Epitopes for human monoclonal antibodies and serotyping antisera against the O-specific polysaccharide of Pseudomonas aeruginosa O11.

Epitopes for Pseudomonas aeruginosa O11-specific human monoclonal antibodies (mAbs) and O11 serotyping antisera have been characterized. These mAbs recognized the O-polysaccharide portion of the lipopolysaccharide. The structure of the O-polysaccharide of O11 has been reported to be comprised of trisaccharide repeating-units as follows: -->3)-alpha-L-FucpNAc-(1-->1)-beta-D-FucpNAc-(1--> 2)-beta-D-Glcp-(1-->. (FucpNAc, 2-acetamido-2,6-dideoxygalactopyranoside.) Data from inhibition studies of binding in enzyme-linked immunosorbent assays and cell-agglutination assays, using monosaccharides and periodate-oxidized O-polysaccharide showed that the glucose residue, especially the C-3-C-6 segment and the beta-anomeric configuration, in the polysaccharide is essential for the epitopes of all anti-O11 mAbs; however, the detailed epitope specificities were different from one another. Furthermore, epitopes for serotyping antisera of O11 seemed to be similar to those for the human mAbs.