OF 4 MURINE, ANTI-SHIGELLA DYSENTERIAE TYPE-1 O-POLYSACCHARIDE ANTIBODIES, 3 EMPLOY V-GENES THAT DIFFER EXTENSIVELY FROM THOSE OF THE 4TH

Three murine, monoclonal antibodies, IgM 5286 F2, IgM 5297 C1, and IgG 5338 H4 were generated against Shigella dysenteriae type 1 O-specific polysaccharide (O-SP)-conjugate. They are specific for the O-SP, whic h is a poly-[alpha-L-rhamnopyranosyl-(1 --> 3)-alpha-L-rhamnopyranosyl -(1 --> 2)-alpha(D-galactopyranosyl-(1 --> -2-deoxy-2-amino-N-acetyl-a lpha-D-glucopyranosyl]. The VH and VL genes of these antibodies were c loned and their sequences determined. They showed 93% homology, but we re quite different to the primary sequence of IgM 3707 E9, of the same O-SP-specificity, previously reported. The fine-specificities of both IgG 5338 H4 and IgM 3707 E9 were for the same disaccharide moiety in the O-SP, while IgMs 5286 F2 and 5297 C1 showed fine-specificity for t he entire repeating unit of the O-SP. Therefore, divergent sequences c an confer upon antibodies similar-, or even identical-carbohydrate-epi tope fine-specificity. In addition, close primary sequence-homology do es not preclude differences in antibody fine-specificity. Published by Elsevier Science Ltd.