 24

what is ADCC

Answer 24

antibody opsonized virus infection cells and cancer cells killed by CTL and NK cells

Question 25

what are the antibody producing B cells

Answer 25

plasmablasts, SLPCS, LLPCS, memory b cells

Question 26

what are plasmablasts

Answer 26

secrete low affinity antibodies - short lived, early

Question 27

what are SLPCs

Answer 27

short lived plasma cells that produce large amounts of both IgG and IgM antibody, survive for 2 weeks

Question 28

what are LLPCs

Answer 28

long lived plasma cells that enter a GC and produce antibody for months-years

Question 29

what are memory b cells

Answer 29

GC derived, class switched and hypermutated -lifelong immunity

Question 30

what is damaged/lost in severe COVID19

Answer 30

germinal centers

bcl6+ b cells and bcl6+ Tfh cells

Question 31

what brings about affinity maturation of antibody

Answer 31

somatic point mutations in V gene

Question 32

examples of subunit vaccines

Answer 32

covid novavax
hep b
HPV

Question 33

what are the mRNA vaccines for covid

Answer 33

moderna and pfizer

Question 34

what are the virus vector vaccines for covid

Answer 34

astrazeneca

Question 35

what is the HAMA effect against mabs

Answer 35

develops antibodies against mab

Question 36

what therapies are mabs used for

Answer 36

rheumatoid arthritis - against inflammatory cytokines