autoreactive antibodies

[Benny Shomer]

Hi.

Anti-DNA Ab's may be divided into several groups. Several of them react
against DNA associated proteins (e.g. histones). This may give some
explanation regarding antigen presentation, although DNA is not a peptide.
Some of these Ab's, are reactive also against positively charged groups
such as phospholipids. Thus, the creation of such antibodies is not
nessecarily against DNA. Molecular mimicry may be playing a great role
here.
If "cryptic" peptide regions on self antigens (i.e. areas on self Ag's not
being normally presented to the immune system) are presented as "dominant"
by a mimicing antigen (i.e. the same area will be proccessed as an
immunogenic peptide), an auto-immune situation may arise. Thus, the self
DNA molecules are not nessecarily the immunogenic molecule.

Regarding the enterance of Ab's to the cell. This probably, is NOT the
mechanism. A "normal" cell destruction may start a local immune reaction
of anti DNA Ab's. This reaction will cause an aggregation of immune
complexes in-situ. These complexes will damage the tissue further, as the
reaction progresses and enhances, in a non-specific manner. As the
reaction progresses further, Phospholipids may serve as sites of reactivity
as well.

Any comments are highly welcome.

Sincerely, Benny Shomer.
 **************************************************************
* Benny Shomer                                                 *
* Tel-Aviv University                                          *
* Sackler School of Medicine, Dept.of Embryology and Teratology*
*--------------------------------------------------------------*
* Snail:  Ramat-Aviv , Tel-Aviv  69978 ,  Israel.              *
* E-mail :  pc386 at ccsg.tau.ac.il                               *
* Tel :  972-3-640-9238     FAX :   972-3-642-2046             *
*                                                              *
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