Immunology 4

Question 1

what’s the use for allelic exclusion

Answer 1

so b-cells can only express 1x functional Ig

Question 2

what fraction of B-cells won’t produce a functional Ig

Answer 2

2/3

Question 3

what controls allelic exclusion

Answer 3

RAG

Question 4

what chain is tried first in allelic exclusion

Answer 4

HC

Question 5

what’re the 3 ways self-reactive antigens are removed

Answer 5

1. clonal deletion
2. receptor editing
3. migrate the cell to the periphery

Question 6

which Igs diffuse more readily to blood

Answer 6

G,E,A

Question 7

describe IgM

Answer 7

1st produced
pentameter
blood infections
activate classical pathway

Question 8

describe IgD

Answer 8

co-expressed w. IgM

Question 9

describe IgG

Answer 9

activates complement system
Neutralisation
opsonisation

Question 10

which Igs can be transferred through breast milk

Answer 10

IgG, IgA

Question 11

describe IgE

Answer 11

against parasites
allergies
bind to mast cells

Question 12

describe IgA

Answer 12

principle Ig in secretions
neutralisation

Question 13

what’re the 2 options for B-cell activation

Answer 13

T-independant antigens
T-dependant antigens

Question 14

what’re the steps of T-independant antigens

Answer 14

activate b-cell without t-cell
2 signals
1. antigens bind to lots of BCR on b-cell surface simultaneously = cross-linkage
2. Antigen binds to TLR on on b-cell surface

Question 15

what’re the steps of T-dependant antigens

Answer 15

require 2 signals to be activated
SIGNAL 1
- antigen binds directly to B-cell
- B-cell engulfs antibody complex
- B-cell digests it -> peptide complex -> APC
- MHC II presentation
SIGNAL 2
- connate T-cell recognises APC
- activate transmem protein (CD40 + CD40L)-
- release interleukins (IL4-6) + cytokines

Question 16

what type of mutation is somatic hypermutation
- how often does this occur
- what controls it

Answer 16

point mutations
- 1:1.10-3
- AID

Question 17

what type of mutation is affinity maturation
- where does this occur
- what does it cause

Answer 17

point mutation
- in IgV regions
- changes in affinity

Question 18

what’s class switching

Answer 18

Ig in the same clone -> different antibody classes can be produced

Question 19

when would ELISA be used

Answer 19

• identifies protein
• conc
• in mixture

Question 20

when would SDS PAGE/immunoblotting be used

Answer 20

• identifies specific proteins
• size & quantities

Question 21

when would immunohistochemistry be used

Answer 21

• diagnostic technique

Question 22

when would flow cytometry/FACS be used

Answer 22

• fluorescently labelled
• in suspension/mixed sample