In fact, "two" specificities equates with four possible L + H chain
combinations, so the waste grows exponentionally.
Bob S.
John Richard Seavitt <jrseavit at artsci.wustl.edu> wrote:
>On Tue, 9 Dec 1997, Andrew Louka wrote:
>> Why one B cell, one specificity? Why not have multiple specificities per
>> B cell - surely this would have been more effective (and energy efficient!).
>Nope. Then you'd have B cells with two or more specific surface
>immunologlobins. Since the B cell couldn't distinquish which one it got
>activated through, it would presumably behave as if all of its receptor
>specificities had been activated. It would await T cell help,
>proliferate, and differentiate into plasma cells. Of course, it would now
>be spending the metabloic energy to produce two or more specific secreted
>antibodies.
>Of course, the odds that the appropriate antigens are present for more
>than one of the antibodies is low, and so the extra production is waste.
>John Seavitt
>P.S. The current setup also allows the use of allelic exclusion to select
>functional rearrangements in BCR genes, which would no longer be a
>possible strategy for a multispecificty B cell.
