Self/nonself discrimination

Michael Scheinost scheini at
Tue Jul 19 08:56:00 EST 1994

In article 308fu0INNcre at,
ejf at (Ephraim Fuchs)  writes:

> Since antigen presenting cells take in antigens randomly from their
> environment, how is their delivery of signal two regulated so as to
> achieve a self/nonself discrimination?

In my opinion it isn't necessary to regulate e.g. the phagocytosis of  
macrophages to achieve a self/nonself discrimination at the level of T  
lymphocyte activation.
Self/nonself discrimination is achieved by the ability of T-cell receptors  
(TCR) of CD4+ T lymphocytes to built a complex with MHC-II, the presented  
anigen and the TCR. No complex (MHC-II-antigen-TCR), no signal for the T  
Normally TCRs won't bind to a complex of MHC-II and self-antigen (negative  



Michael Scheinost                   Internet: <scheini at>

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