Antibody production Flashcards
Where are B cells made?
In the bone marrow
What makes antibodies?
Plasma cells which differentiate from B cells
Draw B cell development
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What are the two signals required for B cells to be activated?
- recognition by the antigen specific membrane Ig molecule.
- signal from an interacting CD4+ T cell= T cell dependent activation.
Why is the T cell signal necessary for activation?
T cells can help B cells be more specific.
How does the B cell interact with the T cell?
-When the B cell binds antigen and becomes activated it internalises the whole complex.
-The B cell can make MHCII molecules.
-The B cell processes the antigen and presents it on its surface in an MHCII molecule.
If a CD4 Tfh cell recognises this then it sends a second signal to the B cell.
-Proliferation of the antigen specific B cells-clonal expansion- and differentiation.
-Some of the B cells become plasma cells secreting IgM
-Some undergo class switching where they make new classes of antibody.
What are the signals which cause the proliferation and differentiation of B cells?
- co-stimulatory molecules e.g CD154 or CD40
- cytokines
What happens in the centroblasts?
B cells are actively proliferating
What is affinity maturation?
Process where high affinity antibody is made.
How are only high affinity antibodies selected?
If they bind antigen with high affinity then they receive a survival signal- if not they die.
What happens during class switching?
B cell is able to change its heavy chain constant region from IgM to IgG or IgE or IgA whilst keeping the same heavy chain variable and light chain.
What is class switching controlled by?
CD4 T helper cells and cytokines.
What do cytokines influence?
Production of different antibody classes.
How much antibody is made.
