Immunodominant groups

All the KDO containing capsular polysaccharides shown in Figure 10 cross react in conventional antisera, mainly due to the fact that O-acetylation is never complete. In comparing native and modified polysaccharides we found that the immunodominant group in all these polysaccharides is KDO, acetylated or not. Closer serological study can be performed with monoclonal antibodies (Soderstrom, T, personal communication). It was found that a monoclonal K13 antibody reacts neither with the K20 nor with the K23 polysaccharides. Evidence was found that this antibody is specific for the P-(4-0-acetyl-KD0)-deter-minant of the K13 polysaccharide. 

Heidelberger demonstrated that the pyruvate acetal substituents of rhizobial polysaccharides behave as immunodominant groups. Furthermore, it has been shown that the configuration of the acetal group also influences the immunological properties of such saccharides [25, 28], and the existence of cross reactivities between pyruvated saccharides of different origin but bearing the same puruvic acid acetal are common phenomena. 

Studies with rabbit anti-polyalanyl antibodies also provided support for the concept of an immunodominant group i.e., the region farthest... 

B. Evidence for Immunodominant Groups in Synthetic Polypeptides with Branched Chains (Multichain Copolymers)... 

Fig. 10.3 General structure of streptococcal cell wall carbohydrate X, N-aae-tylglucosamine for Group A and A-acetylgalactosamine for Group C. Rhamnose (R) Itself is the immunodominant grouping in Group A-variant streptococci. The average molecular weight is about 10,000. From Krause (7).

The ABO blood group substances in the red cell membrane are complex glycosphingohpids the immunodominant sugar of A substance is A -acetyl-galactosamine, whereas that of the B substance is galactose. 

Some plant glycosides and polysaccharides cross-react195,197 with reagents for blood-group antigens, and interesting cross-reactions were also shown by methylated-fucose haptens and L-fucose-specific lectins for example, it was found that 2-O-methyl-L-fucose was immunodominant in the Japanese yew (Taxus cuspidata), and that the 3-0-... 

Epitope The structural part of an antigen that reacts with an antibody. These are groupings of amino acids in globular proteins and sugar side-chains in polysaccharides. The most critical part is called the immunodominant point. 

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