B-cell activation

Question 1

How long is the life of a Bcell?

Answer 1

3-4 days. Must encounter an antigen

Question 2

Open repertoire

Answer 2

Any specificity

Question 3

Tolerance induction

Answer 3

Autoreactive B-cells are killed in the bone marrow

Question 4

Where are immune cells that are autoimmune filtered?

Answer 4

In the bone marrow

Question 5

Where is the self-tolerant repertoire?

Answer 5

Periphery

Question 6

What is the path of a B-cell?

Answer 6

Bone Marrow>Periphery>no antigen dies OR Specific Ag=long-lived memory B-cells

Question 7

What is the primary follicle?

Answer 7

Classroom

Follicular dendritic cells (FDC) show to B cells

Question 8

Secondary Follicle (germinal centre rxn)
What kinds of things happen here?

Answer 8

T-cell dependent
Ag is trapped by FDC
B cells proliferate
Affinity maturation
Bcells with low affinity die
Class switch recombination
Plasma cells and memory cells are produced

Question 9

Where are high affinity B-cells to a specific Ag produced?

Answer 9

Germinal centre

Question 10

Affinity maturation process

Answer 10

RANDOM process wherby the introduction of random nucelotide changes into the DNA of rearranged Ig variable

Question 11

What is hypermutation?

What is it mediated by? dependent on?

Answer 11

Random nucleotide changes

Mediated by AID and is Ag dependent

Question 12

Which B-cells are selected to survive?

Answer 12

High affinity

Question 13

How do low affinity B-cells die?

Answer 13

Apoptosis

Question 14

What are the 2 zones in the germinal centre?

Answer 14

Dark and light zone

Question 15

What happens in the dark zone?

Answer 15

dividing centroblasts

Question 16

Light zone

Answer 16

selection and maturation of centrocytes

Question 17

Hypermutation occurs in the dark zone because

Answer 17

it occurs in replication or dividing centroblasts