Antigen Recognition in Adaptive Immune system

Question 1

What do B cells bind?

Answer 1

Can bind proteins, lipids, carbs

BCR binds DIRECTLY

Each BCR can bind two antigen

Question 2

What do T cells bind? and what do CD8 and CD4s do?

Answer 2

T cell receptor binds MHC:peptide (linear, 8-25 AA) on cell surface, induces changes in cell

CD8- kills virally infected cells

CD4- Activates macrophages to kill stuff and release cytokines

CD4- Bcell activation to pump out antibodies.

Question 3

Combinatorial vs Junctional diversity

Answer 3

Combinatorial- VDJ recombination
Junctional- add nucleotides in junctions

Both happen before antigens are bound in order to increase immunoglobulin repertoire