Super-Antigen

[Ken Frauwirth BioKen]

In article <Per.Tidehag.13.00102726 at Protetik.umu.se>,
Per Tidehag <Per.Tidehag at Protetik.umu.se> wrote:
>I wounder if someone could try to explain to me, what probably is trivial, 
>what a "super-antigen" is, and how it differes from ordinary antigens.
>
>I am a dentist trying to read some immunology
>
>Per Tidehag
>Sweden
A "superantigen" is an antigen that is able to polyclonally activate a wide
variety of T cells which have differing T-cell recptor specificities.  They
require MHC to work (usually Class II MHC), but appear to bind outside of 
the peptide-binding groove.  They also appear to be recognized by all TCR's
containing certain V-beta genes.

Some of the best-known superantigens are bacterial toxins:

-streptococcal enterotoxins A & B (SEA and SEB)
-toxic shock syndrome toxin (TSST)

Some viruses also produce superantigens:

-murine mammary tumor virus (MMTV)
-it has been postulated that HIV may also produce a superantigen, allowing
 it to destroy uninfected T cells

BioKen
-- 
Ken Frauwirth (MiSTie #33025)       _           _
frauwirt at mendel.berkeley.edu       |_) *    |/ (_ |\ |
Dept. of Molec. & Cell Bio.        |_) | () |\ (_ | \|  
Univ. of Cal., Berkeley          Push the button...someone :(