notes 3 - b cells and antibodies

maturations of B cells

• what happens in the bone marrow:

  • where to b cells begin

  • what processes do they go through

  • where do b cells end as

• in the bone marrow b cells begin as early pro-b cells - here they go through receptor formation to develop into pro/pre-b cells - the pro-b cells go through the negative selection/ self tolerance selection process to develop into immature b cell

maturations of B cells

• what happens in the spleen:

• B-cells that move to the spleen are T1 cells

• T1 cells move transition to T2 cells, fully Mature B-cells

• Where do mature primary B cells migrate to?

• what do they express on the surface?

• what does the mature b cell recirculate between?

• what do they help respond to?

• what is the half life of a mature b cells?

• Mature, primary B cells migrate to the lymph nodes/lymphoid tissues

• Express high levels of IgM/IgD on their surfaces as BCR

• Recirculate between blood and lymphoid organs

• Help to respond to antigens with T-cell help by producing antibodies

• Half-life of approximately 4.5 months in periphery

why do b cells have to go through these maturation process?

• it needs to be able to respond to the pathogens (diverse) but also doesn’t attack itself (autoimmunity?)

• If an immature cell does not recognize/bind an antigen, it dies - why?

• where do nieve b cells circulate through and to?

• why does this increase the likelihood og encountering an antigen?

• Antigen recognition by mature B cells provides a survival signal

b-cells receptors

b cell receptor expression

allelic exclusion

Why would you want a B-cell that is only able to produce 1 antibody for 1 antigen?

b cell activation

• what does the activation of the b-cell involve and how is the response brought about ?

thymus-dependent (TD) antigen activation

• what are the steps for this process

thymus independent (TI) b-cell activation

• when antigens bind to BCR (b cell receptor) and PRR or other receptors is the response weaker or stronger?

• whats the difference between TI-1 and TI-2? give examples of each

• when antigens bind to BCR (b cell receptor) and PRR or other receptors the response weaker

b - cell proliferation

• what does b-cell activation results in

• after this result, which is activated by what and produces a clone of identical cells

*not stuck in the membrane

plasma cells

BCR / antibody structure

1. antibody structure (AB)

2. Fab VS Fc

3. antigen binding

   • idiotype vs isotype of antibody

   • avidity vs affinity of anitbody

why have both avidity and affinity?

diversity of antibodys

multiple gene segements

recombination

somatic hypermutation

recombination vs hypermutation