E1 + 2 memory/ Bc Flashcards
what is the recall response of innate cells vs T/Bc
Innate - very fast. But NO recall response: same very time
B/Tc - slower: wks
recall response following rechallenge
is the following quantitative or not
- microscopy
- flow cytometry
- can be specific non quantitative
- specific and quantitative
- flow cytometry is destructive whereas FAS is not
Give an example of how youd identify a cell species using flow cytometry
identifies specific cell population
e.g. Bc with cell surface protein: CD19 using synthesized Ab with covalent fluorophore
what can flow cytometry ID
Also what does forward scatter and side scatter reveal
cell: size, phenotype, health & complexity
Forward scatter = size of cell
side scatter = granularity (structural complexity)
Describe what would be the response to antigen upon
- first exposure
- second exposure
- Primary: inital slow ‘lag phase’ then steady rise until reaches its plateau then falls
- Secondary: must faster rise (peak) A more vigorous response
For Bc what happens to the affinity after 2nd reponse
Bc affinity increases so does somatic hypermutation.
- what is the hallmark antibody of a primary reaction
2. what is seen in secondary response
- IgM
2. small amounts of IgM, larger amounts of IgG, some IgA & IgE
what does repeated exposure to antigen do to Bc memory Reponses
Increases the Bc Ab levels & increases Ab affinity.
- Mutation of genes which code for FAB (variable region) gets better and better
define negative selection
- where does this occur in Bc
Immature Bc bound to self-cell-surface antigen is removed
Occurs in BM
describe development of memory Bc
- Bc precursor rearranges its Ig genes > generation of Bc receptors in BM
- Negative selection in BM
- Mature Bc bound to foreign antigen is activated > migration of Bc to peripheral lymphoid organs & activation
- activated Bc give rise to plasma cells & memory cells> antibody secretion & memory cells in BM & lymphoid tissue.
What is the marker for all Bc
what is CD27 required for
CD19+
CD27 — required for activation into plasma cells (Ab secretion)
CD27 — TNF receptor family – ligand = CD70