Jorg,
You may not be Dr. Kirberg yet, but you certainly deserve your Ph.D,
judging by the erudition of your response!
Rather than argue back and forth, perhaps I should ask you,
What experiment could I or someone else do that would convince you that B
cells cannot activate naive T cells?
If the immune system can discriminate self from nonself and B cells are
capable of activating naive T cells, how do T cells distinguish peptides
from foreign antigens (nonself) from the identical peptide that is
present in a B cell idiotype (self)?
I believe that this second question is what drove Jerne to formulate a
network theory of the immune response (although he wasn't dealing with T
cells at the time). Either that or it drove him to drink.
But, as Mel Cohn has accurately stated, a self-regulating idiotypic
network is impossible because there is no mechanism to ensure that an
id-antigen interaction can be uniquely inductive whereas an id-anti-id
interaction is uniquely suppressive.
If you can provide me a cogent, testable answer to my second question
(about distinguishing idiotypes from foreign antigens), then I will
concede the possibility that B cells can activate naive T cells.
Ephraim Fuchs
ejf at welchlink.welch.jhu.edu