ok, previous posts:
>: i dont think that you mean to say that an idiotype is a linear peptide
>: at all. in fact i _know_ you dont mean to say that. as my mentor always
>: says:>>> "ralph, antibodys and tcells cant read" and that is what you seem
>: to be saying......and this is not what jerne was talking about.
>: idiotypes/idiotypic networks are there to regulate levels of antigen
>: receptors. this includes tcrs to tcr peptides as well as antibodies to
>: antibodies and tcrs. use medline to look up almost any marchalonis et al.,
>: or nov-dec 1994 pnas lake et al., to see some recent network theory, ect.
>B cells process and present their immunoglobulins, much as they process
>and present all self proteins that are synthesized in the cytoplasm.
yes, but we are talking about an idiotype, not a linear peptide, again see
anything about canonicle structures.
>In
>the course of doing so, they will generate peptides that are derived from
>the region that comprises their B cell idiotype,
this can happen in tcells and bcells, and if the cause of autoimmunity, can
sometimes be referred to as determinant spreading, see eli sircarz (sp?) for
some of his det spread refs. it is impossible for an idiotope to be
presented, but a linear epitope of that idiotope _may_ be presented. you
must read these canonicle structure papers. what you are referring to is
the processing and presentation of an _epitope_, such as in the case of our
work, natural human autoantibodies, may be frame work1 peptides, etc- never
the whole idiotype. again, b cells cannot read.
snip, irrelv
>By the way, T cells also process and present their idiotypes, and it has
>been proposed that their is an idiotype network of T cells based upon
>recognition of idiotypes presented by T cells. If I am not mistaken,
>this is felt to be the mechanism of protection against experimental
>allergic encephalomyelitis by immunization with anti-myelin basic protein
>T cell clones (anti-ergotypic T cells or something like this).
this is a specific response against a _family_ of tcrs, eg VB8.2 family, not
the idiotype. tolerance is induced against the family of vb's. probably
against the cdr's or frwks.
>So once again I ask, How do T cells distinguish foreign antigens from
>idiotypes presented by B cells? Why should the former activate and the
>latter not?
i still think you may be missing the process of presentation and activation.
these things see shapes and determinants, not letters of aa's. this is
subclass of immunology that has literature abounding. i will try and find
the canonicle structure papers refs for you.
regards, ralph
Ralph M. Bernstein
Dept of Micro/Immuno
University of Arizona
Ph: 602 626 2585
Fx: 602 626 2100
