prions and immune response

[Jorg Kirberg]

In article <Pine.SOL.3.91.950522095331.9799A-100000 at asrr.arsusda.gov>,
tdiener at ASRR.ARSUSDA.GOV (ncel) wrote:

> On 21 May 1995, Ian A. York wrote:
> 
> > In article <Pine.SOL.3.91.950520202417.1834A-100000 at asrr.arsusda.gov>
tdiener at ASRR.ARSUSDA.GOV (ncel) writes:
> > 
> > >Good question! It has been an old enigma why none of the prion diseases 
> > >elicit an immune response from their hosts (or fever for that matter). 
> > 
> > Am I correct in recalling that the prion protein is highly resistant to 
> > proteases?  If so, since T cells respond to proteolytic fragments, 
> > perhaps there's no opportunity to go through the antigen presentation 
> > route.  
> > 
> > Ian
> 
> PrPSc is only partially resistant to proteases (high conc. or long 
> incubation will degrade it). PrPC is not resistant. I am not an 
> immunologist; thus, somebody else better answer your question. Ted

I am not an virologist, please excuse all mistakes in this direction.
Antibody responses need T and B cells (at least those that are interesting,
meaning of high affinity).
It there would be on the changed prion an epitope 'foreign' enough for
B cells, T cells would still not be able to help the B cell, as T cells
 should be tolerant to this self protein (T cells see only peptide fragments).

Maybe therefore no antibodies. This would predict, that in species where the
prion sequence is different, an antibody response should be possible.

jorg

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Joerg Kirberg                     EMAIL: kirberg at bii.ch
Basel Institute for Immunology    FAX:   41-61-605 13 72
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