E1 + 2 memory/ Bc

Question 1

what is the recall response of innate cells vs T/Bc

Answer 1

Innate - very fast. But NO recall response: same very time
B/Tc - slower: wks
recall response following rechallenge

Question 2

is the following quantitative or not

1. microscopy
2. flow cytometry

Answer 2

1. can be specific non quantitative
2. specific and quantitative
   - flow cytometry is destructive whereas FAS is not

Question 3

Give an example of how youd identify a cell species using flow cytometry

Answer 3

identifies specific cell population

e.g. Bc with cell surface protein: CD19 using synthesized Ab with covalent fluorophore

Question 4

what can flow cytometry ID

Also what does forward scatter and side scatter reveal

Answer 4

cell: size, phenotype, health & complexity

Forward scatter = size of cell
side scatter = granularity (structural complexity)

Question 5

Describe what would be the response to antigen upon

1. first exposure
2. second exposure

Answer 5

1. Primary: inital slow ‘lag phase’ then steady rise until reaches its plateau then falls
2. Secondary: must faster rise (peak) A more vigorous response

Question 6

For Bc what happens to the affinity after 2nd reponse

Answer 6

Bc affinity increases so does somatic hypermutation.

Question 7

1. what is the hallmark antibody of a primary reaction

2. what is seen in secondary response

Answer 7

1. IgM

2. small amounts of IgM, larger amounts of IgG, some IgA & IgE

Question 8

what does repeated exposure to antigen do to Bc memory Reponses

Answer 8

Increases the Bc Ab levels & increases Ab affinity.

- Mutation of genes which code for FAB (variable region) gets better and better

Question 9

define negative selection

- where does this occur in Bc

Answer 9

Immature Bc bound to self-cell-surface antigen is removed

Occurs in BM

Question 10

describe development of memory Bc

Answer 10

1. Bc precursor rearranges its Ig genes > generation of Bc receptors in BM
2. Negative selection in BM
3. Mature Bc bound to foreign antigen is activated > migration of Bc to peripheral lymphoid organs & activation
4. activated Bc give rise to plasma cells & memory cells> antibody secretion & memory cells in BM & lymphoid tissue.

Question 11

What is the marker for all Bc

what is CD27 required for

Answer 11

CD19+
CD27 — required for activation into plasma cells (Ab secretion)
CD27 — TNF receptor family – ligand = CD70