In article <4lkidc$1go at vixen.cso.uiuc.edu>, <afong at uiuc.edu> wrote:
>What are some mechanisms of immunodominance? I know that CD4+ T cells can
>exhibit immunodominance of peptide determinants, but just curious into
>the probable mechanisms.
This is one of those areas that is not well understood, but there are several
theories, any or all wich might contribute to immunodominance.
1) The antigen-processing machinery favors the generation of certain peptides
(and as a variation, for Class I anyway, the peptide transport mechanism
favors the import of certain peptides into the ER), so these are presented
as dominant epitopes.
2) Under the conditions in the cell, some peptides bind better to the MHC than
others, so these are dominant (however, in many cases, subdominant, and even
cryptic, epitopes bind at least as well in vitro).
3) "Holes in the repertoire" (that is, the lack of TCR's that can bind certain
epitopes) determine which epitopes are dominant (this is probably very
limited, since one can often elicit a response against subdominant and
cryptic epitopes if they are introduced as peptides, rather than in the
context of whole protein).
Ken Frauwirth (MiSTie #33025) _ _
frauwirt at mendel.berkeley.edu |_) * |/ (_ |\ |
http://mendel.berkeley.edu/~frauwirt/HomePage/ |_) | () |\ (_ | \|
DNRC Title: Chairman of Joint Commission on In-duh-vidual Affairs