Mouse monoclonal antibodies against outer membrane proteins of a vaccine strain of Neisseria meningitidis B: 4:P1.15

Background. Neisseria meningitidis (Nm) is a Gram negative diplococcus causing bacterial meningitis and fulminant septicemia. In order to allow efficient characterization of infecting strains, antibody reagents for use as analytical tools have proven to be invaluable tools. Similarly, antibodies against relevant bacterial antigens may guide in the selection of components to be included in developing vaccine strategies. Methods. We have thus developed mouse monoclonal antibodies specific for class 1, 3 and 5 antigens expressed by the B:4:P1.15 isolate CU385/83, also being used in a recently developed protective vaccine. In particular, two antibodies CB-Nm.1 and CB- Nm.2 recognize epitopes partly overlapping the subserotype (class 1 antigens) and serotype (class 3 antigen) specificities detected by the previously defined antibodies C6 and 15-1-P4 respectively, were evaluated. Results. As judged by strain recognition, the absolute requirement for binding differs between both the class 1-specific and class 3 specific antibodies suggesting the importance of using multiple antibodies when evaluating subserotype/serotype characteristics of clinical isolates of Nm by serological methods. Conclusion. Furthermore, the development of antibodies crossreactive with subserotype/serotype antigens may partly explain the ability of outer membrane protein vaccine to induce protective activity against strains considered as carrying different class 1 and 3 antigens as determined by available (sub)serotyping reagents.