Opsonic monoclonal antibodies against lipopolysaccharide antigens of Leptospira interrogans serovar hardjo

Six monoclonal antibodes produced from mice immunised with Leptospira interrogans serovar hardjo were directed against determinants in the leptospiral lipopolysaccharide, as indicated by immunodiffusion and enzyme immunoassay (EIA), and opsonised leptospires for phagocytosis by mouse macrophages. Their specificities were studied by agglutination and EIA. Five antibodies reacted with some, but not all, members of the Sejroe and Hebdomadis serogroups, and one antibody agglutinated exclusively members of the Sejroe group thus indentifying a serogroup-specific epitope. None of the six antibodies reacted with representative serovars of any other serogroup.