In article <786232945snz at immunol.demon.co.uk>,
Philip Dore <Philip at immunol.demon.co.uk> wrote:
>I am an immunologist who does not belive in networks.
>However the reason is different. For a significant antibody response to occur
>it is essential that T cells are activated. This is required for the B cells
>to mature and differentiate into plasma cells. T cells see antigens in a
>significantly different way, they require antigens to be degraded to small chunks
>of about 10 amino acids and these are presented to T cells bound to the major
>histocompatability complex. Therefore they have a distinctly differing antigen
>recognition profile to B cells. Any antibody response is unlikely to generate a
>T cell response unless the variable region contained amino acid sequences which
>T cells recognised as foreign. Since T cells are "educated" in an environment
>where there are vast amounts of antibodies the likelihood of significant reaction
>is low.
I have suggested before that although there is lots of antibody circulating,
it is unlikely that there is very much of any *single* idiotype excepte
during an actual immune response. Therefore, unless the T cells are educated
during the infection, there is probably not enough antibody to induce
deletion of idiotype-specific T cells. Furthermore, I'm pretty sure (although
I'd have to hunt for the reference) that anti-idiotype antibodies have been
detected during a normal immune response (*not* immunization with Ab's).
Finally, we know that B cells are constantly developing in the bone marrow.
It is certainly possible for a T cell to react with an antibody that did not
exist when the T cell was selected.
BioKen
--
Ken Frauwirth (MiSTie #33025) _ _
frauwirt at mendel.berkeley.edu |_) * |/ (_ |\ |
Dept. of Molec. & Cell Bio. |_) | () |\ (_ | \|
Univ. of Cal., Berkeley Push the button...someone :(
