Production and characterization of monoclonal antibodies against brucella S [99] surface antigens

ABSTRACT

By immunizing mice with killed whole bacterial cells of Brucella abortus S [99], a panel of six hybridomas producing monoclonal antibodies [mAb] specific for the surface antigens of this bacterium were produced. ELISA was used to screen the hybridoma supernatants. Immunoblots of the cell extract indicated that three mAb were specific for S-LPS [Ba-1, Ba-2, Ba-3] and three others were reactive with major outer membrane proteins [OMP] [Ba-4, Ba-5, Ba-6]. The OMP recognized by these antibodies were the proteins with molecular masses of 25-27 kDa [Ba-4, Ba-5] and 36-38 kDa [Ba-6]. None of the four mAb including Ba-3, Ba-4, Ba-5 and Ba-6 cross reacted with any other bacteria close to Brucella abortus, but Ba-1 and Ba-2 cross reacted with B. melitensis 16M and B. suis. By using cell extract and killed whole cell Ag in ELISA, it was indicated that all mAb except Ba-6 have better reactivity with cell extract Ag, but Ba-6 mAb reacted with killed whole cell Ag better than cell extract Ag