IMMUNOCHEMISTRY OF SALMONELLA O-ANTIGENS - SPECIFICITY AND CROSS-REACTIVITY OF FACTOR-O9 SERUM AND OF ANTIBODIES AGAINST TYVELOSE 13-]A MANNOSE COUPLED TO BOVINE SERUM-ALBUMIN

The octasaccharide Galp(equations found) Rhap, the synthesized disaccharides methyl 3-0-α-tyvelopyranosyl-a-D-mannopyranoside, methyl 3-0-α-tyvelopyranosyI-β-D-mannopyranoside and methyl α-tyveloside, in order of decreasing effectiveness, inhibited the precipitation of S. typhill alkali-treated lipopolysaccharide by O-factor 9 serum. On a molar basis the relative inhibiting activities of the glycosides were 100:22:8:2. With rabbit antiserum raised against 3-0-α-tyvelopyranosyl-D-mannopyranosyl covalently linked to bovine serum albumin the relative inhibitory activities of the four glycosides were 11:100:26:3. These data establish that the 3-0-α-tyvelopyranosyl-α-D-mannopyrano-syl structure is immunodominant in the Salmonella O-antigen 9. The specificity of the antigen-antibody interaction was high: Glycosides in which the tyvelose (3,6-dideoxy-D-arai/«o-hexose) residue had been replaced by abequose (3,6-dideoxy-D-Ar>7o-hexose) or paratose (3,6-dideoxy-D-nVjo-hexose), had less than one fiftieth of the activity of the most active inhibitor in either of the two precipitation systems used. Moreover, the results show that 3-O-α-tyvelopyranosyl-D-mannopyranosyl coupled to bovine serum albumin elicits O-antibodies of higher specificity than those obtained by absorption of antibacterial immune serum. © 1979 S. Karger AG, Basel.