In article <1995Sep1.212404.1 at cc.newcastle.edu.au>,
<mdcabl at cc.newcastle.edu.au> wrote:
>Hi all,
>>I had this question come up in journal club and didn't have clue how to answer
>it. I can't find anything in medline but that doesn't mean much. The question
>was: after TCR engagement of the MHC/peptide, how do the APC and T cell let go?
>And, which cell "gets" the peptide. It was speculated that either the TCR or
>MHC gets cleaved, maybe both... In which case, the molecules might become
>soluble? Anybody have an idea or want to speculate?
>
My understanding of this interaction is that the TCR/MHC binding affinity is
relatively low (esp. compared to antibody/antigen), so normal intercellular
forces are sufficient to separate the two. Almost certainly the peptide
stays with the MHC molecule. As far as cleavage, I don't know for the TCR,
but at least MHC class II molecules are highly resistant to proteolysis, as
one might expect for a molecule that has to survive the endosomal/lysosomal
pathway.
Hope that helps,
BioKen
--
Ken Frauwirth (MiSTie #33025) _ _
frauwirt at mendel.berkeley.edu |_) * |/ (_ |\ |
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DNRC Title: Chairman of Joint Commission on In-duh-vidual Affairs