Protective activity to murine experimental brucellosis conferred by monoclonal antibody ISS/32 anti-B. abortus

The protective properties of the monoclonal antibody ISS/32 anti-B. abortus were estimated by splenic infection with B. abortus 544. Five groups of Balb/c mice were used: two groups, previously vaccinated with a 45/20 antigen and a-LPS antigen, were challenged after 30 days intravenously by inoculation of 2.10(5) cells of B. abortus 544, one group was challenged with the same dose of B. abortus 544 preincubated with MAb-ISS/32 and another one with B. abortus 544 incubated with negative serum; the fifth group infected with B. abortus 544 only served as control. The results, expressed as an index of splenic infection, show significant protective properties of monoclonal antibody ISS/32. The infection index in the MAb-ISS/32 group of mice was a bit lower than in B. abortus 45/20 vaccine group.