Genetics of antigen receptors Flashcards
Where is innate immunity encoded?
In the germline- inherited
What are the receptors of innate immunity and what do they recognise?
Pattern recognition receptors e.g. TLR. Recognise PAMPS and DAMPS.
How is adaptive immunity generated?
Somatically
Example of adaptive immunity receptors.
BCRs and TCRs
Explain clonal selection of lymphocytes.
Progenitor cells give rise to large numbers of naive circulating lymphocytes, each with a different specificity.
When a lymphocyte recognises an epitope in a dangerous context then this useful clone is expanded to combat the threat.
This also generates memory cells.
What two regions do BCRs and TCRs contain?
Complementary determining region and signal transfusing molecules.
What is the effector mechanism of BCR?
Recruited by FcR interactions of different soluble antibody isotypes.
What is the effector mechanism of TCR?
Mediated by cell-contact or local secretion of cytokines.
What do the highly variable and low variability regions on a Kabat and Wu plot translate to?
The loop is a highly variable region which is the antigen binding region on the structure.
The low variability region is the framework which is the complementarity determining region.
What are the two types of light chain?
Kappa or Lambda.
How is variability generated in the antigen binding region?
Lineage specific, developmentally regulated (series of checkpoints), somatic recombination of multiple gene segments.
What do V and J segments join to become?
V exon
Molecularly, how do B cells achieve different antigen binding sites?
They choose different V and J segments via gene rearrangement.
How does the heavy chain achieve its diversity?
It contains an extra type of gene segment called Diversity.
What is the V exon in a heavy chain composed of?
VDJ segments
