I hope someone out there can enlighten me a little with the following
problem:
My understanding of germinal centre development of B cells is that they
require a receptor mediated signal to induce bcl-2 expression and prevent
cell death, and that the ligand for that signal is antigen held in the
form of immune complexes on follicular dendritic cells. One consequence
of this requirement given that somatic mutation also occurs in germinal
centres, is the phenomenon of affinity maturation. My problem then is
that for a monovalent antigen in an Ig transgenic (needless to say
specific for that antigen), the epitope will be inaccessible on
FDC-associated antigen. In that case the developing B cells should die,
leading to a deficit in (i) affinity maturation (ii) memory B cells (iii)
plasma cells in such animals. Is this the case? Has anyone looked? Or
am I missing something obvious?
Paul Travers
ICRF Structural Molecular Biology Unit
Birkbeck College
London