An immunoprotective monoclonal antibody directed against Leptospira interrogans serovar copenhageni.

A monoclonal antibody (mAb) was prepared by hybridoma technology in BALB/c mice immunized to Leptospira interrogans serovar copenhageni. This mAb agglutinated serovars copenhageni and icterohaemorrhagiae to high titres and protected hamsters, dogs and monkeys against challenge with a virulent strain of serovar copenhageni. The mAb gave protection to hamsters at dilutions up to 1 in 1000; at a 1 in 10 dilution the protective effect lasted for at least two weeks. Biochemical analysis by SDS-PAGE and Western blotting indicated that this mAb reacted with an epitope of a carbohydrate nature.