> Why doesn't the B-lymphocyt just proliferate, after it bound its antigene?
Thanks be to heaven it does not!!!
The B cell needs 2 (two) signals to go on with proliferation. The second
signal is usually delivered by T helper.
And how is
> the probability rised to an efficient amount, that an antigene
> specific B-lymphocyt (which has already bound its antigene and
> presents on its surface) meets the T-cells, specific for exactly the
> same antigene?
The probability of the two meeting is facilitated by cytokines,
chemokines, and the lymph nodes in which the events happen and trough
which there is a constant flow of the lymphocytes. Different lymphocytes
will migrate into the lymph node in which activated APC is awaiting the
company. Due to magnetic and gluing (??) properties of cytokines and
chemokines (released by activated APC and other cells which have been
activated BY APC) the lymphocytes - T and B - are trapped and since they
have nothing better to do - cooperate, recognize the antigen and respond
to it.
